Strongyloidiasis in the Northern Territory. Under-recognised and under-treated?

OBJECTIVE

To describe the clinical and laboratory features and management of Strongyloides stercoralis infection in the Top End of the Northern Territory.

DESIGN

A 12-month retrospective review of clinical records of patients confirmed on stool microscopy to be infected with S. stercoralis.

SETTING

The Royal Darwin Hospital (RDH), a 300-bed referral hospital servicing the tropical areas of the Northern Territory, which have a population of 120,000, 21% of which is Aboriginal.

RESULTS

Potentially pathogenic gastrointestinal parasites were identified in 205 patients over the 12 months. Of these, 68 patients had strongyloidiasis--64 were Aboriginal, three were Caucasian and one was of New Guinean origin. Thirty-seven (54%) were under five years of age. Patients came from all regions served by RDH, including urban Darwin. Seventy-five per cent of adults had chronic underlying disease and 80% of children under five years old were below 80% of standard weight for age. Gastrointestinal symptoms were absent in 28%; occasionally, severe disease occurred. Eosinophilia with greater than 0.7 x 10(9) cells/L was present in 57% of patients. Only 57% of cases were treated with thiabendazole.

CONCLUSION

In the Top End of the Northern Territory, Strongyloides infection is endemic in Aboriginal communities, but also occasionally occurs in non-Aboriginal people. It is likely that the infection is frequently not recognised. Current community-based anthelmintic regimens have succeeded in reducing the prevalence of hookworm infection, but strongyloidiasis still appears to be a prevalent condition. The possibility of hyperinfection or disseminated strongyloidiasis in immunocompromised patients such as renal transplant recipients and people infected with the human immunodeficiency virus needs consideration in this endemic area. The interaction in northern Australia of S. stercoralis with human T-lymphotropic virus type I and with undernutrition warrants further study.