[Prevalence of Giardia intestinalis in a farming population using sewage water in agriculture, Settat, Morocco]

This investigation was undertaken to assess the risk linked to the use of raw sewage waters in agriculture, and the prevalence of Giardia intestinalis.

The survey was made on 214 individuals, average age 28.6+/-19.4 years, belonging to two douars using raw sewage waters in agriculture, and 119 individuals, age 31.8+/-19.5 years, belonging to a control douar not using raw sewage waters. These three douars are located in around the city of Settat, in Morocco. Every consenting individual was given a complete clinical examination and 3 stools samples were collected in 3 consecutive days.

The prevalence of G. intestinalis in the exposed population was 11.7% compared to 2.5% in the control population. The relative risk was 4.6. This difference is statistically significant. The most concerned individuals were essentially children between 3 and 14 years of age. Close contact was an important factor of infection in the exposed population, with a higher prevalence in the case of high promiscuity index. In the exposed population, more than 50% of the cases were familial ones. Giardiasis causes a trophic state, essentially in children.

The use of the raw sewage waters in agriculture is responsible for an increased risk of giardiasis. Some preventive measures are mandatory, including hygiene education and an adequate treatment of sewage waters.