control de calidad en el diagnÓstico coproparasitolÓgico en laboratorios clÍnicos pÚblicos de ciudad bolÍvar, venezuela i quality control in coproparasitologic diagnosis in public clinic laboratories of ciudad bolÍvar, venezuela

The quality control during coproparasitologic diagnosis was evaluated in seven public laboratories located in Ciudad Bolivar, Bolivar State. Each clinical laboratory selected was informed of the study and was given 22 fecal samples (20 fresh and 2 preserved). The parasites in these samples were only known to the authors. These samples were analyzed and each laboratory was given a survey based on the items to meet during the three stages of coproparasitologic analysis, according to the norm COVENIN ISO 15189:2004. A total of 154 samples of fresh and preserved feces were analyzed by participating laboratories. The parasites that were most difficult to be identified were Entamoeba histolytica / E. dispar (85.7%), Chilomastix mesnilii (85.7%) and Blastocystis spp. (82.1%), among the protozoa, and Trichuris trichiura (100%) and Ta e nia spp. (78.5%) among the helminths. The main misdiagnoses in fresh feces samples were incomplete diagnosis (58.7%) and changes in diagnosis (40%). Applying a qualifying scale only one laboratory performed a Good diagnosis (13.2%), two Regular (28.5%) and four performed Poor diagnosis (57.1%). In conclusion, the laboratories evaluated do not meet all the procedures in the preanalytical, analytical and postanalytical phases of coproparasitologic diagnosis established in the Venezuelan regulation