Spillover

by David Quammen

  The large number of patients and the small quantity of syringes available to the nursing staff preclude sterilisation by autoclave after each use. Used syringes are simply rinsed, first with water, then with alcohol and ether, and are ready for a new patient. The same type of procedure exists in all health institutions where a small number of nurses have to provide care to a large number of patients, with very scarce supplies. The syringe is used from one patient to the next, occasionally retaining small quantities of infectious blood, which are large enough to transmit the disease.

  How much of this went on? Very much. Pepin’s diligent search through old colonial archives turned up some big numbers. In the period 1927–1928, Eugène Jamot’s team in Cameroon performed 207,089 injections of tryparsamide, plus about 1 million injections of something called atoxyl, another arsenical drug for treating trypanosomiasis. During just the year 1937, throughout French Equatorial Africa, the army of doctors and nurses and semipro jabbers delivered 588,086 injections aimed at trypanosomiasis, not to mention countless more for other diseases. Pepin’s arithmetic totaled up 3.9 million injections just against trypanosomiasis, of which 74 percent were intravenous (right into a vein, not just a muscle), the most direct method of drug delivery and also the best for unintentionally transmitting a blood-borne virus.

  All those injections, according to Pepin, might account for boosting the incidence of HIV infection beyond a critical threshold. Once the reusable needles and syringes put the virus into enough people—say, several hundred—it wouldn’t come to a dead end, it wouldn’t burn out, and sexual transmission could do the rest. Some experts, including Michael Worobey and Beatrice Hahn, doubt that needles were necessary in any such way to the establishment of HIV in humans—that is, to its early transmission from one person to another. But even they agree that injection campaigns could have played a role later, spreading the virus in Africa once it was established.

  This needle theory didn’t originate with Jacques Pepin. It dates back more than a decade to work by an earlier team of researchers, including Preston Marx of the Rockefeller University, who proposed it in 2000 at the same Royal Society meeting on AIDS origins at which Edward Hooper spoke for his oral polio vaccine theory. Marx’s group even argued that serial passage of HIV through people, by means of such injection campaigns, might have accelerated the evolution of the virus and its adaptation to humans as a host, just as passaging malarial parasites through 170 syphilis patients (remember the crazed Romanian researcher, Mihai Ciuca?) could increase the virulence of Plasmodium knowlesi. Jacques Pepin picked up where Preston Marx left off, though with less emphasis on the evolutionary effect of serial passage. Pepin’s main point was simply that dirty needles, used so widely, must have increased the prevalence of the virus among people in Central Africa. Unlike the OPV theory, this one hasn’t been discredited by further research, and Pepin’s new archival evidence suggests that it’s highly plausible, if unprovable.

  Most of those injections for trypanosomiasis occurred in the countryside. City dwellers were less exposed to trypanosomiasis, partly because the tsetse fly doesn’t thrive in urban jungles as well as it does in green ones. One question that needed answering, therefore, was whether any such mania for injecting had also gripped Léopoldville, where HIV met its most crucial test. Pepin’s answer is unexpected, interesting, and persuasive. Never mind trypanosomiasis. He discovered a different but equally aggressive campaign of injections, aimed at limiting syphilis and gonorrhea in the city’s population.

  In 1929, the Congolese Red Cross established a clinic known as the Dispensaire Antivénérien, open to women and men for the treatment of what we used to call venereal diseases. Located in a neighborhood on the east side of Léopoldville, near the river, it was a private facility providing a public service. Male migrants, arriving to seek work, were required by city regulations to report to the Dispensaire for an exam. Anyone experiencing symptoms could visit the place voluntarily, and there was no charge for treatment. But the bulk of the caseload, according to Pepin, “consisted of thousands of asymptomatic free women who came for screening because they were required to do so by law, in theory every month.” The colonial government accepted prostitution as an ineradicable fact but evidently hoped to keep the trade hygienic—so les femmes libres were obliged to get checked.

