我国西南彝族农村地区HIV与血吸虫 蛔虫及鞭虫感染现状调查

目的 目的 了解我国西南彝族农村地区HIV、 血吸虫、 蛔虫及鞭虫感染状况, 调查是否存在混合感染。 方法 方法 在我 国西南部某山区随机选取一个彝族乡开展横断面调查, 检测村民HIV、 血吸虫、 蛔虫及鞭虫感染情况; 并对村民进行问卷 调查, 了解HIV及寄生虫感染的危险因素。 结果 结果 我国西南彝族农村地区居民HIV、 血吸虫、 蛔虫和鞭虫感染率分别为 2.33%、 2.05%、 13.47%和30.59%, 鞭虫与蛔虫共同感染检出率为7.08%, HIV与蛔虫和鞭虫共同感染检出率均为0.23%。 男性以及吸毒是HIV感染的危险因素 ［OR = 3.26, 95% CI：（0.97, 10.95）; OR = 72.86, 95% CI： （18.51, 286.76）］; 厕所与蛔 虫和鞭虫感染间均存在负相关关系 ［OR = 0.51, 95% CI：（0.27, 0.98）; OR = 0.48, 95% CI：（0.28, 0.80）］。与居住在村4的 居民相比, 村1村民感染蛔虫风险较高 ［OR = 3.14, 95% CI：（1.35, 7.27）］; 与居住在村4的居民相比, 居住在村2和村3的 村民鞭虫感染风险较高 ［OR = 3.73,95% CI：（1.92, 7.26）; OR = 4.53, 95% CI：（2.12, 9.68）］。此外, 11～20岁年龄组村民 鞭虫感染风险高于>50岁村民 ［OR = 3.72, 95% CI：（1.59, 8.67）］; 蛔虫与鞭虫感染间存在相关关系 ［OR = 3.11, 95% CI： （1.63, 5.93）］, 未发现与血吸虫感染相关的因素。 结论 结论 我国西南彝族农村居民HIV及寄生虫感染率尤其是鞭虫感染 率较高; 应进一步探索HIV与寄生虫感染, 尤其是与血吸虫感染间的关系。     

Prevalence of gastrointestinal helminthic infections and associated risk factors among schoolchildren in Tilili town,northwest Ethiopia

Objective:To determine the prevalence of gastrointestinal helminthes and associated risk factors among schoolchildren in Tilili town,northwest Ethiopia.Methods:A cross-sectional study involving 383 schoolchildren was conducted between November 2011 to February 2012.Each student was selected using systematic random sampling method.Questionnaire and observation were used to identify socio-demographic and associated risk factors.Fresh stool samples were observed using formal-ether concentration technique.Data were analyzed using SPSS 16.0statistical software.Results:Four species of intestinal helminthes were identified with an overall prevalence of 44.2%(170 of 385 schoolchildren).The predominant parasites were Ascaris lumbricoides(A.lumbricoides)153(39.7%)and Trichuris trichiura(T.trichiura)30(7.8%).One hundred thirty five(35.1%)had single infections and 35(9.2%)were infected with more than one helminthic parasites in which 32(8.4%)were double infections and 3(0.8%)were triple infections.Significant associations were observed between intestinal helminth infection and those of age,grade level,and school variables.Prevalence of hookworm infection was significant in children who did not wear shoes regularly(P0.05).Conclusions:intervention programs and education on personal and environmental hygiene should be implemented for the prevention and control of helminthic infections in the study area.     

