Importance of Nonenteric Protozoan Infections in Immunocompromised People

Abstract

SUMMARY There are many neglected nonenteric protozoa able to cause serious morbidity and mortality in humans, particularly in the developing world. Diseases caused by certain protozoa are often more severe in the presence of HIV. While information regarding neglected tropical diseases caused by trypanosomatids and Plasmodium is abundant, these protozoa are often not a first consideration in Western countries where they are not endemic. As such, diagnostics may not be available in these regions. Due to global travel and immigration, this has become an increasing problem. Inversely, in certain parts of the world (particularly sub-Saharan Africa), the HIV problem is so severe that diseases like microsporidiosis and toxoplasmosis are common. In Western countries, due to the availability of highly active antiretroviral therapy (HAART), these diseases are infrequently encountered. While free-living amoebae are rarely encountered in a clinical setting, when infections do occur, they are often fatal. Rapid diagnosis and treatment are essential to the survival of patients infected with these organisms. This paper reviews information on the diagnosis and treatment of nonenteric protozoal diseases in immunocompromised people, with a focus on patients infected with HIV. The nonenteric microsporidia, some trypanosomatids, Toxoplasma spp., Neospora spp., some free-living amoebae, Plasmodium spp., and Babesia spp. are discussed.

The adaptive potential of a survival artist: characterization of thein vitrointeractions ofToxoplasma gondiitachyzoites with di-cationic compounds in human fibroblast cell cultures

“…First, in individuals with an immature immune system or in immune-compromised patients infection can lead to toxoplasmic encephalitis (TE) or even death. TE occurs as a result of the reactivation of brain cysts that encapsulate slowly proliferating bradyzoites, which then undergo bradyzoite-to-tachyzoite stage conversion, and is common in chronically infected patients, which receive immunosuppressive therapy or suffer from human immunodeficiency virus (HIV) infection (Tenter et al 2000;Barratt et al 2010;Henriquez et al 2010). Secondly, congenital toxoplasmosis poses a major health risk upon primary maternal infection during pregnancy, leading to placental or fetal infection (or both), which often results in abortion or damage of the fetal tissues (Feldman et al 2010).…”

Inhibitory effects of 19 antiprotozoal drugs and antibiotics on Babesia microti infection in BALB/c mice

“…Older, immunocompromised, and asplenic patients experience similar symptoms but with increased severity. Even in immunocompetent patients, babesiosis can persist for many months [3][4][5][6][7][8]. It can quickly become life threatening and cause death if proper clinical treatment is not administered on time.…”

Investigation and management of Toxoplasma gondii infection in pregnancy and infancy: a prospective study

“…The apicomplexan parasites Cryptosporidium spp and Neospora spp are epidemiologically relevant for humans; in particular, it is well-known that C parvum is responsible for clinical manifestations in immunodeficient patients. N caninum does not infect humans, although there is some evidence that it might occur as antibodies to N caninum have also been detected in human samples [32,33] . Because there are some similarities in molecular composition between both of these parasites and Toxoplasma gondii, the use of whole tachyzoites or tachyzoite-derived antigens in standard serological investigations may result in false positives due to a cross-reaction [34] .…”