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

Prevalence of soil-transmitted helminths and associated risk factors among primary school children in Kandahar, Afghanistan: A cross-sectional analytical study

BACKGROUND

Soil-transmitted helminth (STH) infections are global health problem, especially in low-income countries. Main objectives of this study were to estimate the prevalence and intensity of STH and its risk factors among school children in Kandahar city of Afghanistan.

METHODOLOGY/PRINCIPAL FINDINGS

This was a school-based cross-sectional analytical study, with data collected during eight-month-period (May-December, 2022) from 6- and 12-years old school children in Kandahar city, Afghanistan. All the stool samples were examined by saline wet mount method and Kato-Katz technique. Data were analyzed by using descriptive statistics, Chi square test, and multivariate logistic regression. A total of 1275 children from eight schools of Kandahar city were included in this study. Mean age of these children was 8.3 years with 53.3% boys. The overall prevalence of any intestinal parasitic infection was 68.4%. The overall prevalence of STH infection was 39.1%, with Ascaris lumbricoides (29.4%) as the most prevalent STH species. Mean intensity of overall STH infection was 97.8. Multivariate logistic regression revealed playing barefoot (AOR 1.6, 95% CI 1.1-2.2), not washing hands after defecating and before eating (AOR 1.3, 95% CI 1.0-1.7), having untrimmed nails (AOR 1.4, 95% CI 1.1-1.8), and belonging to poor families (AOR 1.3, 95% CI 1.0-1.7) as the risk factors associated with the predisposition of school children for getting STH in Kandahar city of Afghanistan.

CONCLUSIONS/SIGNIFICANCE

There is high prevalence of STH among school children of Kandahar city in Afghanistan. Most of the risk factors are related to poverty, decreased sanitation, and improper hygiene. Improvement of socioeconomic status, sanitation, and health education to promote public awareness about health and hygiene together with periodic mass deworming programs are better strategies for the control of STH infections in Afghanistan.

Micronutrients deficiencies and its correlation with the soil-transmitted helminthic infections among children and non-pregnant women in Nepal: findings from Nepal national micronutrient status survey

Despite having a high risk of soil-transmitted helminths (STHs) infection, no national level study has been conducted to assess incidence and correlates of STHs in Nepal. Thus, we hypothesized that micronutrients and social status are linked with incidence of STHs infection among 6-59 months children and 15-49 years non-pregnant women in Nepal and Kato-Katz technique was adopted to measure the type and intensity of STHs infections using fresh stool specimens and venous blood was used to examine micronutrients biomarkers. Anthropometric measurements such as height and weight, sociodemographic and health status were determined using structured questionnaire. Logistic regression was used to assess unadjusted and adjusted odds ratio (AOR) and the 95% CIs of ORs. The bivariate association of STHs was assessed with the covariates variables. Overall, 12% children and 19% non-pregnant women had STHs infection; A. lumbricoides was the predominant helminth in both study participants. In multivariate model; age, ethnicity, anaemia and zinc deficiency were associated with STHs infections in children. Similarly, higher odds of STHs occurrence was observed among non-pregnant women with vitamin A deficiency. Findings from this study suggest that high-risk population, with a focus on those of lower socioeconomic status should be on priority of deworming program, nutrition intervention, and mass administration of preventive chemotherapy and sanitation champions supplement to reduce the STHs infections in Nepal.

An assessment of implementation and effectiveness of mass drug administration for prevention and control of schistosomiasis and soil-transmitted helminths in selected southern Malawi districts

Background

Mass drug administration (MDA) is one of the key interventions recommended by WHO for prevention and control of neglected tropical diseases (NTD). In Malawi, MDA is widely carried out annually since 2009 for prevention and control of schistosomiasis and soil-transmitted helminths (STH). No study has been carried out to assess effectiveness of the MDA approach and to document perceptions of health providers and beneficiaries regarding use of MDA. This study was done to understand how well MDA is being implemented and to identify opportunities for improvement in MDA delivery in Malawi.

Methods

Designed as a cross-sectional and multi-methods research, the study was carried out in three southern Malawi districts of Chiradzulu, Mangochi and Zomba. In each district, four health centres and 16 villages were randomly selected to participate. A mixed-methods approach to data collection focusing on quantitative data for coverage and knowledge, attitudes and practices assessments; and qualitative data for assessing perceptions of health providers and beneficiaries regarding MDA was used. Quantitative data were processed and analyzed using IBM SPSS software version 26 while qualitative data were analysed using NVivo 12 for Windows.

