Alimentary Transmission of Tick-borne Encephalitis in the Czech Republic (1997–2008)
Authors:
B. Kříž 1,2; C. Beneš 1; M. Daniel 1
Authors‘ workplace:
National Institute of Public Health, Praha
1; Charles University, 3rd Medical Faculty
2
Published in:
Epidemiol. Mikrobiol. Imunol. 58, 2009, č. 2, s. 98-103
Overview
Objectives:
Analysis of cases of tick-borne encephalitis (TBE) with confirmed food-borne transmission in patients who were unaware of tick attachment prior to the onset of illness.
Material and methods:
Data on laboratory confirmed cases of TBE reported in the Czech Republic (CR) in 1997-2008 were obtained from the EPIDAT system. Patient interview data were recorded in a standardised questionnaire form with multiple choices for locality (GIS) and route of transmission to be exported on a weekly basis in electronic form to a protected database of the Ministry of Health of CR. Statistical processing was conducted by ANOVA using Epi-Info CDC Atlanta and STATCALC software.
Results:
TBE has been recognised in CR since 1948 when, for the first time ever in Europe, the TBE virus was isolated from patients and I. ricinus ticks in two Czech and Moravian areas simultaneously (and independently of one another). TBE cases in the Czech Republic have been reported since 1971. In 1997 – 2008 the incidence ranged between 422 cases (1998) to 1029 cases (2006) . Food-borne transmission of TBE was first reported in Czechoslovakia in 1954. At that time, nothing was known of the possibilities of arbovirus transmission by the food-borne route; this was discovered following the TBE epidemic of 1951 in the east Slovak town of Rožňava in which 660 persons were infected, and of these, 271 were hospitalised. The source of infection was contaminated goats’ milk which had been mixed into dairy milk at the local dairy and distributed without pasteurization. The risk of TBE transmission by unpasteurized goats’ milk is associated with the current trend of I. ricinus tick proliferation in foothills and mountainous areas. The shift of the line of their spread from 700 m above sea level to 1200 m means that to up to 8% of the area of the CR (6300 km2) have been newly colonized by ticks. In 1997 – 2008, 64 cases of TBE were recorded in patients who reported consumption of unpasteurized goats’ and dairy milk or unpasteurized sheep’s milk cheese. The majority of cases involved goats’ milk (36 patients, i.e. 56.3%) and sheep’s milk cheese (21 patients, i.e. 32.8%). Dairy milk-borne infection was responsible for 7 TBE cases (10.9%). Of the 64 patients with food-borne TBE, 33 were men (51.6%) and 31 women (48.4%). Thirty-three cases (51.6%) occurred in family outbreaks following purchase of cheese or milk from animal breeders. Twenty-two cases (34.4%) occurred in individual patients and for 9 cases (14.0%) the data are unavailable. The highest age-specific morbidity, i.e. 1.94/100 000, was observed amongst the 5 – 9 years age-group, while in the adult age-groups the rates ranged between 0.17/100 00 (75+ years) and 0.89/100 00 (35 – 44 years). The comparison of TBE cases in child and adult age groups revealed that children in the food-borne TBE group had a 2.5 fold risk of TBE infection over adults. None of the TBE patients was vaccinated against TBE.
Conclusion:
In 1997 – 2008, a total of 7288 cases of TBE were reported. Sixty-four (0.9%) TBE cases were food-borne. In the majority of these cases, TBE virus was transmitted by unpasteurized goats’ milk and caused family outbreaks. The deciding factor in these outbreaks was an attempt to provide healthy diet to offspring.
Key words:
Tick-borne encephalitis – food-borne infection – milk-borne – cheese-borne – goats’ milk.
Sources
1. Blaskovic, D. (Ed.) The epidemic of encephalitis in Roznava natural focus of infection. 1954 .Bratislava, Slovac Academy of Sciences 1954, 1- 314).
2. Czimova, M., Raszka, J., Januska, F., Heinz, P. et al. Familiar Incidence of Tick-borne Encephalitis with Alimentary Transmission. Epidemiol Mikrobiol Imunol 1981, 30, 6, 334-339.
3. Danielova, V. Natural foci of tick-borne encephalitis and prerequisites for their existence. Int J Med Microbiol 2002, 291, Suppl. 33, 183-186.
4. Danielova, V., Daniel, M., Kriz, B. Tick-borne encephalitis in Europe. In: Ebert R. A., Progress in Encephalitis Research, Nova Science Publisher, New York, 2006, 59 – 103.
5. Gallia, F., Rampas, J., Hollender, L. Laboratory infection by TBE virus. CasLekCes.1949, 88, 224 – 229.
6. Gresikova, M. Sekeyova, M. Stupalova, S. Necas, S. Sheep milk-borne epidemic of tick-borne encephalitis in Slovakia. Intervirology. 1975, 5, 1-2, 57-61.
