In China, human infections spiked in early 2009, striking provinces across the breadth of the country. As in earlier years, these cases were occurring without corresponding accounts of poultry outbreaks. WHO officials again concluded that the epidemic among birds was worse than China was reporting and promised, along with FAO, to press their concerns with the Beijing government. “We still have a very serious situation in the agriculture sector,” said Hans Troedsson, who had become WHO’s senior representative in Beijing after leaving Hanoi. “The virus is well-entrenched and circulating in the environment.”
Thailand appeared to fare better. After repeatedly claiming it had
banished the bug only to see it return, the Thai government launched an ambitious campaign to crush it in 2005. About seven hundred thousand village health volunteers were mobilized to watch for any hint of emerging infection. Twice a year, the government conducted nationwide door-to-door inspections, dubbed X-ray surveys, searching for infected poultry. Stricken flocks were culled, their owners compensated. Duck grazing was barred. Reported outbreaks tailed off. But researchers continued to detect the virus in bird samples, and suspicions lingered. Were Thai farmers secretly doping their chickens to look healthy? “Some commercial producers in Thailand are apparently using unauthorized vaccines to protect their flocks and vaccinating without proper oversight from health authorities,” FAO’s infectious disease chief wrote in August 2006.
Elsewhere, the virus kept coming back. The disease reappeared in 2008 and 2009 among the birds of Hong Kong, India, Pakistan, and the West African countries of Benin and Togo. In mid-2008, Nigeria reported its first new H5N1 outbreaks in almost a year, in a pair of poultry markets. When scientists tested the virus, they were dismayed to find it was different from those previously circulating in sub-Saharan Africa, a baffling transplant from either Europe or the Middle East. And after nearly a year, a new case surfaced in ducks in Germany. “Somewhat surprising,” German authorities admitted.
The virus was already entrenched in a few places outside East Asia. Egypt officially acknowledged in July 2008 that H5N1 was endemic in its flocks, primarily in the Nile Delta. Bangladesh was equally unable to root out the disease. Domenech called the crises in those two countries “particularly worrying.”
He also offered a chilling admonition for Europe. Tens of millions of apparently healthy ducks and geese that graze along the Danube River and in the wetlands surrounding the Black Sea could be spreading the infection. “It seems,” he said, “a new chapter in the evolution of avian influenza may be unfolding silently in the heart of Europe.”
Even more chilling was the prospect raised by the debut of H1N1 swine flu in early 2009. What would happen when this new arrival
spread from its apparent source in North America to countries like Indonesia, China, Vietnam, and Egypt, where bird flu was already endemic? What new virus might emerge from the encounter of these two novel strains? “We must never forget that the H5N1 avian influenza is now firmly established in poultry in several countries,” Margaret Chan told an assembly of the world’s top health officials in May 2009. “No one can say how this avian virus will behave when pressured by large numbers of people infected with the new H1N1 virus.” The swine flu virus had already demonstrated an uncanny ability to swap genes and shift shape. Might this highly contagious strain now acquire the attributes that make avian flu so deadly? Or might swine flu finally provide its avian cousin with the keys required to break loose among people? “Do not drop the ball on monitoring H5N1,” Chan urged Asian health ministers at a separate session in Bangkok called to address swine flu. “We have no idea how H5N1 will behave under the pressure of a pandemic.”
In the five years after the virus reemerged in mid-2003, it tallied nearly 390 confirmed human cases and 245 confirmed deaths. For each one of those fatalities, almost precisely one million birds either succumbed to the disease or were slaughtered to contain it. That tremendous disparity between human and avian deaths underscores where the action has been. The bulk of the battle has consisted of culling, vaccinating, testing, and protecting poultry with the soldiers drawn from the ranks of the agricultural and veterinary services. The spread of disease among animals has long been beyond the mandate of public health, receiving little of the attention that a menace of such magnitude deserves.
