One year ago today, a government worker in Oaxaca, Mexico, became the first person to die of swine flu. At the bedsides of other men and women struggling to stay alive in Mexican critical care units, we clinicians noticed early on that this novel H1N1 flu virus diverged from influenza’s usual pattern of activity in striking ways. It began in the Northern Hemisphere, not in Asia, and in mid-spring, not late fall or winter. It also had a worrying predilection for children and young adults, not the elderly and newborns.
In the months after those first deaths, the virus ignited a global pandemic. While the epidemic never became as deadly as we initially feared, it was not as mild as some experts now believe. What’s more, it exposed some serious shortcomings in the world’s public health response.
Those who now describe the pandemic as mild base their conclusion primarily on what, at first, seems like a mortality rate in the United States similar to those seen after seasonal influenza. But my colleagues in developing countries would strongly object.
Though we lack reliable death rates from country to country, certainly no one who helped care for the large number of critically ill patients in Mexico could conclude that the flu in the United States was as severe as in developing countries that lacked our resources.
Here, the vaccine arrived later than estimated, and only about 80 million Americans received it — not nearly enough, but a far higher proportion of the population than in many developing countries. In fact, only 26 of 94 poor countries in need of the protective H1N1 vaccine have even received it so far.
We also cannot count as mild any virus that was so devastating for young adults, along with pregnant women, obese patients and minorities.
Worse yet, this virus made itself particularly hard for clinicians to identify. Whereas doctors associate fever and cough with outbreaks of influenza, one-third of patients admitted to hospitals and up to half of infected outpatients in this pandemic had no fever, yet they were infectious.
And because it is likely that only patients with fever were tested for the presence of the virus, we greatly underestimated the number of people infected. A telling report from Britain showed that when children were tested in cross sectional surveys after the first wave of infection, one in three had antibodies to the virus, meaning that they had been infected — this was 10 times more people than estimated from clinical surveillance.
H1N1 posed huge infection-control problems, especially in hospitals. This was because it was found not only on hard surfaces in the environment, which is common to all influenza strains, but in the stool of patients, a feature of avian influenza.
Public health groups emphasized the necessity of frequent hand-washing, which surely helped reduce transmission. But those groups also disagreed on other preventatives: for instance, the World Health Organization and Society for Health Care Epidemiologists of America recommended the relatively inexpensive surgical mask, whereas the Centers for Disease Control and Prevention argued for the N-95 respirator mask.
In our own country, the virus struck at a time when Americans seemed particularly skeptical about our government and large institutions. The C.D.C. faced an uphill battle to characterize the trajectory of the pandemic, to define its impact, to offer suggestions and to convince a wary public to get vaccinated.
At times, health officials erred in their recommendations. C.D.C. authorities often said that ill children and adults could go back to school or work 24 hours after their fever disappeared — even though young children are contagious for up to three weeks and adults for 5 to 7 days.
It is not an easy task, but our public health authorities need to become clearer about the lexicon of uncertainty — what they know and don’t know about a pandemic. They also need to be transparent about how they devise their recommendations, which often have to balance between infection control and the daily activities of offices and schools. And we need to identify which social distancing techniques truly help control pandemics — for example, does the closing of schools and malls minimize the spread of viruses from infected children to adults?
One year after its appearance, we continue to have many unanswered questions about the virus. Will the novel H1N1 agent become a persistent seasonal virus? Can we produce vaccine more quickly by moving to a cell-based rather than egg-based method? Can we possibly identify the Holy Grail of influenza vaccination, finding a virus target common to all influenza A strains so that we can administer a single vaccination at 10-year intervals?
Even as we work to solve these enigmas, we can try to prepare better for future pandemics. First, we need to approach disease control not as individual nations, but as a global community. In this, Mexico has already set an excellent example. Only 10 days passed between Mexican health authorities’ recognition of a possible new epidemic and their announcement of it, a sharp contrast to the many months in 2003 between the outbreak of SARS in China and its public declaration.
Mexico’s transparency was a policy decision made with full recognition of the unfavorable economic consequences from H1N1, now estimated to have cost almost 1 percent of the gross domestic product. Thanks to that decision, we had an edge in fighting this virus. We should find ways to financially reward early reporting of novel infectious agents, while doing a better job of sharing resources and agreeing on common containment strategies.
Second, we should rely not just on governments for reporting but on the cooperative efforts of international health organizations as well. These groups should set up better sentinel reporting systems in places where new swine or avian variants are most likely to occur — wherever people and pigs or birds live closely together — so that they can identify new virus progeny quickly.
Eventually, we’ll also need to encourage farmers in developing countries to follow agricultural and safety practices that make it less likely that viruses will jump species.
One predicts influenza at his own peril, but it is likely that H1N1 will continue to cause sporadic cases. In some highly susceptible, unvaccinated populations it may even produce local outbreaks.
But the struggle between people and pathogens is a part of life itself. We cannot continue to be surprised every time a new virus emerges. Instead, we must use the lessons we’ve learned during the year since H1N1 arrived to develop more effective public health responses.
Richard P. Wenzel, a professor of internal medicine and a specialist in infectious diseases at Virginia Commonwealth University.