Results

Knowledge levels about schistosomiasis and STH in the districts varied according to disease aspects asked about. Majority are more knowledgeable about what schistosomiasis is (78%) and whether STH are treatable with drugs (97%); with least knowledgeable about the organism that transmits schistosomiasis (18%), types of schistosomiasis (11%) and what causes STH (20%). In 2018 and 2019 the districts registered high coverage rates for praziquantel and albendazole using community-based MDA (73–100%) and using school-based MDA (75–91%). Both the health authorities and community members perceived the MDA approach as good because it brings treatment closer to people.

Conclusion

With the high MDA coverage obtained in communities and schools, the effectiveness of MDA in the target districts is satisfactory. There are, however, several challenges including disproportionate knowledge levels, which are hampering progress towards attainment of the 2030 global NTD goals. There is a need for promotion of community participation and partnerships as well as implementation of other recommended interventions for sustainable prevention and control of schistosomiasis and STH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-07925-3.

Prevalence and associated risk factors of soil-transmitted helminth infections in Kandahar, Afghanistan

Background

Soil-transmitted helminth (STH) infections are still a major health problem, especially in resource-limited countries. The community-based prevalence of STH is unknown in Afghanistan. Main objectives of this study were to estimate the prevalence and associated factors of STH among children in Daman district of Kandahar province in Afghanistan.

Methods

This was a community-based cross-sectional study, with data collected during five months (June–October, 2020) from children living in five villages of Daman district in Kandahar, Afghanistan. All the stool samples were examined by saline wet mount method. Data were analyzed by using descriptive statistics, Chi square test, and multivariate logistic regression.

Results

A total of 1426 children were studied, with majority (61.8%) of males and the mean age of 6.3 years. The overall prevalence of any intestinal parasitic infection was 39.8%. The overall prevalence of STH infection was 22.7%, with Ascaris lumbricoides (18.7%) as the most prevalent STH species, followed by hookworm (7.5%) and Trichuris trichiura (1.4%). Single, double, and triple STH infections were present in 14.9%, 7.2%, and 0.6% of the children, respectively. Multivariate logistic regression revealed that not washing hands after defecating/before eating (AOR 7.0, 95% CI 3.4–14.0), living in mud house (AOR 3.5, 95% CI 1.6–7.4), walking barefoot (AOR 2.2, 95% CI 1.6–3.1), living in overcrowded house (AOR 1.6, 95% CI 1.1–2.3), and practicing open defecation (AOR 1.4, 95% CI 1.1–2.0) as the risk factors associated with the predisposition of rural children for getting STH in Daman district of Afghanistan.

Conclusions

Prevalence of STH is high among children of Daman district in Afghanistan. Most of the risk factors are related to poverty, decreased sanitation, and improper hygiene. Improvement of socioeconomic status, sanitation, and health education to promote public awareness about health and hygiene together with periodic mass deworming programs are better strategies for the control of STH infections in Afghanistan. Also, government and international donor agencies in Afghanistan should help in improving socio-economic status of the rural areas through provision of basic facilities such as piped water, electricity, good housing, and proper toilets.

Soil-transmitted helminth infections and nutritional indices among Filipino schoolchildren

BACKGROUND

Soil-transmitted helminth (STH) infections are still prevalent among schoolchildren in the Philippines. We evaluated the risk factors associated with STH and the relationship between STH and nutritional indices among schoolchildren aged 9-10 years in Laguna province, the Philippines.

METHODS

We used the baseline data from 40 schools enrolled in a randomised controlled trial of the Magic Glasses Philippines health education package. Data on demographic and socio-economic variables, and STH related knowledge, attitudes and practices, were obtained through a questionnaire. Stool samples were collected and assessed for STH egg presence using the Kato-Katz technique. Haemoglobin levels and height and weight of study participants were also determined. The generalized estimating equations approach was used to construct logistic regression models to assess STH-associated risk factors, and the association between any STH infection and anaemia, child stunting, wasting and being underweight. The trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12616000508471).

FINDINGS

Among 1,689 schoolchildren, the prevalence of any STH was 23%. The prevalence of anaemia, stunting, being underweight and wasting was 13%, 20.2%, 19% and 9.5%, respectively. Age, socio-economic status, rural/urban classification of schools and knowledge of STH were significant risk factors for acquiring a STH infection. Moreover, infections with any STH were significantly associated with stunting (P = <0.001) and being underweight (P = <0.003), but not wasting (P = 0.375) or anaemia (P = 0.462) after controlling for confounding covariates.

