© Springer Nature Switzerland AG 2021
C. S. Foster et al. (eds.)Uveitishttps://doi.org/10.1007/978-3-030-52974-1_49

49. Trypanosomiasis

Mahmut Kaya1  
(1)
Department of Ophthalmology, Dokuz Eylul University, Izmir, Turkey
 
Keywords
TrypanosomiasisUveitis

Overview

  • Definition

    • A vector-borne disease caused by protozoal parasites of genus Trypanosoma, with two very different varieties in humans

    • Human African trypanosomiasis (HAT), or “sleeping sickness”

      • Caused by T. brucei rhodesiense and T. brucei gambiense transmitted by infected tsetse flies found only in Africa

      • Found only in sub-Saharan Africa, as tsetse fly is only vector

    • American trypanosomiasis, or Chagas disease

      • T. cruzi transmitted by bloodsucking triatomine bugs, but can spread via blood transfusion, organ transplant, placental transfer, and oral route

      • Found mainly in rural Central and South America, but the United States has 200,000–300,000 cases due to different transmission modes

  • Symptoms

    • HAT: blurry vision, light sensitivity

    • Chagas disease: Lid swelling, no vision change

  • Laterality

    • Unilateral or bilateral

  • Course

    • If untreated, HAT is often fatal within months, while Chagas disease becomes chronic and lifelong

    • Ocular changes are post-inflammatory and not progressive

  • Age of onset

    • All age groups affected

  • Gender/race

    • No gender or racial predilection

  • Systemic association
    • HAT
      • Stage 1 (hematolymphatic)

        • 1–3 weeks after insect bite

        • Fever, headaches

        • Myalgia, arthralgia

        • Rash and swelling of hands and periocular areas

      • Stage 2 (meningoencephalitic)

        • Parasites invade central nervous system (CNS), causing characteristic insomnia and daytime drowsiness, personality changes, gait imbalance, and seizures

        • Fatal if untreated

    • Chagas disease
      • Acute stage

        • Starts 1–2 weeks after insect bite

        • Fever and diffuse lymphadenopathy

        • Rare lethal events from myocarditis and meningoencephalitis

      • Indeterminate stage

        • Asymptomatic

        • Majority of patients

        • May last 10–20 years or indefinitely

      • Chronic stage

        • 20–30% of cases

        • Cardiomyopathy is the most serious complication

        • Megaesophagus and megacolon

Exam: Ocular

HAT

  • Interstitial keratitis

Chagas Disease

  • Romaña’s sign: periorbital swelling from bug bite or direct inoculation of bug feces

  • Post-inflammatory parafoveal RPE atrophy without visual sequelae

Exam: Systemic

HAT

  • Skin chancre at site of insect bite

  • Diffuse, enlarged lymph nodes

  • Neurological/mental status assessment

Chagas Disease

  • Swelling around insect bite

  • Cardiac and pulmonary exams for congestive heart failure

  • Inquire about difficulty with swallowing and bowel movement

Imaging

  • n/a

Laboratory and Radiographic Testing

HAT

  • T. b. rhodesiense

    • Seen easily on blood smear, or lymph node and chancre aspirate

    • Serologic testing not widely used as diagnosis easily made with above

  • T. b. gambiense

    • Difficult to detect in blood

    • Requires (posterior cervical) lymph node aspirate

    • Serologic testing is useful for screening, but diagnosis is based on microscopic detection

  • T. cruzi

    • Seen easily on blood smear in acute stage

    • Serologic testing may be necessary in chronic stage

  • Lumbar puncture

    • Necessary in all HAT patients to determine CNS involvement

Differential Diagnosis

  • n/a

Treatment

Contact the Centers for Disease Control and Prevention (CDC) or World Health Organization (WHO) for specific treatment protocols
  • HAT

    • Suramin

    • Pentamidine

    • Melarsopro

    • Nifurtimox

    • Eflornithine

  • Chagas disease

    • Benznidazole

    • Nifurtimox

Referral/Co-management

  • Infectious Disease

  • Neurology

  • Cardiology

  • Gastroenterology