Chapter 1
INFECTIOUS AND PARASITIC DISEASES
Introduction
Codes for infectious and parasitic diseases are located in Chapter 1. Infectious and parasitic diseases are those which are generally recognized as communicable or transmissible. Conditions covered in this chapter include scarlet fever, sepsis due to an infectious organism, meningococcal infection, and genitourinary tract infections. The table below shows the blocks within Chapter 1 Certain Infectious and Parasitic Diseases and illustrates the general layout by which these conditions are classified.
ICD-10-CM Blocks
A00-A09
Intestinal Infectious Diseases
A15-A19
Tuberculosis
A20-A28
Certain Zoonotic Bacterial Diseases
A30-A49
Other Bacterial Diseases
A50-A64
Infections with a Predominantly Sexual Mode of Transmission
A65-A69
Other Spirochetal Diseases
A70-A74
Other Diseases Caused by Chlamydiae
A75-A79
Rickettsioses
A80-A89
Viral and Prion Infections of the Central Nervous System
A90-A99
Arthropod-Borne Viral Fevers and Viral Hemorrhagic Fevers
B00-B09
Viral Infections Characterized by Skin and Mucous Membrane Lesions
B10
Other Human Herpes Viruses
B15-B19
Viral Hepatitis
B20
Human Immunodeficiency Virus (HIV) Disease
B25-B34
Other Viral Diseases
B35-B49
Mycoses
B50-B64
Protozoal Diseases
B65-B83
Helminthiases
B85-B89
Pediculosis, Acariasis and Other Infestations
B90-B94
Sequela of Infectious and Parasitic Diseases
B95-B97
Bacterial and Viral Infectious Agents
B99
Other Infectious Diseases
Not all infectious and parasitic diseases are found in chapter 1. Localized infections are found in the respective body system chapters.
Exclusions
Reviewing the chapter level exclusions provides information on which conditions may or may not be reported together, as well as some information on infectious conditions found in other chapters.
Excludes1
Excludes2
Certain localized infections are reported with codes from body system related chapters
Carrier or suspected carrier of infectious disease (Z22.-)
Infectious and parasitic diseases complicating pregnancy, childbirth, and the puerperium (098.-)
Infections and parasitic diseases specific to the perinatal period (P35-P39)
Influenza and other acute respiratory infections (J00-J22)
Chapter Guidelines
Detailed official coding and reporting guidelines are provided for:
•Human immunodeficiency virus (HIV)
•Infectious agents as the cause of diseases classified to other chapters
•Infections resistant to antibiotics
•Sepsis, severe sepsis, and septic shock
•Methicillin resistant Staphylococcus aureus (MRSA) conditions
Human Immunodeficiency Virus (HIV) Infections
Guidelines and corresponding ICD-10-CM codes for reporting HIV infections and testing for HIV are listed on the following page.
•Code only confirmed cases. This does not require documentation of positive serology or culture for HIV. The provider’s diagnostic statement that the patient is HIV positive or has an HIV-related illness is sufficient.
•Selection and sequencing of HIV codes:
–Patient admitted for HIV-related condition. The principal diagnosis should be acquired immune deficiency syndrome (AIDS) (B20) followed by additional diagnosis codes for all reported HIV-related conditions.
–Patient with AIDS or HIV-related disease admitted for unrelated condition. The code for the unrelated condition (such as an injury) should be the principal diagnosis followed by the code for AIDS (B20), followed by additional diagnosis codes for all HIV-related conditions that are reported.
–Newly diagnosed patient. Whether the patient is newly diagnosed or has had previous admissions/encounters for HIV conditions does not affect the sequencing decision.
–Asymptomatic HIV. The code for asymptomatic HIV infection status (Z21) is reported when the patient is asymptomatic but the physician has documented that the patient is HIV positive, known HIV, HIV test positive, or any similar terminology. These codes are not used if the physician documents that the patient has AIDS, or when the patient has any HIV-related illness or any conditions resulting from the HIV positive status. In these cases, the code for AIDS is used (B20).
–Patients with inconclusive HIV serology. Inconclusive serology without a definitive diagnosis and without any manifestations associated with HIV is assigned the code for inconclusive laboratory evidence of HIV (R75).
–Previously diagnosed HIV-related illness. Once the patient has developed an HIV-related illness, the code for AIDS (B20) is assigned on every subsequent admission/encounter. Patients previously diagnosed with an HIV-related illness are never assigned the codes for inconclusive laboratory evidence of HIV (R75) or asymptomatic HIV infection status (Z21).
–HIV related illness in pregnancy, childbirth and the puerperium. During pregnancy, childbirth and the puerperium, a patient seen for an HIV-related illness is assigned the principal diagnosis code of O98.7-, Human immunodeficiency [HIV] disease complicating pregnancy, childbirth and the puerperium, from Chapter 15, which is sequenced first followed by the code for AIDS (B20) and then the HIV-related illness.
–A patient with asymptomatic HIV infection status during pregnancy, childbirth or the puerperium is assigned a principal diagnosis code from Chapter 15 of O98.7-followed by the code for asymptomatic HIV infection status (Z21).
–Encounter for HIV testing. A patient being seen to determine his or her HIV status is assigned code Z11.4, Encounter for screening for human immunodeficiency virus [HIV]. Additional codes should be assigned for any associated high risk behavior (e.g., Z72.5-).
–Encounter for HIV testing with signs/symptoms. The code(s) for the signs/symptoms are assigned. An additional code may be assigned if counseling for HIV is provided (Z71.7) during the encounter for the testing.
–Return encounter for HIV test results. If the results are negative, the code for HIV counseling is assigned (Z71.7). If the results are positive, use the guidelines above to select the appropriate code(s).
Infectious Agents as the Cause of Diseases Classified to Other Chapters
Certain infections, particularly localized infections, are reported with codes from the corresponding body system chapter. Many of these codes do not identify the organism, so a second code from Chapter 1 is required to identify the infecting organism. These codes are found in the following three categories:
•B95 – Streptococcus, staphylococcus, and enterococcus as the cause of diseases classified elsewhere
•B96 – Other bacterial agents as the cause of diseases classified elsewhere
•B97 – Viral agents as the cause of diseases classified elsewhere
Infections Resistant to Antibiotics
There are a growing number of pathogenic microorganisms that are resistant to some or all of the drugs previously used to treat the resulting infections. All bacterial infections documented as drug-resistant or antibiotic resistant must be identified. If a combination code is not available to capture the drug resistance, a code from category Z16 Resistance to antimicrobial drugs must be used following the infection code. Codes in category Z16 will be discussed in more detail in Chapter 20.
Sepsis, Severe Sepsis, and Septic Shock
There are significant reporting guidelines for coding conditions that are documented as urosepsis, septicemia, SIRS, sepsis, severe sepsis, and septic shock. The definitions of these terms are sometimes used interchangeably; however, it should be remembered that for coding purposes they are not considered synonymous. The current ICD-10-CM definitions and terminology usage are explained below:
•Urosepsis:
–This term is nonspecific. There is no default code in the Alphabetic Index and it is not to be considered as synonymous with sepsis. Any provider documenting a condition as ‘urosepsis’ must be queried for clarification before any code can be assigned.
•Septicemia:
–Although this term has traditionally been used to refer to a systemic disease associated with the presence of pathogenic microorganisms (bacteria, viruses, fungi, or other organisms) or their toxins in the blood, this term is not referenced in the Tabular List of ICD-10-CM. The term ‘septicemia’ has been replaced with the term ‘sepsis.’ In the Alphabetic Index, there is a cross-reference to ‘sepsis’ when the documentation supports a diagnosis of sepsis. An unqualified diagnosis of septicemia is reported with A41.9 Sepsis, unspecified organism, which has the alternate term septicemia, NOS.
