Sunday was a difficult day. Paula, David, and Michael were scheduled to be on one of the flights out of Port Harcourt too. The roads were crowded. People could take with them only what fit into a single suitcase. Families were emotional as they approached the moment of being split apart. It was especially heart-rending when people of the region stopped us for an explanation. Why were we leaving? And if we felt in danger, should they worry about their own safety? They had no option of leaving. The airport in Port Harcourt was chaotic as soldiers searched through every suitcase before approving it for travel. On the planes, children would be sitting on adults’ laps to maximize the number of people flying out.
Tempers were short. One husband objected when his wife was asked to open her suitcase a second time, saying that it had already been searched. The soldier had the man removed, under guard, to an adjoining room. Only then did the wife realize that her husband had the key to the suitcase. She asked me to see if I could get the key. As I reached the door of the room, I heard the husband asking if he could go out to give the key to his wife. “No,” was the answer. “What would you do if I walked over, gave her the key, and walked right back to this room?” “Shoot you,” the guard replied. Testing the guard, the man stood up—and the guard cocked and leveled his gun. The husband sat down.
I asked the guard, “Could the two of us keep him from getting into even more trouble? Could he give you the key, you give it to me, and I will give it to his wife?” The guard agreed, and tension was reduced, but the husband was not given an opportunity to say good-bye.
The heavily loaded DC-6s finally left the ground but seemed to take forever to get above one hundred feet in altitude. It was the beginning of hard traveling for the women and children; they would be flying from Port Harcourt to Lagos, then to Dakar, Puerto Rico, and finally New York. It was also a depressing moment for the men who remained behind. Dave, Paul, and I drove back to Enugu to continue our work, determined to eliminate smallpox from the region before we ourselves would have to leave.
Arriving at work at the Ministry of Health the next morning, I was surprised to see police and detectives throughout the building. My secretary told me that someone had broken into Dr. Anezanwu’s desk over the weekend and they were getting ready to fingerprint all of the workers. With my recent arrest seared into my mind, I decided this was not the best moment to explain to the ministry what had happened. I told my secretary I would be at the hospital if he needed me. When I went to work the next morning, I heard that the investigators were unable to solve the mystery.
THE LAST OUTBREAK IN EASTERN NIGERIA
Less than six months into using the surveillance/containment strategy, the Enugu team had an opportunity to share what we were discovering with the rest of the West and Central Africa program. The CDC in Atlanta called a meeting in Accra, Ghana, in the first week of July 1967 for all the CDC personnel involved in the West and Central African eradication program. The purpose of the meeting was to see how people were settling in and to identify tactics that were working and could be replicated. Our Enugu team worked hard in our spare moments preparing a presentation. We developed maps that detailed the epidemiology of smallpox in previous years in Eastern Nigeria and summarized the approach we had taken, with graphs and charts showing the preliminary results. Even as we got ready to leave for the Accra meeting, only a single known outbreak remained in the entire Eastern Region, and containment teams were working on it.
Only at the meeting did we realize that while we reported that we had all but eliminated smallpox from our program area, many of the other West African programs were still getting organized. This difference in timing was partly due to political and logistical problems, since USAID negotiated and signed a separate agreement with each of the twenty countries. In some cases, these negotiations required many months. For some attendees, our change in strategy was of little importance because they were not yet far enough along to consider the program in depth. Others, such as Don Millar and Henry Gelfand, who had flown in from Atlanta, were very interested in what we were reporting.
With war brewing, leaving Eastern Nigeria for the meeting was a calculated risk. On May 30, the leaders of Eastern Nigeria had publicly declared the region the Republic of Biafra. However, the American consulate in Enugu had advised us that it would still be a few months before military action began, and we expected to be gone for only a week. Even so, we faced a logistical problem. By this time, there was no official way to cross the border from Biafra into Nigeria and back again. It was common knowledge, though, that people could leave and reenter unofficially at a number of border points. We identified one such a place on the Niger River, had our passports stamped by the Biafrans, hired a large canoe to take us across the river, and then had our passports stamped by Nigerians on the other side. We intended to do the reverse on our return. We then hired a taxi to take us to Lagos, and from there we flew to Accra.
Figure 7. The first cadre of smallpox warriors at a meeting in Accra, Ghana, July 1967
As it turned out, war broke out while we were in Accra. We could not go back to the Eastern Region. Thompson and Lichfield returned to Atlanta. I returned to Nigeria and was assigned by the CDC office in Lagos to work in Northern Nigeria. However, because I had been working in the Eastern Region when the war started, I was arrested almost immediately, held under house arrest for four days at the home of a smallpox worker in Kaduna, and then told to leave the country. I returned to the United States and worked at the CDC on contract for Don Millar, assisting with the African smallpox eradication program from the States while we waited for the end of what we thought would be a short civil war.