Epidemiology of soil-transmitted nematode infections in Ha Nam Province, Vietnam

Baseline epidemiological data are presented from a parasitological survey conducted in Thuy Loi commune, Ha Nam province, Vietnam; a farming community where night soil is routinely used as fertilizer for crops. 177 households were visited and 543 individuals (aged 1–88 years) recruited to the study. Helminth infection intensity was assessed by Kato-Katz to determine the density of parasite eggs per gram of stool (epg). Ascaris lumbricoides, Trichuris trichiura and hookworm infections were the only species detected. 83% of individuals were infected with A. lumbricoides (mean epg = 11971), 94% with T. trichiura (mean epg = 793) and 59% with hookworm (mean epg = 302). Age-dependent patterns of infection prevalence and intensity were similar for A. lumbricoides and T. trichiura , but markedly different for hookworm infection. Similarly, age-dependency in the k-values for the three infections was due to covariance with the respective mean intensities with age rather than to independent age effects, with similar patterns for A. lumbricoides and T. trichiura , and a different pattern for hookworm. Three major conclusions can be drawn from the multiple-species analyses: There is positive interaction between A. lumbricoides and T. trichiura infections; high-intensity A. lumbricoides infections are significantly associated with high-intensity T. trichiura infections; and there is positive interaction between these two species such that infection intensity of A. lumbricoides is higher in individuals with concurrent T. trichiura infection than in individuals without and vice versa.     

Extensive multiparasitism in a village of Yunnan province, People's Republic of China, revealed by a suite of diagnostic methods

Intestinal multiparasitism, the accuracy of different diagnostic techniques, and the influence of sampling effort were studied among 215 individuals in a Bulang village, Yunnan province, People's Republic of China. Behavioral, demographic, and socioeconomic data were obtained by questionnaire. Multiple stool specimens were examined by the Kato-Katz, Koga agar plate, Baermann, and ether-concentration methods. Eight helminth and 7 protozoa species were diagnosed. The prevalence of each of the 3 main soil-transmitted helminths (Ascaris lumbricoides, hookworm, and Trichuris trichiura) exceeded 85%. Blastocystis hominis was the most prevalent intestinal protozoan (20.0%). Over 80% of the individuals harbored 3 or more intestinal parasites concurrently. The infection intensities were predominantly light for hookworm and T. trichiura but moderate for A. lumbricoides. Examination of 3 instead of 1 stool specimen increased the sensitivity of helminth diagnosis, most notably for hookworm. Intestinal multiparasitism is rampant in this rural part of Yunnan province and calls for control measures.     

Targeting newly enrolled low-age school children for the control of the intestinal helminth infection in rural Nepal

This study aims to identify an effective intervention group for the control of the intestinal helminth infection among school-age children in rural Nepal. We examined 1677 stool samples of school-age children from 25 schools and 1014 samples from 25 communities in rural Nepal. We used formalin-ether sedimentation technique for the microscopic examination of the stool samples and identified three major intestinal helminths: Ascariasis lumbricoides, hookworm and Trichuris trichiura. Our results revealed that the newly enrolled under-6-year-old children at the schools were more widely infected with at least one of the three major helminths than those in the communities (odds ratio [OR] 2.29). We detected a significant difference in the prevalence of A. lumbricoides (OR 1.70), hookworm (OR 2.57) and T.trichiura (OR 3.23) between under-6-year-old children at the schools and those at the communities. The study results suggest that an appropriate deworming programme is needed for the newly enrolled under-6-year-old children in the primary schools in Nepal.     

Soil-transmitted helminthiases and health behaviors among schoolchildren and community members in a west-central border area of Thailand

The prevalence of soil-transmitted helminthic infections and health behaviors related to infections in schoolchildren and villagers of a community (4 hamlets) was studied in Hauy Kayeng subdistrict, Thong Pha Phum district, in the north of Kanchanaburi Province. The intestinal helminth infection rate of the schoolchildren was 15.6%. Hookworm infection was the most prominent (9.8%), followed by Trichuris trichiura (6.2%), and Ascaris lumbricoides (2.2%). The community showed higher prevalence rates and was infected with more types of intestinal helminths than the schoolchildren. Thirty-five point two percent (35.2%) of the residents were infected with soil-transmitted helminths, 30.5% with hookworm, 3.4% with A. lumbricoides and 2.2% with T. trichiura. Almost all hookworm cases (94.3%) were light intensity infections, while only 1.3% were heavy infections. Moreover, the hookworm infection rate in the community was found to be much higher when a stool culture method was used (39.1%). With this technique, 2.3% Strongyloides stercoralis infections were detected in the community population. Examination of the health behavior of the study samples showed that approximately 75% always defecated in a toilet. Schoolchildren who always wore shoes comprised 67%, which was lower than the community, at 85%.     