•Systemic Inflammatory Response Syndrome (SIRS):
–SIRS is not formerly defined in the ICD-10-CM guidelines. This term was formerly defined as the systemic response to infection, trauma, burns, or other insult to the body, such as cancer. Codes for SIRS are included in category R65. Symptoms and signs specifically associated with a systemic inflammatory response, and code descriptors containing the terminology systemic inflammatory response syndrome (SIRS) are used only for SIRS of non-infectious origin (R65.10 and R65.11). Severe sepsis is the term used in ICD-10-CM for SIRS due to an infectious process with acute organ dysfunction. For SIRS of non-infectious origin with acute organ dysfunction (R65.11), additional codes are required to identify the specific acute organ dysfunction.
•Sepsis:
–The term sepsis is not specifically defined in the guidelines, although it is generally thought of as SIRS due to infection without acute organ dysfunction. Only one code for sepsis, appropriate to the documented underlying systemic infection, is reported such as A40.0 Sepsis due to streptococcus group A. If the causal organism is not identified, code A41.9 Sepsis, unspecified organism is assigned.
–For sepsis due to a postprocedural infection, assign a code from T81.40-T81.43, Infection following a procedure, or a code from O86.00-O86.03, Infection of obstetric surgical wound, first to identify the site of the infection, if known. Assign an additional code for sepsis following a procedure (T81.44), or sepsis following an obstetrical procedure (O86.04) and an additional code to identify the infectious agent. If the infection follows an infusion, transfusion, therapeutic injection, or immunization, report a code from subcategory T80.2- or T88.0- first, followed by the code for the specific infection.
•Severe Sepsis:
–Severe sepsis is not specifically defined in the ICD-10-CM guidelines. However, guidance can be found in the list of alternate descriptions under the subcategory code R65.2-. Severe sepsis includes: infection with associated acute organ dysfunction; sepsis with acute organ dysfunction; sepsis with multiple organ dysfunction; SIRS due to infectious process with acute organ dysfunction. A minimum of 2 codes are required—the code for the underlying systemic infection must be reported first, followed by the code for severe sepsis, which is further differentiated as being without septic shock (R65.20) or with septic shock (R65.21). Codes from subcategory R65.2 can never be assigned as principal diagnosis. Additional code(s) are required for identifying the associated acute organ dysfunction.
–In cases where severe sepsis was not present on admission but developed during an encounter, the underlying systemic infection and the appropriate code from subcategory R65.2- should be assigned as secondary diagnoses.
–When sepsis or severe sepsis as well as a localized infection, such as pneumonia or cellulitis, are both reasons for admission, the code(s) for the underlying systemic infection is assigned first and a code(s) for the localized infection is assigned secondarily. When severe sepsis is present, the appropriate R65.2- code is also assigned as a secondary diagnosis. If the localized infection is the reason for the admission, and sepsis/severe sepsis develops later, the localized infection should be assigned first followed by the appropriate sepsis/severe sepsis codes.
•Septic Shock:
–Septic shock is circulatory failure associated with severe sepsis, and therefore represents a type of acute organ dysfunction. Two codes are required, the code for the underlying systemic infection and the code for severe sepsis with septic shock (R65.21). The code for septic shock cannot be assigned as the principal diagnosis. Additional codes for any other acute organ dysfunction should also be assigned.
–If a postprocedural infection results in postprocedural septic shock, assign the codes previously indicated for sepsis due to a postprocedural infection followed by code T81.12- Postprocedural septic shock. Do not assign the code for severe sepsis (R65.21) with septic shock. Use additional codes for any acute organ dysfunction.
Methicillin Resistant S. Aureus (MRSA) Conditions
Staphylococcus aureus is found on the skin and in the nasal cavities of 25-30% of the US population. This is called colonization and healthy individuals with S. aureus colonization are called carriers. In most healthy individuals colonization causes no major problems. However, if the organisms get into the body through a cut or an open area, S. aureus can become a serious or even life-threatening infection. If the S. aureus strain is resistant to most antibiotics commonly used to treat staph infections, it is referred to as MRSA. MRSA is found on the skin of approximately 1-2% of healthy individuals. MRSA infections are much more serious and difficult to treat. Like other strains of staphylococcus, MRSA bacteria usually enter the body through a broken area in the skin, although other entry sites include the respiratory tract, surgical or other open wounds, intravenous catheters, and the urinary tract. While most MRSA infections involve only the skin and present as a boil or small bump-like blemishes, serious and often life-threatening infections also occur, including cellulitis, sepsis, and pneumonia. Patients with compromised immune systems are at a significantly greater risk of symptomatic secondary infection.
For coding purposes, S. aureus infections are classified as methicillin resistant, also referred to as MRSA, or methicillin susceptible, also referred to as MSSA. Coding guidelines for reporting S. aureus infections are as follows:
•Combination codes:
–There are combination codes for MRSA sepsis (A41.02) and MRSA pneumonia (J15.212) and for MSSA sepsis (A41.01) and MSSA pneumonia (J15.211). A code from subcategory Z16.11 Resistance to penicillins is not reported additionally for MRSA sepsis or pneumonia because the combination code captures both the infectious organism and the drug-resistant status.
•Other MRSA infections:
–Documentation of a current infection due to MRSA that is not covered by a combination code, such as a wound infection, stitch abscess, or urinary tract infection is reported with the code for the condition along with code B95.62, Methicillin resistant Staphylococcus aureus (MRSA) infection as the cause of diseases classified elsewhere to identify the drug resistant nature of the infection. A code from subcategory Z16.11 Resistance to penicillins is not reported additionally.
•MRSA or MSSA colonization:
–An individual person may be described as being colonized or a carrier of MSSA or MRSA. Colonization means that MSSA or MRSA is present on or in the body without necessarily causing illness. A positive colonization test may be documented as “MRSA/MSSA screen positive” or “MRSA/MSSA nasal swab positive”.
–Documentation of MRSA or MSSA colonization without documentation of a disease process due to MRSA or MSSA is reported with code Z22.322 Carrier or suspected carrier of MRSA or Z22.321 Carrier or suspected carrier of MSSA.
•MRSA colonization and infection:
–For a patient documented as having both MRSA colonization and a current MRSA infection during an admission, code Z22.322 Carrier or suspected carrier of Methicillin resistant Staphylococcus aureus, and a code for the MRSA infection may both be assigned.
Zika Virus Infections
•Code only confirmed cases:
–Only confirmed cases of zika virus as documented by the physician should be coded with A92.5 Zika virus disease or P35.4 Congenital Zika virus disease. This is in exception to the inpatient hospital guidelines. Confirmation does not require documentation of the test performed; the physician’s diagnostic statement that the condition is confirmed is sufficient.
–If the provider documents ‘suspected’, ‘possible’, or ‘probable’ zika, do not assign code A92.5 or P35.4. Assign a code(s) for the reason for the encounter, such as fever, rash, joint pain, or contact with and (suspected) exposure to Zika virus (Z20.821).
General Documentation Requirements
The general documentation requirements related to infectious and parasitic diseases are less problematic than for many other chapters in ICD-10-CM. The main points to consider for chapter 1 have been discussed in the chapter guidelines above: codes for localized infections found within the respective body system chapters, specified terminology such as that related to sepsis and severe sepsis, and the required use of combination codes, or an additional identifying code when a combination code is not provided.
Code-Specific Documentation Requirements
In this section, some of the more frequently reported infectious and parasitic disease codes are listed and the documentation requirements are identified. The focus is on frequently reported conditions with specific clinical documentation requirements. Even though not all codes with significant documentation requirements are discussed, this section will provide a representative sample of the type of additional documentation that is required for infectious and parasitic diseases.
