ABSTRACT

The most important parasitic infections in cancer patients are Toxoplasma gondii and Strongyloides stercoralis.  Both can cause life-threatening disease in immunocompromised patients, where T. gondii can present as encephalitis, pneumonia, fever of unknown origin, myocarditis, hepatitis, and chorioretinitis, and S. stercoralis as the disseminated hyperinfection syndrome.  Effective therapies are available for both, but high case-fatality rates result if these syndromes are not recognized and treated promptly.  Excellent preventative measures are available for both parasites, including prophylactic anti-Toxoplasma therapy or ivermectin treatment for strongyloidiasis in properly selected patients.  Identifying cancer patients at risk for these syndromes is therefore critical, so that these measures can be instituted before life-threatening disease develops.