Impact of intestinal helminth infection on anemia and iron status during pregnancy: a community based study in Indonesia

A cohort study was carried out in Purworejo District, Central Java, Indonesia to investigate prevalence of anemia and low iron stores during pregnancy in relation to intestinal helminth infection. 442 pregnant women were followed until 5-10 weeks postpartum, during the period of April 1996 - August 1998. Information on intestinal helminths, hemoglobin and serum ferritin was collected each trimester. Highest prevalence of anemia in pregnancy (37.1%) was found in the second trimester, while the highest prevalence of low iron stores (49.5%) was found in the third trimester. Most pregnant women (69.7%) were infected with at least one species of pathogenic intestinal helminths. The most common helminth detected was Trichuris trichiura followed by Necator americanus (hookworm) and Ascaris lumbricoides. A significant negative association was found between hookworm infection and serum ferritin at the first trimester (p = 0.010). It is concluded that hookworm infection can interfere iron stores. Other causes of anemia among pregnant women should be considered. Anthelminthic therapy could be given to infected women before conception as public health strategy to improve iron status.     

Prevalence, intensity and risk factors for soil-transmitted helminth infection in a South Indian fishing village

A study of the prevalence, intensity and risk factors for soil-transmitted helminth infection was undertaken among school children aged 5-9 years attending a primary school in the fishing village in Peda Jalaripet, Visakhapatnam, South India. One hundred and eighty nine (92.6%) of 204 children were infected with one or more soil transmitted helminth parasites. The predominant parasite was Ascaris lumbricoides (prevalence of 91%), followed by Trichuris trichiura (72%) and hookworm (54%). Study of age-specific prevalence and intensity of infection revealed that the prevalence and intensity of A. lumbricoides infection was higher among younger children than older children. While aggregation of parasite infection was observed, hookworm infection was more highly aggregated than either A. lumbricoides or T. trichiura. Multivariate analysis identified parental occupation, child's age and mother's education as the potential risk factors contributing to the high intensity of A. lumbricoides infection. Children from fishing families with low levels of education of the mother had the highest intensity of A. lumbricoides infection. As the outcome of chemotherapy programs to control soil transmitted helminth infection is dependant on the dynamics of their transmission, there is a need for further studies to better define the role of specific factors that determine their prevalence, intensity and aggregation in different epidemiological settings.     

Intestinal parasitic infections in schoolchildren of Abha (Asir), Saudi Arabia.

Stool specimens from 1282 children between the age of 5 and 13 years attending 10 primary schools for boys in the city of Abha, southwestern Saudi Arabia, were examined for the presence of intestinal parasites. Of these, 313, (24.4%) were found infected with one or more species of 11 intestinal protozoa and helminths. The most common pathogenic protozoa being Giardia lamblia (10.9%) followed by Entamoeba histolytica (4.1%). The nonpathogenic protozoan, Entamoeba coli had the highest prevalence rate (11.3%) in the children's stools. Hymenolepis nana was the commonest intestinal helminth (3.0%). Other intestinal helminths, including Ascaris lumbricoides, Trichuris trichiura. Schistosoma mansoni, Dicrocoelium dendriticum were detected to a lesser extent. The distribution of the common intestinal infections among the children surveyed were also analysed according to age, nationality and multiplicity of infection. Prevalence of E. histolytica was found to increase with age whereas Giardia infections were less common among older children. This pair of parasite species were strongly associated. Yemeni children had consistently the highest prevalence of infection with protozoa and helminths, followed by Saudi and non-Saudi children.     

