Detection of acquired parasites in laboratory personnel at risk in Theodor Bilharz Research Institute

ABSTRACT

To evaluate the prevalence of intestinal parasitic infections and to investigate the possible associations of clinical status and laboratory findings with the different parasites found in stool samples in personnel at risk in TBRI. Microscopic examination of stool specimens is the cornerstone of detection of intestinal parasites in parasitology laboratories. Fresh, nonpreserved stool specimens are generally used for examination. Because intestinal parasites are shed intermittently, patients are asked to deliver multiple stool samples for examination. Three stool samples were collected in three consecutive days and three alternative days and were examined by direct smear, Merthiolate iodine formaldehyde concentration method [MIFC] and staining with Gimesa and Ziehl-Neelsen. The stool culture for bacteria was identified following standard procedures. Three sequential stool specimens are necessary for reliable detection of intestinal parasites in routine laboratory examinations. In a total of 208 cases [medical personnel, kitchen workers, animal house, Schistosome Biological Supply Centre and different laboratories] were examined, 47% were found infected with at least one parasite. The rates were as follows Giardia lamblia 24%, E. histolytica 22.0%, E. coli 12%, E. vermicularis 10%, H.nana 7%, Dientamaeba fragils 7.0%, S.mansoni [6%], Fasciola spp [3%], and Ancylostoma duodenale [2%]. Of 5 patients who complained of diarrhoea, no intestinal parasites were detected from the samples of stool culture. Stool cultures revealed the isolation of Shigella species from one person. No other enteropathogenic bacteria were isolated from the stools. The data supports the value of standard fecal examinations. Periodic screening of medical personnel is recommended. Protection from passing intestinal parasites between workers and patients is necessary and the hand washing remains the most important contributes factor related to reduction of the frequency of acquired parasites in the lab