Strongyloides stercoralis infections are routinely diagnosed by the microscopic observation of larvae in wet mounts of stool samples. This method has low sensitivity, leading to underestimation of the prevalence of this parasite. Other, most effective diagnostic methods, such as the Baermann technique or the agar culture plate method are not routinely used, at least in our laboratories. lnfections caused by S. stercoralis can become chronic, with decades of evolution. Hyperinfections in immunocompromised patients, such as those suffering AIDS, cancer, diabetes, or alcoholism, lead to bacterial infections secondary to ulceration or parasitic perforation which are often fatal. Such an outcome are frequently associated with corticosteroid treatment. It has recently been established that steroids mimic a parasite hormone causing ecdysis, thus leading to development of infective larvae in the intestine of the host. It is then critical to rule out S. stercoralis infections in patients at risk by means of serial consecutive Baermann tests before the establishment of steroid treatment protocols.

hyperinfections; corticosteroids; Baermann method