  If a person tested positive for syphilis or gonorrhea, he or she would be treated. But the diagnostic testing was imprecise. Any free woman or male migrant who had once been exposed to yaws (caused by a bacterium very similar to the syphilis bacterium, but not sexually transmissible) might flunk the blood test, be classed as syphilitic, and receive a long course of drugs containing arsenic or bismuth. Harmless vaginal flora could be mistaken for gonococcus, the agent of gonorrhea. A woman diagnosed gonorrheic might be injected with typhoid vaccine, or a drug called Gono-yatren, or (even Jacques Pepin seems puzzled by this one) milk. During the 1930s and 1940s, the Dispensaire Antivénérien administered more than forty-seven thousand injections annually. Most were intravenous. Straight into the blood. With increased migration to the city following World War II, the numbers rose. In the early 1950s, the quackier remedies (intravenous milk?) and the metallic poisons gave way to penicillin and streptomycin, which had longer-lasting effects and therefore meant fewer shots. The campaign peaked in 1953, at about 146,800 injections, or roughly 400 per day. Many if not most of those injections were administered to femme libres, sex workers, ladies of hospitality, however you want to describe them, who had multiple male clients. They came and went. The syringes were rinsed and reused. This in a city where HIV-1 had arrived.

  Six years later came the blood sample that yielded the HIV-1 sequence now known as ZR59. One year after that, DRC60. The virus had spread and diversified. It was at large. No one can say whether either of those two patients had ever visited the Dispensaire Antivénérien for a shot. But if they hadn’t, they probably knew someone who had.

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  From this point the story gets huge and various, literally going off in all directions. It explodes out of Léopoldville like an infectious starburst. I won’t try to trace those diverging trajectories—a task for ten other books, with purposes different from mine—but I’ll sketch the pattern, and then focus briefly on one that’s especially notorious.

  During its decades of inconspicuous transmission in Léopoldville, the virus continued to mutate (and probably also to recombine, mixing larger sections of genome from one virion to another), and those copying errors drove its diversification. Most mutations are fatal mistakes, bringing the mutant to a dead end, but with so many billions of virions replicating, chance did provide a small, rich supply of viable new variants. The campaigns of injectable drug treatments, at the Dispensaire Antivénérien and elsewhere, may have helped foster this process by transmitting the virus quickly into more human hosts and increasing its total population. The more virions, the more mutations; the more mutations, the more diversity.

  The HIV-1 group M lineage became split into nine major subdivisions, now known as subtypes and labeled with letters: A, B, C, D, F, G, H, J, K. (Don’t confuse those, if you can help it, with the eight groups of HIV-2, designated A through H. And why are E and I missing? Never mind why. Such edifices of labeling get built piecemeal, like slums of cardboard and tin, not with architectural forethought.) As time passed, as the human population of Léopoldville grew, as travel increased, viruses of those nine subtypes emerged from the city, radiating outward across Africa and the world. Some of them went by airplane and others by more mundane means of transport: bus, boat, train, bicycle, hitchhiking on a transcontinental truck. Foot. Subtype A got to East Africa, probably via the city of Kisangani, halfway between Léopoldville and Nairobi. Subtype C spread to southern Africa, probably via Lubumbashi, way down in the Congolese southeast. Seeping across Zambia, achieving rapid transmission in mining towns full of workers and prostitutes, subtype C proliferated catastrophically throughout South Africa, Mozambique, Lesotho, and Swaziland. It
went on to India, which is linked to South Africa by channels of exchange as old as the British empire, and to East Africa. Subtype D established itself alongside subtypes A and C in the countries of East Africa, except for Ethiopia, which for some reason became afflicted early and almost exclusively with subtype C. Subtype G got up into West Africa. Subtypes H, J, and K remained mostly in Central Africa, from Angola to the Central African Republic. In all these places, after the usual lag of years between infection and full-blown AIDS, people began dying. And then there’s subtype B.

