Seroepidemiologic study on tick-borne encephalitis among forestry workers and farmers from the Lublin region (eastern Poland).

The paper presents the results of seroepidemiologic studies concerning tick-borne encephalitis (TBE) in 1,583 persons (1,261 forestry workers and 233 farmers) from the Lublin region (eastern Poland) occupationally exposed to ticks and in 130 healthy blood donors (a control group). The mean percentage of seropositive reactions in forestry workers amounted to 19.8% and in farmers 32.0%. Based on 5-year research (1994-1998) conducted in 5 districts of the Lublin region, the existence of endemic foci of TBE was detected in the district of Bia a Podlaska, on the areas of Radzyn Podlaski and Parczew, where the percentage of seropositive reactions in forestry workers exceeded 50%. Statistical analysis showed that the frequency of seropositive reactions in forestry workers and farmers was significantly greater compared to control group (p < 0.001 and p < 0.05, respectively). It indicates that these groups are occupationally exposed to TBE virus. In the years 1994-98, a total of nine clinical cases of TBE (acute neuroinfection) in forestry workers and fourteen clinical cases in farmers were confirmed serologically. The effectiveness of specific immunization against TBE was proved on the basis of 100% seroconversion in 56 earlier seronegative forestry workers. The obtained results proved that forestry workers and farmers in Poland are under increased risk of infection with TBE virus.

[Value of different serological tests in the diagnosis of various forms of active ocular toxoplasmosis]. / Wartosc niektórych odczynów serologicznych w diagnostyce róznych postaci czynnej toksoplazmozy ocznej.

The analysis of results of indirect immunofluorescence and direct agglutination reaction in patients with various forms of ocular toxoplasmosis showed that these reactions have a limited value in diagnostics of this condition. One can define a sure diagnosis of active ocular toxoplasmosis when the titre of these reactions are higher than 512. The ELISA IgM reaction is specific for the active form of this disease. The sensitivity of this reaction amounts 43-50%. In cases of iridocyclitis the results of the serological tests were similar to those of the control group; this confirms the hypothesis that the inflammation is evoked by an allergic reaction.

[Detection of the foci of familial toxoplasmosis in rural environment]. / Poszukiwanie ognisk toksoplazmozy rodzinnej w srodowisku wiejskim.

In order to detect centres of family toxoplasmosis in rural environment 24,546 patients, suspected of invasion of T. gondii, 504 healthy persons coming from villages and 1,681 live stock were examined. Among persons suspected of infection of T. gondii, 65 cases of congenital family toxoplasmosis and 19 cases of environment family toxoplasmosis, involving several members of the family were detected. In animals a comparatively high percentage with positive reaction in the direct agglutination test (cattle 55.5%, swine 27.9%, sheep 23.4%) was detected. The following serological tests were applied to humans: complement-binding test (OWD), indirect immunofluorescence test (OIF), direct agglutination test with 2-mercaptoethanol (CA), ELISA IgM and, selectively, immunoperoxidase test IgM (OIP). The results suggest that the environment conditions can play an important role in the occurrence of family toxoplasmosis in our country, especially in the countryside. Detecting active toxoplasmosis in a family member should be a signal to start serological-epidemiological examination of the remaining family members and live stock.