[Influenza in Poland in 1999]

A total of 2,344,773 cases of influenza were reported in Poland in 1999, corresponding to 6066.1 cases per 100,000 population and was 2.8 times higher as compared with 1998. The highest influenza incidence rate (10,770.9 per 100,000) was reported in Małopolskie voivodeship. Children up to 14 years old accounted for 34.9% (818,629; incidence 10,616.2 per 100,000) of all reported influenza cases. A total of 3,925 persons required hospitalization, eight times more as compared with 1998. The number of deaths due to influenza amounted to 402. Compared with 1998, in 1999 reported influenza deaths increased 6.4 times. During the second two weeks of January 1999 four influenza strains of type B were isolated from patients aged 13, 16, 31, and 38. During the first part of February 1999 another two strains of influenza virus type B were obtained from persons aged 35 and 45. All six isolates were related antigenically to the vaccine strain B/Beijing/184/93 and were confirmed by the WHO Collaborating Center for Influenza Reference and Research, London.