CONCLUSION

The study findings emphasise the need for sustainable deworming in tandem with other measures such as the provision of health education, improvements in sanitation and hygiene, and nutritional programs in order to control STH infections and improve morbidity outcomes in schoolchildren.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12616000508471).

Epidemiology of soil-transmitted helminths following sustained implementation of routine preventive chemotherapy: Demographics and baseline results of a cluster randomised trial in southern Malawi

Malawi has successfully leveraged multiple delivery platforms to scale-up and sustain the implementation of preventive chemotherapy (PCT) for the control of morbidity caused by soil-transmitted helminths (STH). Sentinel monitoring demonstrates this strategy has been successful in reducing STH infection in school-age children, although our understanding of the contemporary epidemiological profile of STH across the broader community remains limited. As part of a multi-site trial evaluating the feasibility of interrupting STH transmission across three countries, this study aimed to describe the baseline demographics and the prevalence, intensity and associated risk factors of STH infection in Mangochi district, southern Malawi. Between October-December 2017, a community census was conducted across the catchment area of seven primary healthcare facilities, enumerating 131,074 individuals across 124 villages. A cross-sectional parasitological survey was then conducted between March-May 2018 in the censused area as a baseline for a cluster randomised trial. An age-stratified random sample of 6,102 individuals were assessed for helminthiasis by Kato-Katz and completed a detailed risk-factor questionnaire. The age-cluster weighted prevalence of any STH infection was 7.8% (95% C.I. 7.0%-8.6%) comprised predominantly of hookworm species and of entirely low-intensity infections. The presence and intensity of infection was significantly higher in men and in adults. Infection was negatively associated with risk factors that included increasing levels of relative household wealth, higher education levels of any adult household member, current school attendance, or recent deworming. In this setting of relatively high coverage of sanitation facilities, there was no association between hookworm and reported access to sanitation, handwashing facilities, or water facilities. These results describe a setting that has reduced the prevalence of STH to a very low level, and confirms many previously recognised risk-factors for infection. Expanding the delivery of anthelmintics to groups where STH infection persist could enable Malawi to move past the objective of elimination of morbidity, and towards the elimination of STH. Trial registration: NCT03014167.

The Incidence, Intensity, and Risk Factors for Soil Transmissible Helminthes Infections among Waste Handlers in a Large Coastal Periurban Settlement in Southern Ghana

Soil-transmissible helminthes (STH) infections are among the most common sanitation-related public health problems in poor periurban settlements of tropical regions of low- and middle-income countries. In Ghana, research studies documenting the incidence rate, intensity, and occupational risk factors of STH infections among adults are scanty. A prospective cohort study of 261 waste handlers was conducted to investigate this. Stool samples were collected after 90 and 180 days of treatment with albendazole (400 mg per dose). The geometric mean intensity of STH among waste handlers after 180 days of treatment was 2.8 eggs/gram (light intensity), with an incidence rate of 1.5%. The proportion of waste handlers with light intensity STH infections was 4.8%. The odds of STH infection among female waste handlers were 80% lower when compared with male waste handlers (aOR = 0.2; 95% CI: 0.0-0.8). Waste handlers who used rubber gloves when working were 80% (aOR = 0.2: 95% CI: 0.2-1.9) protected from STH infections compared with those who did not use gloves. Infections with STH among the 261 waste handlers significantly correlated with the type of waste handling activities (LR χ 2 = 15.3; p=0.033) with the highest proportion of infection found among transporters, 2 (40%). Waste handlers should receive periodic antihelminthic treatment, at least once every six months, practice adequate hand hygiene, and use suitable personal protective equipment during work.

Epidemiology of intestinal parasitic infections in preschool and school-aged Ethiopian children: a systematic review and meta-analysis

BACKGROUND

Numerous studies have been carried out on assessing the prevalence of intestinal parasites infections (IPIs) amongpreschool and school-age children in Ethiopia, but there is lack of study systematically gathered and analyzedinformation for policymakers. Therefore, the aim of this systematic review and meta-analysis was to provide a summary on prevalence, geographical distribution and trends of IPIs among preschool and school-age childrenin Ethiopia.

