The Coming Plague

by Laurie Garrett

  When word spread of Bacon’s illness, prayer meetings occurred spontaneously throughout the region and the fear of Lassa fever grew. People wondered, “What can be so terrible that it can kill nurse Bacon?”

  On Good Friday, March 30, Bacon was carried from her home to a small landing strip, where she would board a prop plane bound for the somewhat more sophisticated Phebe Hospital. As her stretcher-bearers wended their way to the airstrip, the people of Zorzor lined the path, some crying out, others sobbing.

  Samples of blood drawn from Bacon and other ailing hospital staff members23 were forwarded to the CDC in Atlanta, and health officials in Liberia, as well as WHO headquarters in Geneva, were alerted. Once again, Penny Pinneo, who had remained in Jos, was asked to donate her services and her blood. Now convinced that God had intended her to survive Lassa for just such a purpose, Pinneo enthusiastically complied.

  Though Pinneo brought two units of antibody-containing plasma, the blood proved useless for Bacon. As Karl Johnson had predicted three years before, antisera was effective for viral hemorrhagic diseases only when given early in the illness.

  On April 4, Esther Bacon died.

  When Esther Bacon fell ill, Tom Monath was just finishing up his research fellowship in virology at the University of Ibadan in Nigeria. The thirty-year-old Bostonian had developed a fascination with insect-carried viral diseases during his medical studies at Harvard, and went to Nigeria to study yellow fever. By March 1972, his work was done, crates were packed, and Monath was already imagining sinking his teeth into a nice juicy all-American cheeseburger when a cable arrived from the CDC.

  “Go to Liberia,” it read, noting there were reasons to suspect Lassa fever had broken out in a tiny mission hospital. He was instructed to link up with Penny Pinneo and get to Zorzor as fast as possible. His job was to find out where Lassa came from and how it was spread.

  For a moment Monath just stared at the cable, struck by a flash of fear. “This is pretty terrifying,” he thought. “Nobody really knows anything about this. It’s highly contagious, and half of the people who got it in Jos died.”

  But hours later, as he unpacked gear he had already prepared for shipping to the United States, Monath deliberately downplayed the assignment, telling his wife it was “no big deal, probably routine.”

  Pinneo and Monath made their way from Lagos to the Liberian capital of Monrovia, and then took a tiny light-wing plane to Zorzor. The moment they landed the pair could feel the pall over the community. Nobody was walking along the roads, and travelers refused to make their usual stopovers for gasoline and food in Zorzor.

  “The air smells like fear,” Monath thought.

  Bacon was still alive—barely. Several hospital beds were occupied by other Lassa patients, and the staff was frankly stupefied by it all. Pinneo and Monath met with the hospital director, Dr. Paul Mertens, and Tom laid out a battle plan.

  “First, we go to Zigida, track down Garbazu, and try to figure out where she got the virus,” Monath said. While Pinneo and Monath searched the village, Mertens would try to determine how the virus spread within his hospital. Because she was immune, Pinneo agreed to be in charge of drawing and handling blood samples.

  Before he left Zorzor, Monath grabbed every mousetrap and net he could find. Though all his training was in insects, Monath knew that Junin and Machupo were rodent-carried diseases, and circumstances just didn’t point to insects in either Jos or Zorzor; if insects had carried the disease the cases would not have all occurred indoors or been primarily among adults. As a rule, insect-carried diseases attacked children more than adults because youngsters tended to play outdoors in watery or wooded areas where they came in contact with mosquitoes, mites, spiders, and such.

  But in Zorzor only one child had Lassa—a newborn who undoubtedly got infected as a result of blood-to-blood contact with its dying Lassa-infected mother.

  As they headed for Zigida, Monath reviewed what he had heard about rodent disease carriers and tried to imagine what a real CDC rodent expert might do in the situation.

  Neither Pinneo nor Monath spoke the Liberian languages of Loma or Kpelle, but the government conducted its affairs in English because the nation was founded by freed American slaves in the nineteenth century, and even in remote villages it was possible to get by with basic English. They found Garbazu and gained village approval to take blood samples from her friends and relatives, set mousetraps, and collect local animals. While Pinneo patiently drew blood from anxious villagers unaccustomed to such procedures, Monath hunted.

