[The clinico-epidemiological characteristics of opisthorchiasis foci in the Yamalo-Nenets Autonomous Okrug and the treatment results with praziquantel]. / Kliniko-épidemiologicheskaia kharakteristika ochagov opistorkhoza v Iamalo-Nenetskom avtonomnom okruge i rezul'taty lecheniia prazikvantelem.

A clinical and epidemiological study of opisthorchiasis foci in the Yamalo-Nenets Autonomous Okrug was carried out. 764 people were surveyed, including 473 aborigines of the north, 207 denizens, and 84 migrants. Opisthorchiasis infection rate in villages was 40.5-45.7%. The intensity of infection was lower than 200 eggs per g faeces. The modelling of opisthorchiasis prevalence performed after Muench showed the highest correlation with the "simple" and "reversible" models. Factors determining the infection spread and limiting its intensity and those influencing the effect of chemotherapy were defined. Theoretically determined radical suppressive low-dose praziquantel chemotherapy was carried out. The efficacy of the drug, 25, 30, 40 and 50 mg/kg, varied from 76.5 to 92.0% (mean 88.1%), and the decrease of the egg density was more than 60%. The incidence of side effects of the therapy averaged 45.3%.

[The comparative characteristics of the clinico-immunological indices in different contingents of opisthorchiasis patients in a hyperendemic focus. 4. The transplacental transmission of Opisthorchis felineus antigens]. / Sravnitel'naia kharakteristika kliniko-immunologicheskikh pokazatelei raznykh kontingentov bol'nykh opistorkhozom v giperéndemichnom ochage. Soobshchenie 4. Transplatsentarnaia peredacha antigenov Opisthorchis felineus.

25 women in labour with chronic opisthorchiasis have been examined. They were representatives of native (7), local (8) and migrated population of the focus. Control group comprised 10 women from the local population free of invasion. Their immune status was assessed by the level of IgA, IgG, IgM, circulating immune complexes (CIC) and specific antibodies in the serum obtained from peripheral and funic veins, as determined by enzyme immunoassay (ELISA). To detect opisthorchis antigens in the serum modified radial immunodiffusion test was used. Antibody titres in ELISA, IgG and CIC levels were the highest in migrated women. Antibody titres in ELISA and IgG level in the newborn of migrated women were also considerably higher than in other newborn. Serum IgM level in all groups of newborn was considerably lower than in their mothers and IgA was altogether undetectable. In 3 native and 2 local women the results of immunodiffusion test were positive. It is suggested that transplacental migration of opisthorchis throughout the neonatal period may lead to tolerance formation.

[Clinico-immunologic indices of various patient contingents in a focus of chronic opisthorchiasis. 3. Dynamics of the indices following praziquantel treatment]. / Kliniko-immunologicheskie pokazateli u raznykh kontingentov bol'nykh khronicheskim opistorkhozom v ochage. Soobshchenie 3. Dinamika pokazatelei posle lecheniia prazikvantelem.

Studies of the time course of the immune status characteristics after praziquantel treatment and of the nature of its side-effects on various groups of opisthorchiasis patients in the focus established significant differences in their immune response to specific treatment. The lack of alterations in the T- and B-immunity systems in aboriginal population of the focus may suggest its tolerance to helminthic antigens. The trend towards cellular immunity stimulation and a significant increase in the levels of circulating immune complexes and specific antibodies in the serum were observed in aboriginal population of the focus. The comers showed significant initial alterations of the immunity status before treatment, pointing to their sensitization to parasitic antigens. Suppression of the infection normalizes several cellular and humoral immunity characteristics--the number of T-helpers, T-lymphocytes, B-lymphocytes, Th/Tc indices, T-lymphocyte functional activity, thus eliminating immune depression. The increased IgG, CIC and specific antibody levels significantly exceeding the normal level, occurrence or enhancement of allergic reactions point to the necessity of performing a desensitizing therapy and using effective cholagogic drugs in the multimodality treatment to rapidly eliminate the parasitic antigen.

[Comparative characteristics of clinical and immunologic indicators of various groups of opisthorchiasis patients in a focus. Aboriginal population]. / Sravnitel'naia kharakteristika kliniko-immunologicheskikh pokazatelei raznykh kontingentov bol'nykh opistorkhozom v ochage. Korennoe naselenie.

Clinical and immunological observations of people belonging to two population groups--aborigens (khanty, mansi, komi) and 40 immigrants--were performed in opisthorchiasis foci of the Tyumen region. Rapid clinical reinvasion of unimmune immigrants (in a 3-4 year period) was established; the aborigens featured subclinical invasion pattern. T-system immunity in immigrants was suppressed, while in the aboriginal group insignificant reduction of the number of T-helpers and significant increase in the number of T-suppressors, lack of apparent mobilization of humoral immunity factors--reduction of the absolute B-lymphocytes number, normal A, G immunoglobulines and CIC levels-were observed. Such T--B immune systems' ratio may indicate immune tolerance of a suppressor type. The observed indicators of aborigens' tolerance to helminths' antigens point to the necessity of differentiated approach to chemotherapy prescription (especially of the repeated courses) in the endemic invasion foci.