Chlamydial Infection of Lower/Other Genitourinary Sites
Chlamydia is the most frequently reported bacterial sexually transmitted disease in the United States with many more cases unreported. Many people do not know they are infected because symptoms can be mild or absent, with half of infected men and three quarters of infected women having no symptoms at all. The bacteria can cause silent damage, particularly to female reproductive organs, and infertility can result.
In ICD-10-CM, there is a combination code for the etiology of infection by Chlamydia trachomatis and the manifestation (site).
Coding and Documentation Requirements
Identify site:
•Lower genitourinary tract
–Bladder/urethra (cystitis, urethritis)
–Vulva/vagina (vulvovaginitis)
–Other specified lower genitourinary tract site (cervix, other sites)
–Unspecified lower genitourinary tract site
•Pelvis/peritoneum/other genitourinary organs
–Female pelvis/peritoneum (female pelvic inflammatory disease)
–Other specified site (epididymis/testis, other sites)
•Unspecified genitourinary site
ICD-10-CM Code/Documentation
A56.00
Chlamydial infection of lower genitourinary tract, unspecified
A56.01
Chlamydial cystitis and urethritis
A56.02
Chlamydial vulvovaginitis
A56.09
Other chlamydial infection lower genitourinary tract
A56.11
Chlamydial female pelvic inflammatory disease
A56.19
Other chlamydial genitourinary infection
A56.2
Chlamydial infection of genitourinary tract, unspecified
Documentation and Coding Example
Twenty-six-year-old female presents with intermittent fever, abdominal cramps, and low back pain. She states she had UTI symptoms about a month ago with frequency and burning. Symptoms resolved with fluids and cranberry juice but sexual intercourse has been uncomfortable since then. Patient is married x 6 months, husband is her only sexual partner. Current medications include oral contraceptives. On examination, this is a well-developed, well-nourished young woman. Temperature 100.6, HR 88, RR 16, BP 100/60. PERRL, ROM and pulses intact in upper extremities. Abdomen mildly tender to palpation in all quadrants but no guarding, rebound tenderness or masses are present. Mild bilateral flank tenderness is also present. Inguinal lymph nodes are slightly enlarged but non-tender to palpation. Vulva and external genitalia normal. Speculum exam difficult to perform due to extreme discomfort. Yellowish white discharge from the endocervix. Culture obtained and sent to lab. Bimanual exam causes severe discomfort. There is moderate cervical motion tenderness, uterus is anteverted in midline and fixed in place, fallopian tubes are enlarged bilaterally and ovaries cannot be palpated due to muscle guarding. Cervical culture is positive for Chlamydia.
Diagnosis: Chlamydial PID.
Diagnosis Code(s)
A56.11
Chlamydial female pelvic inflammatory disease
Coding Note(s)
One combination code identifies both the chlamydial infection and the site of the infection.
Gonococcal Genitourinary Infections
Neisseria gonorrhoeae is a gram-negative bacterium responsible for sexually transmitted gonococcal infections. According to the Centers for Disease Prevention and Control (CDC), it is the second most commonly reported communicable disease. The bacteria cause purulent infection of mucous membranes through sexual contact with an infected person, or through the birth canal. In men, urethral infections cause symptoms that usually result in seeking attention timely enough to prevent sequelae in the individual, but not transmission. In women, the infection may remain asymptomatic until complications such as pelvic inflammatory disease develop. Genitourinary infections can be transmitted to the eyes and throat, and can also spread to the joints and tendons, the heart, the meninges, the abdominal cavity, and the bloodstream.
Gonococcal infections are not classified as acute or chronic. Both upper and lower genitourinary tract infections are specific to site. Codes specific for gonococcal infections of the lower genitourinary tract are divided into whether or not it occurs with periurethral and accessory gland abscess. Note that there is a single subcategory code, A54.1, for reporting gonococcal infections of the lower genitourinary tract with abscess, but multiple subclassified codes for reporting lower genitourinary infections without (A54.0-) abscess, by site. The gonococcal infections of specified sites in the lower genitourinary tract include the term “unspecified” in the descriptor. The term “unspecified” as used here means that these infections have not been specified as occurring with periurethral or accessory gland abscess of the lower genitourinary tract.
Coding and Documentation Requirements
Identify site of infection:
•Lower genitourinary tract
•Pelvis/peritoneum/other genitourinary sites
For lower genitourinary tract, identify presence/absence of complications:
•With periurethral abscess/accessory gland abscess
•Without periurethral abscess/accessory gland abscess
For lower genitourinary tract infection without periurethral or accessory gland abscess, identify site more specifically:
•Bladder/urethra (cystitis/urethritis)
•Uterine cervix (cervicitis)
•Vulva/vagina (vulvovaginitis)
•Other specified lower genitourinary tract site
•Unspecified lower genitourinary tract site
For pelvis/peritoneum/other upper genitourinary sites, identify site/condition more specifically:
•Kidney/ureter (nephritis, pyelitis, ureteritis)
•Female genitourinary system/female pelvic inflammatory disease (endometritis, salpingitis, pelviperitonitis)
•Male genitourinary system
–Prostate (prostatitis)
–Other male genital organs (epididymo-orchitis, seminal vesiculitis)
•Other specified site
ICD-10-CM Code/Documentation
A54.00
Gonococcal infection of lower genitourinary tract, unspecified
A54.01
Gonococcal cystitis and urethritis, unspecified
A54.02
Gonococcal vulvovaginitis, unspecified
A54.03
Gonococcal cervicitis, unspecified
A54.09
Other gonococcal infection of lower genitourinary tract
A54.1
Gonococcal infection of lower genitourinary tract with periurethral and accessory gland abscess
A54.21
Gonococcal infection of kidney and ureter
A54.22
Gonococcal prostatitis
A54.23
Gonococcal infection of other male genital organs
A54.24
Gonococcal female pelvic inflammatory disease
A54.29
Other gonococcal genitourinary infections
Documentation and Coding Example
Nineteen-year-old male presents with painful urination and thick white penile discharge x 1 week. Today he noticed a swollen, painful area on underside of his penis near the scrotum. Patient has been sexually active x 3 years with multiple partners. He rarely uses a condom. On examination, this is a well-developed, well-nourished anxious appearing young man. Abdomen soft with active bowels sounds in all quadrants. Denies flank tenderness. Inguinal lymph nodes are swollen and tender to palpation. Copious white drainage noted from urethra. Culture obtained and sent to lab. Posterior penis at the junction of the scrotum has a 2 cm x 3 cm, firm, tender, erythematous swelling. Area is prepped and draped. Using an 18 g needle with syringe, 3 cc of cloudy yellow fluid is aspirated. Specimen sent to lab for gram stain and culture. Both urethral culture and aspirate fluid are positive for Neisseria gonorrhoeae. Ultrasound examination of the penis and scrotum reveal urethral distensibility and extension of the periurethral abscess into the spongiosum tissue at the bulbar urethra. The patient is admitted to the hospital and started on intravenous antibiotics. He is taken to the OR where the abscess is incised and drained. The wound is packed with antibiotic soaked saline and a dressing applied.
Diagnosis: Cystitis, urethritis, and periurethral abscess due to gonorrhea.
Diagnosis Code(s)
A54.1
Gonococcal infection of lower genitourinary tract with periurethral and accessory gland abscess
Coding Note(s)
The code for gonococcal cystitis and urethritis (A54.01) is not reported additionally because there is an Excludes1 note under subcategory A54.0 for gonococcal infection with periurethral abscess (A54.1), which indicates that code A54.1 is never reported with any codes in subcategory A54.0.
