Diagnostic Medical Parasitology 5th Edition PDF

During the past few years, the field of diagnostic medical parasitology has seen dramatic changes, including newly recognized parasites, emerging pathogens in new geographic areas, bioterrorism considerations and requirements, alternative techniques required by new regulatory requirements, reevaluation of diagnostic test options and ordering algorithms, continuing changes in the laboratory test menus, implementation of testing based on molecular techniques, reporting formats, coding and billing requirements, managed care relevancy, increased need for consultation and educational initiatives for clients, and an overall increased awareness of parasitic infections from a worldwide perspective. We have seen organisms like the microsporidia change from the status of “unusual parasitic infection” to being widely recognized as causing some of the most important infections in both immunocompetent and compromised patients. More sensitive diagnostic methods for organism detection in stool specimens are now commercially available for Entamoeba histolytica, Entamoeba histolytica/ E. dispar, Giardia lamblia, Cryptosporidium parvum, and Trichomonas vaginalis.

Reagents are actively being developed for other organisms such as Dientamoeba fragilis and the microsporidia. We have seen Cyclospora cayetanensis coccidia become well recognized as the cause of diarrhea in immunocompetent and immunocompromised humans. We continue to see new disease presentations in compromised patients; a good example is granulomatous amebic encephalitis caused by Acanthamoeba spp., Sappinia diploidea, and Balamuthia mandrillaris. With the expansion of transplantation options, many parasites are potential threats to patients who are undergoing immunosuppression, and they must be considered within the context of this patient group. Transfusion-associated transmission of potential parasitic pathogens continues to be problematic. Transfusion in general is becoming more widely recognized as a source of infection, and donors are also more likely to come from many areas of the world where parasitic infections are endemic. With expanding regulatory requirements related to the disposal of chemicals, laboratories are continuing to review the use of mercury compounds as specimen fixatives and learning to become familiar with organism morphology when using substitute compounds. Permanent staining of fecal smears confirms that none of the substitute fixatives provide results of the same quality found with the use of mercuric chloride-based fixatives.