Helminth infections and risk factor analysis among residents in Eryuan county, Yunnan province, China

Whilst infections with soil-transmitted helminths are common across China, the public-health significance of Schistosoma japonicum and food-borne helminths is more focalized. Only few studies have investigated the local epidemiology of helminth infections in rural China, including risk factor analysis. We collected stool and blood samples from 3220 individuals, aged 5-88 years, from 35 randomly selected villages in Eryuan county, Yunnan province, China. Stool samples were subjected to the Kato-Katz technique and examined for helminth eggs. Blood samples were tested for Trichinella spp., S. japonicum and cysticerci-specific antibodies. Data on individual and family-level risk factors were collected using questionnaires. The prevalence of Ascaris lumbricoides, Taenia spp., Trichuris trichiura and hookworms was 15.4%, 3.5%, 1.7% and 0.3%, respectively. The seroprevalence of Trichinella spp. was 58.8% and that of cysticercosis 18.5%. The egg positivity rate of S. japonicum in the 13 known endemic villages was 2.7%, and the corresponding seroprevalence was 49.5%. We observed a strong spatial heterogeneity in the families' economic status. S. japonicum infections were more prevalent among the Han than Bai nationality (odds ratio (OR)=3.77, 95% confidence interval (CI)=1.97-7.23) and tobacco growers (OR=3.66, 95% CI=1.77-7.60) and was only found at elevations below 2150 m above sea level. A. lumbricoides and Taenia spp. infections were more prevalent at altitudes above 2150 m when compared to lower settings (OR=1.51, 95% CI=1.24-1.84 and OR=5.32, 95% CI=3.42-8.28, respectively). The opposite was found for T. trichiura (OR=0.31, 95% CI=0.14-0.70). Our findings can guide the design and spatial targeting of control interventions against helminth infections in Eryuan county.     

Soil-transmitted helminthiasis in rural south-west China: prevalence, intensity and risk factor analysis

Only few studies in rural China have explored the epidemiology of intestinal helminth infections and identified risk factors for transmission. The study was carried out in Simao and Mengla counties, where single fecal samples were collected from 317 school-aged children and from 94 inhabitants of a single village. Fecal specimens were examined with the Kato-Katz thick smear method and examined for helminth eggs. Data regarding socio-demographic and behavioral risk factors were collected using questionnaires. In Simao County the overall soil-transmitted helminthes (STH) prevalence was 40.2% (2.7, 5.4 and 35.7% for ascariasis, trichuriasis and hookworm infection, respectively). The STH infection rates were significantly higher in Mengla County, with an overall prevalence of 68.3% (19.0, 34.6 and 47.3% for ascariasis, trichuriasis and hookworm infection, respectively). Females were less likely to be infected with Trichuris trichiura (OR 0.29; 95% CI 0.15-0.56) and with hookworms (OR 0.55; 95% CI 0.33-0.93) than males. Hookworm infections were more prevalent among those 12 years of age or older (OR 2.9; 95% CI 1.2-7.1). Children of mothers with educational attainment of secondary school or higher had a protective effect against T. trichiura (OR 0.18; 95% CI 0.06-0.54) and hookworm (OR 0.21; 95% CI 0.09-0.51) infections. In the village survey, hookworm was the most prevalent species (62.8%) with infection seen in those 50 years of age and older. Based on recommended intervention strategies by the World Health Organization, Simao County should opt for school-based deworming once each year, while Mengla County should implement a similar strategy biannually, but should include the elderly population.     

