About Medical Parasitology

During the past few years, the field of diagnostic medical parasitology has seen numerous changes including newly recognized parasites, alternative diagnostic techniques required by regulatory requirements, implementation of new immunoassay techniques, the development of parasitology molecular identification panels, the use of new single vial collection fixatives that allow the Ova and Parasite examination, fecal immunoassays, special stains, and molecular testing, and an overall increase in awareness of parasitic infections. Pathogens such as the microsporidia and Cyclospora cayetanensis have moved from the category of "unusual organisms" to becoming more widely recognized as causing important human infections, particularly in the compromised patient.

Newer diagnostic methods continue to be developed, with an emphasis on procedures that are not based on microscopic recognition of subtle organism morphologic details. As laboratories reduce the number of personnel and cross-training and cross-coverage become much more common, the number of laboratorians trained to perform and interpret diagnostic parasitology procedures is diminishing. As fewer trained individuals enter the field of diagnostic microbiology, education and consultation for the laboratorian will continue to grow in importance. It will continue to be difficult to maintain well-trained staff in some specialty areas of the laboratory. It becomes even more important to provide well-written laboratory protocols and to standardize laboratory protocols for consistency.

The basic approach to diagnostic parasitology should be no different from that used in other areas of microbiology. There are publications containing guidelines and recommended procedures for this field. If these recommendations and general guidelines are not followed, then there may be questions concerning the qualifications of the laboratory performing the diagnostic work. Not every laboratory will provide the exact same testing in diagnostic parasitology; however. there are a few guidelines that should be common practice. At the very least, the clinician should always be informed as to the limitations of those procedures that are being used. Because it is difficult for the medical staff to maintain expertise in every available diagnostic procedure within microbiology, it is important to establish close communication between the laboratory and clinicians. Complete and frequent communication is important, particularly when related to the clinical relevance of any diagnostic procedure within the context of quality patient care. Therapeutic intervention often depends on the results obtained from these procedures, so the clinician must be aware of the limitations of each test method and the results obtained.

The field of medical parasitology has taken on additional relevance and importance for several reasons. Improved means of travel has made the world a smaller place, with any number of "exotic" pathogens just a plane ride away! An individual's chances of exposure to parasites not endemic to his or her homeland and the possibility of acquiring or transmitting certain infections have been increasing. This situation emphasizes the need for obtaining a correct and complete history from the patient. It is also important to recognize the parasites commonly found within certain areas of the world and the makeup of the patient population being seen in any particular health facility.

We know that patients with immune defects are particularly at risk for a number of parasitic infections, some of which may cause unusual symptoms in this patient population. It is important for the laboratorian and physician to understand these infections and to recognize the most appropriate diagnostic methods.

In other areas of microbiology, therapy is often begun based on patient history and symptoms. This approach is generally not used in cases of parasitic infection. Thus, understanding the geographic range, life cycle, clinical disease, diagnostic methods, therapy, epidemiology and control become very important. Even more important are the use of appropriate diagnostic procedures, accompanied by a complete understanding of the limitations of each. If certain incomplete procedures are used, incomplete information may be provided to the physician, leading to incomplete or inappropriate patient care.

Information that will be presented throughout this web site will address diagnostic methods, newly recognized emerging parasitic infections, and commonly asked questions in diagnostic medical parasitology. We will also discuss some of the organisms, including diagnostic methods, organism morphology and clinical relevance.

We encourage your comments and suggestions and thank you for your interest.

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