N'zara
LASSA, EBOLA, AND THE
DEVELOPING WORLD'S ECONOMIC
AND SOCIAL POLICIES
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Improvement in health is likely to come, in the future as in the past, from modification of the conditions which lead to disease, rather than from intervention into the mechanisms of disease after it has occurred.
âThomas McKeown, 1976
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The microbe is nothing; the terrain everything.
âLouis Pasteur
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While his colleagues in Atlanta anguished over Swine Flu damage control, Joe McCormick was content to finally have a chance to uncrate several thousand pounds of laboratory equipment and build his remote Lassa Fever Research Unit in Sierra Leone. It hadn't been easy getting all the gear by ship from Atlanta to Freetown and by assorted trucks along the sporadically paved roads to Segbwema.
But here he was, at long last, on his own, in charge, doing what he most loved: science. Months earlier, long before he was detoured off to the Sudan to chase down the Ebola virus, McCormick sat down with Karl Johnson and mapped out a strategy for his Lassa research.
There was so much to do.
He wanted to find out just how widespread Lassa virus infection was in the West African
Mastomys
rat population. McCormick planned to do antibody tests on thousands of Sierra Leonians to see how many had ever been infected with the virus.
“While I'm at it, might as well check for antibodies to Marburg and Ebola. Wouldn't it be a kick if it turned out those things were up there,” McCormick told Johnson just before he left Zaire.
Pat Webb would later join Joe, and that pleased him. She was one of the best field lab workers he'd ever seen, and McCormick knew he could count on Webb's data: it would always be reliable. He appreciated her
caustic, opinionated way of looking at the world, always coupled with a great sense of humanity. She could be counted on for ample hilarity.
Not long after getting settled in and starting up laboratory operations, McCormick received a cable from the U.S. Embassy in Freetown summoning him for a top secret meeting. After traversing the backbreaking roads from Segbwema to Freetown, McCormick was informed that his presence was required immediately at the U.S. Embassy in nearby Monrovia, Liberia. It was an official diplomatic summons, passed from the Liberian government of President William R. Tolbert, Jr., to the Carter administration in Washington. The U.S. State Department cabled word to its embassy in Freetown that Liberia had requested McCormick, by name. And he had better go.
When McCormick finally reached the U.S. Embassy in Monrovia, he was informed that the Tolbert government, which was aligned with that of the United States in Africa's crazy-quilt mixture of Cold War allegiances, was concerned about the recent arrival in the country of four Soviet scientists. The Soviets, who were interested in Lassa research, had arrived in Monrovia a few days earlier, unannounced, requesting unusual and basically unobtainable supplies, such as tanks of liquid nitrogen and various compressed gases.
The U.S. Embassy set up a formal meeting, attended by McCormick, the four Soviets, and representatives of the U.S. and Liberian governments. One of the Soviets was a bona fide scientist: Sasha Kachenko had collaborated years earlier with Karl Johnson on studies of hemorrhagic fevers in Russia and the Ukraine. The true identity of the other three was less clear, though Joe was certain at least one was a KGB agent. The fellow certainly didn't know anything about basic biology. It was obvious after twenty minutes of vague conversation that the Soviets had no lucid plan for studying the Lassa virus.
“Hell,” McCormick told embassy officials, “it sounds like they're just going to wander around collecting rodents.”
Once outside the embassy, far from electronic surveillance, the Soviet team pressed McCormick for assistance. They wanted Lassa antibodies, reagents, and, most important, samples of the virus. They also wanted to know how to do Lassa research.
Convinced it would be dangerous to turn over samples of such a lethal virus to men he was certain worked directly or circuitously for Soviet intelligence, McCormick simply smiled and told his luncheon companions that all such requests would have to be submitted in writing to the director of the CDC in Atlanta.
Throughout 1977 and 1978 the Soviet researchers continued importuning McCormick and the CDC for Lassa virus samples. And the CIA grilled McCormick after every contact with the Russians. McCormick and then former CDC director David Sencer were convinced that both sides in the
Cold War feared the other was developing Lassa as an instrument of biological warfare. As a weapon, Lassa certainly had many desirable characteristics: better than 90 percent lethality in nonimmune populations, extraordinary virulence that needed only minute doses for infection, apparent viral tolerance of a variety of hostile environments, and, most important, no clear treatment or antidote. Furthermore, because of the circumstances surrounding Mandrella's infection, military researchers on both sides of the Iron Curtain were convinced that lethal infection could result from inhalation of the virus.
1
The Soviets had first approached the U.S. government five years earlier, requesting a sample of the Lassa virus during a Moscow visit by U.S. Secretary of State Henry Kissinger. Because he had publicly vowed complete openness in United States/U.S.S.R. information exchange as part of ongoing nuclear and biological arms negotiations between the Nixon and Brezhnev administrations, Kissinger ordered the CDC in 1972 to accede to the Soviet request.
2
Sencer later did so by personally hand-carrying a vial of the virus to Moscow.
It was, therefore, unclear to the CDC in 1977â78 why the Soviet researchers in Liberia needed further samples of the virus, and though the superpowers had signed a treaty forbidding biological weapons use and development, the U.S. agency remained suspicious of Soviet intentions.
