SMALLPOX CLAIMS ITS LAST VICTIMS
When Don Millar took over domestic service programs at the CDC in 1970, including immunization, I took his place as director of the Smallpox Eradication Program. Once again, we were pleased to be back in Atlanta at a crucial time medically. Our third son, Robert, was born at Emory, and on the same day, he was transferred to Egleston Children’s Hospital with hyaline membrane disease. He made a full recovery, but we were reminded that such facilities are not available to parents in many parts of the world.
The CDC continued to share its experience and knowledge with other WHO-sponsored programs around the world. The experience of concentrating on the smallpox virus to direct vaccination activities to the most efficient places worked in other geographic areas also. Consistently, focusing on a new area would eliminate the virus. This usually occurred in less than twelve months after a change in strategy to concentrate on surveillance/containment.
Leo Morris, a statistician from the CDC, had been assigned to work in Brazil. Working with Ciro de Quadros, the physician who headed the Brazil smallpox program, they concentrated on surveillance/containment, and soon Brazil became smallpox free. With that event, an entire hemisphere was free of the disease. The CDC also continued to contribute people to the WHO for assignments to countries around the world.
It was then time to deal with unnecessary deaths due to smallpox vaccine use in the United States. Physicians Mike Lane and John Neff, both former EIS officers, had exhaustively studied the toll of smallpox vaccine in the United States. One person in the United States died about every other month as the result of receiving a smallpox vaccination. In addition, many persons were hospitalized for complications that included a generalized infection from the vaccine, neurologic complications, and, in some cases, the continuing growth of the virus locally, eventually requiring amputation of an arm.
The fear of smallpox in this country was so great that this vaccine carnage had been acceptable in the past. But now it was time to reevaluate and to have the best risk data available, especially if we were to suggest halting infant smallpox vaccination. In 1965, a review at the beginning of the WHO program found forty-three countries endemic with smallpox; that is, smallpox transmission was continuous within the country. This review clarified several issues. Spread of smallpox from those forty-three countries to nonendemic countries induced great fear, but the importations could be stopped. Indeed, it was possible to predict how many generations of smallpox, as well as the number of cases, might follow a new introduction. Second, rough estimates of the risk of exporting smallpox from disease-endemic countries could be calculated on the basis of the incidence of smallpox in each country and the volume of traveler traffic in and out of the country. The higher the incidence of smallpox in a country, the greater the risk for exportation. Also, the greater the volume of traffic from that country, the greater the risk of a traveler’s reaching another country with smallpox.
But a third factor also became obvious: Europe appeared to act as a filter for the United States. In those days, there were far fewer direct flights from the United States to Africa or Asia. Europe, therefore, continued to have importations, while the United States had recorded no importations of smallpox since 1949. Travelers from Africa and Asia often stopped for some time in Europe before continuing their travel to the United States. If they were in the incubation period of smallpox, they would likely develop symptoms in Europe before continuing their trip.
The loss of seven people a year in the United States due to the smallpox vaccine increasingly seemed too high a price to pay for smallpox freedom. Theoretically, an importation might lead to ten to twenty cases of smallpox and perhaps six deaths. However, it would require an importation every year to equal the adverse impact then resulting from the domestic smallpox vaccination program. While an importation and even one death would bring critics to the forefront, arguing that we had not protected the public, discussions with the Advisory Committee on Immunization Practices, state health officers, and state epidemiologists finally led to the conclusion that we must take this action, even while smallpox continued to rage, especially in India, Pakistan, and Bangladesh.
Case Manual
With the help of Seth Leibler, head of training at the CDC, an ingenious program was implemented. Training workers in every state would be time consuming and ephemeral. The turnover of staff and the loss of skills not used would require a continuing training program beyond the capacity of the CDC. So Leibler and his staff developed a program called Comprehensive Action in a Smallpox Emergency (CASE).
