Diagnosis of gastrointestinal parasites among hospitalized patients attending Al-Nasser Paediatric Hospital, Gaza, Palestine

Aims  The aim of this study was to determine the prevalence of the diagnosed gastrointestinal parasites among hospitalized children attending the Al-Nasser Paediatric Hospital. Method  This was a cross-sectional study among hospitalized children attending the Al-Nasser Paediatric Hospital. The study included 522 children during the period May 2002 to May 2003. Data collection included two methods: medical laboratory results for the examination of stool specimens and a questionnaire. Wet mount using saline and Lugol’s iodine and formal ether sedimentation techniques were employed in the present study. Results  Evidence for infection with the gastrointestinal parasites was found in 176 (33.7%) of the children. The intestinal parasites were most prevalent in females (38.8%). The most highly prevalent parasite was found to be Entamoeba histolytica/dispar (26.4%) and the monthly high prevalence of intestinal parasites was in February (54.5%). The prevalence of intestinal parasites increased significantly with increasing age for both Giardia lamblia and E. histolytica/dispar. Conclusions  The study showed a high prevalence of E. histolytica/dispar infection among hospitalized children. Hygiene and health measures should be reviewed in the hospital where nosocomial infection cannot be excluded. The diagnostic techniques for stool specimens should be reviewed and improved. Physicians in hospitals and private clinics should be aware of intestinal parasitic diseases when requesting stool specimens and prescribing drugs.     

Intestinal amoebiasis, giardiasis and geohelminthiases: their association with other intestinal parasites and reported intestinal symptoms.

In order to determine reported signs and symptoms that may predict an intestinal parasitic infection, 241 schoolchildren in western C?te d'Ivoire were interviewed with a simple questionnaire and their stool specimens were examined over several consecutive days. Special emphasis was placed on (i) assessing infections by Entamoeba histolytica/E. dispar, Giardia duodenalis and by intestinal worms, (ii) looking for associations between these parasites, and (iii) looking for associations between these parasites and commonly perceived intestinal signs and symptoms. Complete questionnaire results, intestinal helminth infections derived from 4 Kato-Katz thick smears, and intestinal protozoa infections assessed on a single day by a formalin-ether concentration procedure were obtained from 209 children (87%). A logistic regression modelling approach showed that an infection with E. histolytica/E. dispar was significantly associated with an Entamoeba coli infection. However, for G. duodenalis, hookworm and Ascaris lumbricoides, no association was found between any of these parasites and other intestinal parasites. In a multivariate analysis reported diarrhoea was the only symptom positively associated with an E. histolytica/E. dispar infection (P = 0.028). Its diagnostic performance showed a low sensitivity (28%), a high specificity (85%) and moderate positive and negative predictive values (52% and 67%, respectively). Surprisingly, reported 'turning stomach' was less often reported by children infected with G. duodenalis (borderline significance, P = 0.057). It is concluded that reported diarrhoea could be a symptom worth exploring further for the rapid identification of schoolchildren infected with E. histolytica/E. dispar.     

Prevalence of Bacteria and Intestinal Parasites among Food-handlers in Gondar Town, Northwest Ethiopia

Food-handlers with poor personal hygiene working in food-service establishments could be potential sources of infection due to pathogenic organisms. The study was undertaken to determine the prevalence of bacteria and intestinal parasites among 127 food-handlers working in the cafeterias of the University of Gondar and the Gondar Teachers Training College, Gondar, Ethiopia. Fingernail contents of both the hands and stool specimens were collected from all the 127 food-handlers. The samples were examined for bacteria and intestinal parasites following standard procedures. Coagulase-negative staphylococci were the predominant bacteria species (41.7%) isolated from fingernail contents, followed by Staphylococcus aureus (16.5%), Klebsiella species (5.5%), Escherichia coli (3.1%), Serratia species (1.58%), Citrobacter species (0.8%), and Enterobacter species (0.8%). Shigella species were isolated from stool samples of four food-handlers (3.1%). None of the food-handlers was positive for Salmonella species and Shigella species in res-pect of their fingernail contents. No intestinal parasites were detected from fingernail contents. Intestinal parasites detected in the stools of the food-handlers included Ascaris lumbricoides (18.11%), Strongyloides stercoralis (5.5%), Entamoeba histolytica/dispar (1.6%), Trichuris trichiura (1.6%), hookworm species (0.8%), Gardia lamblia (0.8%), and Schistosoma mansoni (0.8%); 1.6% of the study subjects were positive for each of A. lumbricoides, T. trichiura, hookworm, and G. lamblia. The findings emphasize the importance of food-handlers as potential sources of infections and suggest health institutions for appropriate hygienic and sanitary control measures.Key words: Bacteria, Cross-sectional studies, Diarrhoeal diseases: Food-handlers, Hygiene, Intestinal diseases, Parasitic, Parasites, Ethiopia     