Herpes Simplex
Herpes simplex is caused by one of two variants of the herpes simplex virus (HSV) which are designated as HSV-1 and HSV-2. HSV-1 commonly affects the mouth, lips, and conjunctiva of the eye. When it affects the mouth and face, it is often referred to as a “fever blister” or “cold sore”. HSV-2 commonly affects the genitalia. Both variants are spread by direct contact. While some individuals have no symptoms, others get blisters at the site where the virus has entered the body. The blisters may be itchy and painful. The first outbreak is typically the most severe and may be accompanied by fever, body aches, and pain and burning around the site of the outbreak. While the initial outbreak eventually resolves, the virus remains in the body and once infected most people continue to have periodic outbreaks that may be triggered by illness, stress, fatigue, hormone changes, sun exposure, or exposure to extreme heat or cold.
Herpes simplex is classified in category B00 for sites other than the genitals. Anogenital herpes infection is classified with infections with a predominantly sexual mode of transmission (A50-A64) in category A60.
Coding and Documentation Requirements
Identify HSV site/manifestation/complication:
•Anogenital
–Female
»Cervicitis
»Vulvovaginitis
–Male
»Penis
»Other male genital organ
–Perianal skin/rectum
–Other urogenital site
–Unspecified urogenital site
–Unspecified site, anogenital region
•Disseminated
•Eczema herpeticum
•Gingivostomatitis/pharyngotonsillitis
•Hepatitis
•Nervous system
–Encephalitis
–Meningitis
–Myelitis
•Ocular (eye)
–Conjunctivitis
–Iridocyclitis
–Keratitis
–Other specified ocular disease
–Unspecified ocular disease
•Vesicular dermatitis
–Ear (otitis externa)
–Face
–Lips
•Other specified site/manifestation/complication
•Unspecified site/manifestation/complication
ICD-10-CM Code/Documentation
A60.00
Herpesviral infection of urogenital system, unspecified
A60.01
Herpesviral infection of penis
A60.02
Herpesviral infection of other male genital organs
A60.03
Herpesviral cervicitis
A60.04
Herpesviral vulvovaginitis
A60.09
Herpesviral infection of other urogenital tract
A60.1
Herpesviral infection of perianal skin and rectum
A60.9
Anogenital herpesviral infection, unspecified
B00.0
Eczema herpeticum
B00.1
Herpesviral vesicular dermatitis
B00.2
Herpesviral gingivostomatitis and pharyngotonsillitis
B00.3
Herpesviral meningitis
B00.4
Herpesviral encephalitis
B00.50
Herpesviral ocular disease, unspecified
B00.51
Herpesviral iridocyclitis
B00.52
Herpesviral keratitis
B00.53
Herpesviral conjunctivitis
B00.59
Other herpesviral disease of eye
B00.7
Disseminated herpesviral disease
B00.81
Herpesviral hepatitis
B00.82
Herpes simplex myelitis
B00.89
Other herpesviral infection
B00.9
Herpesviral infection, unspecified
Documentation and Coding Example
Fifteen-year-old Caucasian female presents to Urgent Care Clinic with a history of fever and malaise x 3 days, severe sore throat, and painful blisters on her lips and chin when she awoke this morning. She has been on a river rafting trip with her family for the past week, camping out at night and in the sun all day. She has no chronic medical problems and no known allergies. She has been taking 400 mg of Ibuprofen 2-3 x day for the past 3 days. T 100.8, P 74, R 14, BP 100/58, O2 Sat. 99% on RA. On examination, this is a quiet, cooperative, ill appearing adolescent female. Skin is tan, mild sunburn on her shoulders and face. PERRLA, conjunctiva mildly red and moist. Nares patent with clear, thin secretions. Lower lip is markedly swollen with clusters of fluid filled vesicles extending from the left corner to just right of midline and from the vermilion border into the oral mucosa. There are also scattered vesicles on the epidermis of chin and the left side of the upper lip along the vermilion border. Oral exam is somewhat limited because the patient has trouble opening her mouth due to pain from the lesions on the lip. Additional vesicles are noted on the gums on the lower left side and the pharynx appears red, tonsils swollen and covered with a gray exudate. Neck is supple, cervical and supraclavicular lymph nodes can be palpated. Heart rate is regular, breath sounds are clear. Abdomen soft with active bowel sounds. Patient recalls tingling and itching of her gums and lips prior to the eruption of the rash.
Impression: Herpes viral infection of oropharynx, gums, lips and chin, R/O Strep/bacterial infection.
Plan: Vesicles cultured for virus. Rapid strep negative. Bacterial culture of tonsils sent to lab. Valacyclovir 1 gram BID x 10 days. Keep blisters moist using Vaseline and may use viscous lidocaine topically for pain. Continue Ibuprofen as needed. Stay out of the sun and RTC in 2 days for recheck.
Follow up visit: Afebrile. Culture positive for HSV-1, negative for strep. Throat is still painful and the gums, lips, and chin have fresh scattered vesicles. Old lesions appear ulcerous with gray exudate on a red base with some covered with crusts/scabs. She is prescribed Mupirocin 2% ointment for the lesions. Continue Valacyclovir. Follow up with PMD if symptoms not improving. Patient is cautioned that HSV can reoccur with stress, fatigue, sun exposure, and extreme heat and cold.
Diagnosis Code(s)
B00.1
Herpes vesicular dermatitis
B00.2
Herpesviral gingivostomatitis and pharyngotonsillitis
Coding Note(s)
Two codes are also required. There is a specific code for herpes vesicular dermatitis (B00.1) and a combination code (B00.2) that captures both the lesions on the gums (gingivostomatitis) and throat and tonsils (pharyngotonsillitis).
Intestinal Infectious Diseases
Intestinal infectious diseases may be caused by a variety of bacteria, amoebas, protozoa, and viruses. When the infection is caused by contaminated food, the condition may be referred to as food poisoning. The term “food poisoning” generally refers to any illness resulting from a foodborne pathogen that causes intestinal symptoms such as nausea, vomiting, and diarrhea. The term food poisoning groups illnesses by symptoms rather than by the pathogen that causes the illness such as a toxin, bacterium, virus, or parasite. While lay people still refer to an illness caused by food as food poisoning, public health departments recognize and classify food poisoning as either due to an infection (bacterium, virus, parasite, or other microorganism), or due to a toxin. The terms used are foodborne infection and foodborne intoxication.
This terminology change can be clearly seen in the alphabetic index. If the term “Intoxication, food” is referenced, foodborne toxins are listed but because “food intoxication” and “food poisoning” are still used interchangeably, referencing the term “Poisoning, food” in ICD-10-CM will still yield codes for foodborne illnesses caused by both toxins and infections. It is also possible to find the correct code by referencing “Enteritis, infectious”, or “Infection” followed by the specific microorganism, such as Shigella.
Some of the more common causes of intestinal infectious diseases include:
•Bacterial
–Campylobacter
–Clostridium perfringens
–Escherichia coli
–Listeria
–Salmonella
•Protozoal
–Giardiasis [lambliasis]
•Viral
–Adenovirus
–Rotavirus
–Norovirus
Bacterial Food Poisoning / Intoxication
Some of the more common bacterial causes of food poisoning are classified in category A05; however, these conditions are now referred to as foodborne intoxications. Other bacterial causes of food poisoning, food intoxication, and gastroenteritis are found throughout categories A00-A09.
Coding and Documentation Requirements
Identify bacterial cause of gastroenteritis/food poisoning/intoxication:
•Bacillus cereus
•Botulism
•Clostridium perfringens [C. welchii]
•Staphylococcal
•Vibrio
–Parahaemolyticus
–Vulnificus
•Other bacteria
•Unspecified bacteria
ICD-10-CM Code/Documentation
A05.0
Foodborne staphylococcal intoxication
A05.1
Botulism food poisoning
A05.2
Foodborne Clostridium perfringens [Clostridium welchii] intoxication
A05.8
Other specified bacterial foodborne intoxications
A05.3
Foodborne Vibrio parahaemolyticus intoxication
A05.5
Foodborne Vibrio vulnificus intoxication
A05.4
Foodborne Bacillus cereus intoxication
A05.8
Other specified bacterial foodborne intoxications
A05.9
Bacterial foodborne intoxication, unspecified
Documentation and Coding Example
History: This 28-year-old female became suddenly ill this afternoon with stomach pain and cramping, nausea, and vomiting. She states that she went out for pizza with friends and she and 2 other people also got a salad from the salad bar. The friends had planned to go out to a movie, but within an hour of eating both she and the 2 friends who had salad started to experience stomach pain and nausea. She went home and her symptoms became more severe. She now has severe stomach pain and cramps that cause her to double over in pain. She has been vomiting and now has dry heaves.
