Epidemiological Surveillance of Influenza and Other Respiratory Diseases in Military Personnel. Prevention of Influenza and Other Respiratory Diseases - Laboratory Studies. July 1986-Jun 1987

摘要

The last annual report covering the period through 30 June 1986 left unanswered the question of why the vaccine apparently had been less effective during the Influenza B outbreak than in previous years. Studies were completed during the summer months which showed that when the sera of vaccinated individuals were tested against strains isolated from the Lowry outbreak or against B/Ann Arbor/86 virus, the protective level of antibody was clearly demonstrated to be 32. This was not made clear when sera were tested with ether split B/USSR/83. The 1986-87 season was notable for a sharp outbreak of H1N1 Influenza A, which began before the Christmas break, probably reached a peak during the Christmas holiday, and tailed off during January, with the last case detected during mid-February. Again it was found that the H1N1 virus caused very little illness in individuals over the age of 35. Attack rates in students were difficult to estimate because the outbreak appeared to be peaking at the time the students took a two-week Christmas break. In the permanent party, which for the most part remained on the Base over the Christmas holiday, attack rates were relatively high in the younger segment of the population. No Influenza B viruses were isolated during this season. Influenza A of the H3N2 subtype was isolated from two civilians during this period but none were found at Lowry Air Force base. In the civilian population the virus appeared to spread very poorly, in each case causing a cluster of only two or three other identified illnesses. (aw)