Prevalence,molecular epidemiology,and zoonotic potential of Entamoeba spp. in nonhuman primates in China

Amebiasis is a major public-health concern. It has a global distribution, and is listed as the third leading parasitic cause of human mortality. To survey the prevalence and assess the potential zoonotic transmission of Entamoeba spp. in nonhuman primates (NHPs) in China, 2688 fresh fecal specimens were collected from NHPs reared in farms or zoos/parks or free ranging in 13 districts. The overall prevalence of Entamoeba spp. infection determined with microscopy analysis was 39.4% (1059/2688). Higher infection rates were detected in the free ranging group (41.1%, 169/411) and in animals < 1 year old (58.7%, 556/947). Gene fragments were successfully amplified 463 (87.2%) out of the 531 selected specimens (approximately half of the total microscopy-positive specimens). Polymerase chain reaction (PCR) amplification identified 386 (83.4%) Entamoeba dispar and 287 (62.0%) E. coli infections, and among these, 210 (45.4%) were mixed infections. And that the E. dispar and E. coli had also been detected in humans. In phylogenetic analysis, the E. dispar and E. coli sequences clustered with reference E. dispar and E. coli, respectively. In conclusion, nonhuman primates infected with Entamoeba species, with high prevalence and zoonotic potential, should be considered when evaluating the maintenance of Entamoeba spp. and its transmission between animal reservoirs and humans.     

Effect of School Based Treatment on the Prevalence of Schistosomiasis in Endemic Area in Yemen

Background

Schistosomiasis and soil transmitted infection is a major health problem of children from rural areas of developing countries including Yemen. In an attempt to reduce this burden, the Ministry of Public Health and Population in Yemen established in 2002 a programme for Schistosomal, soil transmitted infection control that aimed to reduce morbidity and prevalence rates of Schistosomiasis, and Soil transmitted helminthes to less than 5% by 2015. The study was conducted to assess the current prevalence and intensity of schistosomal infection among schoolchildren in rural areas of the Taiz governorate after 6 years of running National Control Programme.

Methods

Grade 3 schoolchildren from Shara''b Al-Raona district of Taiz Governorate were examined for infections with Schistosoma mansoni using Modified Kato–Katz method and S. haematobium applying filtration method in 1998/1999, comparing the prevalence and intensity of infection with base line study, which was done 6 years ago.

Results

The S. mansoni prevalence in the study population was 31%, while the prevalence of S. haematobium was 18.6%. This result considerably is similar to the prevalence of base line study. The intensity of mild, moderate and severe infection for S. mansoni reached to 15.9%, 60.6% & 23.5% respectively. The severity of S. haematobium infection was 68.4%. It was exceptionally found that the prevalence of S. haematobium is increased.

Conclusion

The high prevalence of schistosomiasis and low effectiveness of control programme against schistosomal infection in the study area demands consideration of alternative treatment approaches.     

