Exposure to worm infections in the womb may protect a newborn infant from developing eczema, a study funded by the Wellcome Trust suggests. A large trial in Uganda showed that treating a pregnant woman for worm infections increased her child's chances of developing the allergic skin disease.
Published this week in the journal Pediatric Allergy and Immunology, the research supports the so-called 'hygiene hypothesis', which proposes that exposure to infections in early childhood can modify the immune system and protect the child from allergies later in life.
The World Health Organisation estimates that one in five of the world's population suffers from allergic diseases such as asthma and eczema, but this epidemic is no longer restricted to developed countries: more than four out of five deaths due to asthma occur in low and lower-middle income countries. The declining incidence and prevalence of infectious diseases including chronic infection by worms known as helminths is widely considered to be an important contributor contributing to this increase.
Helminth infection can cause symptoms ranging from mild anaemia through to stomach pain and vomiting, depending on how intense the infection is, but very often people have no symptoms at all. The parasitic worms tend to enter the body through contaminated food or water, mosquito bites or through walking in bare feet on contaminated soil.
A preliminary study carried out at the MRC/UVRI Uganda Research Unit on AIDS in Entebbe, Uganda in 2005 showed a reduced risk of eczema among infants whose mothers had worms and suggested an increased incidence among infants of mothers who received albendazole a commonly used drug to treat worm infection during pregnancy compared to infants whose mothers received a placebo.
In a follow-up study, researchers carried out a randomised, double-blind trial on 2,507 pregnant women in Uganda, comparing those treated with either a
|Contact: Craig Brierley|