By January 1990, the Ebola strain that infected the Reston monkey house has gone back into hiding in the rain forest. The Army returns the monkey house to Hazleton, which begins buying monkeys from the same monkey farm it used before. Less than a month later, animals begin dying of Ebola once again. This time the Army, the C.D.C., and Hazleton decide to leave the monkeys alone and see what happens. The Ebola spreads much like the flu does, causing runny noses, coughing, and pneumonia as well as more Ebola-like symptoms. It spreads easily and quickly, and is almost always fatal. It moves through the air ducts, and monkeys in other rooms begin dying.
In an incredibly frustrating and inexplicable turn of events, Hazleton repeats the exact same actions that led to the Ebola outbreak in the first place, and the virus makes its way to American shores once again. This pattern emphasizes the staggering ignorance and denial that humans display when it comes to infectious disease, and the massive threat that globalization potentially poses to human health internationally.
In mid-February, a caretaker named John Coleus cuts his thumb while performing a necropsy on a monkey infected with the Ebola virus. The C.D.C., however, decides not to isolate him, a decision that USAMRIID finds appalling. Coleus even has minor surgery in the midst of his incubation period. He never, however, falls ill. Meanwhile, all the monkeys in the monkey house die.
The case of John Coleus is similar to Milton Frantig, Peter Jahrling, and Tom Geisbert—this strain of Ebola does not appear to affect humans. The C.D.C.’s decision not to isolate him, however, proves how quickly people can become complacent about a previously terrifying illness.
Eventually a disturbing discovery is made: although Jarvis Purdy, Milton Frantig, John Coleus, and a fourth colleague never fall ill, all eventually test positive for Ebola Reston (as the strain is now called). For some reason, apparently, the virus never makes humans sick. The fact remains, however, that all the men except for Coleus got the infection through the air, meaning that Ebola is able to enter the body through the lungs.
At first, characters and readers alike take this apparent lack of human cases of Ebola to be a positive development. In truth, however, the knowledge that this strain of Ebola can travel through the air (or so they suspect) only increases the sense of menace. If it was a strain that did kill humans, an epidemic could have begun.
General Russell reveals to Preston that he was even more terrified of Ebola after the mission was over, when he realized how easily the virus could be transmitted. He compares its potential for destruction to a combination of the Black Death and influenza. No one, however, understands why Ebola Reston was symptomless in humans—Preston speculates that some tiny mutation in the virus’s genetic code must have rendered it harmless to humans but lethal to monkeys. He suggests, however, that another mutation could easily go in the other direction.
The lack of understanding of Ebola Reston reveals how little we still know about the virus, despite having directly battled it in the Reston monkey house. The tiny genetic mutation that leads it to be harmless to humans again shows how important luck and chance are in these kinds of situations. The mutation could just as easily have made the virus more lethal, which would have inevitably led to an outbreak in America.
Preston goes to visit Nancy Jaax. She offers to show him Ebola, and he looks at slides of a monkey’s testicle and lung, both ravaged by an Ebola Zaire infection. At a higher magnification he is able to see inclusion bodies, the huge bricks of Ebola that are slowly taking over the cell. Nancy explains that when in the lungs, these inclusion bodies would be able to make their way (through coughs) directly into the air.
The narrator’s visit to Nancy Jaax helps us to appreciate the infinitesimally small margin by which we escaped true catastrophe. This terrifying conclusion (that Reston is transmitted through the air alone) is now disputed, however, by Nancy Jaax herself—it is more likely that the virus spread through aerosol sprays used in cleaning the monkey cages, or else other equipment or “husbandry” practices.
In March 1990, the C.D.C. puts stricter restrictions on monkey importation and revokes the licenses of three companies, including Hazleton, charging them with violating quarantine rules. The licenses are later reinstated, but the companies lose millions of dollars as the importation of monkeys briefly comes to a halt. Many in USAMRIID, however, still praise Dan Dalgard and his company for their decision to hand over the monkey house to the Army. The monkey house, meanwhile, stays vacant to this day. Tom Geisbert and Peter Jahrling—who is now the principal scientist at USAMRIID—name the new virus Ebola Reston. In Jahrling’s office, Geisbert and Preston compare Zaire to Reston and wonder why Zaire is hot in humans while Reston is not. Preston asks if “we dodge[d] a bullet.” Jahrling, however, cautions against this kind of talk, warning that Reston could mutate into something more dangerous at any time.
Preston begins to wrap up loose ends, but cautions us not to become complacent about Ebola Reston simply because it never caused any large-scale epidemic. Through his discussion with Peter Jahrling, he reminds us that Reston is almost genetically identical to Zaire, the most deadly form of Ebola, and hammers home the point that it was only by chance that Reston did not happen to affect humans. This passage is meant to remind us of our vulnerability at all times to these kinds of infectious diseases, and to warn us that another such occurrence may prove far more deadly than the virus at the Reston monkey house did.
C. J. Peters eventually becomes chief of the Special Pathogens Branch of the C.D.C. He too believes that Ebola can spread through the air, although he has never tested Ebola Reston in an experiment setting (doing so would be perceived as too close to germ warfare). As a result, he cannot say for sure whether Ebola can travel in this way—but if it can, he asserts, “that’s about the worst thing you can imagine.”
The ominous tone of this section continues as Peters emphasizes how alarming it is to find an Ebola strain that can travel through the air (although this fact is now considered scientifically disputable). He also reminds us of the uncertainty that still surrounds the virus.
Preston sums up what’s happened: Marburg, Ebola Sudan, and Ebola Zaire have been joined by a fourth strain: Ebola Reston. Two C.D.C. researchers named Anthony Sanchez and Heinz Feldmann analyze the genetics of the filovirus families and find that Zaire and Reston are almost identical. Preston goes on to explain that one of the seven proteins that makes up the Reston virus is probably slightly different than that of Zaire—and it is this slight difference that kept it from causing symptoms in humans. The Army and the C.D.C., however, never downgrade Reston from its Level 4 status because of how infectious it is. A small change to its genetic code might make it not only contagious, but deadly.
In this passage, Preston helps readers to understand the large-scale implications of the events that he’s just recounted. We also learn that despite Ebola Reston’s apparent harmlessness to humans, it is still categorized as a Level 4 virus—a fact that emphasizes how dangerous Reston could become with only a small change to its genetic makeup. Considering how fast viruses mutate, this shift from symptomless to deadly could take place at any time, a reminder of nature’s power and fickleness.
Preston next contemplates why Reston supposedly comes from Asia while Zaire comes from Africa. The most obvious possibility is that Ebola traveled from Africa to Asia on a plane, possibly during the importation of wild African animals, which some wealthy people in the Philippines enjoy keeping on their estates to illegally hunt. He acknowledges, however, that this is only a guess, and that the source of Reston, like that of all filoviruses, is ultimately a mystery. It is likely, though, that “the entire Reston outbreak started with a single monkey in the Philippines”—a monkey that picked up Ebola Reston from an unknown source.
The theme of globalization returns as Preston discusses the mysterious origin of Ebola Reston. We learn that the source may come from human greed and arrogance (through the importation of African animals to the Philippines), and are reminded once again of the mystery that surrounds the origins of many epidemics. Preston does emphasize, however, that the outbreak probably started small—with a single monkey—a stark symbol of how easily one case of Ebola could become a worldwide pandemic.