METHODS

The search were carried out in Medline via PubMed, Scopus, Science Direct, Web of Science, and Google Scholar from 1996to July2019 for studies describing prevalence of IPIs among preschooland school-age children. We conducted meta-regression to understand the trends and the source of heterogeneity and pooled the prevalence using 'metaprop' command using STATA software version 14.

RESULTS

Eighty-three(83) studies examining 56,786 fecal specimens were included. The prevalence of IPIs was 48%(95%CI: 42 to 53%) and showedsignificantly decreasing trends 17% (95% CI: 2.5 to 32%) for each consecutive 6 years) and was similar in males and females. The pooled prevalence in years 1997-2002, 2003-2008, 2009-2014 and > 2014 was 71% (95% CI: 57 to 86%), 42% (95% CI: 27 to 56%), 48% (95% CI: 40 to 56%) and 42% (95% CI: 34 to 49%), respectively. Poly-parasitism was observed in 16% (95% CI: 13 to 19%,) of the cases.

CONCLUSION

Intestinal parasite infections are highly prevalent among preschool and school-age children and well distributed across the regional states of Ethiopia. Southern and Amhara regional states carry the highest burden. We observed significant decreasing trends in prevalence of IPIs among preschool and school-ageEthiopian children over the last two decades. Therefore, this study is important to locate the geographical distribution and identified high risk areas that should be prioritized further interventions, which complement global efforts towards elimination of IPIs infections by 2020.

Intestinal parasite infections and associated factors among inmates of Arba Minch prison, southern Ethiopia: cross sectional study

Background

Intestinal parasitic infection is one of the parasitic infections affecting people living in prison. Helminths and intestinal protozoan infections are the most common parasitic infection that may cause serious life-threatening diseases in inmates living in developing countries. This study was aimed to investigate the prevalence and associated factors of intestinal parasitic infections (IPIs) among inmates living in Arba Minch prison, southern Ethiopia.

Methods

Institutional based cross sectional study was conducted on Arba Minch inmates, southern Ethiopian. Pre-tested semi-structured questionnaire was used to gather the data of socio-demographic characteristics, hygiene status of the prisoners, sanitation condition of the prison, and associated factors for IPIs by face to face interview. Direct wet-mount examination and formol-ether sedimentation techniques were used to examine intestinal parasitic infection from stool specimens. Binary logistic regression analysis was used to see the association between different variables and the IPI. Odds ratio with 95% CI was computed to determine the presence association and strength of the associated factors.

Result

A total of 320 prisoners were participated in this study. Of these, 154(48.1%) of them were infected with one or more intestinal parasites. Eight different intestinal parasites species were identified and Giardia lamblia was the predominant parasite. Among infected inmates, nearly one out of four of them had multiple parasitic infections dominated by Giardia lamblia and E. histolytica/dispar co-infection. Sleeping in group [AOR = 1.9; 95% CI: (1.0–3.8)], married prisoners [AOR = 1.8; 95% CI: (1.1–2.9)], and hand washing habits after handling soil [AOR = 2.4; 95% CI: (1.0–5.6)] were independently associated with IPI.

Conclusion

High prevalence of intestinal parasitic infection was detected in Arba Minch inmates, southern Ethiopian. Absence of hand washing, marital status, and way of sleeping were the factors associated with the IPI. Implementation of mass drug administration, education on water, sanitation and hygiene (WASH) and periodic screening of intestinal parasitic infection is very important to reduce the high prevalence IPIs in prison.

A prevalence survey of enteral parasites in preschool children in the Mangochi District of Malawi

BACKGROUND

Helminthic and protozoan infections are common, particularly in low- or middle-income countries. Although an association between parasite carriage and markers of poor growth have been shown in some studies, systematic reviews have suggested only a modest impact of clearing carriage. The prevalence of these pathogens and the effect that they have on growth in preschool children has never been investigated in Malawi.

METHODS

One hundred ninety-three children aged 0-72 months were randomly recruited from rural villages in the Mangochi district of Malawi. Formol-ether concentration was performed on stool and the samples examined with a light microscope. Anthropometric data was taken for each child and the haemoglobin measured with a point of care test.

RESULTS

The mean age of the children was 2 years 4 months. Overall prevalence of intestinal parasite infection was 37.3%. Protozoa were found in 28.5% of children, while helminths were found in 8.8%. The most commonly found organisms were Giardia lambia (12.4%), Entamoeba coli (10.4%) and Hookworm species (3.6%). Stunting was seen in 47.8% of children, 12.9% were underweight and 5.0% were wasted. No significant association was found between markers of poor growth and infection with any intestinal parasite.