Prevalence of Intestinal Parasitic and Bacterial Pathogens in Diarrhoeal and Non-diarroeal Human Stools from Vhembe District, South Africa

In the present study, a cross-sectional survey of intestinal parasitic and bacterial infections in relation to diarrhoea in Vhembe district and the antimicrobial susceptibility profiles of isolated bacterial pathogens was conducted. Stool samples were collected from 528 patients attending major public hospitals and 295 children attending two public primary schools and were analyzed by standard microbiological and parasitological techniques. Entamoeba histolytica/E. dispar (34.2%) and Cryptosporidium spp. (25.5%) were the most common parasitic causes of diarrhoea among the hospital attendees while Giardia lamblia (12.8%) was the most common cause of diarrhoea among the primary school children (p<0.05). Schistosoma mansoni (14.4%) was more common in non-diarrhoeal samples at both hospitals (16.9%) and schools (17.6%). Campylobacter spp. (24.9%), Aeromonas spp. (20.8%), and Shigella spp. (8.5%) were the most common bacterial causes of diarrhoea among the hospital attendees while Campylobacter (12.8%) and Aeromonas spp. (12.8%) were most common in diarrhoeal samples from school children. Vibrio spp. was less common (3% in the hospitals) and were all associated with diarrhoea. Antimicrobial resistance was common among the bacterial isolates but ceftriaxone (91%) and ciprofloxacin (88.6%) showed stronger activities against all the organisms. The present study has demonstrated that E. histolytica/dispar, Cryptosporidium, Giardia, and Cyclospora are common parasitic causes of diarrhoea in Vhembe district while Campylobacter spp. and Aeromonas are the most common bacterial causes of diarrhoea in Vhembe district of South Africa.Key words: Antibiotic resistance, Bacteria, Diarrhoea, Drug resistance, Microbial, Epidemiology, HIV, Parasites, South Africa     

Prevalence and intensity of intestinal parasitic infections in relation to nutritional status in Mexican schoolchildren

Undernutrition and intestinal parasitic infections affect childhood development and morbidity in many developing countries. Undernutrition may increase susceptibility to parasitic infections which in turn impair the nutritional status of the host. The relationship between intestinal parasitic infections and nutritional status in 400 Mexican schoolchildren was investigated. More than half of the children in the study showed intestinal parasites and polyparasitism. The prevalence of helminth infections was significantly higher in Oaxaca than in Sinaloa (P < 0.05). Z scores for weight-for-age (WA) and height-for-age (HA) were much lower in children of Oaxaca than in Sinaloa (P < 0.001). A significantly higher Z score for weight-for-height (WH), WA, and HA were found in non-infected versus infected children (P < 0.05). Higher prevalences of intestinal infections were found in children with lower HA and WA than in normally nourished children (P < 0.05). Higher intensities of Ascaris lumbricoides and Trichuris trichiura were found in the schoolchildren of Sinaloa than in Oaxaca (P < 0.01). Negative and significant associations were found between Hymenolepis nana and T. trichiura infection (eggs per gram) and nutritional status. Intestinal parasitic infections may be regarded as main risk factors associated with poor nutritional status in Mexican schoolchildren.     

Asymptomatic Intestinal Parasitic Infestations among Children Under Five Years in Selected Communities in the Ho Municipality,Ghana

BackgroundThe study investigated intestinal parasitic infestations (IPIs) and possible risk factors associated with asymptomatic children under five (5) years in five (5) selected communities in the Ho Municipality.MethodsThe study design was cross- sectional, with a simple random sampling technique involving 150 asymptomatic children under 5 years from 5 selected communities (Klave, Hoe, Freetown, Dave and Godokpe) in the Ho Municipality. A questionnaire was used to obtain socio-demographics and other relevant parameters. Direct wet preparation, formol-ether concentration and Modified ZN staining techniques were used for the identification of intestinal parasites from participants'' stool samples. The Fisher''s exact test and binary logistic regression analysis were used to determine the difference in IPIs proportions and assess the risk factors associated with IPIs respectively.ResultsThe overall IPIs cases was 14% (21/150). Cryptosporidium spp was most predominant [5.3% (8/150)], followed by Entamoeba spp [3.3% (5/150)], Cyclospora cayetenensis [2.7% (4/150)], Ascaris lumbricoides [1.3% (2/150)], Giardia lamblia [0.7% (1/150)] and Strongyloides stercoralis [0.7% (1/150)]. Children in rural communities (23.4%) recorded significantly higher case rate compared to those in urban communities (9.8%0), (p=0.04). Lower educational attainment of mother [OR=0.55, 95% CI (0.37 – 0.83), p-value = 0.015] and residence in rural communities [OR = 0.53, 95% CI (0.33–0.88)], p-value = 0.025] were significantly associated with IPIs.ConclusionAsymptomatic IPIs are quite prevalent among children under 5 years in the Ho Municipality. The study thus recommends active sensitization programs for parents/guardians on preventive measures and school health programs should be instituted in rural communities.     

