Hookworm trials

25 August 2005

A new clinical trial is exploring how deliberate infection with hookworms may help to reduce the symptoms of asthma and allergic disease.

In previous studies in Ethiopia, the research team, led by John Britton at the University of Nottingham, found that hookworm infection may be protecting against allergic diseases such as asthma. They also identified the dosages of hookworm needed for this protection.

The parasite infections are thought to turn down the host's immune response. As well as aiding parasite survival, this also makes the immune system less likely to respond to the environmental triggers of asthma or allergic responses. Indeed, at least part of the reason for the rise of asthma in developed countries may be the drop in parasite infections resulting from improved living conditions.

The new funding will allow the team to conduct clinical trials of parasite infections in individuals with asthma, to test the effectiveness of hookworm infection in reducing allergic symptoms. During the trials, taking place back in Nottingham, people with asthma will be infected with measured doses of the hookworm larvae, which cause relatively mild symptoms. The study will also provide valuable insights into how the parasites modulate immune responses.

The research will also have implications for hookworm eradication programmes, which could affect the prevalence of asthma and allergic disease in developing countries.