  Sometime around 1966, subtype B crossed from Léopoldville to Haiti.

  How it did that is unknown, and can probably never be known, but Jacques Pepin’s archival burrowing provides new support for one plausible old scenario. When the Belgian government abruptly relinquished its African colony, on June 30, 1960, under the stern encouragement of Patrice Lumumba and his movement, tens of thousands of Belgian expatriates—almost an entire middle class of civil servants, teachers, doctors, nurses, technical experts, and business managers—found themselves unwelcome and uncomfortable in the new republic, and they began flooding homeward. Crowding the planes for Brussels. Their departure created a vacuum, since the Belgian regime had pointedly avoided educating its colonial subjects. There wasn’t a single Congolese medical doctor, for instance. Few teachers. The country suddenly needed help. The World Health Organization responded, sending physicians, and the United Nations (through its Educational, Scientific, and Cultural Organization, UNESCO) also began enlisting skilled people to work in the Congo: teachers, lawyers, agronomists, postal administrators, and other bureaucrats, technicians, and professionals. Many of those recruits came from Haiti. It was a natural fit: The Haitians spoke French as did the Congolese; they came from African roots; they had education but very little opportunity at home under the dictatorship of Papa Doc Duvalier.

  During the first year of independence, half the teachers sent by UNESCO to the Congo were Haitians. By 1963, according to one estimate, a thousand Haitians were employed in the country. Another estimate says that a total of forty-five hundred Haitians served hitches in the Congo during the 1960s. Evidently there’s no surviving, authoritative manifest. Anyway, lots of Haitians, thousands. Some brought families, some came alone. Among the single men, we can assume, few remained celibate. Most of them probably had Congolese girlfriends or visited femmes libres. For a few years it may have been a good life. But the Haitians were less needed and less welcome as the Congo began training its own people, especially after Joseph Désiré Mobutu seized power in 1965. Less still when, in the early 1970s, he changed his name to Mobutu Sese Seko, changed his country’s to Zaire, and announced a policy of Zaireanisation. Many or most of the Haitians, during those years, went home. Their time of being useful and appreciated black brothers from the Americas had passed.

  At least one of those returnees, probably among the earliest of them, seems to have carried HIV-1.

  More specifically: Someone brought back to Haiti, along with Congolese memories, a dose of HIV-1 group M subtype B.

  You can see where this is going, but you might not expect how it gets there. Jacques Pepin’s research shed some new light on what may have happened in Haiti during the late 1960s and early 1970s to multiply and forward the virus. One thing that happened was that, from a single HIV-positive person in 1966 or thereabouts, the virus spread fast through the Haitian population. Evidence for that spread came later, from blood samples given by 533 young mothers in a Port-au-Prince slum, who agreed in 1982 to participate in a measles study at a local pediatric clinic. Tested retrospectively, those samples revealed that 7.8 percent of the women had been HIV-positive. That number was startlingly high, for such a newly arrived virus, and caused Pepin to suspect that “there must have been a very effective amplification mechanism” operating in Haiti during the early years—more effective than sex. He found a candidate: the blood plasma trade.

  Plasma, the liquid component of blood (minus the cells), is valuable stuff for its antibodies and albumin and clotting factors. Demand for it rose sharply during the period around 1970, and to meet the demand a process called plasmapheresis was developed. Plasmapheresis entails drawing blood from a donor, separating the cells from the plasma by means of filtering or centrifuging, putting the cells back into the donor, and keeping the plasma as a harvested product. One advantage of this process is that it allows donors (who are usually in fact sellers, paid for their trouble and needing the money) to be tapped often rather than just a couple times per year. Giving up your plasma, for the good of others or for profit, doesn’t leave you anemic. You can go back and give again the following week. One disadvantage of the procedure—and it’s a huge one, but wasn’t recognized in the early days—is that a plasmapheresis machine, gargling your blood and the blood of many other donors over the course of days, can infect you with a blood-borne virus.