Prevalence of intestinal parasites in young Quichua children in the highlands of rural Ecuador

The prevalence of intestinal parasites in young Quichua children was assessed in 20 rural communities in the highlands of Ecuador in August 2005. The caregivers of 293 children aged 12-60 months were interviewed about the status of child health, household socioeconomic and environmental factors, and water-use practices and were requested to collect a faecal sample from the study child. Two hundred three (69.3%) of the 293 children provided faecal samples that were tested for parasites. The overall prevalences of infection for specific agents were Entamoeba histolytica or dispar 57.1%, Ascaris lumbricoides 35.5%, Entamoeba coli 34.0%, Giardia intestinalis (lamblia) 21.1%, Hymenolepis nana 11.3%, Cryptosporidium parvum 8.9%, Chilomastix mesnili 1.7%, Hymenolepis diminuta 1.0%, Strongyloides stercoralis 0.7%, and Trichuris trichiura 0.5%. The prevalence of parasites increased with age. Water storage, water treatment, consistent latrine-use, and participation in a community-based clean water project were not strongly associated with the prevalence of intestinal parasites, although having dirt floors was a risk factor for infection with E. histolytica or dispar and G. intestinalis.     

Anemia and intestinal parasitic infections in primary school students in Aracaju, Sergipe, Brazil.

Anemia is estimated to affect half the school-age children and adolescents in developing countries. The main causes are parasitic infections, malaria, and low iron intake. This study aimed to describe the prevalence of anemia, parasitic infections, and nutritional status of children attending public primary schools in Aracaju, Northeast Brazil. Of 360 students, 26.7% were anemic, and prevalence was higher in children under 8 and over 15 years of age. Overall prevalence of intestinal parasites was 42%, with Ascaris lumbricoides (28.7%), Trichuris trichiura (15.6%), and hookworm (1. 7%) most frequently found. There was an association between parasitic infections and poor sanitary conditions, but there was no association between anemia and presence of intestinal parasites. Height-for-age Z scores were lower than the NCHS standard, and prevalence of stunting was 5.4%. Although intestinal parasites were not associated with anemia, children with parasites had lower nutritional indices (weight- and height-for-age Z scores) than those without parasites.     

Health Status of Immigrant Children and Environmental Survey of Child Daycare Centers in Samut Sakhon Province,Thailand

Samut Sakhon is a Thai province popular among immigrants attracted to work in factories and the Thai food industry, especially people from Myanmar. Poor personal-hygiene behaviors, crowded accommodation and limited sanitation, result in health problems among immigrant workers. Various infectious diseases among this group are seen and managed by Samut Sakhon General Hospital. The impact of intestinal parasitic infections on public health is well known; they can spread from infected immigrant areas to uninfected areas via close contact and fecal-oral transmission from contaminated food and water. This study aimed to determine the prevalence of intestinal parasitic infections among 372 immigrant children at 8 child-daycare centers during their parents’ work time, by physical examination, fecal examination, and examination of the environment around the centers. Physical examinations were generally unremarkable, except that head-lice and fingernail examinations were positive in two cases (0.8 %). The results showed intestinal parasitic infections to be highly prevalent, at 71.0 %. These infections comprised both helminths and protozoa: Trichuris trichiura (50.8 %), Enterobius vermicularis (25.2 %), Ascaris lumbricoides (15.3 %), hookworm (11.6 %), Giardia lamblia (10.2 %), Endolimax nana (3.5 %), Entamoeba coli (2.7 %), and Blastocystis hominis (0.5 %). The environmental survey found a small number of houseflies near the accommodation to be positive for helminthic eggs (0.2 %), including A. lumbricoides, E. vermicularis, hookworms, Taenia spp., and minute intestinal flukes. Regarding the high prevalence of intestinal parasitic infections among children, it has been conjectured whether they were infected, along with their parents, during their daily lives before or after settling in Thailand. Intestinal parasites among immigrant children may involve a significant epidemiological impact, since immigrant children can serve as carriers and transmitters of disease.     

