Nematode intestinal parasites of children in rural Guinea, Africa: prevalence and relationship to geophagia

BACKGROUND: Intestinal parasitism is common among children in developing countries, but the risk factors for infection are not well characterized. METHODS: A stool examination was performed on 286 randomly selected children aged 1-18 years from three rural villages in Guinea, Africa. Information collected by questionnaire was used to examine the relationship between geophagia and infection with intestinal nematodes acquired by ingestion versus skin penetration. RESULTS: Fifty-three per cent of children were infected by at least one type of soil-transmitted nematode. Geophagia was reported by parents to occur in 57%, 53%, and 43%, of children ages 1-5, 6-10, and 11-18 years, respectively. The pattern of geophagia by age and gender of the children more closely resembled the infection pattern for the two orally acquired and soil-transmitted nematodes (Ascaris lumbricoides, Trichuris trichiura) than it did the infection pattern for the two soil-transmitted nematodes that infect by skin penetration (hookworm, Strongyloides stercoralis). CONCLUSIONS: These findings demonstrate that geophagia is an important risk factor for orally acquired nematode infections in African children. Education regarding geophagia prevention should be an integral component of any soil-transmitted parasite control programme.     

Geophagia is not associated with Trichuris or hookworm transmission in Zanzibar, Tanzania

Geophagia may be harmful as a method for the transmission of geohelminths. In this study, we pose two questions in a representative sample of 970 pregnant women from Pemba Island, Zanzibar, Tanzania. Can consumed earth be a vector for geohelminth infection? And do geophagists have differential parasitic infection? The parasitological content of 59 non-food substance samples was analysed. Cross-sectional data regarding pica behaviour were collected through interviews conducted by local researchers. Ascaris, Trichuris and hookworm status was ascertained through Kato-Katz smears. The prevalence of geophagia at baseline was 5.6% and the overall prevalence of Ascaris, Trichuris and hookworm infection was 5.6%, 33.2% and 32.9%, respectively. No consumed soil samples contained infectious parasitic stages, and only one of the consumed pica substances (charcoal) contained parasites of potential risk to human health. In bivariate analyses, neither the prevalence nor the intensity of infection with Ascaris, Trichuris or hookworm differed significantly by geophagia status. Furthermore, in multivariate models, geophagia was not a significant predictor of helminth infection status. We conclude that geophagia is not a source of Trichuris or hookworm infection among pregnant women in Pemba (insufficient power to evaluate the effect of Ascaris), which is in contrast to existing findings of helminth infection and geophagia.     

Coverage and costs of a school deworming programme in 2007 targeting all primary schools in Lao PDR

Infections with soil-transmitted helminths (STHs) are among the commonest infections in Lao PDR. Recent investigation in this country showed that intestinal helminths currently infect the majority of school-aged children. The Lao Government has addressed the problem by organizing regular anthelminthic chemotherapy with mebendazole 500mg for school and pre-school children in conjunction with health education activities incorporated into the national school curriculum. The school deworming campaign in Lao PDR reached a national coverage rate of 95% at a cost of US$0.124/head for two rounds of deworming per year. The programme operates under the umbrella of the national school health programme. After 1 year (two rounds of deworming) the intervention reduced the prevalence of Ascaris lumbricoides from 60% to 20% and of Trichuris trichiura from 42% to 31%. Although infection was not eliminated by the deworming interventions, over 90% of those children who remain infected had a 'light' infection. The virtual absence of high and moderate intensity infection demonstrates the effectiveness of periodical deworming in reducing morbidity due to STHs. We expect that additional rounds of deworming will further reduce the STH prevalence in Lao PDR.     

Geophagia in rural Mississippi: environmental and cultural contexts and nutritional implications.

