Economic evaluation of preventive programmes against congenital toxoplasmosis

Benefit-cost analysis are applied to different strategies aimed at preventing congenital toxoplasmosis. The first strategy involves health education of pregnant women on how to avoid toxoplasma infection. The second strategy comprise serological surveillance in pregnancy combined with prenatal diagnosis and chemotherapy. The cost of health education is less than the cost of the serological screening, but health education will most likely lead to a haphazard testing of individuals and thereby increasing the cost. The best and most rational approach, and the programme which will prevent most cases and save most money for the society, is a combination of both programmes. Compared with the results of any of the two strategies alone, the benefits of the combined programme will increase significantly, while the cost (NOK 165 per participating woman) will only add fractions to that of the serological screening programme. The benefits of the strategies are influenced by many uncertain factors such as the discount rate, the incidence of infection, the intrauterine transmission rate, the outcome of pregnancy, the prognosis of the offspring, the sensitivity of the screening tests and the effectiveness of the programme. After applying a sensitivity analysis, both programmes were found to be of economic benefit to society at an incidence of maternal toxoplasmosis of 1-1.5 per 1000. Thus the pilot screening initiated in Norway to determine the incidence of infection, seems justified.