Prevalence of Intestinal Parasites in Bakery Workers in Khorramabad,Lorestan Iran

Background

Food contamination may occur through production, processing, distribution and preparation. In Iran especially in Khorramabad, 33° 29'' 16" North, 48° 21'' 21" East, due to kind of nutrition, culture and economic status of people, bread is a part of the main meal and the consumption of bread is high. In this study, the bakery workers were studied for determining of intestinal parasites prevalence.

Methods

The study was carried out during September to November 2010 in Khorramabad. All the 278 bakeries and the bakery workers including 816 people were studied in a census method and their feces were examined for the presence of parasites by direct wet-mount, Lugol''s iodine solution, and formaldehyde-ether sedimentation, trichrome staining, and single round PCR (For discrimination of Entamoeba spp).

Results

Ninety-six (11.9%) stool specimens were positive for different intestinal parasites. Intestinal parasites included Giardia lamblia 3.7%, Entamoeba coli 5.5%, Blastocystis sp. 2.1%, Entamoeba dispar 0.4%, Hymenolepis nana 0.1%, and Blastocystis sp. 0.1%.

Conclusion

In order to reduce the contamination in these persons, some cases such as stool exam every three months with concentration methods, supervision and application of accurate health rules by health experts, training in transmission of parasites are recommended.     

The prospect of malaria elimination in the Arabian Peninsula: A population genetic approach

BackgroundIn the Arabian Peninsula malaria control is progressing steadily, backed by adequate logistic and political support. As a result, transmission has been interrupted throughout the region, with exception of limited sites in Yemen and Saudi Arabia. Here we examined Plasmodium falciparum parasites in these sites to assess if the above success has limited diversity and gene flow.MethodsWe examined 108 P. falciparum isolates in three sites in Yemen (Taiz, Dhamar and Hodeidah) and 91 isolates from Saudi Arabia (Jazan). Nine microsatellites were analyzed for allelic diversity, multi-locus haplotype and inter-population differentiation.ResultsDiversity at each locus (unbiased heterozygosity [H]) was relatively lower in Yemen; (Hodeidah, H = 0.615, Taiz, H = 0.66, Dhamar, H = 0.481), compared to Saudi Arabia (Jazan, H = 0.76). Microsatellites were distributed widely and private alleles, detected in a single population, were rare.Pairwise comparisons revealed that parasites population in Dhamar was relatively distanced (F_ST = 0.19). However, Taiz (Yemen) (F_ST = 0.065) and Hodeidah (F_ST = 0.107) populations were closer to that in Jazan (Saudi Arabia). Nonetheless, parasites in the four sites can be considered as one population.ConclusionAlthough malaria risk in Saudi Arabia has been cut considerably, the extent of diversity and parasite genetic structure are indicative of a large population size. Elimination strategy should target demographic factors that favor parasite dispersal and flow of imported malaria.     

Comparison of Microscopy and PCR for Detection of Giardia Lamblia and Entamoeba Histolytica in Human Stool Specimens in a Resource Limited Setting in Western Kenya

BackgroundAccurate diagnosis of Giardia lamblia and Entamoeba histolytica is important since these intestinal parasites account for a significant proportion of morbidity and mortality globally. Microscopy is the key diagnostic test used for diagnosis of the two parasites. Other tests including rapid diagnostic tests and polymerase chain reaction have been developed to improve the detection of these parasites. Most of these newer tests are not affordable in resource limited settings, hence the over reliance on microscopy. The objective of this study was to determine the reliability of microscopy in a resource limited setting in Western Kenya, a region endemic for the two intestinal parasites.MethodsPolymerase chain reaction, the gold standard test, was performed on stool samples suspected for G. lamblia and E. histolytica. Microscopy was then performed on the same samples and the two tests compared.ResultsMicroscopy was found to be 64.4% sensitive, 86.6% specific for the detection of G. lamblia. Additionally, this test was 64.2% sensitive and 83.6% specific for the diagnosis of E. histolytica. Cohen''s kappa values of 0.51 and 0.47 were determined for microscopy for G. lamblia and E. histolytica respectively. McNemar''s test revealed a significant difference between the two tests, P<0.001.ConclusionThis study found microscopy to be a reliable diagnostic test in this resource limited setting.     

