Investigation of parasitic agents in diarrheic patients in a rural population

ABSTRACT

Infectious intestinal diseases are highly prevalent and diarrhea is among the commonest complaints. A cross sectional study was carried out on 56 diarrhea1 cases of El Shobak El Sharki villagers [Guiza Governorate]. The study aims at investigating the parasitic causative agents of diarrhea and comparing four different techniques for diagnosis. These were Merthiolate-Iodine-Formaldehyde [MIF] concentration technique, Modified Ziehl Neelsen [ZN] staining technique, Enzyme Imrnunoassay [EIA] and Merifluor Cryptosporidium /Giardia lmmunofluorescence Assay [IFA]. Depending on the diagnosis by the four methods together, Giardia lamblia was found in 46.4%, Cryptosporidium parvum in 37.5%, and Entamoeba histolytica in 7.1% of diarrheic cases. Comparison of the different techniques showed that IFA was superior in diagnosing C. parvum [90.5% sensitivity], while ZN stain had a sensitivity of 85.7%. The technique of EIA was not so efficient in diagnosing C. parvum [28.6% sensitivity]. As regards the diagnosis of G. lamblia, sensitivity of IFA was 84.6%, while EIA showed 65.4% sensitivity. Giardia lamblia could be diagnosed by MIF technique which showed u sensitivity of 30.8%. The four techniques showed 100% specificity with all studied protozoa. Many factors were correlated to the positive findings. Cryptosporidium parvum was found more in adult age groups than younger ones the reverse is true as regards infection with G. lamblia. Drinking water and swimming in water canals were potential sources of transmission, also finding the same parasite in members of the same family is discussed. In conclusion C. parvum represented more than one third the number of causative agents of diarrhea in rural population having diarrhea. So, health care professionals must be aware of the different diagnostic procedures plus its specific treatment. Routine stool analysis depending on MIF and modified ZN staining techniques is a cost-effective tool for screening of diarrhea. If the results are negative and parasitic agents for diarrhea could not be excluded clinically, referral should be made to reference laboratory to do Cryptosporidium/Giardia Merifluor IFA technique. If negative results are still obtained, repetition of IFA technique for successive days is recommended