Though the Soviet effort in Africa over the coming years was far larger than anything McCormick and Webb could muster in Sierra Leone on their meager CDC funds, it accomplished nothing. Four separate teams of Soviets “were wandering around in a thick fog, with no sense of direction,” McCormick told Webb. Both the CDC scientists felt that a golden opportunity to do stellar collaborative work was lost. The Americans couldn't conduct research in Guinea because the United States did not have diplomatic relations with President Sékou Touré's left-wing government. Similarly, the Soviets couldn't freely roam about the countryside in search of Lassa in Senegal, Liberia, Sierra Leone, or Nigeria.
For years separate and often isolated research was conducted, and both superpowers would eventually shut down their West African Lassa laboratories, leaving the Africans the ultimate losers. At McCormick's insistence the CDC would maintain a collaborative Lassa research effort with Sierra Leone and occasionally Nigeria well into the 1990s. But the Soviet operations would be abandoned in 1984 following a Guinean coup d'état, leaving behind no obvious scientific legacy.
3
As time went on in the late 1970s, McCormick wasn't even sure his efforts in Sierra Leone constituted a lasting legacy for the people of that nation. Though he, Webb, and other CDC colleagues amassed an impressive store of information, they had tremendous difficulty in translating the newfound knowledge into meaningful action. The virus was carried by the
Mastomys
rats, which were ubiquitous throughout the villages, swamps, and forests of West Africa. The rats lived inside huts and homes, people
toleratedâeven ateâthe rodents, and the rats urinated on stored grains and the dusty dirt floors. Once people became ill, they went to hospitals that failed to follow hygienic practices aimed at preventing spread of the virus from patient to patient.
McCormick drew blood samples from hospitalized patients in Sierra Leone's eastern province, discovering that on any given day some 5 to 15 percent of the adult patients were infected with the deadly virus. McCormick and his CDC colleagues surveyed the remote villages of the country's northern savanna area, finding that up to 40 percent of the adult residents of some locales had antibodies against Lassa, which proved that they had been previously exposed to the virus. Nationwide, nearly 9 percent of Sierra Leone's citizens tested positive for antibodies against the virus.
4
Together with Guido van der Gröen, then with the Institute of Tropical Medicine in Antwerp, McCormick collected all available blood studies and data on Lassa from all over Africa for the World Health Organization. In 1977 a second type of Lassa virus was discovered in
Mastomys
rats in Mozambique, and eventually one or the other Lassa strain was found in the blood of those rodent species in every country in which they were able to look, from Mozambique and Zimbabwe in the southeastern corner of Africa all the way up to Senegal and Mali in the northwest.
McCormick and van der Gröen told WHO that the scope of rodent and human infection in Africa clearly showed that what had seemed an extraordinarily rare and mysterious disease in 1969 when Penny Pinneo took ill was actually a highly endemic problem in scattered villages across the continent.
5
When an infectious vector-borne disease was that thoroughly entrenched, and its carrierâthe ratâthat perfectly adapted to cohabitation with human beings, classic public health training dictated just three options for limiting the further spread of the disease: a vaccine, a cure, or elimination of the vector.
But there was no Lassa vaccine, nor did one appear likely in view of the lack of interest in developing one at the laboratories and pharmaceutical companies of the wealthy nations. McCormick's initial hopes that stockpiling plasma from people who had recovered from Lassa would result in a storehouse of curative antiserum were quickly dashed. He soon discovered that few people made sufficient antibodies to be useful in preventing full-blown disease in other infected individuals. Indeed, he found most people didn't even muster a strong enough immune response to prevent their own reinfection, and repeated episodes of Lassa fever were fairly common.
In the villages of Sierra Leone, fevers were a constant presence and had been for millennia. The people assumed most fevers were caused by mosquito-borne diseasesâmalaria and yellow feverâor by sorcery and evil spirits. McCormick discovered that about one out of every ten cases of high fever in the villages was caused by the Lassa virus.
Most of the timeâperhaps over 98 percent of the timeâpeople recovered
from Lassa fever, but their illnesses lasted many days, even weeks. During that time they were unable to work, and McCormick could see the enormous economic toll Lassa took on the villages. In contrast, if people got infected in a hospital, through blood-to-blood contamination of medical equipment, their chances of getting sick and dying were far greater: 16 percent of such infections were fatal.
McCormick and Webb experimentally treated Lassa with a new injectable drug called ribavirin. The antiviral drug had already proven effective in treating some other viral infections by blocking the ability of the viruses to reproduce. It worked on Lassa, McCormick and Webb found, provided it was administered before full-blown symptoms developed.
From the beginning, however, McCormick knew that impoverished societies like Sierra Leone could never afford to buy enough ribavirin, build enough hospitals, and train adequate personnel to curtail Lassa fever deaths. As he struggled to find a solution, including searching for ways to eliminate
Mastomys
rats, McCormick began to appreciate the scale of the problem. As had many Europeans and North Americans before him, and as would others afterward, McCormick was acquiring a deep sense of the “infrastructure” problem. Every day his midwestern can-do mettle was put to the test as his time was wasted repairing an electrical generator, rebuilding a washed-out bridge, sewing up holes in mosquito nets, negotiating receipt of illegible carbon copies of documents from self-important bureaucrats, training bright unskilled people in basic hospital practices, and traveling from one incredibly remote location to another.
“It does sometimes matter whether you know how many logs it takes to float a Land-Rover,” McCormick would tell his colleagues back in Atlanta.