A large notebook contained a folded diagram that would be unfolded and affixed to a wall in the state or county experiencing a suspected or known case of smallpox. The chart was called a PERT chart (program evaluation and review technique) and used techniques developed by the US Navy in the 1950s to outline the critical path of decisions and actions required to reach an objective. The PERT chart allowed the state or local health department staff to see, step by step, the actions required. It meant that all of the essential steps could be taken at first suspicion of a smallpox emergency, even before the CDC could deploy a person or a team. The training consisted of a visit to every state health department to walk through the steps, put the chart on the wall, and provide familiarity with how the health department staff would respond.
Now, of course, the entire procedure would be online, saving the on-site visits. Yet there was something important in visiting each state, seeing who would be given responsibility, and having them identify with the person they would call on in an emergency.
The full procedure was never implemented. To the credit of the modelers, who could demonstrate that the risk of smallpox was very low in the United States, even while it existed elsewhere, we had no importations. However, the early parts of the PERT chart were used repeatedly while ruling out the possibility of smallpox in a traveler with a rash.
A traveler on a plane arriving with a suspicious rash would be isolated in a holding room at the airport. Specimens of the lesions would be obtained and hand-carried to Atlanta. (The importance of the diagnosis dictated the extra cost of a person’s traveling with the specimens to eliminate the chance of specimens being lost.) When the specimen arrived at the CDC, day or night, Jim Nakano, a virologist heading the CDC smallpox laboratory, would personally examine the specimen. Nakano developed the first smallpox lab in the United States and diagnosed the world’s last naturally occurring case of smallpox, in a person in Somalia. (There were two laboratory-acquired cases in the United Kingdom following global eradication.) He and his staff would immediately take the specimens, prepare them, and then examine them under an electron microscope. He would attempt to grow viruses from the specimen, but he was so confident of the electron microscope examination that he would provide a preliminary diagnosis within several hours of the specimen’s arrival. It was then possible to release the traveler from isolation at an airport. In the meantime, foreign quarantine workers would have identified every person on the flight, with a forwarding address, in the event they had to be vaccinated.
In India
In the summer of 1973, along with Paula and our three sons, David, Michael, and Robert, I went to India, working under the auspices of the WHO.
I benefited from the short-term volunteers Millar freely provided from his workforce to work in smallpox eradication in various countries. (The Bureau of State Services, which he headed, was the largest service-delivery program at the CDC, providing domestic immunizations, tuberculosis and sexually transmitted disease screening, dental work, and other activities, so he had an enormous public health workforce, not only in Atlanta but in all of the states.) Work in the field was a constant problem-solving experience. If an outbreak required more guards placed at the homes of smallpox patients to vaccinate visitors, the CDC short-term volunteer would hire day laborers or borrow people from other health programs. If smallpox patients attempted to leave their home to get food, the CDC person was authorized to provide food services. Rumors of new smallpox cases would trump the plans for that day as the CDC worker figured out how to pursue the rumors.
Workers would return to the United States exhausted but energized with a feeling of accomplishment. Millar once wrote to say he had no idea whether they were helping in the fight against smallpox but to please continue to ask for them. He said that they came back different people, intolerant of roadblocks and focused on solving problems.
India agreed to implement the search-and-containment strategy with the first search involving four states for six days in October 1973. It was a shock, during what was the low transmission season, to find 10,000 new cases of smallpox in two states—cases unknown to the authorities. It overwhelmed our ability to respond with containment. Within six months, India mastered both the search for cases and the response to contain those outbreaks. Soon villages were searched, house by house, and tens of thousands of health workers contained outbreaks. At one time, there were more than 6,000 pending outbreaks, and a single state, the state of Bihar, was discovering 1,500 new smallpox cases a day, one new case each minute.
From a peak of more than 11,000 cases of smallpox reported in a single week in a single state, in May 1974, India went to zero cases of smallpox in the entire country in twelve months.
This may be the most dramatic twelve-month period ever recorded in public health history.