One of the best aspects of the 2009 novel H1N1 flu virus is that most people infected get nothing worse than the symptoms of a bad cold.
But the worst and most mysterious aspect is that the disease strikes an unusually large number of healthy young people and can be fatal for adolescents and young adults even when they receive intensive care treatment, according to two studies released Monday.
“Young healthy people who have had no underlying condition: that is humbling and mysterious. It is rare, but once you see it, you never forget it. You pour in the antibacterials and pray,” Dr. John Bartlett, a professor of medicine and a former director of infectious diseases at the Johns Hopkins University School of Medicine, told The Washington Times.
The two surveys, released by the Journal of the American Medical Association for the Nov. 4 issue, covered intensive care unit (ICU) patients in Mexico and Canada during the early phases of the global H1N1 pandemic.
Both showed that the largest numbers of H1N1 deaths occurred in the adults and early middle-age ranges - 21 of 24 deaths in the Mexican study occurred in the 20-to-50 age group, as did 14 of the 29 Canadian deaths.
The Mexican study also showed that the largest number of ICU admissions occurred in that age group.
This is not the usual pattern for flu, which hits the youngest and the oldest, Dr. Bartlett said about the studies, with which he was not involved.
The surveys also showed a considerable gap in the deadliness of the virus commonly referred to as swine flu. Mexican hospitals had more than twice the fatality rate among flu cases that already had become bad enough to reach the ICU, where most received medical ventilation and the best possible medical care.
The 24 deaths in Mexico occurred within two months of ICU admission among 58 patients in six hospitals, a mortality rate of 41 percent. Just 17 percent of 168 Canadian ICU cases - 29 people - had died within that survey’s 90-day follow-up period.
The average patient age in the Canada study was 32.3 years; in Mexico, 44 years. Twenty-one, or 36 percent, of Mexican patients were obese; no similar figure was given for Canada. In all cases, conditions worsened upon admission to the hospital, “often in young adults,” the Canadian study noted.
The lead author of the Canadian study, Dr. Anand Kumar, commented how unusual it was to have the patients become so ill so suddenly and warned of a real risk that local health care systems in the U.S. and anywhere else “would be overwhelmed.”
“These people were not just a little bit ill. They were spectacularly ill,” Dr. Kumar told Health Day News. “To see 40 patients like this simultaneously in the ICU, all struggling for their lives, all in the space of a few weeks - that’s really unusual.”
However, epidemiologists such as Dr. Bartlett cautioned against hysteria based on the two studies, calling it “a numbers game” that depends on how widespread the H1N1 virus becomes and noting also that “infectious care centers are breeding grounds for diseases.”
“Nobody knows all the people who got sick with it,” he said. “Keep in perspective the number of people who have died from flu is small compared to the numbers infected.”
The disparity in the Canadian and Mexican figures, he suggested, “probably means is a better level of care, especially for very complicated care given in an intensive-care unit in a modern facility. We can [keep people alive on respirators] for a long time.”