Examination: This is a young woman in acute distress. B/P 108/60, T 99.2, P 92, R 18. Abdomen is soft, tender to palpation, with hyperactive bowel sounds. ENT normal. Skin warm and dry.
Impression: Staphylococcal food poisoning.
Plan: Patient instructed to rest. When her stomach settles, she should begin taking ice chips and progress to clear fluids. She was given a prescription for Phenergan 25 mg to be taken every 4-6 hours as needed for nausea. She was told that the symptoms usually subside in 1-3 days and was told to return if symptoms become more severe.
Diagnosis Code(s)
A05.0
Foodborne staphylococcal intoxication
Coding Note(s)
Some foodborne pathogens causing gastrointestinal symptoms are classified as bacterial foodborne intoxications and not poisoning.
Listeriosis
Listeriosis is a disease caused by eating food contaminated with the bacterium Listeria monocytogenes. It is classified under other bacterial diseases and is reported by specified manifestation, such as cutaneous listeriosis (A32.0) or oculoglandular listeriosis (A32.81), or by a combination condition with the etiology and the manifestation, such as listerial sepsis (A32.7) or listerial endocarditis (A32.82).
Coding and Documentation Requirements
Identify site/manifestation:
•Cutaneous
•Endocarditis
•Meningitis
•Meningoencephalitis
•Oculoglandular
•Other form/manifestation, which includes:
–Cerebral arteritis
•Sepsis
•Unspecified listeriosis
ICD-10-CM Code/Documentation
A32.0
Cutaneous listeriosis
A32.11
Listerial meningitis
A32.12
Listerial meningoencephalitis
A32.7
Listerial sepsis
A32.81
Oculoglandular listeriosis
A32.82
Listerial endocarditis
A32.89
Other forms of listeriosis
A32.9
Listeriosis, unspecified
Documentation and Coding Example
This 75-year-old male presents to the ED in obvious distress with a fever of 101.6, blood pressure 70/40, pulse 120, respirations 28. He states he has not been feeling well for several days with nausea, vomiting, and tiredness. His wife states that today he has experienced periods of confusion, which she believes to be due to the fever. Due to the number of listeria cases over the past several weeks, the patient was queried about whether he has consumed any cantaloupe and he stated that he had eaten some approximately 3 weeks ago, but has not had any since.
Impression: Sepsis with septic shock likely due to listerial infection. Infectious disease consultation requested. Blood tests ordered.
Follow-up: Listerial sepsis confirmed by laboratory tests with septic shock.
Diagnosis Code(s)
A32.7
Listerial sepsis
R65.21
Severe sepsis with septic shock
Coding Note(s)
Septic shock is circulatory failure associated with severe sepsis, and, therefore, it represents a type of acute organ dysfunction. The code for septic shock cannot be assigned as a principal diagnosis. In ICD-10-CM, for all cases of septic shock, the code for the systemic infection should be sequenced first, followed by code R65.21. Any additional codes for other acute organ dysfunctions should also be assigned. Septic shock indicates the presence of severe sepsis. Code R65.21 Severe sepsis with septic shock, must be assigned if septic shock is documented in the medical record.
Meningococcal Infections
Meningococcal infection is a serious, potentially fatal bacterial infection caused by the bacterium Neisseria meningitides. It causes meningococcal meningitis, an inflammation of the membranes surrounding the brain and spinal cord; meningococcemia, the presence of N. meningitides in the blood; meningococcal heart disease which may affect the endocardium, myocardium, and/or pericardium; meningococcal arthritis, an infection of the joints; and may also affect other organs such as the eyes and adrenal glands. Specific documentation is required for meningococcemia as to acute or chronic nature, and for arthropathy as meningococcal arthritis or post meningococcal arthritis.
Meningococcemia
Coding and Documentation Requirements
Identify meningococcemia:
•Acute
•Chronic
•Unspecified
ICD-10-CM Code/Documentation
A39.2
Acute meningococcemia
A39.3
Chronic meningococcemia
A39.4
Meningococcemia, unspecified
Documentation and Coding Example 1
Nineteen-year-old male college student presents with a 4-week history of intermittent fever, headaches, malaise, and joint pain. He states he has no appetite and has lost about 15 lbs. Temperature is 100.2 degrees, HR 94, RR 22, BP 92/60. This is a thin, ill-appearing young man. PERRL, conjunctiva mildly red. Oral and nasal mucous membranes are moist and slightly red. Cervical, axillary, and inguinal lymph nodes are enlarged and tender to touch. Abdomen is soft, bowel sounds present in all quadrants. Liver is palpated at 2 cm below the RCM, spleen is not palpated but patient c/o tenderness with palpation of the upper left quadrant. Smooth pinpoint petechial rash noted on back, neck, and lower extremities. Patient cannot recall if he has been immunized against meningitis. A CBC, blood cultures, and PT, PTT are obtained. Blood culture is positive for Neisseria meningitides.
Diagnosis: Chronic meningococcemia.
Diagnosis Code(s)
A39.3
Chronic meningococcemia
Coding Note(s)
The codes for meningococcemia are listed in the Alphabetic Index under three main terms: Infection, Meningococcemia, and Sepsis.
Meningococcal Arthropathy
Coding and Documentation Requirements
Identify meningococcal arthropathy:
•Current/acute meningococcal arthritis
•Post-meningococcal arthritis
ICD-10-CM Code/Documentation
A39.83
Meningococcal arthritis
A39.84
Post-meningococcal arthritis
Documentation and Coding Example 2
Forty-four-year-old female presents with a chief complaint of right swollen, painful elbow. Patient states she was acutely ill approximately 10 weeks ago with fever, headache, nausea, and vomiting. She was diagnosed with meningococcemia, hospitalized and treated with antibiotics. She has continued to feel tired since the illness. On examination, she is afebrile, HR 80, RR 14, BP 112/70. Fingers and wrists bilaterally are slightly red and mildly swollen. Right elbow is erythematous, diffusely tender to palpation and warm to touch. Patient complains of pain with active and passive ROM. A patchy erythematous macular rash is also noted on both lower extremities. Small amount of purulent appearing synovial fluid is aspirated from right elbow and sent to the lab for gram stain, culture, cell count, and crystal analysis. Blood for CBC, sed rate drawn and sent to lab. Synovial culture is positive for Neisseria meningitides.
Diagnosis: Post-meningococcal arthritis.
Diagnosis Codes:
A39.84
Post-meningococcal arthritis
Coding Note(s)
To locate the correct code in the Alphabetic Index for chronic or post meningococcal arthritis, reference Arthritis, post meningococcal. Only the code for current, acute meningococcal arthritis is listed under Arthritis, meningococcal, or Arthritis, in (due to), meningococcus.
Scarlet Fever
Scarlet fever is caused by a bacterial infection with Streptococcus Group A. Scarlet fever is typically a complication of strep throat or less commonly a skin infection caused by Group A strep. The most common symptom is a red, rough-feeling skin rash. Scarlet fever is easily treated with antibiotics. However, serious complications can occur if it is not treated including rheumatic fever, kidney disease, ear infection, skin infection, throat abscess, pneumonia, or joint inflammation.
In ICD-10-CM, there are combination codes for scarlet fever and any complications, such as scarlet fever with myocarditis (A38.1).
