Milk-borne outbreak of tick-borne encephalitis in Olsztyn Province
Jezyna, C.; Weglińska, T.; Nawrocka, E.; Falecka, W.; Wielizcko-Gebska, L.; Rodkiewicz, T.; Piesiak, Z.; Ciesielski, T.
Przeglad Epidemiologiczny 30(4): 479-489
1976
ISSN/ISBN: 0033-2100 PMID: 1037030 Document Number: 68
An outbreak of tick-borne encephalitis transmitted by cow milk is described for the first time in Poland. The disease was diagnosed in 15 cases, one being fatal within 6 days. Six cases were serologically positive with central nervous symptoms, and in 8 cases the disease ran as gastritis or gastroenteritis with only slight symptoms of central nervous system involvement. The patients were city inhabitants, and except two they had no contact with agriculture or forestry and were not attacked by ticks. In 11 patients serological tests for tick-borne encephalitis virus were positive to high titers, with a tendency to increase, and persisted for a long time after disappearance of clinical symptoms. Among 16 healthy contacts tested 25% were serologically positive, and among 11 domestic animals tested the results were positive in only one cow whose milk was drunk by the patients. Immunological analysis of the sera tested pointed to a recent contact with tick-borne encephalitis virus. Seroepidemiological surveillance, which was performed in 1971/72 among forestry workers in Poland, showed arbovirus antibodies to occur in 12.3% of 389 persons tested in the area now involved in the epidemic. Alimentary rout of infection by drinking raw cow milk was confirmed.
Document emailed within 1 workday
