Prevalence and Risk Factors for Intestinal Protozoan Infections with Cryptosporidium, Giardia, Blastocystis and Dientamoeba among Schoolchildren in Tripoli, Lebanon

Abstract

BackgroundIntestinal protozoan infections are confirmed as major causes of diarrhea, particularly in children, and represent a significant, but often neglected, threat to public health. No recent data were available in Lebanon concerning the molecular epidemiology of protozoan infections in children, a vulnerable population at high risk of infection.Methodology and Principal FindingsIn order to improve our understanding of the epidemiology of intestinal pathogenic protozoa, a cross-sectional study was conducted in a general pediatric population including both symptomatic and asymptomatic subjects. After obtaining informed consent from the parents or legal guardians, stool samples were collected in January 2013 from 249 children in 2 schools in Tripoli, Lebanon. Information obtained from a standard questionnaire included demographic characteristics, current symptoms, socioeconomic status, source of drinking water, and personal hygiene habits. After fecal examination by both microscopy and molecular tools, the overall prevalence of parasitic infections was recorded as 85%. Blastocystis spp. presented the highest infection rate (63%), followed by Dientamoeba fragilis (60.6%), Giardia duodenalis (28.5%) and Cryptosporidium spp. (10.4%). PCR was also performed to identify species and genotypes of Cryptosporidium, subtypes of Blastocystis, and assemblages of Giardia. Statistical analysis using a logistic regression model showed that contact with family members presenting gastrointestinal disorders was the primary risk factor for transmission of these protozoa.ConclusionsThis is the first study performed in Lebanon reporting the prevalence and the clinical and molecular epidemiological data associated with intestinal protozoan infections among schoolchildren in Tripoli. A high prevalence of protozoan parasites was found, with Blastocystis spp. being the most predominant protozoans. Although only 50% of children reported digestive symptoms, asymptomatic infection was observed, and these children may act as unidentified carriers. This survey provides necessary information for designing prevention and control strategies to reduce the burden of these protozoan infections, especially in children.

Epidemiology and Prevalence of Blastocystis spp. in North Cyprus

“…22,40,41 However, Abdulsalam and others and Osman and others detected no significant difference in the rates of blastocystosis between drinking treated and untreated water, and suggested that the level of contamination of groundwater by Blastocystis was likely to be low. 2,15 In the present study, majority of the participants used bottled water (80.4%), and the remaining consumed tap water (19.6%), but no statistical difference was found in the infection rates between the two groups.…”

“…Our finding was inconsistent with those of previous studies in which significant relation was detected between blastocystosis and gastrointestinal symptoms in symptomatic individuals. 1,2,15,37 In the present study, the most common Blastocystis STs were ST3, ST2, ST1, and ST4. Among these, only four STs (ST1, ST2, ST3, and ST4) are common throughout the world and their distribution also depends on geographic regions.…”

“…positivity were detected in Senegal (100%), 16 Qatar (71.1%), 19 and Lebanon (63%). 2 In our study, the prevalence of Blastocystis spp. infection was noted to be 24 (10.5%), 24 (10.5%), and 64 (27.8%), by direct microscopy, trichrome method, and PCR, respectively.…”

“…is the most widespread protists in the gastrointestinal tract of humans and in a variety of animal species. [1][2][3][4] The routes of transmission of Blastocystis spp. are similar to those of other enteric parasites: the organisms can be acquired via fecal-oral pathway through contaminated food and water or by exposure to animals.…”

“…varies between 0.5% and 23.1% in developed countries and 22.1% and 100.0% in developing countries. 1,2,[15][16][17][18][19][20] Generally, the high prevalence of infection is associated with demographic, socioeconomic, and epidemiological factors. 1,15,21,22 Although a large number of studies on Blastocystis spp.…”