Epidemiological survey of the prevalence of intestinal parasites among schoolchildren in Sari, northern Iran

Parasitic infection is highly prevalent throughout the developing countries of the world. Research on the prevalence of intestinal parasitic infections in various geographic regions is a prerequisite for the development of appropriate control strategies. A cross-sectional study was conducted to determine the prevalence of intestinal parasitic infections among schoolchildren in public primary and secondary schools in the urban areas of Sari, Mazandaran province, northern Iran. The study was conducted from November 2009 to June 2010. A total of 1100 stool samples from 607 males and 493 females aged 7-14 years were examined by direct wet mounting, formalin-ether concentration, and Ziehl-Neelsen and trichrome permanent staining methods. A parental questionnaire for common risk factors was completed for each participant. Mono- or poly-parasitism was detected in 367 (33.3%) of the children (32.6% of males and 34.2% of females). Various species of protozoan or helminth infections were detected: Blastocystis hominis seemed to be the most prevalent parasite (13.5%) followed by Giardia lamblia (10.6%), Entamoeba coli (7.2%), Endolimax nana (1.5%), Enterobius vermicularis (2.2%), Trichostrongylus sp. (2.1%) and Strongyloides stercoralis (1.6%). The prevalence of intestinal parasite infections in females was slightly higher than in males, though without a statistically significant difference (p=0.56). No age association was detected, and a slightly lower positive association with increasing age was observed (p=0.33). A significant association was observed with parents' educational level, household income and practice of hand washing before meals (p<0.01). Although paediatric pathogenic intestinal parasite infections are not more prevalent in this geographical area than in other regions, improvements in personal hygienic conditions and behavioural characteristics is important to completely control parasitic infections in schoolchildren in northern Iran.     

Intestinal parasitism and Vibrio cholerae infection among diarrhoeal patients in Kolkata, India

In this study, we have analysed the epidemiological significance of the concurrent infections caused by Vibrio cholerae and intestinal parasites among different age groups of hospitalized diarrhoeal patients in Kolkata. A total of 3556 stool samples collected during 1996-2004 were screened for vibrios and parasites. The seasonality of V. cholerae and parasitic infections were studied in detail. The detection rates for Ascaris lumbricoides and Giardia lamblia infection were more than for the hookworm, Trichuris trichiura and Entamoeba histolytica. V. cholerae O1 was identified as the predominant serogroup among diarrhoeal patients. The highest rates for V. cholerae infection were in the 2-5 years age group and combined infection of V. cholerae and parasites was recorded among children aged between 2 and 10 years.     

Prevalence and predictors of intestinal helminthiasis among school children in jimma zone; a cross-sectional study

Background

Globally, millions of people suffer from intestinal parasitic infections. These infections are among the most common resulting in considerable morbidity and mortality. In Ethiopia and particularly in Jimma and its surroundings intestinal parasitic infections are highly prevalent because of low living standards and poor environmental sanitation. The objective of the survey was to determine the prevalence and predictors of intestinal parasitosis among school children in four woredas of Jimma zone surrounding Gilgel gibe hydraulic dam and serve as a base line data to help evaluate health promoting activities for the future and monitor those already delivered to the community.

Methods

A cross-sectional study was carried out in October, 2008 in four Woredas of Jimma zone bordering Gilgel Gibe Dam. Children attending grades 1–8 in the schools located within 10 Kms ofthe Dam in the four bordering woredas and those living 30 Kms away from the shore line were the study subjects. Six hundred twenty four and 321 children were selected from the schools around Gilgel Gibe dam and from the schools in Bulbul, respectively. Data on background of participant was collected and stool specimen collected and processed. Data were filtered and entered into computer then analyzed using SPSS for windows version 13.0.1.