Patterns of infection with intestinal parasites in Qatar among food handlers and housemaids from different geographical regions of origin

Intestinal parasitic infections were surveyed among recently arrived immigrant workers in Qatar destined for employment in food handling occupations. Two overlapping datasets (female workers surveyed in 2005 and 2006, and both sexes in 2006) were analyzed. Seven species were detected, 3 nematodes (Trichuris trichiura, hookworms and Ascaris lumbricoides) and 4 protozoans (Entamoeba histolytica/dispar, non-pathogenic Entamoebae, Blastocystis hominis and Giardia lamblia). Overall prevalence of infections, all species combined was 33.9% (13.6% for nematodes and 24.8% for protozoa). There was a significant female bias in the prevalence of all species combined, all protozoans combined, T. trichiura and A. lumbricoides. Among females, the prevalence of many species fell between 2005 and 2006, but G. lamblia almost tripled and E. histolytica/dispar increased 10-fold. Africa workers were less likely to carry T. trichiura and hookworms but more likely to have gastrointestinal protozoa. The highest overall prevalence of T. trichiura was 26.3% among females from the Philippines in 2005. None of the Indonesian workers were infected with A. lumbricoides whereas those from the Indian sub-continent and the Philippines were more likely to carry hookworms. Quantitative data reflecting abundance of infection (summary statistics are provided), showed the same trends but could not be analyzed further because of the overall low prevalence of each of the species detected. Multiple species infections were not common, although some individuals (0.1%) had 5 species concurrently.     

Concurrent urinary and intestinal schistosomiasis and intestinal helminthic infections in schoolchildren in Ilobu, South-western Nigeria

A cross-sectional study was conducted in a schistosome-endemic rural community in Southwestern Nigeria. We assessed prevalence and intensity of soil-transmitted nematodes and the co-occurrence with Schistosoma haematobium and Schistosoma mansoni. Urine and stool samples from 419 schoolchildren were examined, and a questionnaire was administered to obtain socio-demographic characteristics. In total, 78.3% (328/419) were infected with at least one helminth species, with a prevalence (mean egg-count) of 55.1% (3069.2) of Ascaris lumbricoides, 41.1% (127.5) of S. haematobium, 22.7% (98.6) of hookworms, 17.9% (161.3) of Trichuris trichiura, and 10.3% (12.9) of S. mansoni. Multiple infections were significantly more common among children from households with more playmates, absence of toilet facilities and low income level (all p<0.001). Children with heavy hookworm burden were at a significantly higher chance of acquiring S. mansoni (OR=36.35; 95% Cl: 13.22-100.97; p<0.0001). The risk of S. mansoni and A. lumbricoides infections was increased in co-infections with S. haematobium. Logistic regression analysis revealed infections by hookworms and S. mansoni (adjusted odds ratio [aOR]=3.90, 95% Cl: 2.03-7.46; p<0.0001), and by hookworms and T. trichiura (aOR=2.46, 95% Cl: 1.44-4.22; p=0.001) as significant risk factors for multiple infections. Our study shows that polyparasitism is common in the study area. Focused interventions such as mass treatment with anthelminthics and health education are needed to improve the well-being of the affected population.     

Polyparasitism with Schistosoma haematobium and soil-transmitted helminth infections among school children in Loum, Cameroon

Prevalence and abundance of Schistosoma haematobium and soil-transmitted helminths (STH) were assessed among a total of 1600 pupils (urine, n = 1190; faecal samples, n = 1454) attending five schools in Loum, Littoral Province, Cameroon, with the specific aim of assessing the extent of polyparasitism and the extent to which infections were focused in particular subsets of the study group. Prevalence of S. haematobium was 62.8% with an abundance (arithmetic mean of egg counts) of 54 eggs/10 ml urine. For the STH these were 47.7% and 619 eggs per gram of faeces (EPG) for Trichuris trichiura, 65.5% and 3636 EPG for Ascaris lumbricoides, and 1.4% and <0.1 EPG for hookworms. Most children (90.3%) were infected with at least one of these four species, the largest proportion (34.3%) carrying two species; 27.4% carried three and 1.1% carried concurrently all four species of parasites. The average number of species harboured increased with age, as did the prevalences of S. haematobium and T. trichiura but not that of A. lumbricoides. All STH showed marked differences in prevalence between the five schools but only T. trichiura varied significantly between sexes. Mean abundance of infection varied significantly between age classes, among schools and between the sexes, with females showing heavier mean EPGs for A. lumbricoides and T. trichiura and males higher mean eggs/10 ml urine for S. haematobium infections. A highly significant association was detected between A. lumbricoides and T. trichiura, that was not context-dependent. This was confirmed in quantitative analyses after controlling for differences in abundance between schools, sexes and age classes. A weaker context-dependent association (prevalence data) was detected between S. haematobium and A. lumbricoides (sex- and age-dependent) but quantitative associations between these two species, as well as between S. haematobium and T. trichiura, were not convincing.     

