For the second week in a row, influenza-like illnesses on college campuses, generally assumed to be primarily pandemic H1N1 influenza, have dropped, this time a whopping 37%. A total of 3,933 new cases were reported on college campuses enrolling nearly 3 million students during the week ending Nov. 20, a 37% lower rate than in the week before, according to the American College Health Assn. The previous week, the group reported a 27% drop in infections, the first such drop of the academic year.
Seven hospitalizations and no deaths were reported for the week ending Nov. 20. All but seven states reported significant declines in activity from the previous week, and just 90% of campuses reported new cases, compared with 95% the prior week. Preliminary data show that only 4% of students on the campuses have been vaccinated against swine flu to date.
In other swine flu news:
-- A Charleston, W. Va., physician has contracted swine flu--twice. Dr. Debra Parsons, a pediatrician at Kid Care West in the suburb of Cross Lanes, and her son first contracted the flu in August and testing revealed that it was swine flu. Both recovered, but in October they began suffering symptoms again, and this time the disease was worse. Again, samples were sent to local laboratories, which confirmed they had swine flu. Local health authorities were skeptical, so samples from both illnesses were sent to the Centers for Disease Control and Prevention laboratories in Atlanta, where both were confirmed positive for swine flu.
Dr. Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases, said such events are rare, but not unheard of. Every year, one or two such cases are reported for seasonal flu, "but we don't think that is a common event in the population." The most likely explanation is that the immune systems of Parsons and her son did not build up a sufficient immune response to the first infection, allowing a second one. Similarly, the swine flu vaccine, like the seasonal flu vaccine, is not 100% effective, so a small number of people who receive it will still develop the disease.
-- The government of China said today that it had detected eight cases of a mutated swine flu virus, although the mutant forms are not resistant to antiviral drugs and could be prevented by vaccines. Mutations of influenza viruses are common, but scientists fear that the pandemic H1N1 virus will mutate into a form that will make it either more lethal or resistant to Tamiflu and other antiviral drugs. Virtually all seasonal flu strains now circulating have mutated to develop such resistance. The Chinese government has released few details about the mutated strain, other than to say that its spread has been restricted.
The news follows reports last Friday of similar mutations detected in Norway. Norwegian authorities said it appears the mutations allow the virus to grow more deeply in the lungs, potentially making the resulting disease more serious. At least two of the victims of the mutated virus died, but several of them only had a mild disease and recovered easily. Schuchat said there have been sporadic reports of the mutation around the world and that it is not yet clear whether the virus is more virulent or not.
-- Reports from Japan say that 132 influenza patients throughout the country have developed encephalopathy, a swelling of the brain, since July. In a normal flu season, only about 40 to 50 patients develop such neurologic problems, health authorities there said. The ages of the victims ranged from 1 to 67, but most were under 15. Twenty-two of the victims were 7 years old. The normal age for encephalopathy sufferers is 1 to 3 years old. Three of the victims have died and an additional seven have developed aftereffects such as paralysis and mental or nerve disorders.
-- Thomas H. Maugh II