We investigated geophagia in the black population of rural Holmes County, Mississippi. Twenty-five sources of geophagical clays were located and most of the sources are associated with rural settlements throughout the county. Clays are taken from subsurface soil horizons, and all but one of the sources come from the upland portion of the county. Geophagia occurs among 57% of women and 16% of children of both sexes, but it is not found among adult males or adolescents. Average daily comsumption of clay is 50 g. Our data indicate geophagia is not correlated with hunger, anemia, or helminthic problems, but it may contribute to the common problem of hypertension. Geophagia has been suggested as one of the factors leading to hyperkalemia, but our data do not support this notion.     

Group B Streptococcus Recto-Vaginal Colonization in Near-Term Pregnant Women,Southwest Ethiopia

BackgroundGroup B Streptococcus (GBS) is recognized as an important cause of maternal and neonatal morbidity and mortality. Maternal vaginal carriage of GBS (Streptococcus agalactiae) can lead to vertical transmission to the neonate at the time of delivery. However, little is known about its prevalence, predictors and antibiotic susceptibility pattern in Jimma, Ethiopia. This study assessed the prevalence, antimicrobial susceptibility pattern and determinants of GBS recto-vaginal colonization among near-term pregnant women.MethodsA cross-sectional study was conducted from May to August 2015 at Jimma University Medical Centre in Southwest Ethiopia. Data through questionnaire and GBS isolates from vaginal and rectal swabs were collected. Antimicrobial susceptibility testing was performed.ResultsThe overall prevalence of GBS colonization among near term pregnant women (35–37 weeks) was 16.3% (22/135). The majority of GBS isolates were sensitive to Ampicillin and Penicillin G with 95.5% and 90.1%, respectively. Erythromycin and clindamycin were resisted by 50% and 40.9% of the isolates, respectively, whereas gentamicin was resisted by all isolates. GBS colonization was significantly associated with a history of preterm delivery (PTD) (AOR: 6.3, 95% CI: 1.42, 28.3) and history of urinary tract infection (UTI) during current pregnancy (AOR: 6.4, 95% CI, 1.95, 21.1).ConclusionOur study indicated that one among six near-term pregnant women had recto-vaginal GBS colonization. In places where universal screening is not feasible, selective screening for factors particularly history of PTD and UTI during current pregnancy may be a reasonable option. Antibiotic susceptibility testing should be performed while using Erythromycin, Clindamycin or Gentamicin.     

Helminth infection is associated with dampened cytokine responses to viral and bacterial stimulations in Tsimane forager-horticulturalists

BackgroundSoil-transmitted helminths (STHs) and humans share long co-evolutionary histories over which STHs have evolved strategies to permit their persistence by downregulating host immunity. Understanding the interactions between STHs and other pathogens can inform our understanding of human evolution and contemporary disease patterns.MethodologyWe worked with Tsimane forager-horticulturalists in the Bolivian Amazon, where STHs are prevalent. We tested whether STHs and eosinophil levels—likely indicative of infection in this population—are associated with dampened immune responses to in vitro stimulation with H1N1 and lipopolysaccharide (LPS) antigens. Whole blood samples (n = 179) were treated with H1N1 vaccine and LPS and assayed for 13 cytokines (INF-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, GM-CSF and TNF-ɑ). We evaluated how STHs and eosinophil levels affected cytokine responses and T helper (Th) 1 and Th2-cytokine suite responses to stimulation.ResultsInfection with Ascaris lumbricoides was significantly (P ≤ 0.05) associated with lower response of some cytokines to H1N1 and LPS in women. Eosinophils were significantly negatively associated with some cytokine responses to H1N1 and LPS, with the strongest effects in women, and associated with a reduced Th1- and Th2-cytokine response to H1N1 and LPS in women and men.Conclusions and implicationsConsistent with the ‘old friends’ and hygiene hypotheses, we find that STHs were associated with dampened cytokine responses to certain viral and bacterial antigens. This suggests that STH infections may play an essential role in immune response regulation and that the lack of STH immune priming in industrialized populations may increase the risk of over-reactive immunity. Lay Summary: Indicators of helminth infection were associated with dampened cytokine immune responses to in vitro stimulation with viral and bacterial antigens in Tsimane forager-horticulturalists in the Bolivian Amazon, consistent with the ‘old friends’ and hygiene hypotheses.     