It was not until September 1968 that Paula and our two boys and I finally returned to Nigeria, this time to Lagos. I was hired by the International Committee of the Red Cross as a deputy field officer under the supervision of Dr. Wolfgang Bulle, my church program supervisor, who had been hired as the field commander. He asked me to develop surveillance systems detailing refugee movements, food acquisition and use, and disease problems in the refugee camps in areas reclaimed by the federal army. Workers detailed by CDC maintained this program over the next fifteen months.
After Enugu fell to federal forces, I had the opportunity to revisit our flat in Enugu. The military arranged for a police officer to accompany me. The flat was barren except for six inches of files covering the floor. With the police officer standing guard, I began to sort through the papers to see if anything should be salvaged. Coming across a picture, I handed it to the police officer and said, “This is my family.” Soon he placed his gun against the wall and got on his knees and began to straighten papers. He said that he had been present at the fall of Enugu and that our flat had been ransacked by federal troops. He apologized for what had happened to our belongings. The juxtaposition of fierceness and tenderness in this man’s behavior characterized many interactions during this time of civil war.
It had been more than a year since any of us on the CDC smallpox team had been in Enugu, and during that time we had no way of finding out whether that last outbreak had been contained or not. It was a great moment when we finally discovered that the containment had been successful and stopped transmission for the entire region. Indeed, the Eastern Region had had no reported cases of smallpox during the two and a half years of fighting. For a few suspected cases of smallpox, it was possible to get specimens from these patients to the laboratory; analysis showed the rashes were due to vaccinia and not smallpox; the strain of vaccinia was the same as that in the smallpox vaccine being used in the area.
If we had known how small the window of opportunity would be when we embarked on the new strategy, we undoubtedly would have taken a more aggressive approach—mounting more containment teams, increasing the number of vaccinations for each outbreak. Yet proceeding as we did turned out to be enough.
ERADICATION ESCALATION IN WEST AND CENTRAL AFRICA
In 1967, as eradication efforts expanded not only in the twenty African c
ountries but also to other parts of the world, approximately 130,000 cases of smallpox were reported to WHO. Given the estimated ratio of reported cases to actual cases, WHO later estimated that the number was actually in the millions. Of the forty-four countries that reported cases that year, smallpox was considered endemic in thirty-three of them; that is, continued smallpox transmission did not depend on importations from other countries. These included Brazil, Sub-Saharan Africa, Indonesia, and especially the area stretching from Afghanistan eastward through Pakistan, India, and Nepal to Bangladesh.
After the success of the surveillance/containment approach in Eastern Nigeria in 1967, Don Millar became an enthusiastic advocate of the strategy. While I was at the CDC, he and I developed an effort codenamed Eradication Escalation for introducing the strategy throughout the West and Central African program. This effort would include identifying and containing chains of transmission during the seasonal low period of smallpox transmission, since every chain broken during the low period meant far fewer cases to deal with during the following high season.
The approach caught on at different rates and to varying degrees in different countries. For one thing, the original agreement between each country and USAID called for a combined measles and smallpox vaccination program. Since administering the measles vaccine to every child between six months and six years of age required a mass vaccination approach, adopting the surveillance/containment strategy meant managing two very different methodologies at the same time. In some countries the CDC teams were able to do this. In Dahomey (now Benin), twelve independent smallpox teams on motorcycles—smallpox outbreak chasers, if you will—traveled the country responding to outbreaks and containing them while others were doing mass vaccinations.
Moreover, the CDC staff had been trained to apply mass vaccination as the primary strategy. The idea of making surveillance/containment the primary strategy felt too risky and counterintuitive to some, while others embraced it. In Sierra Leone, for instance, which had some of the highest smallpox rates in the world, the director of the program, Donald Hopkins, used surveillance/containment with great success.
Once a geographical area began the surveillance/containment strategy, smallpox rarely persisted there for more than twelve to fifteen months. Eventually, all twenty countries in the CDC program made use of this approach, and smallpox disappeared from each one. Nigeria was the most daunting challenge because of its large population—which equaled that of all the other nineteen countries combined. Stan Foster, head of the Nigerian program, was successful to varying degrees in getting the strategy adopted in the Northern, Western, and Midwest regions. Nigeria recorded its final case of smallpox in May 1970.
West and Central Africa was expected to be the most challenging region of the world for smallpox eradication, yet it became the first geographical area in the WHO program to become free of smallpox. The program goal had been to eliminate smallpox within five years. The last case was reported from Nigeria only three years and six months after the program’s start—and the program was under budget. Former U.S. surgeon general Julius Richmond, commenting on the miracle of smallpox eradication in West Africa in such a short time, said that the smallpox workers sent by CDC were “simply too young to realize they couldn’t do it.” In fact, they were well chosen for the job, people who proved they could meet any problem—difficulties with vehicles, jet injectors, camels, communications, or government officials—with high spirits and humor. And they were armed with an appropriate tool for the task.
