Scanning electron micrograph of an adult Ancylostoma duodenale.
Among parasitic worm infections, hookworm stands out as perhaps the most insidious and dangerous for those living with poverty. As much as 10% of the world's population is infected with one of two species, Anyclostoma duodenale and Necator americanus. These parasites are associated with extreme poverty and thrive in unsanitary environments polluted by human waste. Often infection is mild or asymptomatic, but for many, the chronic loss of blood causes iron-deficient anemia, which robs children and adults of their physical and mental vitality, and poses serious health risks during pregnancy to both mother and child. Treatment primarily employs benzimidazole drugs (albendazole and mebendazole) which are given as single oral doses - convenient and efficient in terms of treating as many people as possible. However, these drugs rarely provide complete cure and there are strong concerns regarding the emergence of drug resistance - a phenomenon that has already occurred for benzimidazole drugs in the animal health sector.
What is it?
Infective larvae found in contaminated human waste actively infect skin and pass through the heart and into the lungs. Larvae are coughed up, swallowed and eventually grow to adulthood in the GI tract. Adult worms attach to the intestinal mucosa and feed on blood. The loss of blood in heavy infestations directly causes or exacerbates existing iron-deficient anemia. Male and female worms pair and generate thousands of eggs per day. These eggs are passed out in the feces and hatch to eventually develop as infective larvae.
Where does it occur?
Hookworm is most prevalent in a zone girdling the earth between the 30th parallel north and south of the equator, i.e., Central and South America, South and South-East Asia (Western Pacific), and Africa.