Earth-eating and reinfection with intestinal helminths among pregnant and lactating women in western Kenya

We conducted a longitudinal study among 827 pregnant women in Nyanza Province, western Kenya, to determine the effect of earth-eating on geohelminth reinfection after treatment. The women were recruited at a gestational age of 14-24 weeks (median: 17) and followed up to 6 months postpartum. The median age was 23 (range: 14-47) years, the median parity 2 (range: 0-11). After deworming with mebendazole (500 mg, single dose) of those found infected at 32 weeks gestation, 700 women were uninfected with Ascaris lumbricoides, 670 with Trichuris trichiura and 479 with hookworm. At delivery, 11.2%, 4.6% and 3.8% of these women were reinfected with hookworm, T. trichiura and A. lumbricoides respectively. The reinfection rate for hookworm was 14.8%, for T. trichiura 6.65, and for A. lumbricoides 5.2% at 3 months postpartum, and 16.0, 5.9 and 9.4% at 6 months postpartum. There was a significant difference in hookworm intensity at delivery between geophagous and non-geophagous women (P=0.03). Women who ate termite mound earth were more often and more intensely infected with hookworm at delivery than those eating other types of earth (P=0.07 and P=0.02 respectively). There were significant differences in the prevalence of A. lumbricoides between geophagous and non-geophagous women at 3 (P=0.001) and at 6 months postpartum (P=0.001). Women who ate termite mound earth had a higher prevalence of A. lumbricoides, compared with those eating other kinds of earth, at delivery (P=0.02), 3 months postpartum (P=0.001) and at 6 months postpartum (P=0.001). The intensity of infections with T. trichiura at 6 months postpartum was significantly different between geophagous and non-geophagous women (P=0.005). Our study shows that geophagy is associated with A. lumbricoides reinfection among pregnant and lactating women and that intensities built up more rapidly among geophagous women. Geophagy might be associated with reinfection with hookworm and T. trichiura, although these results were less unequivocal. These findings call for increased emphasis, in antenatal care, on the potential risks of earth-eating, and for deworming of women after delivery.     

Cross-sectional parasitological survey for helminth infections among fish farmers in Nghe An province, Vietnam

A total of 964 adult fish farmers in five eastern districts in Nghe An province, Vietnam were investigated in late 2004 for food-borne trematodes and other helminth infections using duplicate Kato-Katz thick smears prepared from single stool samples. Eggs of fish-borne trematodes and of Fasciolopsis buski were found in 0.6 and 0.7% of farmers, respectively. Infection prevalences with soil-transmitted helminths (STHs), namely Ascaris lumbricoides, Trichuris trichiura and hookworm, were 34.8, 50.7 and 51.3%, respectively, and 81.8% were infected with at least one of the three STHs. While A. lumbricoides and T. trichiura were more prevalent in the eastern districts compared to the more western districts, the opposite was true for hookworm infections. The widespread prevalence of STH infections in fish farmers suggests that control of these infections in school-age children only may be inadequate. Identification of the human behavioural factors and environmental features responsible for the distribution and frequency of STHs among adults is needed as well as a sensitive diagnostic test of fish-borne trematodes at species level.     

