by The Pandemic Century- One Hundred Years of Panic, Hysteria
It is an all too common story. In the wake of the epidemic, the Brazilian government approved cash-transfer programs for poorer families and promised to invest $35 million a year in specialized rehabilitation centers. At the same time, the Pernambuco state authorities pledged $5 million for the construction of regional centers for infants with CZS. But at the close of 2016, the National Congress approved a constitutional amendment freezing public spending for twenty years, and at the time of writing most of the centers have yet to be built. Instead, as austerity measures bite, women like dos Santos struggle to find the money for essential medicines and care. Nor is there any indication that the authorities are prepared to make the investments necessary to rectify the systemic water and sanitation problems. Instead, the government has been shifting the responsibility for mosquito control back onto households through awareness campaigns targeting housewives.
This is not the only way that the underlying social and environmental conditions that gave rise to the outbreak continue to be neglected. As Human Rights Watch discovered when it visited Brazil to interview women in Pernambuco and Paraíba on the first anniversary of the epidemic, roughly a quarter of the women and girls who gave birth to babies with microcephaly were below the age of twenty. Yet this is precisely the group least likely to have access to contraception and sexual and reproductive health information. Nor was Human Rights Watch impressed by the state of the favelas they visited, reporting that it was common to find channels running with raw sewage and mosquitoes breeding in refuse-clogged canals and marshes behind people’s homes.
“Brazilians may see the health ministry’s declaration of the end of the Zika emergency as a victory,” commented Amanda Klasing, senior women’s rights researcher at Human Rights Watch. “But . . . Brazilians’ basic rights are at risk if the government doesn’t reduce mosquito infestation over the long term, secure access to reproductive rights, and support families raising children affected by Zika.”
That is a verdict with which Liana Ventura concurs. Of the 325 children being treated by her foundation, just two were private referrals—everyone else came through the public health system. Yet two years on from the epidemic, nearly half are still awaiting the results of Zika serology tests. “There is still so much that we don’t know about the pathology of Zika and microcephaly, but at the moment, frankly, it’s a struggle,” she told me. “Let’s hope it doesn’t take another epidemic to make the world sit up and take notice.”
BEFORE CHECKING OUT of my hotel I decided to go for a stroll on the promenade at Boa Viagem. When I had left for Ipitunga in the morning the waves were covering the rocks that form a barrier with the roadside and there was no beach to be seen, but by 4 p.m. the tide had receded to reveal Recife’s famous reefs, and the sand was now studded with beach umbrellas and children splashing happily in the channels and puddles left by the ebbing waters. With a light offshore breeze, the conditions were perfect for surfing, but to my surprise there were no surfers to be seen beyond the breakers, nor did anyone appear to be venturing into the sea to swim. The reason soon became apparent when within a few yards of the beach I was confronted by a fierce red and white sign that read “Perigo” (danger) and below it, in English, “Danger—Shark Zone.” This was followed by the outline of a shark in yellow and advice on when to avoid bathing. Some of the advice was commonsensical. Swimmers should not venture into the sea “with bleeding or wearing bright objects” or when they were “drunk” or “alone.” However, bathing was also not advised “in open waters,” “at high tide,” or at “dawn and dusk.” In other words, pretty much anytime except the daylight hours when the tide was out.
A little further along the beach, I spotted a lookout station and approached the lifeguard. Until the early 1990s, he explained, Boa Viagem had been a popular surfing destination. Then, in 1992, came the first in a series of shark attacks. By 2013 Boa Viagem had suffered fifty-eight such attacks, twenty-one of them fatal, forcing the authorities to ban surfing and post shark warning signs. No one was sure of the reason for the sudden change in the sharks’ behavior, but most experts blamed it on the construction in the 1980s of a new container port at Suapes, twelve miles south of Recife. During construction, workers had dredged the estuaries and built docks that protruded far out into the ocean. The dredging of the estuaries was thought to have been particularly disruptive to the breeding and feeding patterns of bull sharks, who generally stay close to shore and are able to tolerate fresh water. However, the more serious shark infestation coincided with the completion of the container port and the subsequent explosion in ship traffic in the 1990s. The larger ocean-going vessels brought with them migratory tiger sharks, attracted by the waste and rubbish thrown overboard. Drawn into Port Suapes, it is thought that these tiger sharks, which are expert scavengers, rapidly developed a taste for the coastal waters and began feeding on the untreated sewage that spills into the sea every day from Recife’s canals and rivers. The result is that today even lifeguards avoid swimming at Boa Viagem, preferring to train in chlorinated pools, and if they are forced to intervene in a life-or-death situation at sea their preferred mode of transport is a jet ski.