The combined effect of the Lymphatic Filariasis Elimination Programme and the Schistosomiasis and Soil-transmitted Helminthiasis Control Programme on soil-transmitted helminthiasis in schoolchildren in Tanzania

The combined effect of the Lymphatic Filariasis Elimination Programme (LFEP) and the National Schistosomiasis and Soil-transmitted Helminthiasis Control Programme (NSSCP) on soil-transmitted helminthiasis (STH) was evaluated. In September 2004, before mass drug administration (MDA) with ivermectin and albendazole by the LFEP in October, the prevalence and intensity of STH were recorded in 228 pupils in one primary school. After 8 months, all available pupils were re-examined, and the prevalence of Ascaris lumbricoides, Trichuris trichiura and hookworm had decreased from 0.9 to 0.7% (P=0.84), from 4.8 to 0.7% (P=0.004) and from 45.6 to 11.9% (P<0.001), respectively. Overall, 81.2% of the schoolchildren stated that they were treated by the LFEP in October 2004. After the 8 months follow-up, pupils were treated with praziquantel and albendazole by the present project (substitute for the NSSCP). After another 4 months (at 12 months follow-up), the prevalence of hookworm infection was reduced to 4.8% (P=0.003), while the prevalence of T. trichiura was reduced to 0.3% (P=0.54) and the prevalence of A. lumbricoides remained unchanged. Mass co-administration of ivermectin and albendazole by the LFEP had a significant effect on STH, which was further amplified by treatment with praziquantel and albendazole 4 months later.     

High latrine coverage is not reducing the prevalence of soil-transmitted helminthiasis in Hoa Binh province, Vietnam

A baseline epidemiological survey for parasite infections was conducted between December 2007 and January 2008 in 155 villagers in a rural commune in Hoa Binh province, Vietnam. The prevalence of Ascaris lumbricoides, Trichuris trichiura and hookworm infection was 13.5%, 45.2% and 58.1%, respectively. At least one of the parasites was detected in 72.3% of the samples. We found no association between infection with A. lumbricoides or T. trichiura and engagement in agriculture, while hookworm infection was more prevalent in populations having frequent contact with soil. Agricultural use of human faeces was not correlated with any of the infections. We suggest that the consumption of vegetables that are commonly fertilized with human faeces in the community has led to the high infection rates with A. lumbricoides and T. trichiura, rather than the manipulation of faeces in farming activity. This also explains the high infection prevalence, despite high latrine coverage (98.1%) in the study population. The presence of latrines alone is not sufficient to reduce the prevalence of helminthiasis in a rural agricultural community if fresh faeces are used as fertilizer.     

Geophagy and its association with geohelminth infection in rural schoolchildren from northern KwaZulu-Natal,South Africa

The social pattern of geophagy (soil-eating) and its possible role in the transmission of Ascaris lumbricoides, Trichuris trichiura and hookworm were investigated in a rural area of South Africa between March 1998 and July 1999. Schoolchildren (median age = 10.7 years; interquartile range 8.3-14.8 years) were examined for geohelminth infection at baseline and re-examined 3 and 29 weeks after treatment with albendazole. Interviews were conducted with the pupils in order to find out about their socio-economic background and their behaviour regarding geophagy. Soil-eating was less frequent in boys (39%), where it decreased with age, than in girls (53%), where no such age trend was apparent. The habit was more common in children from families of higher socio-economic status. The baseline prevalence of A. lumbricoides infection was higher in pupils who regularly ate soil from termite mounds (28%) when compared with non-geophageous pupils (19%; prevalence ratio (PR) = 1.46; 95% confidence interval (95% CI) 1.04-2.03). In contrast it was markedly lower in the groups who preferred eating tree termite soil (13%; PR = 0.67; 95% CI 0.43-1.04) or soil from other sources (8%; PR = 0.40; 95% CI 0.15-1.04). This pattern was still apparent after adjusting for possible confounders and was also found when analysing A. lumbricoides reinfection. In contrast, differences in prevalence of T. trichiura and hookworm infection between groups with different soil preference were small.     