  Night after night Monath crouched by candlelight, a net grasped tightly in one well-gloved hand, the other constantly adjusting his respirator. In this manner he captured dozens of bats, always aware that the fangs of the animals that were thrashing about in his nets might carry the deadly virus. With only a flickering candle to illuminate his actions, Monath carefully placed each captured bat in a thermos full of liquid nitrogen, freezing their bodies for future study at CDC high-security laboratories in Atlanta.

  Monath failed to find the animal culprit responsible for the original Zigida cases, but blood tests of 133 villagers showed that, in addition to Garbazu, four people had survived bouts of Lassa fever.

  Back at the hospital, Mertens and Monath were joined by Jordi Casals, who was sent by the CDC. Together they scoured the building for pests, but eventually were forced to conclude that the mini-epidemic constituted a classic case of nosocomial transmission: spread of disease between patients and medical staff.24 Nurse Esther Bacon, they decided, clearly became infected during the dilation and curettage performed on Garbazu, who presumably somehow contracted Lassa fever in Zigida.

  Garbazu was on the Curran Lutheran Hospital ob-gyn ward from March 1 to 19. During that time Nessie, who was recuperating from a kidney infection during pregnancy, lay in the bed that was beside Garbazu’s for a few days, sharing her newfound friend’s food and water. Nessie recovered nicely from her pyelonephritis and was discharged. Five days later she returned, suffering a soaring fever. Nessie died of Lassa.

  Liberian midwives Jetty Ziegler and Phebe Hollwanger, having tended to both Nessie and Garbazu, fell ill in mid-March, but recovered fully from Lassa after a few weeks’ time.

  Sarah wasn’t so lucky. Bedded just twenty feet downwind from Garbazu, the Kpaiyean villager was recuperating from an emergency caesarean section and caring for her newborn baby. The very day Garbazu left Curran Lutheran Hospital, Sarah developed a sudden searing headache, her fever spiked at 103°F, and she was unable to sit up. On April 4 her birth canal began hemorrhaging so severely that Sarah went into shock and died. Four days later her baby succumbed.

  In all, eleven women got Lassa in Zorzor in 1970, all of whom had been in the Lutheran hospital; seven were members of the staff. Four people died: Esther Bacon, a Liberian obstetrics patient named Sarah, her newborn baby, and Juanita Akoi, a Liberian nursing assistant.25 Two of the survivors were rendered hearing-impaired, one was completely deaf.

  The team tested fifty-nine other patients who had been in the hospital during March—six tested positive for Lassa. Among the fifty-seven hospital staff members, in addition to the seven known to have had the disease, two more tested positive. Both had worked on the obstetric ward tending to Sarah, Garbazu, and Nessie.

  Nessie’s case particularly troubled the researchers because it implied Lassa could have a long latency time (nineteen days), and could even recur. The prospect of Lassa relapses among his staff was particularly unnerving for Mertens.

  Further evidence of relapses emerged when the team studied hospital records going back five years. In the end, they were convinced many past cases of unexplained feverish ailments could be considered Lassa; one such former patient was tracked down, tested, and found to have antibodies against Lassa, showing he had, indeed, once been infected with the virus.

  Because the scientists couldnâ€�
��t pin down the original source(s) of the Liberian epidemic, Mertens knew he should expect additional cases of the disease in the future.26 Though he could do nothing to prevent village outbreaks, Mertens was determined that the disease would never again be spread within his hospital. The entire staff was trained in proper disease control measures, hygiene, instrument sterilization, and other classic practices that have been used with general success to block the hospital spread of microbes since the days of Baron Joseph Lister.27

  Monath had barely caught his breath and was, once again, preparing to return to the United States when Peace Corps physician Michael Gregg, then working in Sierra Leone, contacted the CDC. The volunteer doctor was convinced Lassa had struck. Once again, Monath gathered up Casals and Pinneo. The trio made their way in September 1972 to Freetown, capital of Sierra Leone, and were joined by CDC investigators David Fraser, Paul Goff, and Carlos (“Kent”) Campbell. Together, they solved the Lassa mystery, though their efforts went largely unnoticed back home in the wake of the Watergate break-in and heated U.S. presidential elections.