CONCLUSIONS

We found that prevalence of helminth infection was low in preschool children living in the Mangochi district compared to international standards. However a significant proportion of the preschool population are infected with protozoa, particularly Giardia lambia. In this cohort, despite a significant prevalence of stunting, helminth infection was not significantly associated with any markers of poor growth. The significance of protozoal carriage and contribution to growth restriction in this context creates further avenues for future research.

Inactivation of pathogens in ecological sanitation latrines in Malawi: An observational follow up study

Introduction

In Malawi, EcoSan sludge from ecological sanitation (EcoSan) latrines has been found to contain helminths, Salmonella and E. coli above WHO recommended levels making sludge unsuitable for direct handling and use on food crops. This research investigated survival of pathogens in EcoSan sludge with time after sealing the pit.

Method

An observational longitudinal follow-up study was conducted where EcoSan latrines were followed from August 2015 to July 2016 in Blantyre and Chikwawa in Southern Malawi. The study enrolled 51 latrines in total with 35 latrines [13 fossa alterna (FAs) and 22 urine diverting dry latrines (UDDLs)] remaining at the end of study. Samples were collected five times from each latrine and examined for helminths, Salmonella and E. coli in the laboratory. Poisson regression was employed to assess factors that significantly contribute to pathogen die off at p<0.05.

Results

Average concentrations of all pathogens investigated reduced over 12-month follow-up period except for Salmonella which increased. A. lumbricoides, increased to 2.3 viable eggs during the second sampling and decreased to 0.4 viable eggs per gram after 12 months of follow-up. Time was the only consistent predictor for concentration of helminths. Type of latrine and location were not significant predictors of helminths concentration (p>0.05). However, Salmonella and E. coli colonies were significantly higher in UDDLs (Blantyre) than FAs (Chikwawa) (p<0.05).

Conclusion

Pathogen concentration was highest after recommended six months of storage posing a public health risk to those handling and using it for agriculture purposes. It is therefore recommended that the current guidelines be reviewed to suit Malawi context. A storage period of one year or more is recommended.

Risk factors for childhood enteric infection in urban Maputo, Mozambique: A cross-sectional study

BACKGROUND

Enteric infections are common where public health infrastructure is lacking. This study assesses risk factors for a range of enteric infections among children living in low-income, unplanned communities of urban Maputo, Mozambique.

METHODS & FINDINGS

We conducted a cross-sectional survey in 17 neighborhoods of Maputo to assess the prevalence of reported diarrheal illness and laboratory-confirmed enteric infections in children. We collected stool from children aged 1-48 months, independent of reported symptoms, for molecular detection of 15 common enteric pathogens by multiplex RT-PCR. We also collected survey and observational data related to water, sanitation, and hygiene (WASH) characteristics; other environmental factors; and social, economic, and demographic covariates. We analyzed stool from 759 children living in 425 household clusters (compounds) representing a range of environmental conditions. We detected ≥1 enteric pathogens in stool from most children (86%, 95% confidence interval (CI): 84-89%) though diarrheal symptoms were only reported for 16% (95% CI: 13-19%) of children with enteric infections and 13% (95% CI: 11-15%) of all children. Prevalence of any enteric infection was positively associated with age and ranged from 71% (95% CI: 64-77%) in children 1-11 months to 96% (95% CI: 93-98%) in children 24-48 months. We found poor sanitary conditions, such as presence of feces or soiled diapers around the compound, to be associated with higher risk of protozoan infections. Certain latrine features, including drop-hole covers and latrine walls, and presence of a water tap on the compound grounds were associated with a lower risk of bacterial and protozoan infections. Any breastfeeding was also associated with reduced risk of infection.

CONCLUSIONS

We found a high prevalence of enteric infections, primarily among children without diarrhea, and weak associations between bacterial and protozoan infections and environmental risk factors including WASH. Findings suggest that environmental health interventions to limit infections would need to be transformative given the high prevalence of enteric pathogen shedding and poor sanitary conditions observed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02362932.

Geographical distribution of soil transmitted helminths and the effects of community type in South Asia and South East Asia - A systematic review

BACKGROUND

Soil-transmitted helminth (STH) infections are among the most prevalent neglected tropical diseases (NTD) worldwide. Since the publication of the WHO road map to combat NTD in 2012, there has been a renewed commitment to control STH. In this study, we analysed the geographical distribution and effect of community type on prevalence of hookworm, Trichuris and Ascaris in south Asia and south east Asia.