Mass treatment for intestinal helminthiasis control in an Amazonian endemic area in Brazil

The objective of the present study was to estimate the prevalence of soil-transmitted helminthiasis and evaluate the sanitary conditions and the role of a mass treatment campaign for control of these infections in Santa Isabel do Rio Negro. A cross-sectional survey was carried out in 2002, to obtain data related to the sanitary conditions of the population and fecal samples for parasitological examination in 308 individuals, followed by a mass treatment with albendazole or mebendazole with coverage of 83% of the city population in 2003. A new survey was carried out in 2004, involving 214 individuals, for comparison of the prevalences of intestinal parasitosis before and after the mass treatment. The prevalences of ascariasis, trichuriasis and hookworm infection were 48%; 27% and 21% respectively in 2002. There was a significant decrease for the frequency of infections by Ascaris lumbricoides (p < 0.05; OR / 95% CI = 0.44 / 0.30 - 0.65), Trichuris trichiura (p < 0.05; OR / 95% CI = 0.37 / 0.22 - 0.62), hookworm (p < 0.05; OR / 95% CI = 0.03 / 0.01 - 0.15) and helminth poliparasitism (p < 0.05; OR / 95% CI = 0.16 / 0.08 - 0.32). It was also noticed a decrease of prevalence of infection by Entamoeba histolytica / dispar (p < 0.05; OR / 95% CI = 0.30 / 0.19 - 0.49) and non-pathogenic amoebas. It was inferred that a mass treatment can contribute to the control of soil-transmitted helminthiasis as a practicable short-dated measure. However, governmental plans for public health, education and urban infrastructure are essential for the sustained reduction of prevalences of those infections.     

Urban/rural differences in prevalence and risk factors for intestinal helminth infection in southern Malawi

Urbanization may increase the risk of human infection with intestinal helminths. A cross-sectional survey was conducted to investigate the prevalence, intensity and potential risk factors of acquiring such infection, among children aged 3-14 years in similar urban and rural communities in southern Malawi. Stool samples were collected from 553 children (273 urban and 280 rural). The overall prevalence of helminth infection was significantly higher in the urban subjects than in the rural (16.5% v. 3.6%; P < 0.001), mostly because of differences in the prevalence of Ascaris lumbricoides infection. Living in an urban community was associated with a significantly higher risk of infection [odds ratio (OR) = 5.3; 95% confidence interval (CI) = 2.6-12.1], even after controlling for potential confounding factors. In the urban community, risk factors included having pools of water/sewage around houses (OR = 3.0; CI = 1.4-6.5), not wearing shoes (OR = 7.1; CI = 2.7-19.2), not attending school (OR = 2.8; CI = 1.2-6.5), having mothers with 4-8 years of education (OR = 5.2; CI = 2.0-14.0), and having mothers below 35 years of age (OR = 4.09; CI = 1.39-16.28). In this part of Africa, efforts to reduce helminth infections may best be focused on reducing geohelminth burden in urban areas.     

Moderate- and low-intensity co-infections by intestinal helminths and Schistosoma mansoni, dietary iron intake, and anemia in Brazilian children

To determine the role of moderate- and low-intensity infections with Schistosoma mansoni and intestinal helminths (hookworm, Trichuris trichiura, Ascaris lumbricoides) on the prevalence of anemia and their relationship to iron consumption, a cross-section of 1,709 children in rural Brazil was studied. All participants were selected for infection with one or multiple helminthic parasites, and demographic, anthropometric, and dietary intake were surveyed. The prevalence and intensity were as follows: hookworm infection, 15.7% and 8.6 eggs/g; T. trichiura, 74.8% and 190.5 eggs/g; A. lumbricoides, 63% and 1,905.5 eggs/g; S. mansoni, 44.5% and 60.3 eggs/g. There was no increase in odds ratio for anemia with any combination of intestinal helminths without S. mansoni infection. By logistic regression, the odds ratio for having anemia when infected with S. mansoni and two intestinal helminths was 1.7 (95% CI, 1.1-2.5) and for S. mansoni and three intestinal helminths was 2.4 (95% CI, 1.2-4.6) compared with children with a single parasite species. Children with an adequate intake of iron had no increased odds of anemia independent of the combination of parasite infections.