However, WHO still took a cautious stance. In 1968, the WHO Expert Committee report, while accepting the importance of both strategies, was not prepared to accept surveillance/containment as the primary strategy in highly endemic situations. The report states,
The objective of the smallpox eradication programme is achieved by reducing the prevalence of smallpox to the point where transmission of the disease is terminated. Normally, as a first step, this requires systematic mass vaccination with potent freeze-dried vaccine to reduce the prevalence of disease. Simultaneously, however, a case-detection and reporting system should be established or improved to permit prompt application of containment measures, thereby interrupting further transmission. Both these aspects of the eradication programme must receive adequate attention but perhaps greater weight should be given to mass vaccination in highly endemic, poorly vaccinated areas, shifting the emphasis to case detection and reporting as endemic disease declines and a more satisfactory state of herd immunity is achieved.2
Attitudes were changing by 1968, but the herd immunity strategy still drove WHO’s thinking.
The twenty-country program yielded several new insights into the epidemiology of smallpox, each of which helped to refine the eradication strategy. Both folklore and textbooks described smallpox as a disease of rapid transmission. In fact, the CDC workers discovered that the virus spread with more difficulty than expected, often requiring multiple incubation periods even within one household or compound. The virus’s tenacity in continuing to infect new generations within a household was confused with high transmissibility, which explains its false reputation as a highly contagious disease. This understanding of the epidemiology meant that the natural progression of an outbreak could indeed be interrupted.3
We also observed the accumulated wisdom of countless generations who had faced the disease. During an outbreak temporary structures were constructed outside a village to house patients. Persons who had recovered from smallpox were in charge of bringing food to the patients and caring for them. It was common knowledge that having had the disease itself provided solid immunity. Experience also showed that few people who had a visible smallpox vaccination scar got smallpox, and that cases were extremely rare in persons with a history of a second vaccination.
Gradually, we also discovered that the incubation period for vaccinia virus, the virus used in vaccine, was slightly shorter than the incubation period for the smallpox virus itself. Therefore, vaccinating a person on the day of exposure to smallpox could prevent the disease. Indeed, we eventually learned that vaccination even several days after exposure could prevent or at least reduce the severity of the disease. In the race between the two viruses, the vaccine virus could win.
THE SURVEILLANCE / CONTAINMENT STRATEGY: NEW OR NOT NEW?
Was the surveillance/containment strategy that was proving so effective with smallpox new or not new? The two basic parts of the strategy were not new. Surveillance is the basis for all disease control programs at CDC and elsewhere in the world. One could not work at CDC without deeply internalizing the idea that disease control requires accurate knowledge about the disease and its environment and that this knowledge is obtained through surveillance systems. Response, or control, was based on surveillance findings.
The global smallpox program was designed to reduce smallpox virus transmission by means of mass vaccination to a point where attention could be placed on individual outbreaks and chains of transmission. The WHO program, from the beginning, envisioned surveillance and containment as the follow-on strategy after mass vaccination. Henry Gelfand and D. A. Henderson describe the original strategy for the West Africa program in a 1966 article in the Journal of International Health. They state that the goal of the program “being eradication, an attempt will be made to vaccinate the entire population, regardless of age or previous vaccination status, in as short a time as possible”—in other words, to do mass vaccination. They go on to say that this will probably take two or three years. Because 100 percent coverage is unrealistic, “a second mass cycle of vaccination will probably be carried out within the 5-year lifetime of the program.” In addition, they say that because disease surveillance is “grossly incomplete,” the “epidemiologists will be intimately concerned with the mobilization of every available reporting source . . . so that no case of smallpox will go unreported and uninvestigated.” The idea was to pinpoint areas of transmission not eliminated by mass vaccination. Finally, they list what they regard as the mo
re important new elements of the program. These included a regional approach, the use of lyophilized vaccine and jet injectors, a systematic assessment and surveillance program, and adequate resources.4
The handbook for all CDC workers in the program, titled West and Central African Smallpox Eradication/Measles Control Program: Manual of Operations, clearly sets out the program’s expectations: to develop a mass vaccination program and to complete the program within three years, before immunity could wane:
Since the target with respect to smallpox is eradication, a finite goal, and since this involves a careful systematic vaccination of all ages and segments of the population, operational procedures and techniques focus principally on smallpox vaccination . . . smallpox eradication will be realized by successfully reducing, through vaccination, the number of susceptibles in the West African population to the point where it is impossible for the disease to sustain itself in a continuous chain of transmission.
Since the objective of the vaccination campaign is to induce a high level of immunity in the population . . . [and since] after three years, the proportion of persons with full immunity falls gradually and “breakthroughs” become more frequent . . . obtaining total coverage in three years requires realistic planning.5
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