Fulminant toxoplasmosis causing fatal pneumonitis and myocarditis

Abstract

The obligate intracellular protozoa Toxoplasma gondii is a serious cause of morbidity and mortality in patients with AIDS. Toxoplasmosis most frequently manifests as life-threatening encephalitis, although extracerebral sites may be involved with or without toxoplasmic encephalitis. Consequently, toxoplasmosis can present in an unusual manner, and may not be included in the differential diagnosis in the absence of encephalitic symptoms. There are few reports of fulminant toxoplasmic myocarditis resulting in death. Toxoplasmic pneumonitis is responsible for less than 1% of HIV-related pulmonary complications, and can occasionally cause fatal septic shock. Two such clinicopathological presentations of toxoplasmosis are reported here. One patient presented with cardiorespiratory signs and symptoms, whilst the second patient presented with pneumonitis and renal failure. Neither patient was initially known to be HIV-infected, nor did they have clinical symptoms indicating toxoplasmic encephalitis. Toxoplasmosis was only diagnosed on autopsy and had resulted in death by causing a fulminant myocarditis and a pneumonitis. As overwhelming toxoplasmosis infection may prove rapidly fatal, these two case reports serve as a clinical reminder to consider toxoplasmosis in the differential diagnosis of HIV-infected patients who present with severe cardiorespiratory signs and symptoms. Furthermore, the cases emphasize the potential importance of early tissue biopsy in patients presenting with immunosuppression-associated organ failure, and show the importance of requesting a postmortem examination if the cause of death cannot be ascertained in vivo.