In August 1957, the “Asian flu” was exactly where “swine origin influenza A (H1N1)” is today. A new strain of the influenza virus had emerged in the spring, an aggressively infectious illness that triggered sporadic outbreaks throughout the Northern Hemisphere’s summer, a normally flu-free season. As scientists raced to develop and produce a vaccine, Americans debated how seriously to take the threat of a pandemic.
During the warm months, the illness struck mostly in group-living situations such as summer camps and military bases. But the virus was spreading inexorably, and the fall’s mass gathering of children in the new school year would be like wind blowing on dry grass that had been showered with sparks. By October, the country was afire with influenza.
The pandemic virus of 1957 caused an illness that was briefly harsh but rarely fatal. Like this year’s strain, it emerged in the spring and smoldered over the summer, its traditionally quiet season. More than 80 summer camps have suffered flu outbreaks in the past two months; in 1957 the picture was much the same.
As with many pandemic strains, the Asian flu also had an inordinate effect on younger people. By the time the 1957 pandemic was over, 40 percent of deaths had occurred among people younger than 65, a much larger fraction than in outbreaks of seasonal flu. The pandemic of 1957 may be a particularly instructive model for what’s to come.
The origins of the flu outbreak reported in Hong Kong in April 1957 remain shrouded in mystery. What was soon known, however, was that it had an unusually high “attack rate”: A substantial fraction of people fell ill once the virus began to circulate in a community. That prompted US officials to ask for samples of the virus, and the first arrived in Washington on May 13. Scientists soon determined it was a radically new strain of the H2N2 class of influenza.
The new bug hopscotched its way into North America, striking first on naval vessels and coastal military installations. Flu appeared in Newport, R.I., on June 2 and soon after in California. The attack rate was 30 percent on the ships and 5 to 10 percent on shore stations, according to the reports from the Communicable Disease Center (now the Centers for Disease Control and Prevention).Soon, the virus moved into the civilian world.
The first well-studied outbreak occurred in Grinnell, Iowa, where 1,688 people from 43 states and 9 countries, most of them women, had gathered in June for a church conference. Ultimately, 350 people became ill.
In the hot summer weather, children’s camps were among the few places where flu continued to spread. Camp Roosevelt in Maryland had 70 cases and closed early on July 11. In Northern California seven camps reported flu, with 123 out of 505 children contracting the infection. That attack rate of 24 percent was actually an underestimation of what lay around the corner with the opening of school.
Late in August, the Association of State and Territorial Health Officers endorsed use of the vaccine. It encouraged people to stay at home and not go to the hospital unless they were seriously ill. It warned hospitals of a flood of patients. It recommended that schools stay open unless there was a dire shortage of students, teachers or bus drivers. It suggested that group meetings not be postponed or canceled.
Meanwhile, a preview of the fall drama was under way in Tangipahoa Parish, in southeast Louisiana.Public schools there — still segregated — had opened as usual in mid-July. (The early start allowed a long break in the spring when children picked strawberries, the region’s cash crop.) Two weeks into the term, the black schools, which were generally more crowded, began experiencing high absenteeism from flu. By Aug. 5, 10 of the 12 black schools had closed for a week. The seven white schools stayed open, although several had single-day absentee rates of nearly 50 percent.
CDC epidemiologists learned that flu had hit high schools before elementary schools. A person’s risk of becoming ill rose steadily with the size of the family. Blood sampling and questionnaires ultimately led the scientists to calculate an astonishing attack rate: 60 percent of children.
By the end of August, the epidemic was on the wane in or essentially gone from China, Japan, the Philippines, Malaya, India and other parts of Asia where it had spread explosively in the spring.
The H2N2 pandemic strain of 1957 was so contagious and it encountered such a susceptible world that it out-competed all the other strains of influenza.
© The Washington Post