Yet if there is any possibility of postponing future human flu pandemics, whether born of H5N1 or another strain, it means reducing the circulation of these viruses in animals. The less the microbe spreads and replicates, the fewer times the dice are rolled. And the less often the dice are rolled, the longer it will likely take for the virus to mutate or reassort into an epidemic strain.
By contrast, once a pandemic strain emerges and begins passing
easily from one person to another, the only hope will be to retard its ineluctable progress by using antiviral drugs, quarantines, and other measures to keep people from mixing. A delay of even a few days would be no mean achievement. This could provide more time to start producing and distributing vaccines. Though they wouldn’t come soon enough for those infected at the beginning of the pandemic, millions of lives could be spared if vaccines arrive in time for those sickened toward the tail end. Yet ultimately, this is a rear-guard action. “You accept a victory as slowing the virus down,” offered Michael Ryan, WHO’s head of epidemic alert and response.
For much of their history, the fields of human and animal health have been divorced and introspective. When bird flu outbreaks were reported across Southeast Asia in early 2004, relations were strained between WHO and its sister agency, the FAO. Though officials on the ground tried at times to craft ad hoc alliances, tensions simmered over turf and money. Since then, these two UN agencies and the independent World Organization for Animal Health have taken steps to enhance cooperation, convening joint strategy sessions and setting up a common early-warning system to share information about bird flu and other diseases. But for many in public health, the fight in the animal kingdom has remained an afterthought.
“I don’t think the medical community has paid enough attention to the veterinary community in terms of the risks for humans,” said veteran scientist Dr. Michael Perdue. “It is the responsibility for human health, for the medical community, to reach out.” Perdue told me that means, for instance, pressing to get money for cash-strapped veterinary counterparts and helping set up more labs for testing animal diseases.
In 2006 Perdue joined the U.S. Department of Health and Human Services, where he took a leading role in preparing the United States for the coming epidemic. By the end of 2008, the department had spent about $1 billion toward creating a stockpile of antiviral drugs sufficient to treat about a quarter of the U.S. population. Another $1.5 billion went toward the development of advanced technologies for making pandemic vaccines, while nearly $1 billion more was invested in setting up a stockpile of prepandemic vaccines, which are based on
current H5N1 subtypes and might afford limited protection to medical staff and other vital personnel in the early days of an epidemic. These measures, too, could save millions of lives, though they are powerless to preclude the inevitable.
Perdue, a genial Mississippi native, has a rare perspective on flu. He has hunted it on both sides of the species divide. As a microbiologist, he long probed the mysteries of avian influenza at the U.S. Department of Agriculture’s elite poultry research lab in Athens, Georgia. Once the disease launched its unprecedented attack on Southeast Asia, WHO called for reinforcements, and Perdue crossed to the human health side, signing on to the agency’s global influenza program in Geneva. From there, he was repeatedly dispatched to investigate human outbreaks. WHO is in a bind, he told me. As long as the virus remains primarily an animal disease, the agency must often defer to agriculture officials, who have priorities beyond fighting infectious disease—for instance, promoting livestock development. “It’s sort of animal health versus human health. It’s challenging,” Perdue said. “The problem is, once it becomes a human virus and WHO is clearly engaged, then maybe it is too late, because then it’s off and running.”
The trail of the fatal strain led me from one end of Southeast Asia to the other. I tracked the virus across nine countries, through hospitals and laboratories, into chicken coops, rice paddies, wet markets, and cockfighting rings. Yet few places were as remote and none as awesome as the floodplain of the Tonle Sap.
For much of the year, this lake in northwestern Cambodia is modest, covering slightly more than a thousand square miles at depths of about a yard. But each June, monsoon rains swell the Mekong River and its tributaries, forcing the water to back up into the lake and transforming it into the largest freshwater body in all of Southeast Asia. The lake’s waters overflow the banks and inundate another five thousand square miles, covering nearly a tenth of Cambodia’s area. Fields and forests are submerged. Then, with the coming of the dry season each October, the waters drain away.
