الفهرس 
Diarrhea and Parasitic InfectionsOnly 14 pages are availabe for public view
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Abstract
Diarrhea is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. One of the most important cause of diarrhea that are mainly seen in children & immunocompromized individuals are the intestinal spore forming parasites.
The intestinal spore-forming parasites (intestinal coccidians & Microsporidia) have important similarities in epidemiology, disease pathogenesis, clinical manifestations, diagnosis, and treatment, yet, Microsporidia is now placed among fungi.
Specific diagnosis depends on the stool examination and the use of appropriate staining techniques.
Several studies have implicated intestinal protozoa in the differential diagnosis of Irritable bowel Syndrome (IBS) & also as a cause of chronic urticaria of unknown origin, examples of these protozoa : Blastocystis hominis & Giardia lamblia .
The present work was planned to identify and estimate the prevalence of human intestinal parasites in patients being evaluated for diarrhea with special emphasis on intestinal spore forming parasites. The relationship between intestinal parasites and chronic urticaria of unknown etiology as well as irritable bowel syndrome (IBS) was also investigated. The effectiveness of 3 different staining techniques for intestinal spore forming parasites detection was evaluated, as well as some risk factors of parasitic infection in the community.
The study included 250 patients presented with diarrhea (acute, chronic or recurrent) with or without other gastrointestinal manifestations including cases diagnosed as irritable bowel syndrome and chronic urticaria of unknown etiology with history of recurrent diarrhea. In addition 140 individuals were chosen as controls.
Each stool specimen collected from cases was examined in parallel by the following techniques:
1-Direct and concentrated wet mounts in saline and in lugol’s iodine .
2-Permenant staining with: Trichrome stain, modified Ziehl-
Neelsen stain, modified safranin stain and modified acid fast trichrome stain .
The study revealed that the overall prevalence of intestinal parasites in 390 examined individuals (cases and controls) was (24.3%). Cases with diarrhea showed higher percentage of infection than in asymptomatic controls (32% vs. 10.7%) (P< 0.001).
Blastocystis hominis was detected in both cases with diarrhea (12.8%) & controls (6.4%) (P<0.05) and it was found as the most frequent parasite. Spore forming parasites were detected in both cases with diarrhea (8.4%) & controls (2.1%) (P<0.05) &Giardia lamblia was detected in both cases with diarrhea (7.6%) & controls (1.4%) (P<0.05)
Entamoeba coli & Entamoeba histolytica/E.dispar were found only in cases with diarrhea with percentage 1.2% & 0.8% respectively, while H.nana was 1.2% among cases & 0.7% among controls.
The frequency of parasitic infection was higher in immunocompromized individuals (30.8%) in comparison to immunocompetent ones(20.3%) (P<0.05) & in children (28.97%) more than in adults (16.55%) (p<0.01).
The frequency of parasitic infections was higher in patients coming from rural areas (38.8%) than in patients coming from urban areas(20% ) (p<0.001), in patients with history of contact with domestic and farm animals (38.38% vs. 19.58%) ( p<0.001), in patients drinking water without using filters ( 28.1% vs. 7.14%) (p<0.001) and in patients with bad hand hygiene (35.5% vs. 27%) with average hand hygiene and (14.18%) with good hand hygiene (p<0.001)
The study revealed that the overall prevalence of intestinal spore forming parasites in total 390 examined individuals, was (6.15%),Cryptosporidium spp. was leading the list (3.58%), followed by Microsporidia (2.1%), then Cyclospora(0.5%). SFP prevalence was higher among cases (8.4%) than controls (2.14%)(P< 0.05)
Cryptosporidium frequency was (4.8%) among cases & (1.4%) among controls , while Microsporidia was (2.8%) among cases & (0.7%)among controls and Cyclospora was (0.8%) among cases and was not found among controls. In this study Isospora belli and Sarcocystis were not detected.
Immunocompromized individuals showed higher frequency of SFP than immunocompetent individuals (10% &3.73% respectively) (P‹0.05).Also children showed higher percentage of SFP infection than adults (8.97% vs. 1.37%) (p<0.01). The use of unfiltered water was found to be a risk factor of SFP infection.
Recurrent attacks of diarrhea were the most common presentation of diarrhea. Diarrhea associated with abdominal cramps was found in (58.3%) of patients.
Blastocystis hominis was the only parasite detected in 4 patients out of 20 (20%) IBS patients and presented with recurrent diarrhea. The parasite was detected also in one /7 patients (14%) with chronic urticaria of unknown origin and suffering from diarrhea.
Using the different permanent staining techniques, 14 cases of Cryptosporidium were diagnosed, 2 cases of Cyclospora & 8 cases of Microsporidia.
Both modified safranin stain & AFT stain detected the same percentage of Cryptosporidium (92.85%) & Cyclospora (100%), while MZN stain detected (78.57%) of cases of Cryptosporidium & only one case of Cyclospora (50%). MZN stain detected (100%) of cases of Microsporidia, while modified Safranin& AFT detected only (50%) of cases.
Modified safranin stain was found to be a highly sensitive and specific test for detection of Cryptosporidium. MZN stain showed higher specificity (97.3%) but was less sensitive. AFT nearly have close results to SAF with lesser specificity.
Modified safranin stain showed better results for detection of Cyclospora (2/2) than MZN stain (1/2) in detecting the parasite. The stain also demonstrated superior results when coefficients of variation (CVs) were compared (80% vs. 65% respectively) (P< 0.05). AFT was comparable to safranin stain in diagnostic yield (2/2) with insignificant lower CVs (75%).
Kappa test (test of agreement) results showed that MZN /SAF, MZN /AFT and SAF/ AFT combinations increased the Cryptosporidium diagnostic yield more than that by each stain alone with the superiority of MZN /SAF due to the easy recognition and identification of oocysts by the 2 stains. No combination increased the Cyclospora & Microsporidia diagnostic yields.