Intestinal helminth infections among reproductive age women in Vietnam: prevalence, co-infection and risk factors.

Intestinal helminth infections are a significant public health problem for Vietnamese women, but prevalence and risk factor data are scarce. The objectives of this paper were to (1) determine the prevalence of helminth infections among women; (2) investigate interactions among intestinal helminth species in individuals and (3) identify risk factors that contribute to intestinal helminth infections. In a nationwide survey conducted in 1995, 9550 households in 53 provinces were covered using a stratified two-stage cluster survey. Stool specimens were examined by Kato-Katz technique. Of 5,127 women, 76% were infected with one or more helminth species, 36% with hookworm, 59% with Ascaris lumbricoides and 28% with Trichuris trichiura. A. lumbricoides and T. trichiura were more likely to be concurrent than expected by chance. There was significant interaction between prevalence and intensity of infection in all three species. All three helminth species were more common in certain ecologic zones than others. Hookworm infection was associated with farming [Odd ratio (OR) = 2.1] and lack of a closed latrine (OR = 2.0), A. lumbricoides with use of untreated feces as fertilizer (OR = 1.2) and coinfection with T. trichiura (OR = 2.1) and T trichiura with A. lumbricoides co-infection (OR = 2.1). Our findings suggest that reproductive-age women, especially rural farmers, should be included among the high priority groups for helminth control programs through mass chemotherapy and improving sanitation.