Coding and Documentation Requirements
Identify scarlet fever as with or without complications:
•Scarlet fever with complications
–Otitis media
–Myocarditis
–Other complications
•Scarlet fever without complications
ICD-10-CM Code/Documentation
A38.0
Scarlet fever with otitis media
A38.1
Scarlet fever with myocarditis
A38.8
Scarlet fever with other complications
A38.9
Scarlet fever, uncomplicated
Documentation and Coding Example
Nine-year-old female presents with a sore throat, fever, general malaise, and rash. Parent states child was well until four days ago when she complained of a sore throat, headache, fever to 101 degrees and that her rash appeared yesterday. On examination, the child is in no acute distress. She is well nourished but appears slightly dehydrated. Child is cooperative and quiet throughout the examination. Mucous membranes are dry and pink, tongue is slightly swollen and very red. Throat is bright red with spotty white exudate. No nasal drainage noted. The left ear has mild otitis media with effusion, right ear has a bulging tympanic membrane with middle ear effusion and inflammation. Fine red rash covers neck and trunk and is especially pronounced in the axilla bilaterally. Rash is dry and sandpapery to touch, skin is peeling slightly around the neck. Child denies itching, upset stomach, vomiting, or diarrhea. Rapid strep test (throat) positive.
Diagnosis: Scarlet fever, right acute otitis media, left otitis media with effusion.
Diagnosis Code(s)
A38.0
Scarlet fever with otitis media
J02.0
Streptococcal pharyngitis
Coding Note(s)
In ICD-10-CM, there is an Excludes2 note listed under code J02.0 for Scarlet fever (A38.-). This note indicates that the condition is not part of the scarlet fever, but it is possible for a patient to have both scarlet fever and strep throat at the same time. Because both scarlet fever and strep throat are documented, both conditions are reported.
Sepsis
The term septicemia is often used for infections of the bloodstream. In ICD-10-CM, this term is not used and has been replaced with the term sepsis. When the term “septicemia” is referenced in the Alphabetic Index, there is a cross-reference to see “sepsis” when the documentation supports a diagnosis of sepsis. An unqualified diagnosis of septicemia would be reported with A41.9 Sepsis, unspecified organism, which has the alternate term ‘septicemia NOS’.
Streptococcal Sepsis
Streptococcal sepsis (formerly termed septicemia) is the most common form of sepsis. Streptococcal sepsis must be identified as due to group A, group B, S. pneumoniae, other type, or unspecified type. Coding for streptococcal sepsis is also determined by whether the sepsis is documented as postprocedural; subsequent to immunization, infusion, transfusion, or other therapeutic injection; following an abortion or ectopic or molar pregnancy; occurring during labor; or is documented as puerperal.
Coding and Documentation Requirements
Septicemia is no longer used as coding terminology.
For streptococcal sepsis, designate agent:
•Group A
•Group B
•S. pneumoniae
•Other
•Unspecified
For severe sepsis, assign a code from subcategory R65.2 and specify:
•With septic shock
•Without septic shock
For severe sepsis, identify any acute organ dysfunction.
Note: A code from category A40 is reported as a secondary diagnosis to identify the specific bacterial agent for the following diagnoses:
•Postprocedural streptococcal sepsis (T81.44-)
•Streptococcal sepsis during labor (O75.3)
•Streptococcal sepsis following abortion (O03.37, O03.87)
•Streptococcal sepsis following induced termination of pregnancy (O04.87) or failed attempted termination of pregnancy (O07.37).
•Streptococcal sepsis following ectopic or molar pregnancy (O08.82)
•Streptococcal sepsis following immunization (T88.0)
•Streptococcal sepsis following infusion, transfusion or therapeutic injection (T80.2)
For puerperal sepsis:
•Do not report the codes from category A40.
•Use code O85 as the principal diagnosis and B95.0, B95.1, B95.3, B95.4 or B95.5 as appropriate to identify the organism.
ICD-10-CM Code/Documentation
A40.0
Sepsis due to streptococcus, Group A
A40.1
Sepsis due to streptococcus, Group B
A40.3
Sepsis due to Streptococcus pneumoniae
A40.8
Other streptococcal sepsis
A40.9
Streptococcal sepsis, unspecified
Documentation and Coding Example
Twenty-two-year-old female in good health until 2 days prior to admission. She presents to ED with a 2-day history of shaking, chills, fever, and dry cough. Tonight, she feels like she cannot catch her breath and has sharp pain with inspiration on the left side. On examination, this is an acutely ill-appearing young woman. Color pale with cyanosis of the oral mucosa and nail beds. Neck veins are distended. Apical HR regular with an audible ventricular gallop. Breath sounds have course rales throughout, decreased BS in left lower lobe with dullness on percussion. Abdomen soft, non-tender with active BS. There is a well healed midline abdominal scar extending from xiphoid to pubic symphysis. Patient states she had a skiing accident at age 14 and sustained multiple rib fractures, collapsed lung and a ruptured spleen. She underwent exploratory abdominal surgery at the time and spleen was removed. Patient is placed on supplemental oxygen, 2 L/m via nasal cannula with increase in O2 saturation to 95%. Arterial blood gas drawn. IV placed and blood drawn for CBC, sed rate, CRP, cultures. Chest x-ray obtained and shows an area of consolidation in left lower lobe. Thick rust-colored sputum sample obtained after nebulizer treatment by respiratory therapy. Sample sent to lab for gram stain, culture. Patient admitted to medical floor for observation, respiratory treatment and antibiotic therapy. Sputum and blood cultures positive for S. pneumoniae.
Diagnosis: Pneumonia due to S. pneumoniae complicated by sepsis.
Diagnosis code(s)
A40.3
Sepsis due to Streptococcus pneumoniae
J13
Pneumonia due to S. pneumoniae
Z90.81
Acquired absence of spleen
Coding Note(s)
If the reason for the admission is both sepsis or severe sepsis and a localized infection, such as pneumonia or cellulitis, a code for the underlying systemic infection should be assigned first and the code for the localized infection should be assigned as a secondary diagnosis.
If the patient is admitted with a localized infection such as pneumonia, and sepsis/severe sepsis doesn’t develop until after admission, the localized infection should be assigned first, followed by the appropriate sepsis/severe sepsis code(s).
Staphylococcal Sepsis
Staphylococcus, particularly S. aureus, is a frequent cause of infections that are usually localized, but staphylococcal infections can become systemic resulting in sepsis. In ICD-10-CM, there are four codes for staphylococcal sepsis and include sepsis due to methicillin susceptible S. aureus, methicillin resistant S. aureus, other specified staphylococcus, and unspecified staphylococcus. Coding for staphylococcal sepsis is determined by whether the sepsis is documented as postprocedural; occurring subsequent to immunization, infusion, transfusion, or other therapeutic injection; following an abortion or ectopic or molar pregnancy; occurring during labor; or is documented as puerperal.
Coding and Documentation Requirements
Septicemia is no longer used as coding terminology.
For staphylococcal sepsis, designate agent:
•Due to Methicillin resistant S. aureus (MRSA)
•Due to Methicillin susceptible S. aureus (MSSA)
•Other specified staphylococcal sepsis
•Unspecified staphylococcal sepsis
For a diagnosis of severe sepsis, assign a second code from subcategory R65.2 and specify:
•Severe sepsis with septic shock
•Severe sepsis without septic shock
Note: A code for the type of staphylococcus (A41.01, A41.02, A41.1, A41.2) is reported as a secondary diagnosis to identify the specific bacterial agent for the following diagnoses:
•Postprocedural staphylococcal sepsis (T81.44-)
•Staphylococcal sepsis during labor (O75.3)
•Staphylococcal sepsis following abortion (O03.37, O03.87)
•Staphylococcal sepsis following induced termination of pregnancy (O04.87) or failed attempted termination of pregnancy (O07.37).
