March 4, 2019
Hookworm infections in humans are an important cause of malnutrition, anemia, and possibly retardation in physical and mental development in some tropical countries. Ancylostoma duodenale and Necator americanus are the primary cause of human infections. However, other zoonotic hookworms, including Ancylostoma ceylanicum and Ancylostoma caninum, also have potential to infect humans. Hookworm infections have been estimated to account for approximately 3.2 × 106 estimated disability adjusted life years (DALYs). Various health improvement programs, such as mass chemotherapy, sanitation improvement, and use of footware has reduce the burden of hookworm infections. However, infection rate still remains very high in some developing countries.
Some species adult hookworm can survive 5-7 years in their human host and a female worm produces 1.0 × 104-3.0 × 105 ova/day. Hookworm ova are released into wastewater mainly through faeces of infected hosts. The prevalence of hookworm ova in wastewater matrices depends on the magnitude of infection in the community. The presence of ova in wastewater does not pose a direct health risks to humans. However, under favourable conditions, viable hookworm ova hatch into infective larvae. These may survive several days in wastewater matrices. When wastewater is used as irrigation water for crop production, agricultural workers, consumers and wider population may become infected with hookworm larvae through direct and indirect exposure to the infectious larvae. This chapter outlines the numbers of hookworm ova in raw wastewater, treated wastewater and sludge samples. The chapter also discusses detection methods for viable hookworm ova from environmental waters, and considers removal and inactivation of hookworm eggs and larvae in wastewater treatment.