METHODOLOGY

We conducted a systematic review of open-access literature published in PubMed Central and the Global Atlas of Helminth Infection. A total of 4182 articles were available and after applying selection criteria, 174 studies from the region were retained for analysis.

PRINCIPAL FINDINGS

Ascaris was the commonest STH identified with an overall prevalence of 18% (95% CI, 14-23%) followed by Trichuris (14%, 9-19%) and hookworm (12%, 9-15%). Hookworm prevalence was highest in Laos, Vietnam and Cambodia. We found a geographical overlap in countries with high prevalence rates for Trichuris and Ascaris (Malaysia, Philippines, Myanmar, Vietnam and Bangladesh). When the effect of community type was examined, prevalence rates of hookworm was comparable in rural (19%, 14-24%) and tribal communities (14%, 10-19%). Tribal communities, however, showed higher prevalence of Trichuris (38%, 18-63%) and Ascaris (32%, 23-43%) than rural communities (13%, 9-20% and 14%, 9-20% respectively). Considerable between and within country heterogeneity in the distribution of STH (I2 >90%) was also noted. When available data from school aged children (SAC) were analysed, prevalence of Ascaris (25% 16-31%) and Trichuris (22%, 14-34%) were higher than among the general population while that of hookworm (10%, 7-16%) was comparable.

CONCLUSIONS/SIGNIFICANCE

Our analysis showed significant variation in prevalence rates between and within countries in the region. Highlighting the importance of community type in prevalence and species mix, we showed that tribal and rural communities had higher hookworm infections than urban communities and for ascariasis and trichuriasis, tribal populations had higher levels of infection than rural populations. We also found a higher prevalence of ascariasis and trichuriasis in SAC compared to the general population but comparable levels of hookworm infections. These key findings need to be taken into account in planning future MDA and other interventions.

Estimating the Health Risk Associated with the Use of Ecological Sanitation Toilets in Malawi

Use of Ecological Sanitation (EcoSan) sludge is becoming popular due to increasing price of organic fertilizers in Malawi; however, there is little evidence on the associated risks. Quantitative microbiological risk assessment (QMRA) was done to determine health risks associated with use of EcoSan. Pathogens considered included Escherichia coli (E. coli), Salmonella, and soil transmitted helminths (STHs). Exponential and Beta Poisson models were used to estimate the risk from helminthic and bacterial pathogens, respectively. Main exposure pathways were through poor storage of sludge, contamination of foods during drying, walking barefoot on the ground contaminated with sludge, pit emptying without protection, and application of sludge in the fields. Estimated annual risk for Ascaris lumbricoides, Taenia, and hookworms was approximately over 5.6 × 10⁻¹ for both Fossa Alternas (FAs) and Urine Diverting Dry Toilet (UDDTs). Risk from E. coli and Salmonella was 8.9 × 10⁻² and above. The risks were higher than WHO acceptable risk for use of faecal sludge in crops of 10⁻⁴ infections per year. Promoters and users of EcoSan latrines need to consider advocating for strict guidelines to reduce the risk.

Is there a difference in prevalence of helminths between households using ecological sanitation and those using traditional pit latrines? A latrine based cross sectional comparative study in Malawi

Background

Studies have shown that households using sludge from human excreta for agriculture are at an increased risk of soil transmitted helminths. However, while use of ecological sanitation (EcoSan) latrines is increasing in most African countries including Malawi, few studies have been done to check whether use of such sludge could potentially increase the prevalence of helminthic infections among household members as a results of exposure to faecal sludge/compared to use of traditional latrines.

Methods

A cross sectional study was done targeting households using EcoSan and traditional pit latrines. Samples were collected from both types of latrines in Chikwawa (rural) and Blantyre (urban) districts. These two districts have a high number of EcoSan latrines in southern region of Malawi. 156 latrines were sampled (n = 95 traditional; n = 61 EcoSan), and processed following standard guidelines using modified triple floatation method. Identification of helminth ova (Ascaris lumbricoides, hookworms, Trichuris trichiura, Taenia spp. and Diphyllobothrium latum) was done using standard microscopy methods. The difference between the prevalence and mean concentration of helminths between the two types of latrines was tested using Chi Square and t test respectively.