•Staphylococcal sepsis following ectopic or molar pregnancy (O08.82)
•Staphylococcal sepsis following immunization (T88.0)
•Staphylococcal sepsis following infusion, transfusion or therapeutic injection (T80.2)
For puerperal sepsis:
•Do not report the codes A41.01, A41.02, A41.1, or A41.2.
•Use code O85 as the principal diagnosis and B95.61, B95.62, B95.7, or B95.8 as appropriate to identify the organism.
ICD-10-CM Code/Documentation
A40.01
Sepsis due to Methicillin susceptible Staphylococcus aureus
A40.02
Sepsis due to Methicillin resistant Staphylococcus aureus
A41.1
Sepsis due to other specified staphylococcus
A41.2
Sepsis due to unspecified staphylococcus
Documentation and Coding Example
Fifty-eight-year-old nurse presents with a 2-day history of large, painful, erythematous swelling on left anterior thigh. Over the past 8 hours she has developed fever, chills, nausea, and weakness. Temp. 101.8, RR 20, HR 96, BP 88/50. Patient states that she does post-op care for surgical patients with infections. On examination, patient is an anxious, ill-appearing female. Mucous membranes are moist and pink. Skin color is pale, very warm, and dry to touch. PERRL. There is no lymph enlargement in upper body. Lungs are clear to auscultation. Heart rate regular without murmur. Abdomen soft, non-tender with decreased bowel sounds in all quadrants. Liver palpated at RCM, spleen is not palpated. Inguinal lymph nodes enlarged and very tender bilaterally. Right lower extremity unremarkable. Left lower extremity has mild edema in foot/calf and weak pedal and post tibial pulses. A 6 cm x 4 cm erythematous area is noted on the anterior thigh approximately 10 cm above knee. The lesion is firm, warm to touch with a soft purplish/red center. IV started in right upper extremity. Blood cultures, CBC sent to lab. Incision and drainage performed on left thigh lesion and culture sent to lab. Blood and wound cultures both positive for methicillin resistant Staphylococcus aureus.
Diagnosis: Thigh abscess complicated by sepsis.
Diagnosis Code(s)
A41.02
Sepsis due to methicillin resistant S. aureus
L02.416
Cutaneous abscess of left lower limb
B95.62
Methicillin resistant S. aureus as the cause of diseases classified elsewhere
Coding Note(s)
If the reason for the admission is both sepsis or severe sepsis and a localized infection, such as pneumonia or cellulitis, a code for the underlying systemic infection should be assigned first and the code(s) for the localized infection should be assigned as a secondary diagnosis. Since both the blood and the wound cultured positive for methicillin resistant Staphylococcus aureus, code B95.62 is assigned to identify the causative organism for the localized thigh abscess.
Viral Diseases of the Central Nervous System, Specified
Viruses can be spread through different mediums. Arthropods are invertebrates with an exoskeleton, jointed appendages, and a segmented body. Arthropod-borne infections are caused by viruses transmitted through invertebrates such as ticks and mosquitoes. Other invertebrates that are not arthropods, such as worms, may also transmit viruses. ICD-10-CM provides codes that distinguish arthropod-borne viral fevers and infections of the central nervous system by the vector of transmission, but there are no codes specifically designating non-arthropod borne viral illnesses. The codes for viral infections of the central nervous system are specific to site and must be specified as the brain (encephalon) (A85, A86) or meninges (A87). There are 3 codes available for reporting non-arthropod-borne viral encephalitis: enteroviral (A85.0), adenoviral (A85.1), and other specified viral encephalitis (A85.8). When the condition is not specified as encephalitis or meningitis, the code for other specified viral infections of the central nervous system not elsewhere classified (A88.8) is used. There is also a code for unspecified viral infection of central nervous system (A89).
Coding and Documentation Requirements
Specify viral type of encephalitis:
•Adenoviral
•Enteroviral
•Other viral, which may include the following descriptors:
–Encephalitis lethargica
–Von Economo disease
•Unspecified
Specify viral type of meningitis:
•Adenoviral
•Enteroviral, which may include:
–coxsackievirus
–echovirus
•Lymphocytic choriomeningitis
•Other viral
•Unspecified
•Other specified viral infection of the CNS
ICD-10-CM Code/Documentation
A85.0
Enteroviral encephalitis
A85.1
Adenoviral encephalitis
A85.8
Other specified viral encephalitis
A70.0
Enteroviral meningitis
A87.1
Adenoviral meningitis
A87.2
Lymphocytic choriomeningitis
A87.8
Other viral meningitis
A88.8
Other specified viral infections of central nervous system
Documentation and Coding Example
Twenty-two-month-old male presents with a 4-day history of URI symptoms. Parent states he is usually very active and happy but has been irritable all day, crying inconsolably especially when touched or picked up. His URI symptoms have included fever to 102.6, nasal congestion, conjunctivitis, and cough. On examination, the patient has a maculopapular rash on the back of his head and neck. Child admitted to pediatric floor with suspected acute viral meningitis and placed in respiratory isolation. Neurological functioning continued to decline after admission. Symptoms included agitation, confusion, and seizures. Cross section and 3-D MRI imaging revealed inclusion bodies in the neurons and glial cells of the brain.
Diagnosis: Acute inclusion body encephalitis.
Diagnosis Code(s)
A85.8
Other specified viral encephalitis
Coding Note(s)
In the Alphabetic Index, the code is found under Encephalitis, acute, inclusion body.
Viral Diseases of Central Nervous System, Unspecified
There are two codes for unspecified viral diseases of the central nervous system, one for unspecified viral encephalitis (A86) and one for unspecified viral infection of the central nervous system when the condition is not specified as encephalitis or meningitis (A89).
Coding and Documentation Requirements
For viral infection of the CNS specify:
•Viral encephalitis/encephalomyelitis/meningoencephalitis NOS
•Viral infection of CNS, NOS
ICD-10-CM Code/Documentation
A86
Unspecified viral encephalitis
A89
Unspecified viral infection of the central nervous system
Documentation and Coding Example
Thirty-year-old male presents with a 3-day history of flu-like symptoms, fever, headache, fatigue, muscle and joint pain, congestion and cough. Today he noticed neck stiffness and severe sensitivity to light. Patient denies exotic travel but recently spent a week skiing in Colorado. He denies falls or injuries but states he developed a large sore on this lip which he attributed to excessive sun exposure. On examination, this is an ill appearing, thin white male lying quietly with his eyes closed. Skin color is pale/pasty, skin is cool and clammy to touch. Temperature 98.2, HR 90, RR 20, BP 100/66. Unable to examine pupils due to extreme sensitivity to light. Limited anterior/posterior neck flexion due to pain with movement. Mild lymph node swelling noted in cervical area. No other lymphadenopathy appreciated. Hyperactive reflexes noted in all extremities. HR regular without murmur. Fine scattered rales noted in lungs bilaterally, clear with coughing. Abdomen soft and non-tender. Liver palpated at RCM, spleen is not palpated. Denies flank pain or difficulty with urination. Lower extremities are without edema, pulses are intact. Blood samples obtained for CBC, culture, sed rate, herpes antibody testing. Neuroimaging obtained with MRI scan of head and neck. Lumbar puncture performed and CSF sent to lab for gram stain, cell count, culture, protein, glucose, lactic acid, IgG antibodies, CRP. Patient is admitted with a diagnosis of probable viral encephalomyelitis.
Final diagnosis: Viral encephalomyelitis.
Diagnosis Code(s)
A86
Unspecified viral encephalitis
Coding Note(s)
In the Alphabetic Index, under Encephalomyelitis, follow the instruction “see also Encephalitis”. The code is found under Encephalitis, viral/virus. Since the specified type is not known, the code for unspecified viral encephalitis is reported.
