Strongyloides stercoralis hyper-infection syndrome in HIV⁺/AIDS patients in Iran

Abstract

Strongyloides stercoralis is an intestinal nematode in humans, distributed through tropical and subtropical regions of the world. In most individuals, the infection has a chronic nature due to auto-infection at the low level. Accelerated auto-infection, mainly after an alteration in immune status, can cause a syndrome of severe hyper-infection or potentially fatal disseminated strongyloidiasis. Due to the increasing numbers of immunocompromised patients in Iran, strongyloidiasis is an emerging public health concern in the country. In the current study, which was carried out between 2003 and 2005, for the investigation on strongyloidiasis in HIV⁺/AIDS patients, a total of 781 patients were examined by agar plate culture, formalin ether concentration, and direct smear preparation of stool samples. According to the results, 2 out of 781 HIV⁺/AIDS patients were found infected with S. stercoralis, but both patients were at the progressive stage of AIDS and showing severe hyper-infection syndrome. In both cases, numerous rhabditiform and filariform larvae were found in fresh stool direct smears, and rapid and intensive development of parasite in agar plate cultures. In conclusion, in the progressive stages of AIDS, as a result of immunosuppression conditions or in the context of chemotherapy, S. stercoralis is capable of inducing overwhelming infection.