Serologic studies on the behaviour of influenza virus type A in persons of greater São Paulo during 1976, 1978 and 1979

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: S. Takimoto, R. P. de S. Carvalho, H. G. Pereira, C. S. Pannuti, M. S. Pereira, L. F. de Salles-Gomes
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 1986
• Subjects: Influenza virus type A; Sera epidemiologic study; Different agegroups; Hemagglutination inhibition test; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1590/S0036-46651986000600007; https://doaj.org/article/1da1a05e1daa4630b6f4c0120b46d3aa

Sera of persons of different age groups collected in 1976, 1978 and 1979 were tested for the presence of HI antibodies against various strains of the H3N2 and H1N1 subtypes of influenza virus. The occurrence of infection by H3N2 subtype was recorded during the 1976-1978 period but in 1979, circulation of this subtype of virus was limited. The prevalence of antibody against A/São Paulo/1/78 (H1N1) was significantly higher than that of antibody to A/USSB/90/77 (HIND in 1978. However in 1979 the predominant strain was A/USSR/90/77 (HIND. Persons under 20 years of age were the most affected by H1N1 subtype. Antibodies to H1N1 subtype were detected in sera of individuals older than 20 years in 1976, before the re-emergence of this strain. Serological results indicate that infections by H3N2 subtype in 1978 occurred in 65.4% of young children (0-4 year group). About 47.0% of children from the 0-4 year group had antibodies to H1N1 subtype in 1979. Antibodies to swine influenza virus were detected in 60% of 60+ year old people.