Water sources may be a significant part of the transmission of roundworm infections. Hence, proper water treatment alone can decrease roundworm transmission by 18 percent. The findings of the study are published in the journal PloS Medicine.
The discovery emerged from a two-year study, which examined the effects of water quality, sanitation, handwashing, and nutritional interventions on rates of the intestinal worm and Giardia infections in rural Kenya.
Water treatment alone was sufficient to cause an 18 percent reduction in infection rates in roundworm (Ascaris) infections; the reduction was 22 percent when water treatment was combined with improved sanitation and handwashing with soap. None of the interventions reduced the prevalence of Giardia infections among the young children studied.
High re-infection rates have prevented school-based mass drug administration programs from controlling the transmission of these parasitic infections. The study authors hypothesized that improved water quality, sanitation, hygiene, and/or nutrition could interrupt the environmental transmission of parasites, but few trials evaluating these interventions have measured actual infections as an outcome. In contrast to aggressive medical treatment programs, the water treatment, sanitation, and handwashing approaches represent a sustainable approach to disease control.
"Out of all the interventions we tested, we were extremely surprised that water treatment appeared to be the most effective at reducing roundworm infections. Water treatment is a relatively unexplored strategy for intestinal worm control," said Amy Pickering, assistant professor of civil and environmental engineering at Tufts University, and first author of the study.
"At least 800 million people in the world are infected by a roundworm (Ascaris lumbricoides), so even a relative reduction of 18 percent from water treatment interventions could have a major beneficial impact. Our study also suggests that water treatment could complement large-scale deworming medication delivery programs in the global effort to eliminate roundworm infections."
With re-infection rates reaching 94 percent after deworming treatment for roundworm infection, a combined approach of mass drug administration and environmental controls (water, sanitation, hygiene) could be critical to gaining the upper hand on these endemic infections, the researchers say.