Impact of Community-Based Nutrition Education on Geophagic Behavior and Dietary Knowledge and Practices among Rural Women in Nakuru Town,Kenya: A Pilot Study

Objective

Geophagia, the deliberate consumption of rocks, soil, or clay, is prevalent in developing countries, particularly sub-Saharan Africa. Health risks associated with this behavior include parasitosis, heavy metal poisoning, nutrient deficiencies, and poor birth outcomes. This pilot study was designed to reduce geophagic practices and improve nutrition among rural Kenyan women.

土源性线虫感染对儿童生活质量影响因素分析

目的:探讨土源性线虫(STH)感染对儿童生活质量的影响,为提高儿童尤其是STH感染儿童生活质量提供依据。方法:采用Kato-Katz法,对小学5～6年级儿童进行粪便病原学检查,一送三检查蛔虫、钩虫、鞭虫等土源性线虫虫卵,并按WHO标准感染度分级为轻、中、重度感染;应用SF-12量表对参与粪检的507例儿童进行问卷调查。结果:回收合格问卷472份。STH感染175例,感染率37.1%。中重度以上感染79例,感染率16.7%;中重度STH感染儿童生理评分(PCS)和心理评分(MCS)(14.32±3.69和16.08±4.17),低于轻度感染儿童PCS和MCS(15.54±3.37和17.30±4.39)及未受感染儿童PCS和MCS(16.86±3.37和18.68±3.84),差异有统计学意义(P<0.001);逐步回归分析显示,影响儿童生活质量的主要因素:土源性线虫感染、母亲文化、过去1个月经常腹痛、饭前便后不洗手、过去1个月是否患病等。结论:STH感染影响儿童生活质量。做好学龄儿童卫生保健,养成良好卫生习惯,重视儿童慢性疾病的预防与控制,提高父母文化是改善STH感染儿童生活质量的重要途径。     

Cross-sectional relationship between HIV, lymphatic filariasis and other parasitic infections in adults in coastal northeastern Tanzania

The relationship between HIV, lymphatic filariasis, malaria (Plasmodium falciparum) and intestinal helminths (Ascaris lumbricoides, Trichuris trichiura and hookworm) was assessed in a cross-sectional study conducted in 2002 among 907 adults in Tanga Region, Tanzania. Overall prevalences were 7.9% for HIV, 43.5% for Wuchereria bancrofti-specific circulating filarial antigen (CFA), 12.3% for P. falciparum, 1.2% for A. lumbricoides, 7.1% for T. trichiura and 75.7% for hookworm. Anaemia was assessed separately for males and females and was found to be more prevalent among females (58.8%) than males (34.8%). When sex and age were controlled for, there was a statistically significant positive association between HIV and W. bancrofti (CFA) infection and between malaria and HIV, but not between malaria and W. bancrofti (CFA) infection. Hookworm infection was positively associated with W. bancrofti (CFA) infection but, surprisingly, negatively associated with HIV. Infection with HIV and hookworms, but not malaria, was associated with a significant reduction in haemoglobin concentration. These associations are likely to reflect underlying mechanisms that need to be clarified to better understand the role of co-infections in HIV pathogenesis, and vice versa.     

