Indeed, the ability of hookworms and other helminths to modulate inflammation is so effective that some researchers are intentionally infecting human participants with low subclinical doses of larvae to treat a range of inflammatory diseases 9вЂ“ 12, spurring discovery efforts to mine hookworm genomes and proteomes for new macromolecules to be used in the treatment of some autoimmune and allergic disorders that plague industrialized countries.

Moreover, in the absence of a protective immune response, reinfection can rapidly occur, sometimes within 4вЂ“6 months in areas of high transmission 8.ДЄlthough hookworms are clearly a major human pathogen, recent investigations into the immunobiology of hookworm infection have highlighted the вЂJekyll and HydeвЂ™ nature of this parasite. Safe drugs are available to combat human hookworm infection, but their efficacies are variable to the point that some MDA campaigns are rendered ineffective owing to outright drug failure 6, 7. Although hookworm infection has mostly been eliminated through economic development (rather than mass treatment) in western European countries, the United States, South Korea and Japan, the disease burden remains unacceptably high in many low-income and middle-income countries, despite implementation of mass drug administration (MDA) programmes 5.

This understanding resulted in the formation of the Rockefeller-funded Human Hookworm Eradication Campaign 3, which is the first example of modern-day public health philanthropy (the original 1920 silent film can be viewed online 4). Indeed, hookworm infection, of which Necator americanus infection is the predominant human disease, has had a major influence on human history in the early 1900s, hookworm infection was recognized as a major cause of anaemia and lost productivity in the southern United States. Alternative and newer estimates indicate that hookworm infection results in 4.1 million DALYs lost, as well as possibly over US$100 billion in global economic losses 2. Hookworm infection affects almost 500 million people in the tropical regions of the world, accounting for 3.2 million disability-adjusted life years (DALYs) lost annually and ranking among the most important of the neglected tropical diseases in terms of causes of morbidity 1. Hookworms are soil-transmitted nematode parasites that can reside for many years in the small intestine of their human hosts, where they suck blood and can cause iron deficiency anaemia (IDA) in individuals who harbour moderate and high numbers of adult worms, which is known as hookworm disease. This area of endeavour might well yield new biotherapeutics for autoimmune and allergic diseases. However, hookworms could also be a resource as hookworms have the capability to regulate the host's inflammation, researchers are experimentally infecting patients to treat some inflammatory diseases as an approach to discover new anti-inflammatory molecules.

In addition, efforts are underway to develop a human hookworm vaccine through publicвЂ“private partnerships. Thus, other control strategies aimed at improving water quality, sanitation and hygiene are needed. Although anthelmintic drugs are available and widely used, their efficacy varies and the drugs do not prevent reinfection. Accordingly, the host switches to an immune-tolerant state that enables hookworms to reside in the gut for many years. Humans mount an immune response to hookworms, but it is mostly unsuccessful at removing adult worms from the bowel. Almost 500 million people in developing tropical countries are infected, and simulation models estimate that hookworm infection is responsible for >4 million disability-adjusted life years lost annually. Adult worms feed on the blood of a host and can cause iron deficiency anaemia, especially in high-risk populations (children and women of childbearing age).

Hookworms are soil-transmitted nematode parasites that can reside for many years in the small intestine of their human hosts Necator americanus is the predominant infecting species.

How to treat severe hookworms in humans