Summary
Best practices in documentation of infectious and parasitic diseases require information on the infectious organism as well as the site of the infection. Coders will find that some aspects of coding infectious and parasitic diseases are streamlined because of many combination codes that identify both the infection and the manifestation. Some disease processes such as sepsis require an understanding of updated terminology and definitions and the detailed documentation required to code the complete clinical picture correctly. Capturing the most specific diagnosis will likely require physician training and more frequent queries of physicians to assign the proper codes.
Resources
Documentation checklists are available in Appendix A for the following condition(s):
•Sepsis, Severe Sepsis, Septic Shock, and SIRS
Clinical indicator checklists are available in Appendix B for the following condition(s):
•Sepsis, Severe Sepsis, Septic Shock, and SIRS
Chapter 1 Quiz
1.The code for a carrier or suspected carrier of an infectious disease without manifestation of acute illness is reported with a code from what chapter?
a.Chapter 1 – Certain Infectious and Parasitic Diseases
b.The appropriate body system chapter
c.Chapter 21 – Factors Influencing Health Status and Contact with Health Services
d.There are no codes for carrier or suspected carrier status
2.Which statement about localized infections is true?
a.Localized infections reported with codes from body system chapters always identify the infectious organism
b.The infectious organism may be reported with a code from categories B95-B97
c.Localized infections always require an additional code for infectious organism
d.The code for the infectious organism is always the first listed diagnosis with the site of the infection reported as a secondary code
3.Sepsis with septic shock (R65.21) is classified as a type of severe sepsis. Why?
a.It always involves failure of multiple organ systems
b.It is caused by kidney failure
c.It is associated with respiratory failure
d.It generally refers to circulatory failure associated with severe sepsis and is therefore a type of acute organ dysfunction
4.When a nasal swab is performed and documented as positive for MRSA screen but the patient has no manifestations of infection or illness, the condition is reported as:
a.Z22.322 Carrier or suspected carrier of MRSA, for patients documented as having MRSA colonization
b.B95.62 MRSA infection as the cause of diseases classified elsewhere
c.A49.02 MRSA infection, unspecified site
d.A41.02 Sepsis due to MRSA
5.Sepsis due to meningococcus is coded as:
a.Acute meningococcemia (A39.2)
b.Chronic meningococcemia (A39.3)
c.Unspecified meningococcemia (A39.4)
d.Any of the above depending on whether the condition is documented as acute, chronic, or is unspecified
6.Gonococcal infections are classified by site. Which site is considered to be part of the lower genitourinary tract in the classification of gonococcal infections?
a.Kidney
b.Bladder
c.Prostate
d.Epididymis
7.Chlamydial infection of the lower genitourinary tract has specific codes for what sites?
a.Bladder/urethra, vulva/vagina
b.Bladder/urethra, cervix, vulva/vagina
c.Bladder/urethra, cervix, epididymis, testis
d.Urethra, cervix, epididymis, testes
8.A diagnosis of listerial sepsis is reported as follows:
a.A32.7 Listerial sepsis, R65.20 Severe sepsis without septic shock
b.A32.7 Listerial sepsis, R65.10 SIRS of non-infectious origin without acute organ dysfunction
c.R65.20 Severe sepsis without septic shock
d.A32.7 Listerial sepsis
9.Documentation of severe sepsis always requires a minimum of:
a.1 code
b.2 codes
c.3 codes
d.4 codes
10.Herpes simplex virus infections are classified in which categories?
a.A60, B00
b.A60, B00, B10
c.A60, B08, B10
d.B00, B10
Chapter 1 Answers and Rationales
1.The code for a carrier or suspected carrier of an infectious disease without manifestation of acute illness is reported with a code from what chapter?
c.Chapter 21 – Factors Influencing Health Status and Contact with Health Services
Rationale: Carrier or suspected carrier status is reported with codes from category Z22 in Chapter 21.
2.Which statement about localized infections is true?
b.The infectious organism may be reported with a code from categories B95-B97
Rationale: Localized infections may or may not identify the infectious organism in the code descriptor. If the code descriptor does not identify the infectious organism, a code from category B95-B97 should be listed additionally when the specific infectious organism is documented. If the infectious organism is part of the descriptor for the localized infection, such as strep throat (J02.0), a second code from Chapter 1 is not required. The code for the infectious organism may or may not be the first listed diagnosis. Sequencing instructions differ depending on a number of factors and sequencing instructions contained in ICD-10-CM should be followed for each specific circumstance.
3.Sepsis with septic shock (R65.21) is classified as a type of severe sepsis because:
d.It generally refers to circulatory failure associated with severe sepsis and is therefore a type of acute organ dysfunction
Rationale: According to the Official ICD-10-CM Coding Guidelines – Septic shock is circulatory failure associated with severe sepsis, and, therefore, it represents a type of acute organ dysfunction. For all cases of septic shock, the code for the systemic infection should be sequenced first, followed by code R65.21. Any additional codes for other acute organ dysfunction should also be assigned.
4.When a nasal swab is performed and documented as positive for MRSA screen but the patient has no manifestations of infection or illness, the condition is reported as:
a.Z22.322 Carrier or suspected carrier of MRSA, for patients documented as having MRSA colonization
Rationale: According to the Official ICD-10-CM Coding Guidelines – A positive MRSA colonization test might be documented by the provider as “MRSA screen positive” or MRSA nasal swab positive”. Assign code Z22.322 Carrier or suspected carrier of MRSA for patients documented as having MRSA colonization.
5.Sepsis due to meningococcus is coded as:
d.Any of the above depending on whether the condition is documented as acute, chronic, or is unspecified
Rationale: In the Alphabetic index under Sepsis, meningococcal, all three codes are listed. In order to select the most specific code the provider must document the sepsis as acute or chronic. If this is not documented, the code for unspecified should be used.
6.Gonococcal infections are classified by site. Which site is considered to be part of the lower genitourinary tract in the classification of gonococcal infections?
b.Bladder
Rationale: Gonococcal cystitis/urethritis is reported with code A54.01. This is classified in subcategory A54.0-Gonococcal infection of the lower genitourinary tract without periurethral or accessory gland abscess. The remaining sites are reported with codes from subcategory A54.2-.
7.Chlamydial infection of the lower genitourinary tract has specific codes for what sites?
a.Bladder/urethra, vulva/vagina
Rationale: Only the bladder (cystitis)/urethra (urethritis) and vulva/vagina (vulvovaginitis) have specific codes. The other lower genitourinary tract sites are reported with code A56.09 Other chlamydial infection lower genitourinary tract. Codes for the cervix, epididymis, testes are not classified under the lower genitourinary tract and are reported with a code from subcategory A56.1-Chlamydial infection of pelviperitoneum and other genitourinary organs.
8.A diagnosis of listerial sepsis is reported as follows:
d.A32.7 Listerial sepsis
Rationale: Documentation of listerial sepsis without documentation of severe sepsis, organ failure, or septic shock is reported with a single code A32.7.
9.Documentation of severe sepsis always requires a minimum of:
b.2 codes
Rationale: Severe sepsis requires a minimum of two (2) codes. The underlying systemic infection is coded first, followed by a code from subcategory R65.2-Severe sepsis. In the case of a diagnosis of severe sepsis with septic shock in the absence of other documented organ failure, a sepsis code from Chapter 1 and code R65.21 for severe sepsis with septic shock would be reported. Because severe sepsis is defined as involving organ dysfunction or failure, additional codes are typically required to identify any specific organ dysfunction, so in most cases more than 2 codes would be necessary.
10.Herpes simplex virus infections are classified in which categories?
a.A60, B00
Rationale: Herpes simplex virus infections are reported with codes from category A60 for anogenital regions and with codes from category B00 for other organs, such as skin and eyes.