Although control measures have successfully reduced the burden of schistosomiasisin some countries in recent years, the complexity of transmission in many settings requires interdisciplinary research and integrated interventions.
Breaking the transmission ofschistosomiasis可以集中on several parts of the parasite’s life cycle. The current mainstay of control in endemic countries is annual mass drug administration (MDA) with praziquantel, targeting adult worms in an infected person and therefore reducing the egg production and onwards transmission. Other control measures include safe water supply (reducing risk of infection through infested water contact), adequate sanitation (reducing the risk for excreted eggs to reach the water to hatch), behavior change (improving water and sanitation practices as well as MDA uptake and health seeking behavior) and vector control (reducing the amount of intermediate host snails). Each of these control measures comes with opportunities and challenges such as efficacy, feasibility, acceptability and cost. And as one of theneglected tropical diseases, schistosomiasis is not often at the top of the global health agenda, even further challenged by several public health resources being re-allocated to the COVID-19 pandemic in recent years.
由于这些挑战transmis的控制sion and disease,areas with persistent high endemicitycan remain. This phenomenon can be attributable to sustained untreated infections but even in areas with high MDA coverage, often reinfections occur after treatment. Interestingly, even in areas where people live in close proximity to water bodies where the intermediate host snails are present, such as Lake Victoria, some people get rapidly reinfected where others remain uninfected. Identifying factors driving reinfection as well as factors protecting people from infection is a complex challenge but could provide helpful insights towards control in these areas.
By using a unique interdisciplinary approach of epidemiological, ethnographic and malacological methods we aimed tobetter understand water contact behaviors and their interplay with infection riskin an area with persistent high endemicity in Uganda. Mixing quantitative and qualitative methods allowed for findings to confirm, contrast or complement each other as well as inform targeted data collection.
We found that water contact happened frequently, including for domestic, personal care, recreational, commercial and religious purposes, either directly at various water sources or indirectly with previously collected water. Risk behaviors included swimming and fetching-for-money, skipping school, going to a larger variety of water contact sites and sites with specific snail species, contacting water during midday when snails are reported to shed more parasites and not collecting rainwater. Most intermediate host snails were found during the dry season.
Control programs focussed on MDA do not address all the complexities of schistosomiasis infection and additional efforts are needed to work towards the target ofeliminating schistosomiasis as a public health problem by 2030.Interdisciplinary research on such complex issues can offer more complete, balanced and robust perspectives and provide useful recommendations for much-needed integrated control measures.
Let’s work together to make a disease that has plagued humans forthousands of yearsfinally come to a halt.
Comments