Recurrent Strongyloides stercoralis infection in an HIV+ patient.

Although infection with Strongyloides stercoralis is often subclinical, some infections persist for decades due to the parasite's autoinfective lifecycle. Hyperinfection syndrome, however, characterized by a massive increase in parasite burden as a result of host immunosuppression causes a myriad of clinical symptoms and is associated with high mortality. Use of corticosteroids and infection with HTLV-1 virus are the biggest traditional risk factors for hyperinfection syndrome, though its development can occur with virtually any degree of immunosuppression. Recurrent hyperinfection syndrome, though rare, has also been demonstrated in persons with ongoing immunosuppression, prompting many experts to recommend continued prophylactic treatment in at risk populations. We present the case of a recurrent S. stercoralis hyperinfection occurring four years after previous treatment with anti-helminthic therapy in a patient with AIDS with intermittent adherence to antiretroviral therapy (ART), highlighting diagnostic and treatment issues in the management of recurrent S. stercoralis infection.

Recombinase Polymerase Amplification Compared to Real-Time Polymerase Chain Reaction Test for the Detection of Fasciola hepatica in Human Stool.

Fasciola hepatica is the most widely distributed trematode infection in the world. Control efforts may be hindered by the lack of diagnostic capacity especially in remote endemic areas. Polymerase chain reaction (PCR)-based methods offer high sensitivity and specificity but require expensive technology. However, the recombinase polymerase amplification (RPA) is an efficient isothermal method that eliminates the need for a thermal cycler and has a high deployment potential to resource-limited settings. We report on the characterization of RPA and PCR tests to detect Fasciola infection in clinical stool samples with low egg burdens. The sensitivity of the RPA and PCR were 87% and 66%, respectively. Both tests were 100% specific showing no cross-reactivity with trematode, cestode, or nematode parasites. In addition, RPA and PCR were able to detect 47% and 26% of infections not detected by microscopy, respectively. The RPA adapted to a lateral flow platform was more sensitive than gel-based detection of the reaction products. In conclusion, the Fasciola RPA is a highly sensitive and specific test to diagnose chronic infection using stool samples. The Fasciola RPA lateral flow has the potential for deployment to endemic areas after further characterization.