  About two hundred miles east of Freetown, not far from the borders of Guinea and Liberia, Lassa fever struck among villagers and diamond mine workers. At first glance the epidemic seemed a repeat of those in Jos and Zorzor: hospital-based. But it didn’t take long for Monath and Casals to recognize that most of the people then suffering Lassa in Panguma Hospital acquired their infections somewhere else. A search through the medical records of six hospitals in the region revealed sixty-three cases of what looked suspiciously like Lassa, occurring between October 1, 1970, and October 1, 1972, with the numbers of sick having increased steadily over the two years.

  Once again, Monath donned thick gloves and a respirator to hunt wild animals in the villages and mining camps around Panguma. Casals and Pinneo took blood samples from hospital staff members. The hunt was on. Cats and dogs were grabbed by the villagers, who held the animals still while Campbell, Casals, and Monath drew blood samples. Hundreds of traps for rats and mice were set, bats were netted in the night. Again, the wild animals bared their fangs at their captors, who carefully killed the beasts with gloved hands.

  “This is fantastic!” Monath thought, sensing the possibility that here, in these Sierra Leone villages, the animal that carries Lassa viruses would finally be found. So great was the excitement that the team members kept their fears private, never voicing anxieties about getting the dreaded disease. The shorter, older meticulous Monath kept a watchful eye on Kent, however. Towering over everyone, Campbell had the lanky strong build of a basketball player and the impulsive swift movements of an athlete.

  Indeed, twenty-six-year-old Campbell got so wrapped up in the quest that he suggested the team do something they would all later agree was “really, really dumb”: take phlegm samples from deep inside the lungs of Lassa patients lying on the wards of Panguma Hospital. Temperatures in Sierra Leone were hitting 110°F and humidity topped 90 percent, so Monath and Campbell often found their protective gear (consisting of latex surgical gloves, facial respirator masks, surgical cotton gowns and foot coverings) intolerable and “fudged a little,” as Campbell put it, creating spots along their masks and gowns that allowed air circulation. Young Campbell, who had just signed on for a two-year hitch with the CDC to avoid the Vietnam War draft, enjoyed working with the older, more experienced Monath. Though Monath was an urbane Bostonian and Campbell hailed from eastern Tennessee, both men had spent formative years at Harvard studying medicine and public health. Campbell planned to return to Harvard when his CDC hitch was over, to complete his pediatric residency.

  Monath, Campbell, and the rest of the group collected more than 640 animals: mice, rats, shrews, bats, and house pets. The animals’ lungs, hearts, spleens, kidneys, and blood were carefully removed with sharp dissection scalpels wielded cautiously by gloved hands. All were placed in liquid nitrogen, meticulously labeled, and prepared for overseas air shipment to the maximum-security laboratory at the CDC in Atlanta.28

  While the team anxiously awaited results, they studied the villages carefully, trying to see what was unique about those that had Lassa cases. In all the eastern Sierra Leone villages around Panguma and nearby Tongo, people lived in large extended families that resided in houses made of mud coated with cement. Their roofs were of iron sheets or thatching, the floors packed mud. Harvested grains were stored in sacks and baskets inside the homes.

  The villages were clusters of homes encircling a clearing. Outside the village lay some croplands and rain forest; at times it was hard to tell where one stopped and the other began. Because it was the rainy season, people—and animals—tended to spend their time in shelters.

  When the team captured animals they noticed three types of mice and rats scurrying about the villages, and one type—the Mastomys natalensis rat—was present in greater numbers in villages stricken with Lassa.

  To the joy of all the research team members, CDC laboratory analysis confirmed their hunch. Of 350 animal species initially tested, only Mastomys natalensis turned up positive for Lassa virus infection. Better yet, the infected rats came from the same villages where humans had the disease.

  Though the major puzzle was finally solved,29 two questions remained: why had the Mastomys suddenly become a problem in key villages; and how did the rats pass Lassa virus on to the people?