Results

Of the total latrines tested, 85.9% (n = 134) had at least one species of helminth while 84.6% (n = 132) had at least a STH, with 82.0% (n = 50) in EcoSan and 86.3% (n = 82) in traditional pit latrines. There was no significant difference between the prevalence of helminths in EcoSan and traditional pit latrines [χ² = 0.43 (1), P = 0.5]. The prevalence of Ascaris lumbricoides was significantly higher in EcoSan than in traditional pit latrines [χ² = 5.44 (1) p = 0.02] while prevalence of hookworms was significantly higher in traditional pit latrines than in EcoSan latrines [χ² = 13.98 (1) p < 0.001]. The highest concentration of helminths per gram of faecal sludge was in traditional pit latrines [31.2 (95% CI 19.1–43.2)] than in EcoSan latrines [26.4 (95% CI 16.5–36.3)].

Conclusion

There was no significant difference between overall prevalence of helminths between households using EcoSan and those using traditional pit latrines. However, Ascaris lumbricoides was significantly higher in households using EcoSan latrines. EcoSan users need awareness on safe ways of handling faecal sludge in order to reduce chances of reinfection from Ascaris lumbricoides. Further research should be undertaken on household members to identify those infected and potential routes of infection to enable preventive targeting.

Intestinal parasitic infections in Iranian preschool and school children: A systematic review and meta-analysis

Parasitic infections are a serious public health problem because they cause anemia, growth retardation, aggression, weight loss, and other physical and mental health problems, especially in children. Numerous studies have been performed on intestinal parasitic infections in Iranian preschool and school children. However, no study has gathered and analyzed this information systematically. The aim of this study was to provide summary estimates for the available data on intestinal parasitic infections in Iranian children. We searched 9 English and Persian databases, unpublished data, abstracts of scientific congresses during 1996-2015 using the terms intestinal parasite, Giardia, Cryptosporidium, Enterobiusvermicularis, oxyure, school, children, preschool, and Iran. We conducted meta-analysis using STATA, and for all statistical tests, p-value less than 0.05was considered significant. Among the 68,532 publications searched as a result, 103 were eligible for inclusion in the study. The prevalence rate of intestinal parasitic infections was 38% (95% CI- 33%, 43%). Prevalence of protozoa, helminthic intestinal infections, and non-pathogenic parasites was 16.9%, 9.48%, and 18.5%, respectively, which affected 14.27% males and 15.3% females. The rate of infection in preschool and school children was 38.19% and 43.37% respectively. Giardia, Enterobiusvermicularis and Entamoeba coli were the most common among protozoa, helminthic, and non-pathogenic infections (15.1%, 16.5%, and 7.1%, respectively). The data analyses indicated that the prevalence of intestinal parasitic infection is decreasing in Iranian preschool and school children. Improvement of sanitation, personal hygiene, increased awareness of people, seasonal variations, and health education can be effective in reducing parasitic infections in different communities.

Improving the understanding of schistosomiasis among adolescents in endemic areas in Brazil: A comparison of educational methods

OBJECTIVE

To evaluate the effectiveness of two teaching strategies, both guided by the concept of dialogicity, on adolescents' knowledge about schistosomiasis and adherence to diagnostic fecal testing.

METHODS

Two teaching strategies related to schistosomiasis were developed, an educational video and group conversation, which were tested in two groups of students aged 10-15 years old. Before and after the intervention, a questionnaire was applied to assess participants' knowledge about schistosomiasis and, after the intervention, two fecal samples were requested from each participant. Comparisons were performed by paired t- and McNemar tests.

RESULTS

Both strategies resulted in statistically significant improvements in knowledge between the pre- and post-tests. Students who watched the video had a higher return rate of fecal samples and percentage of correct questionnaire answers, mainly on questions about schistosomiasis infection.

CONCLUSION

Teaching strategies based on dialogue favored the construction of concepts about schistosomiasis that can influence the adoption of positives attitudes related to health.

PRACTICAL IMPLICATIONS

Using teaching strategies based on the concept of dialogicity can favor the increase of knowledge of school age children about schistosomiasis and can influence behavioral change related to health.

Decreasing prevalence of intestinal parasitic infections among school-aged children in Nepal: a systematic review and meta-analysis

BACKGROUND

In the last two decades there have been several studies describing the prevalence of intestinal parasites in Nepal; however, there is a lack of surveillance data in the country.