Enteroparasitosis in pregnant and post-partem women in Rio de Janeiro

From November 1989 to May 1991, in Rio de Janeiro, Brazil, the prevalence of intestinal parasitosis was investigated in 795 women coming from the Public Health Services, who were divided into three groups: 490 pregnant women in pre-natal care period, 104 after-delivery women and 201 non-pregnant women (control). Coproparasitologic tests were run using the Sedimentation through Centrifugation, Faust, Kato-Katz and Baermann-Moraes methods. Positivities were found ranging from 37.6% to 53.6% for pregnant women, 38.3% for non-pregnant women and 69.2% for after-delivery women, with statistically significant differences between the rates of pregnant women and after-delivery women, and with no statistic difference between the groups of pregnant and non-pregnant women. The most frequent parasites found were A. lumbricoides and T. trichiura. The conclusion was that the control of intestinal parasitosis is not a priority in the pregnant population studied because, in spite of the regular assistance provided during the pre-natal care period, they keep on infected.     

Epidemiology of helminth infections and their relationship to clinical malaria in southwest Uganda

It has recently been suggested that helminth infections may adversely influence susceptibility to other infections, including malaria. To investigate this hypothesis in a sub-Saharan African setting, surveys of helminth infections were conducted in 2003 among individuals who had been under weekly active case detection for clinical malaria during the preceding 18 months in four villages in Kabale District, southwest Uganda. Overall, 47.3% of individuals had at least one intestinal nematode species infection: hookworm, Ascaris lumbricoides and Trichuris trichiura were detected in 32.1, 17.4 and 8.1% of individuals, respectively. We found evidence of significant household clustering of A. lumbricoides, T. trichiura and hookworm, and clustering of heavy infection of each species. The association between helminth infection and clinical malaria was investigated in two villages and no evidence for an association was observed between the presence of infection or heavy infection and risk of malaria.     

The impact of iron supplementation on reinfection with intestinal helminths and Schistosoma mansoni in western Kenya

A randomized, placebo-controlled, double-blind trial was carried out in 1994-96 among 231 children and 181 adults in order to determine the effects of iron on reinfection rates and intensities of hookworm, Ascaris lumbricoides, Trichuris trichiura and Schistosoma mansoni. Adults given 60 mg elemental iron twice-weekly for 12 months had significantly lower reinfection rates of A. lumbricoides (16.7% vs 31.9%, P = 0.046), T. trichiura (6.9% vs 20.6%, P = 0.03) and S. mansoni (38.3% vs 61.8%, P = 0.008) compared to adults given placebo. In contrast, adults allocated to iron had a significantly higher reinfection rate of hookworm at the 4-month examination (11.1% vs 0%, P = 0.009), but the difference was not significant at 8- and 12-month follow-up examinations. Iron supplementation had no effect on reinfection intensities in adults. Surprisingly, iron supplementation had no effect on either reinfection rates or intensities in children. Multiple logistic regression analyses controlling for baseline infection status confirmed the effect in adults of iron on A. lumbricoides, T. trichiura and S. mansoni reinfection rates. The effect is suggested to be due to reduced risk behaviour, to improved immune function or to unfavourable host gut conditions caused by an increased oxidative stress. In each case, the lack of effect in children remains to be explained. In contrast, iron supplementation apparently was short-lived in favour of hookworm infection, an effect that needs further clarification. The findings suggest that iron supplementation has a role to play in helminth control programmes and that intraluminal factors may contribute to the regulation of some helminth infections.     

Intestinal parasite infections in a semiarid area of Northeast Brazil: preliminary findings differ from expected prevalence rates

We report on intestinal parasite infection prevalence in a population sample from S o Raimundo Nonato, Southeast Piau State, Brazil, aimed at comparison with previous studies on Trichuris trichiura and Ascaris lumbricoides infection. A total of 265 stool specimens were collected and examined by spontaneous sedimentation. Approximately 57% of specimens were infected with at least one parasite species. Entamoeba coli (35.8%), Endolimax nana (13.6%), Hymenolepis nana (9.4%), and hookworm (9.4%) were the most frequently observed parasites. Two cases of roundworm infection were detected, probably acquired outside the region. T. trichiura eggs were not found. Interestingly, neither A. lumbricoides nor T. trichiura has been found in local prehistoric human coprolites. Nevertheless, hookworm infection has been present in the region for at least 7,000 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.     