  Monath’s group noticed that Mastomys had tough turf competition in the form of the larger, more aggressive black rat, Rattus rattus. In some villages, the people had driven out or eaten the big black rats, leaving smaller brown Mastomys virtually unopposed on the playing field. Mastomys often came out of neighboring fields and took shelter from the rains inside homes.

  Less clear was how the rats gave people Lassa. Few of the humans who were infected could recall being bitten, and the team was unable to prove one way or another that Mastomys could pass the virus in its urine, as had already been seen with Junin and Machupo.

  Back at the hospitals in Tongo and Panguma, Pinneo’s lifesaving antibodies once again were used in hopes they would help in the recovery of two Lassa patients. But the team discovered in laboratory studies that antibodies from the original Nigerian strain of Lassa virus (now dubbed Pinneo) reacted poorly with the Sierra Leone virus. Weaker still was the reaction to Monath’s Liberian strain. This meant there were at least two widely divergent strains of Lassa viruses in West Africa, and Pinneo’s antiserum could not be counted on to save patients—and scientists—who got Lassa outside of the Jos region of Nigeria.

  It was possible, the group concluded, that Pinneo’s antiserum had no real effect on the two Sierra Leone patients to whom it had been given, as there were indications that both women were already recovering.30

  Any comfort Pinneo’s units of blood carefully stored at the CDC might have provided to doctors, nurses, and researchers working in West Africa in the 1970s clearly had to be muted.31

  Because Mastomys was a common African rat, found in fields and villages from Sudan to South Africa, it seemed possible dozens of additional strains of Lassa lurked on the continent—strains Pinneo’s antiserum might not be able to combat.

  Back at Columbia University, John Frame was convinced Lassa fever could be found throughout West Africa if a scientific search was carried out. With a paltry budget of only $5,000, Frame and Casals screened the blood of missionary workers from countries all over West Africa. They found evidence of Lassa infection in people stationed in Mali, Upper Volta,32 Ivory Coast, Zaire, and possibly the Central African Republic. That meant Lassa existed in at least eight countries.33

  Kent Campbell had a similar idea. Mischievously, he thought he could combine some smart science with a CDC-paid extended trip through Ireland by offering to screen nuns who had in the past worked at Panguma Hospital. Since its opening in the 1950s Panguma had been staffed by the Sisters of the Holy Rosary, an Irish Roman Catholic order. The
nuns tended to rotate through the African hospital, returning to Ireland after a year or two, so several dozen women who could have been exposed to Lassa now lived in Ireland. Campbell told the CDC that testing those women might reveal the answer to a key question: had Lassa been around Sierra Leone for decades but gone unnoticed amid the plethora of diseases people suffered, or was the virus new?

  He argued persuasively to the Atlanta bosses: “If you weren’t paying close attention, you wouldn’t be able to distinguish Lassa from malaria. They look exactly the same until the tail end of Lassa when the hemorrhaging starts.”

  Campbell got the okay, hopped a commercial jet to London, connected with his wife, Liz, and the two of them happily embarked for the Emerald Isle. For four days Kent and Liz traveled all over Ireland, from convent to convent, testing the nuns and sightseeing. For Kent, it was a welcome relief from the hard work in Sierra Leone; for Liz it was a break from pacing about their Atlanta home worrying about her husband’s safety.

  One afternoon two of the Sisters took the Campbells to Blarney Castle, where they, like thousands of Americans before them, bent to kiss the Blarney stone. When they returned to their car, Kent suddenly reeled, feeling as if he’d been hit hard on the back of the head. Within seconds, sweat poured out of his skin and he became terribly feverish.

  By the time the Sisters got the Campbells back to their hotel, Kent was delirious and running a 107°F fever. Liz was hysterical. The Sisters called London authorities, who ordered Kent transferred immediately to the hospital of the London School of Hygiene and Tropical Disease.

  Later that day, the Campbells boarded a commercial Aer Lingus jet, and flew without special precautions, amidst hundreds of tourists. No one had instructed Liz to do otherwise, and Kent was in no condition to do more than follow Liz’s orders. On arrival in London, again without extraordinary precautions, they grabbed a taxi to the London School. And once inside the hospital, the ailing Kent was placed on an ordinary isolation ward and treated by doctors and nurses who had no idea what should be done.