RISK-FACTORS FOR TOXOPLASMA-GONDII INFECTION IN PREGNANCY - RESULTS OF A PROSPECTIVE CASE-CONTROL STUDY IN NORWAY

From 1992 to 1994, a prospective case-control study designed to identi fy preventable risk factors for Toxoplasma gondii infection in pregnan cy was conducted in Norway. Case-patients were identified through a se rologic screening program encompassing 37,000 pregnant women and throu gh sporadic antenatal testing for Toxoplasma infection. A total of 63 pregnant women with serologic evidence of recent primary T. gondii inf ection and 128 seronegative control women matched by age, stage of pre gnancy, expected date of delivery, and geographic area were enrolled. The following factors were found to be independently associated with a n increased risk of maternal infection in conditional logistic regress ion analysis (in order of decreasing attributable fractions): 1) eatin g raw or undercooked minced meat products (odds ratio (OR) = 4.1, p = 0.007); 2) eating unwashed raw vegetables or fruits (OR = 2.4, p = 0.0 3); 3) eating raw or undercooked mutton (OR = 11.4, p = 0.005); 4) eat ing raw or undercooked pork (OR = 3.4, p = 0.03); 5) cleaning the cat litter box (OR = 5.5, p = 0.02); and 6) washing the kitchen knives inf requently after preparation of raw meat, prior to handling another foo d item (OR = 7.3, p = 0.04). In univariate analysis, travelling to cou ntries outside of Scandinavia was identified as a significant risk fac tor, but this variable was not independently associated with infection after data were controlled for factors more directly related to the m odes of infection.