Strongyloides stercoralis infection and antenatal care

To the Editor: Strongyloides stercoralis is a soil-transmitted helminth infection that affects more than 100 million people worldwide. It is known to be common in the Indigenous communities of northern Australia, with recorded prevalence often in the region of 30%–40%.1

Reliable enzyme-linked immunosorbent assay (ELISA) testing for the worm means that a sensitive and specific test is now available.2 However, ELISA testing is currently only performed in central laboratories, resulting in inevitable delays in diagnosis.

Strongyloides infection in pregnancy presents at least a theoretical threat to the mother's health. While chronic Strongyloides infection can be relatively symptom-free, hyperinfection syndrome can ensue in immunocompromised patients, resulting in proliferation of infection, subsequent septicaemia, and a high mortality rate even in the best of circumstances. The administration of systemic steroids is known to be a common iatrogenic cause of the condition.3 In theory, should a woman require treatment with a steroid in the course of her pregnancy (for example, in the treatment of premature labour), then administering the drug in the presence of Strongyloides infection represents a considerable risk.

A recent report from the United States outlines such a case.4 A Haitian patient, 25 weeks pregnant and not known to be carrying a worm infection, presented to a New York hospital in premature labour, was administered steroids for the benefit of the fetus, and subsequently developed Strongyloides hyperinfection. The fetus was delivered stillborn, and the mother died of overwhelming sepsis.

S. stercoralis screening is already included in the routine health assessment of some refugee and migrant populations entering Australia, and is employed in well adult checks in some Aboriginal communities. Many unanswered questions remain over the prevalence of the infection in women of childbearing age, the possible effects of infection on the course of a normal pregnancy, and the safety of the principal treatment, ivermectin, during pregnancy.5 However, given the evidence currently available, we believe that all relevant authorities involved in the antenatal care of women resident in the communities of northern Australia should consider adding S. stercoralis ELISA testing to their routine antenatal and preconception screening.