It was transatlantic shipping and the international search for profits that had first brought Aedes to this coast, too. No one can be sure when Aedes first made landfall in Brazil. Perhaps it was as early as the 1530s when the first Portuguese colonists arrived at Olinda, a colonial town just north of Recife, and discovered the natural harbor formed by the confluence of the Capibaribe and Beberibe Rivers and the long sea wall guarding the estuary. But most likely the mosquito arrived later in the sixteenth century when Portuguese ships loaded with slaves destined for Pernambuco’s sugarcane plantations began crossing from the west coast of Africa. By 1637, when the Dutch took possession of the plantations and moved the colonial capital to Recife, the sugarcane business was booming. However, by now British and Dutch slavers making the middle passage to the Caribbean had introduced the virus of yellow fever to Barbados. In 1685 the first outbreak was recorded in Recife, inaugurating a cycle of arbovirus epidemics, the threat of which—except for a brief period in the 1940s and 1950s—has never gone away.
Today, mosquitoes are once again making the crossing, this time breeding in car tires filled with rain water as they once bred in the casks of fresh drinking water beside slaves chained below decks.# And as they do so it is unlikely that Zika will be the last arbovirus to accompany them. Nor, when you factor in the growth of international jet travel, would you wish to bet against other viruses and microbial pathogens, to which local people may have little or no immunity, hitching a ride to Brazil in airplanes.
Predicting what that pathogen might be and when it will make landfall is a fool’s errand. Like the lifeguards at Boa Viagem, all we can do is scan the horizon for dorsal fins and other lurking threats, and while we may not be able to alter the facts of global travel and commerce, we can address the local sanitary and environmental conditions that have made Recife and other Brazilian cities so hospitable to the Aedes and other disease-carrying mosquitoes. That is not a matter of knowledge but of political will.
* It is also likely that due to repeated exposure to the virus, most Asian populations were immune to Zika.
† There have been no further outbreaks on Yap since 2007. This is most likely because the majority of islanders now possess immunity to Zika. It is only when herd immunity wanes and there are sufficient numbers of susceptibles again that a new epidemic may erupt.
‡ By contrast, Zika virus has been isolated from semen up to 188 days after the onset of symptoms.
§ These malformations and nervous system deficits would later by labeled congenital Zika syndrome (CZS).
¶ A. albopictus is also the principal vector of West Nile virus.
# This is almost certainly how Aedes albopictus, the principal vector of chikungunya, and a mosquito previously restricted to Southeast Asia, reached the Americas, reproducing in ornamental bamboo and disused car tires on ships de
stined for Texas, from whence it spread via interstate trucking routes to Mexico and Latin America.
EPILOGUE
THE PANDEMIC CENTURY
“Messieurs, c’est les microbes qui auront le dernier mot.”
—LOUIS PASTEUR
Sharks never attack swimmers in the North Atlantic. Flu is a bacterial disease and a threat to infants and the elderly, not young adults in the prime of life. Ebola is a virus endemic to forested regions of equatorial Africa—it can’t reach a major city in West Africa, let alone one in North America or Europe.
As the pandemic century draws to a close, we know better than to trust the pronouncements of experts. Battered by their repeated failure to predict deadly outbreaks of infectious disease, even the experts have come to recognize the limits of medical prognostication. This is not only because microbes are highly mutable—that has been known since Pasteur’s time—but because we are continually lending them a helping a hand. Time and again, we assist microbes to occupy new ecological niches and spread to new places in ways that usually only become apparent after the event. And to judge by the recent run of pandemics and epidemics the process seems to be speeding up. If HIV and SARS were wake-up calls, then Ebola and Zika confirmed it. “Despite extraordinary advances in medical Science, we cannot be complacent about the threat of infectious diseases,” acknowledged the National Academy of Medicine in a report published just weeks before Zika became a pheic. “The underlying rate of emergence of infectious diseases appears to be increasing.”
