coproscopy

Coproscopy, also known as coprology, is the microscopic examination of feces to identify intestinal parasites and related conditions. Its primary purpose is to detect parasitic life stages such as helminth eggs, protozoan cysts and trophozoites, and occasionally larvae. Coproscopy may also document fecal blood, fat, mucus, or inflammatory cells that help characterize gastrointestinal disease.

Specimen collection and processing are key to reliable results. Fresh stool is preferred, ideally collected on multiple days to account for intermittent shedding. Preservatives or transport media (such as formalin or polyvinyl alcohol) may be used for storage. Laboratory workflow typically combines macroscopic inspection with several microscopic techniques, including direct wet mounts and concentration methods to enhance parasite recovery.

Microscopic techniques commonly employed include flotation methods (using solutions like zinc sulfate or sodium nitrate) to recover eggs and cysts, and sedimentation methods (such as formalin-ethyl acetate) for heavier material. Stains such as trichrome or iodine aid in identifying protozoa, while modified acid-fast staining helps detect certain coccidia. Immunological assays and molecular methods, including antigen tests and PCR, are increasingly used to improve sensitivity and specificity for parasites such as Giardia and Cryptosporidium.

Targets frequently identified in human and veterinary samples include Giardia lamblia, Entamoeba species, Cryptosporidium, Cyclospora, Isospora, and helminth eggs from Ascaris, Trichuris, and hookworms. Limitations include intermittent parasite shedding, low parasite burden, and reliance on specialized skills; thus, multiple samples and, when needed, adjunct tests are recommended for accurate diagnosis.