Soil-transmitted helminth infections at very high altitude in Bolivia

A cross-sectional study of soil-transmitted helminthiases in the Northern Bolivian Altiplano was carried out over the 6-year period 1992-97. Prevalences, intensities and associations were analysed from coprological results obtained in 31 surveys (28 in schools and 3 in individuals of all age-groups) performed in 24 Aymara communities located between the city of La Paz and Lake Titicaca, at an altitude of 3800-4200 m. Ascaris lumbricoides and Trichuris trichiura were detected, with local prevalences in the range 1.2-28.0% and 0.0-24.0%, respectively. Significant differences in prevalence rates of trichuriasis were detected, with highest prevalences in male schoolchildren and in subjects aged > 40 years. The global intensity ranged from 24 to 86,544 eggs per gram of faeces (epg) and from 24 to 4560 epg for ascariasis and trichuriasis, respectively. Higher intensities were noted in girls. A. lumbricoides egg counts were statistically significantly higher in the 5-8-years age-group. A positive association between A. lumbricoides and T. trichiura infections was detected. The proportion of heavy infections for A. lumbricoides was 0.1% and 1.0% in the school and community surveys, respectively. No heavy infection for T. trichiura was detected. The very high altitude and its severe environmental conditions may determine the relatively low prevalences and intensities in this area.     

学龄儿童生长发育迟缓及其与土源性线虫感染的关系

【目的】 了解学龄儿童生长发育迟缓现状及其相关影响因素。 【方法】 在广西、海南两地农村地区,对3个乡15个学校的1 031名9~12岁儿童生长发育进行现况调查,调查内容包括:填写问卷、病原学检测、体格测量以及实验室检测等。问卷涉及儿童、家长及家庭经济状况等信息。病原学粪便检测采用Kato-Katz涂片法一送三检查三种主要土源性线虫 (钩虫、蛔虫和鞭虫) 虫卵并感染度分级为轻、中、重度感染。测量儿童身高体重并采用WHO标准计算年龄别身高(Height-for-age, HA)的Z评分值,作为评定儿童生长发育迟缓的指标。检测血红蛋白评价儿童是否贫血。使用EpiData3.0软件建立数据库,SPSS16.0软件进行统计分析。 【结果】 儿童生长发育迟缓(HAZ<2)264人,占25.6%。生长发育迟缓的危险因素:1)中重度土源性线虫感染(OR=1.927,95%CI:1.194~3.110);2)贫血(OR=3.26,95%CI:2.02~5.27),母亲的文化程度(OR=2.13,95%CI:1.39~3.25)。土源性线虫感染378例,感染率为36.7%;中、重度感染173例,感染率为16.8%。单纯蛔虫、钩虫和鞭虫感染的感染率为11.2%(115/1 031)、11.5%(119/1 031)和4.9%(51/1 031),混合感染的感染率为9.1%(93/1 031)。贫血(Hb<120 g/L)135人,患病率为13.1%。 【结论】 生长发育迟缓在研究地区患病率高,且土源性线虫感染,尤其是中重度感染是生长发育迟缓的重要危险因素。     

Age-related prevalence, intensity and frequency distribution of gastrointestinal helminth infection in urban slum children from Kuala Lumpur, Malaysia

The gastrointestinal helminth infection status of 1574 children living in a slum area of Kuala Lumpur, Malaysia was assessed by quantitative coprology. Almost two-thirds were infected with Trichuris trichiura, 49.6% with Ascaris lumbricoides, and 5.3% with hookworm. Infection prevalence rose rapidly to a stable asymptote at 7 years of age, and the age-intensity profile was convex with maximal values in the 5-10 year age classes. This pattern was the same for males and females, but differed markedly between different ethnic groups. The frequency distributions of A. lumbricoides and T. trichiura were highly overdispersed (k values were 0.21 and 0.27, respectively), and age-dependent over the 0-8 year age classes. This suggests that the force of infection with these nematodes is lower in infants than in older children.