Why this should be the case—if it is the case—is a matter of ongoing research and conjecture. Certainly urbanization and globalization would appear to be key factors. The mega-cities of Asia, Africa, and South America, like Athens in the time of Thucydides, provide ideal conditions for the amplification and spread of novel pathogens by concentrating large numbers of people in cramped and often unsanitary spaces. Sometimes technology and alterations of the built environment can mitigate the risks that such overcrowding presents for the transfer of pathogens to people. The plague abatement measures in the Mexican quarter of Los Angeles in 1924 may have been brutal and morally questionable (certainly, it is hard to imagine community activists in California tolerating the wholesale demolition of minority neighborhoods and the mass slaughter of squirrels today), but at the time they were effective in removing the threat of plague from downtown Los Angeles and its harbor. Likewise, air conditioners and modern cooling systems are very effective ways of insulating people from the mosquitoes that breed in and around urban high rises and favelas, but as the Legionnaires’ disease outbreak demonstrated, and SARS confirmed, water towers and fanned air can also present new disease risks, particularly in closed environments such as hotels and hospitals.
Greater global interconnectivity driven by international travel and commerce is undoubtedly another key factor. While in the sixteenth century it took several weeks for smallpox, measles, and other Old World pathogens to reach the New World, and even longer for the vectors of diseases like yellow fever to become established in the Americas, today international jet travel means that an emerging virus can be in any country or continent on the globe within seventy-two hours. It is not the microbes that are doing this, but our own technology. Any one of us could be like Johnny Chen, the Hong Kong businessman who, without knowing that he was harboring a deadly virus, introduced SARS to Vietnam by the simple expedient of boarding a plane bound for Hanoi. Indeed, tens of millions of us annually make such trips in aircraft either for business or pleasure, and as flights become cheaper and passengers make more and more journeys, the risks are only likely to grow. Herded into airline waiting rooms, then crammed into economy row seats, we resemble nothing so much as the captive Amazonian parakeets who introduced psittacosis to Baltimore and other US cities in 1929. The difference is that the parakeets had no choice about their accommodation, whereas we do. As the environmental historian Alfred Crosby put it, international jet travel is like “sitting in the waiting room of an enormous clinic, elbow to elbow with the sick of the world.” Yet budget airlines continue to grow in popularity.
Other pathogens take a more leisurely and circuitous route to our cities and living rooms. HIV is one such example; Zika is another. The difference is that whereas scientists had known about the Zika virus since 1947 and did not consider it a pressing disease threat, HIV really was an unknown unknown. Indeed, until the clinical symptoms of AIDS announced themselves to physicians in the early 1980s, no one could have known that HIV had been spreading silently and stealthily in homosexual communities and other at-risk groups in North America for several years, or that the virus had reached Haiti from Africa, where it had likely been circulating under the radar for decades. That only became apparent once scientists had the technological tools for tracking the depletion of CD4 cells that is the signature of HIV infection and developed a conceptual understanding of retroviruses. Before then, medics and public health officials could hardly be accused of being overly complacent or of somehow missing the alarm. On the contrary, the CDC had been warning about rising STD rates in homosexuals for some time.
This was not the case with Ebola. “It looks like, smells like, tastes like regular outbreaks in previous areas,” the CDC’s resident Ebola expert Pierre Rollin informed his superiors in May 2014. But Rollin was wrong, not because the virus that appeared in Guinea-forestière had suddenly mutated or changed in ways that Rollin and his colleagues could not have anticipated, but because they had failed to properly absorb the lessons of the previous twelve large outbreaks of Ebola in Africa. In particular, they had forgotten the importance of engaging with local chiefs and village headmen in order to convince the sick of the necessity of rapid isolation and of presenting at Ebola treatment units. Instead, distrusting the motives of foreign medical teams, patients hid in their villages or consulted traditional healers, skewing the official Ebola case counts. The result was that by the time people with Ebola began reporting to ETUs in large numbers, many were already at the point of death and it was too late. There was no time to close the highways, as the DRC authorities had done in 1995 when the Kikwit Ebola outbreak threatened to spread to Kinshasa. Instead, Ebola had already crossed the border and was festering in Freetown and Monrovia.