Over the generations, Cambodians have adapted to the furious but predictable mood swings of their habitat. Many have built their homes on stilts to stay clear of the rising waters. Some inhabitants migrate with the shoreline, dismantling their dwellings as the water advances and reassembling them farther out. Others live on houseboats or floating homes of thatch, palm fronds, and clapboard mounted on bamboo rafts. This ecosystem has also made the shores of the lake and the surrounding floodplain a unique wintering ground for Asia’s wild birds.
It was the birds that brought me to the Tonle Sap. The monsoon was only weeks away, and soon they would migrate to summer breeding grounds in China, Japan, Siberian Russia, and even across the Bering Sea to North America. What if the birds were infected? Would the virus follow the multitude of flyways that radiate out from the Tonle Sap?
Few outside of Cambodia had heard of this wilderness. Yet here, in utter silence but for the occasional ruffle of wings, with no other sign of human life on this vast, flat expanse, I wondered whether a plague could be taking shape. If so, no place on Earth would be left untouched.
I came to the Tonle Sap floodplain looking for the virus. I found an insight. I realized we’re all living on a floodplain.
Several times each century, a novel flu strain emerges, often from the fountainhead of Southeast Asia. Death and disorder wash across the face of the planet. Sometimes they just skim the surface; other times they deluge all that lies before them. Then they recede. This cruel cycle isn’t as predictable as that of the Tonle Sap waters. But it is equally inevitable.
Those who live around the Tonle Sap have adapted with forethought and creativity to nature’s challenge. They have learned to ride out the flood. We have yet to do so.
For much of the last generation, the silence has been deceiving. Not since 1968 had a new flu virus menaced humanity and circled the world. But the outbreaks of avian flu that multiplied over the early years of this new century made it hard to continue mistaking luck for a
change in the laws of nature. “The present situation is unique,” Margaret Chan has admonished from her bully pulpit in Geneva. “In the past, pandemics have always announced themselves with a sudden explosion of cases, and taken the world by surprise. For the first time in history, we have been given an advance warning.” She calls this an “unprecedented opportunity” for countries and communities to get ready.
Then swine flu broke out. Researchers initially concluded it was spreading as vigorously as each of the three last pandemic strains. But soon it seemed the attack rate was no greater than that for ordinary flu bugs. Still, the epidemic’s ultimate course remained uncharted. Public health officials once more were making fateful decisions, whether, for instance, to embark on a crash vaccine program amid scientific uncertainty. Like all flu viruses, especially those so new to us, swine flu remained unpredictable. Its message, however, was unmistakable. Again, get ready.
Though governments have recently taken steps to gird the world for a pandemic, too little has been done. As I write, epidemic planning for hospitals and public health systems remains wanting. Preparations in other essential sectors, in particular those to ensure supplies of food, water, electricity, and fuel and to maintain public order, are even more deficient.
It’s surprising how few people know the horrors of 1918. Perhaps that cataclysm is overshadowed in memory by the final months of World War I, a conflict that recast the geopolitics of the world and defined a generation. Perhaps epidemics exist outside of history, ideology, and meaning, and their imprint vanishes like footsteps on the beach, especially when people have no one to blame for their tragedy, no grievance to harbor. It could be that people simply want to forget suffering. Or maybe we believe, as an advanced civilization, we’ve moved beyond plagues. By that reasoning, 1918 belongs to another, remote era of little relevance to today.
After I started this book, I told friends and colleagues what I was writing. The response wasn’t what I expected. Time after time, they would
mention relatives who had died during the Spanish flu, a grandfather’s brother, a distant cousin. My architect told me his uncle and two other kin are buried in Jamaica after perishing in 1918. Then, several months before I finished the first draft, I discovered evidence of another visitation.
Growing up, I’d heard the story about how my grandmother’s mother, Yetta, had died as a young woman back in Poland. No one seemed to know precisely when, and no one ever mentioned the word
influenza
. We never connected it to anything else going on in the world at the time. All we knew was that she had been killed by some respiratory disease, maybe tuberculosis, maybe what they called grippe back then.