Chapter 54 : Immunological and Molecular Approaches for the Diagnosis of Parasitic Infections

Abstract:

Definitive diagnosis of parasitic infections is made by identification of parasites in properly collected specimens or in affected tissues. Microscopy for observation and identification of parasites is the laboratory method of choice for the diagnosis of some important parasitic infections, namely, malaria, babesiosis, and enteric parasitic infections. There are, however, important parasitic diseases that cannot be diagnosed by microscopic examination of clinical specimens. In infections such as angiostrongyliasis, schistosomiasis, paragonimiasis, and strongyloidiasis, parasites may be detected in stool or other specimens, but due to the limitations of intermittent shedding or sampling, direct observation of parasites is not sensitive or reliable. So, for these infections and others caused by parasites that are localized and sequestered in tissues, such as baylisascariasis, cysticercosis, echinococcosis, toxocariasis, toxoplasmosis, or trichinellosis, detection of specific antibodies is almost always required to confirm clinical suspicion.