7. Holzmann, H., Heinz, XH. Tick-borne encephalitis outbreak owing to consumption of fresh cheese from unpasteurized goat milk. Virusepidemiologische Information, 2008, Medizinische Universität Wien, 17, 8, 2-4.
8. Jezyna, C., Weglinska, T., Nawrocka, E. et al. Milk-borne outbreak of TBE in Otsztyn Province, Przegl Epidemiol 1976, 30, 4, 479-489.
9. Juceviciene, A., Vapalahti, O., Laiskonis, A., Ceplikiene., J, Leinikki, P. Prevalence of tick-borne-encephalitis virus antibodies in Lithuania. J Clin Virol 2002, Jul, 25, 1, 23-27.
10. Kerbo, N., Donchenko, I., Kutsar, K., Vasilenko, V. Tick-borne encephalitis outbreak in Estonia linked to raw goat milk. Euro Surveill 2005, 10, 6,
11. Kohl, I, Kozuch, O, Eleckova, E, Labuda, M, Zaludko, J. Family outbreak of alimentary tick-borne encephalitis in Slovakia associated with a natural focus of infection. Eur J Epidemiol 1996, Aug, 12, 4, 373-375.
12. Krejcí, J. The epidemic of viral meningoencephalitis in Vyskov. Lek Listy, 1949, 73 – 75, 112 – 116, 132 – 134.
13. Krejcí, J. Isolation of the virus of human meningo-encephalitis from a tick. Lek Listy 1950, Jul, 15, 5, 14, 6-9.
14. Labuda, M., Eleckova, E., Lickova, M., Sabo, A. Tick-borne encephalitis virus foci in Slovakia. Int J Med Microbiol 2002, Jun, 291, Suppl. 33, 43-47.
15. Materna, J., Daniel, M., Metelka, L., Harcarik, J. The vertical distribution, density and the development of the tick Ixodes ricinus in mountain areas influenced by climate changes. (The Krkonoše Mts., Czech Republic). Int J Med Microbiol 2008, 298, S1, 25– 27.
16. Materna, J., Daniel, M., Danielova, V. Altitudinal distribution limit of the tick Ixodes ricinus shifted considerably towards higher altitudes in Central Europe: results of the three years monitoring in the Krkonoše Mts. (Czech Republic). Centr Eur J Publ Health, 2005, 13, 24-28.
17. Matuszczyk, I, Tarnowska, H, Zabicka, J, Gut, W. The outbreak of an epidemic of tick-borne encephalitis in Kielec province induced by milk ingestion. Przegl Epidemiol 1997, 51, 4, 381-388.
18. Orolinova, M. The epidemic of TBE -Sheep cheese- in the district Vsetin. Proceedings of Czech Microbiol.-epidemiol. Conference, 2000, Breclav.
19. Pazdiora, P., Moravkova, J., Brij, Z., et al. Alimentary transmission in Familiar Incidence of Tick-borne Encephalitis. Prakticky lekar 1994, 74, 5, 209-210.
20. Pazdiora, P., Benesova, J., Bohmova, Z et al. The prevalence of tick-borne encephalitis in the region of West Bohemia (Czech Republic) between 1960-2005. Wien Med Wochenschr 2008, Feb.158, 3-4, 91-97.
21. Rampas, J., Gallia, F. Isolation of encephalitis virus from tics Ixodes ricinus. Cas Lek Ces 1949, 88, 1179 – 1180.
22. Raska K. et al. 1954, Epidemiology of Roznava encephalitis. 93-110, in Blaskovic, D.ed. The epidemic of encephalitis in Roznava natural focus of infection, Bratislava Slovak Academy of Sciences, 314.
23. Vereta, LA, Skorobrekha, VZ, Nikolaeva, SP, et al. The transmission of the tick-borne encephalitis virus via cow‘s milk. Med Parazitol (Mosk). 1991, May-Jun, 3, 54-56.
24. Zeman, P., Januska, J., Orolinova, M., Stuen, S., Struhar, V., Jebavy, L. High seroprevalence of granulocytic ehrlichiosis distinguishes sheep that were the source of an alimentary epidemic of tick-borne encephalitis, Wien Klin Wochenschr 2004, Sep 30, 116, 17-18, 614-616.
25. Zaludko, J, Vrbova, O., Hachlicova, R. et al. Familiar epidemics of tick-borne encephalitis in central Povazie, Bratisl Lek Listy, 1994, Nov, 95, 11, 523-526.
26. Outbreak of tick –borne encephalitis, presumably milk-borne, Weekly Epidemiological Record 1994, 19, 140-141.
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Hygiene and epidemiology Medical virology Clinical microbiologyArticle was published in
Epidemiology, Microbiology, Immunology
2009 Issue 2
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