  This happened to hundreds of paid plasma donors in Mexico during the mid-1980s. It happened to a quarter million luckless donors in China. Jacques Pepin thinks it happened in Haiti too.

  He found reports of a plasmapheresis center in Port-au-Prince, a private business known as Hemo Caribbean, that operated profitably during 1971 and 1972. It was owned by an American investor, a man named Joseph B. Gorinstein, based in Miami, with links to the Haitian Minister of the Interior. Donors received $3 per liter. Their vitals were checked before they could sell plasma, but of course nobody screened them for HIV—which didn’t yet exist as an acronym, or an infamous global scourge, only as a quiet little virus that lived in blood. According to an article that ran in The New York Times on January 28, 1972, Hemo Caribbean was then exporting between five and six thousand liters of frozen blood plasma to the United States each month. The wholesale customers were American companies, which marketed the product for use in transfusions, tetanus shots, and other medical applications. Mr. Gorinstein wasn’t available for comment.

  Papa Doc had meanwhile died, in 1971, and been succeeded by his son Jean-Claude (Baby Doc) Duvalier. Annoyed by the Times publicity, Baby Doc ordered that Gorinstein’s plasmapheresis center be closed. The Haitian Catholic Church condemned the blood trade as exploitation. Beyond that, the story of Hemo Caribbean drew little notice at the time. No one yet realized how devastating blood-product contamination could be. Nor did the CDC’s Morbidity and Mortality Weekly Report mention it, a decade later, when breaking the news that Haitians seemed especially at risk for the mysterious new immune-deficiency syndrome. Randy Shilts didn’t mention it in And the Band Played On. The only allusion to Haitian blood plasma that I recall, from the years before Jacques Pepin’s book, came during my conversation with Michael Worobey in Tucson.

  Shortly before publishing on DRC60 and ZR59, Worobey coauthored another notable paper, dating the emergence of HIV-1 in the Americas. The first author was a postdoc named Tom Gilbert, in Worobey’s lab, and in the anchor position was Worobey himself. This was the work, based on analyses of viral fragments from archived blood cells, that placed the arrival of HIV-1 in Haiti to about 1966, give or take a few years. It appeared in the Proceedings of the National Academy of Sciences. Soon afterward, Worobey got a peculiar email from a stranger. Not a scientist, just someone who had caught wind of the subject. A reader of newspaper coverage, a listener to radio. “I think he was from Miami,” Worobey told me. “He said he worked in an airport that dealt with the blood trade.” The man had certain memories. Maybe they haunted him. He wanted to share them. He wanted to tell Worobey about cargo planes arriving full of blood.

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  The next leap of the virus was small in distance and large in consequence. Port-au-Prince is just seven hundred miles from Miami. A ninety-minute flight. Part of the project that Tom Gilbert undertook, in Worobey’s lab, was to date when HIV-1 had arrived in the United States. To do that he needed samples of old blood. Whether the blood had reached America in bottles, in bags, or in immigrant Haitians didn’t much matter for this purpose.

  Worobey, ser
ving as Gilbert’s adviser, remembered a study of immunodeficient Haitian immigrants that had been published twenty years earlier. It had been led by a physician named Arthur E. Pitchenik, working at Jackson Memorial Hospital in Miami. Pitchenik was an expert on tuberculosis, and beginning in 1980 he noticed an unusual incidence of that disease, as well as Pneumocystis pneumonia, among Haitian patients. He sounded the first alarm about Haitians as a risk group for the new immunodeficiency syndrome, alerting the CDC. In the course of clinical work and research, Pitchenik and his colleagues drew blood from patients and centrifuged it, separating serum from cells, so they could look at certain types of lymphocyte. They also froze some samples, on the assumption those might be useful to other researchers later. They were right. But for a long time no one seemed interested. Then, after two decades, Arthur Pitchenik got a call from Michael Worobey in Tucson. Yes, Pitchenik said, he would be glad to send some material.