Exposure to the parasitic roundworm Ascaris lumbricoides among young men can cause a striking reduction in lung function and nearly five times higher odds of having asthma compared to the non-exposed, study shows. A recent study by a team of scientists in collaboration with University of Bergen, Tartu University Hospital Lung Clinic, the University of Birmingham and the University of Cape Town, found that younger men exposed to Ascaris had a striking reduction in lung function and nearly five times higher odds of having asthma compared to the non-exposed. These effects were independent of smoking and other exposures such as house dust mites.

Curiously, the research that was published in the Journal of Allergy and Clinical Immunology pointed out that among women, lung function was not significantly lower in the Ascaris seropositive. In fact, the seropositive appeared to have even less asthma than the rest. This is the first research of its kind to show substantial gender differences in terms of helminth (parasitic worms) exposures and subsequent outcomes in humans. The researchers also found that Ascaris infection in Europe might be an overlooked risk factor for asthma and respiratory health.