Why do poor sanitation and unsafe water supplies increase the spread of parasitic disease?

Poor sanitation and unsafe water supplies are primary drivers of parasitic disease because they facilitate the transmission of parasitic infections by allowing pathogens to persist and circulate within human populations.12

When communities lack access to clean water supplies and adequate sanitation, individuals are frequently exposed to contaminated sources that may harbor various parasites, such as roundworms, tapeworms, and amoebae. In many regions, poverty and a lack of health education exacerbate these conditions, creating environments where multiple parasite infestations become commonplace. Furthermore, the absence of medical relief prevents the interruption of the parasite infection cycle, allowing these diseases to be maintained indefinitely.321

The risk is further heightened in areas where humans live in close proximity to livestock, as this intimate contact can facilitate the spread of coexisting parasites. Ultimately, the combination of inadequate hygiene and contaminated water is a major factor in chronic illness and early mortality, particularly in tropical regions where such parasitism is endemic.12