What is still not known at the time of writing is how Ebola reached Guinea-forestière in the first place or why it emerged in Meliandou. As with HIV, the virus is thought to have spilled over into human communities in southeastern Guinea when people interacted with the local wildlife. As with the SARS coronavirus, bats are the prime suspect. Yet so far no one has succeeded in recovering live Ebola virus from any species of bat, let alone one in West Africa.* You might say that disease ecologists know the virus is out there and that from time to time the virus gets into bats, but no one can say for sure whether bats are the primary reservoir or simply an intermediary host for the virus. And what applies to Ebola also applies to other emerging and reemerging infectious diseases of unknown provenance. Since 1940, scientists have identified 335 new human infectious diseases. Nearly two-thirds are of animal origin, and of these 70 percent originate in wildlife, with bats harboring a higher proportion than any other mammal. The good news is that in recent decades scientists have identified several of these viruses; the bad news, according to a recent survey, is that for every bat species there may be seventeen viruses out there still waiting to be discovered, and ten more in the case of each species of rodent and primate. Nor is that an end to the unknown microbial threats. Half of all EID events are caused by bacteria and rickettsial organisms, a reflection of the large number of drug-resistant microbes that, thanks to the abuse of antibiotics, are now present in the environment.
Writing at the highpoint of the so-called conquest of infectious disease seventy years ago, René Dubos observed that “microbial disease is one of the inevitable consequences of life in a world where nothing is stable.” In a rapidly changing world it was incumbent on scientists, he suggested, to “avoid pride of intellect and gu
ard against any illusion or pretense as to the extent and depth of what he knows.” Instead, Dubos advised medical researchers to “develop an alertness to the unexpected, an awareness of the fact that many surprising effects are likely to result from even trivial disturbances of ecological equilibrium.”
To their credit, modern medical researchers can no longer be accused of complacency about drug-resistant pathogens, such as the strains of multidrug-resistant tuberculosis and malaria now circulating in Africa and Southeast Asia. Chastened by the criticism of its handling of the 2014–2016 Ebola epidemic, the WHO is also wary of appearing complacent. That is why, in February 2018, it added a new pathogen to its list of potential pandemic threats. Recognizing the limits of current scientific knowledge, the WHO designated the pathogen “Disease X” in acknowledgment that “a serious international epidemic could be caused by a pathogen currently unknown to cause human disease.” In other words, to borrow Donald Rumsfeld’s terminology, Disease X is an “unknown unknown.”
Concerned that an unanticipated infectious disease outbreak due to bioterrorism or a natural event could kill some 30 million people at some point in the next decade, Bill Gates is also stepping up efforts to improve the surveillance of EIDs and responses to epidemics through the work of his charitable foundation. And in 2017 Facebook founder Mark Zuckerberg and his wife, Priscilla Chan, added their considerable wealth to these efforts, joining with the Bill and Melinda Gates Foundation and Bloomberg Philanthropies in an initiative called Resolve. Headed by former CDC director Tom Frieden, Resolve’s ambition is to save 100 million lives globally by investing in the prevention of cardiovascular disease and giving countries the ability to respond to outbreaks of Ebola and other emerging viruses more quickly. Meanwhile, noting that “pandemics are one of the most certain uninsured risks in the world today,” the World Bank recently established a $500 million emergency facility to provide “surge” funding to fight explosive outbreaks of “six viruses that are most likely to cause a pandemic.” Prompted by the slow response to the Ebola epidemic, the idea is to use bond issues to build a cash fund that can be disbursed rapidly to resource-poor countries before outbreaks of bird flu, SARS, and other viral diseases of zoonotic origin become global health threats. But even before the insurance fund was up and running, a fast-spreading outbreak of pneumonic plague in Madagascar in September 2017 had exposed a fatal flaw in the World Bank’s scheme, for, of course, plague is a bacterial disease and therefore not covered by the emergency facility. In other words, it was a risk that no one had foreseen.