A Serosurvey of Toxoplasmosis in Manitoba

• Published in: Canadian journal of public health 1981-03, Vol.72 (2), p.111-117
• Main Authors: SEKLA, L., STACKIW, W., RODGERS, S.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age groups; Animals; Antibodies; Blood plasma; Cats; Cattle; Congenital toxoplasmosis; Cord blood; Female; Geographic regions; Humans; Infections; Manitoba; Pregnancy; Serologic Tests; Toxoplasma; Toxoplasmosis; Toxoplasmosis - epidemiology; Toxoplasmosis - immunology; Toxoplasmosis, Animal - epidemiology; Toxoplasmosis, Animal - immunology; Women
• ISSN: 0008-4263; 1920-7476

A total of 61,775 human and animal sera were tested during the years 1976-1978 to estimate the extent of Toxoplasma infection in Manitoba. For the purpose of analysis the sera tested were divided into 8 categories: a. "pregnant women", b. "cord bloods" from Toxoplasmapositive mothers, c. "TORCH", children under 2 years of age with signs of a congential infection of an undetermined etiology, d. "diagnostic", specifically requesting tests for Toxoplasmosis, e. "febriles", requesting tests for Infectious Mononucleosis, Brucellosis or Salmonellosis, f "immunosuppressed", g. "miscellaneous", sera submitted for various serological procedures, h. "animals". The tests used on human sera were an indirect haemagglutination test (IHA), an indirect fluorescent antibody test (IFA) and a specific IgM fluorescent antibody test (IgM IFA). Sera were first screened at a 1:60 dilution by IHA. The sera found to have Toxoplasma antibodies were then tested at a serum dilution of 1:16 by IFA. The presence of Toxoplasma antibodies in the latter was considered indicative of exposure to Toxoplasma gondii and used to determine the prevalence of Toxoplasmosis. Recent infections were diagnosed by showing either seroconversion or a four-fold rise in antibody titres in paired sera tested simultaneously or by detecting specific IgM antibodies in single sera. The testing of 55,527 pregnant women showed that 95.1% had no Toxoplasma antibodies and therefore, were "susceptible". The annual rate of acquisition of antibodies in pregnant women was calculated to have been 0.12% in 1976 and 0.16% 1977. In 129 pregnant women the serological finding indicated a recently acquired Toxoplasma infection. However, so far none of their babies were proven to have congenital Toxoplasmosis, possibly because of the poor follow-up. In the diagnostic category, more cases of Toxoplasmosis were observed in the summer months, the most common presenting symptomatology being a febrile illness which in certain instances affected several members of a family simultaneously. In the miscellaneous category, Toxoplasma antibodies were more prevalent in males, Winnipeggers, and zoo personnel. In the animal sera tested Toxoplasma antibodies were found more frequently in cats. Manitoba's findings were compared with those reported from other Canadian provinces. Durant les années 1976 à 1978, un total de 61, 775 sérums humains et animaux ont été examinés pour déterminer l'incidence de la Toxoplasmose au Manitoba, Aux fins d'an