Human hookworm infection: Is effective control possible? A review of hookworm control efforts and future directions.

Human hookworm, a soil-transmitted helminth (STH) infection caused by either Necator americanus or Anclystoma duodenale, is a major cause of morbidity globally and predominantly affects the world's poorest populations. Transmitted primarily by larval invasion of exposed skin, the adults inhabit the host small intestine, where they consume host blood. The resultant chronic iron deficiency anemia can lead to stunted growth and cognitive deficits in children, reduced work capacity in adults, and a variety of pregnancy complications. Historically, successful STH elimination has only been achieved in regions with concomitant significant economic growth. Since 2001, control of the STHs has been attempted via single-dose mass deworming of at-risk school-aged and preschool-aged children within STH-endemic countries, with the goal of morbidity reduction. Research questioning this strategy has grown in recent years, and current studies are evaluating the effectiveness of novel deworming strategies, including multidrug regimens and expansion of deworming to entire communities. While footwear campaigns may be associated with reduced odds of hookworm infection, the evidence supporting the impact of water, sanitation, and hygiene (WASH) interventions upon hookworm is mixed. Progress towards a human hookworm vaccine continues, with promising results from recent Phase 1 trials and several others ongoing. Integrated STH control programs, which combine mass deworming with WASH interventions, are relatively unstudied but may be a promising advancement. Whether interruption of STH transmission can be achieved apart from significant economic growth remains unanswered, but likely the implementation of intensive, integrated control programs will be necessary to achieve that goal.