[Differences in influenza epidemics in Osaka City--epidemiological surveillance of infectious disease].
Influenza viruses in outpatients with influenza symptoms in Osaka City were analyzed in an epidemiological surveillance of infectious disease between 1989 and 1993. During influenza epidemics a mixed prevalence of several types of influenza viruses existed. Three types of influenza viruses, AH1, AH3 and B, were isolated during the 1990/1991 season. Remarkably the three types of viruses were discovered in samplings collected on the same day and within a narrow area inside a radius of 800-1,000m from the surveyed hospitals. Different types of viruses were detected between brothers and among school children from same housing complexes. Influenza AH3 viruses detected in 1992/1993 season differed in antigenicity from those detected in the 1990/1991 and 1991/1992 seasons. Therefore it appears that mutation of the AH3 virus contributed to the large-scale influenza epidemic which occurred in the 1992/1993 season.
Murakami
T
T
Osaka City Institute of Public Health and Environmental Sciences.
Haruki
K
K
Seto
Y
Y
Kimura
T
T
Shibe
K
K
Minoshiro
S
S
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology*; D007564:Japan / Q000453:epidemiology; D008297:Male; D011159:Population Surveillance