Results

Of the 937 selected individuals, 855 participated in the study giving a response rate of 91.2%. The prevalence of intestinal parasitosis was 47.1% where 174 (20%) had Ascaris lumbricoides monoinfection; 4.3% had dual infection involving Ascaris lumbricoides and hookworm and 0.2% had triple infection but all the infections were of light intensity. In addition, there was no association between prevalence of intestinal parasitosis with availability or regular use of latrine and clinical symptoms.

Conclusion

The prevalence and intensity of intestinal parasites in the study area is lower than national, urban and rural setting of Jimma zone. These might be due to a better awareness of the study community on prevention of intestinal parasitosis following increased health promoting activities in the area, delivered through various activities of Jimma Public health training program.     

Reassessment of the epidemiology of amebiasis: State of the art

The epidemiology of amebiasis has dramatically changed since the separation of Entamoeba histolytica and Entamoeba dispar species, and the worldwide prevalence of these species has not been estimated until recently. The most cited data regarding prevalence, morbidity, or mortality due to amebiasis is the 1986 Walsh report, in which 100,000 deaths are reported to occur worldwide each year due to medical complications of invasive amebiasis. However, the prevalence values of Entamoeba histolytica infection could be completely erroneous since the estimations were performed prior to the molecular characterization of E. histolytica and E. dispar species. Moreover, Entamoeba moshkovskii, another morphologically indistinguishable human parasitic Entamoeba, was not mentioned or considered as a contributor to the prevalence figures in endemic areas. However, recent available prevalence and morbidity data obtained through molecular techniques allow the construction of a more reliable map of endemic regions of amebiasis all over the world [the Asian subcontinent (India, Bangladesh), Africa, Asian Pacific Countries (Thailand, Japan), South and Central America (Mexico, Colombia)]. The epidemiology of infectious diseases focuses on identification of factors that determine disease distribution in time and space, transmission factors responsible for the disease, clinical manifestations, and progression in the host, with the goal being the design of realistic intervention and prevention strategies in a reasonable period of time. In the present review, we will describe how molecular tools have made actual knowledge regarding the epidemiology of amebiasis possible. We will also analyze the most relevant available data on prevalence, morbidity, geographic distribution, patterns of transmission, exposure, and risk factors for infection in the human host. Our intention is to emphasize the recent molecular typing methods applied in genotyping Entamoeba species and strains, and to assess their value and limitations. Finally, we will discuss those areas of the host–parasite relationship that are still not fully understood, and the scientific challenges to approach this important public health problem in the future.     

Prevalence of Intestinal Parasites among Food-handlers in Shiraz,Iran

Background:

Parasitic intestinal infections are still among socioeconomic problems in the world, especially in developing countries like Iran. Food-handlers that directly deal with production and distribution of foods between societies are one of the most important sources to transmit parasitic infections to humans. The aim of this study was to determine the prevalence of intestinal parasitic infections among food-handlers in Shiraz, Iran.

Methods:

In this cross-sectional study, 1021 feces samples were randomly collected from food-handlers in Shiraz, central Iran from August to September 2013. Two different methods, routine direct fecal examination and Formalin –Ethyl acetate concentration as a complementary technique, were done to detect parasites.

Results:

The prevalence of parasitic organisms was 10.4% in the food-handlers. The most species of the protozoan parasites were G. lamblia, E. coli and B. hominis; meanwhile, only one infection by H. nana (0.1%) was detected in this group. Mixed infections were observed in 13.2% (n=14/106) of positive cases. The majority of participants were male (57%); however, data analysis showed significant statistical difference in the rate of infection between females 11.9% (n=53/444) and males 9% (n=52/577) (P=0. 024). There was no significant statistical difference in the rate of infection among different educational and occupation groups.

Conclusion:

Although decreasing of helminthic infections is distinct, but infecting with protozoan parasites is still important in food-handlers. Concentration technique is more useful than direct smear technique, especially for detection parasites in low number. High level of education in our study showed that training courses in this group could be effective in the implementation of control and prevention programs.