METHODS

We searched literature in PubMed, MEDLINE, EMBASE, Google Scholar and local peer-reviewed journals published from 1990 to 2015 for studies describing prevalence of intestinal parasites among school-aged children. We conducted meta-regression to understand the trend over time and pooled the prevalence using 'metaprop' command in STATA 12.1.

RESULTS

Thirty-one studies examining 12 080 fecal specimens were included. The prevalence of intestinal parasitic infections showed a significantly decreasing trend (OR 0.56; 95% CI 0.43-0.73 for each consecutive 5 years) and was similar in males and females. The pooled prevalence in years 1996-2000, 2001-2005, 2006-2010 and 2011-2015 was 61.1% (95% CI 51.47-70.26), 53.2% (95% CI 20.94-83.99), 32.7% (95% CI 26.57-39.21) and 20.4% (95% CI 15.04-26.25), respectively. The proportion of helminths among total intestinal parasites was higher in rural areas 57.6% (95% CI 43.54-71.61), and proportion of protozoa among total intestinal parasites was higher in urban areas 68.4% (95% CI 63.23-73.62). Poly-parasitism was observed in 7.7% (95% CI 5.57-9.73) of children.

CONCLUSION

We observed a significantly decreasing trend in prevalence of intestinal parasitic infections among school-aged children in Nepal over the last two decades.

Trends in prevalence of soil-transmitted helminth and major intestinal protozoan infections among school-aged children in Nepal

OBJECTIVES

To assess the trends in prevalence of soil-transmitted helminths (STHs), Entamoeba histolytica and Giardia lamblia among school-aged children in Nepal between 1990 and 2015.

METHODS

Systematic literature search in PubMed, MEDLINE, EMBASE, Google Scholar and local peer-reviewed journals for papers published between 1990 and December 2015. We conducted metaregression and meta-analyses to pool studies where applicable.

RESULTS

Thirty-nine studies that examined a total of 14 729 stool specimens were included in the meta-analyses. The metaregression of prevalence of hookworms, roundworm, and whipworm showed a significantly decreasing trend over time. In or after 2004, the pooled prevalence of hookworm infections was 1.53% (95% CI, 0.73-2.59), of roundworm 4.31% (95% CI, 2.52-6.53) and of whipworm 2.89% (95% CI, 1.33-4.97) vs. 16.54% (95% CI, 7.64-27.97) for hookworm, 25.20% (95% CI, 13.59-38.97) for roundworm and 11.54% (95% CI 4.25-21.76) for whipworm in 1993-2003. E. histolytica and G. lamblia had stable prevalence since early 1990s, with a pooled prevalences of 4.12% (95% CI, 2.73-5.77) and 9.40% (95% CI, 7.15-11.92), respectively. The prevalence of G. lamblia was significantly higher in urban areas.

CONCLUSIONS

We observed a sharp decrease in prevalence of STHs among school-aged children in Nepal in the past decade with prevalences dropping below 5% for STHs with no variation in prevalence in rural and urban areas. However, the prevalence of E. histolytica and G. lamblia remained stable over time. These results suggest that school-based deworming programmes rolled out during the study period had an observable impact on prevalence of STHs.

Intestinal helminth infections among children of district Shopian of Kashmir Valley, India

Intestinal helminth infections are amongst the most common infections worldwide. Studies in other districts of Kashmir Valley revealed a high prevalence of intestinal helminth infections among the children. The objectives of the current study were to determine the prevalence of intestinal helminth infections among children of Shopian district and to identify associated socio-demographic and environmental actors, behavioral habits and also related complaints. Stool samples were collected from 352 children and a questionnaire was filled for each case. The samples were processed using both simple smear and zinc sulphate concentration methods, and then microscopically examined for intestinal helminths. Of the 352 children surveyed, 75.28 % had 1, or more, helminth parasites. Prevalence of Ascaris lumbricoides was highest (71.8 %), followed by Trichuris trichiura (26.4 %), Enterobius vermicularis (13.9 %) and Taenia saginata (5.3 %). Conditions most frequently associated with infection included the age group, water source, boiled or unboiled water, defecation site, personal hygiene, and the extent of maternal education. The study shows a relatively high prevalence of intestinal helminths and suggests an imperative for the implementation of control measures.

A controlled, before-and-after trial of an urban sanitation intervention to reduce enteric infections in children: research protocol for the Maputo Sanitation (MapSan) study, Mozambique

INTRODUCTION

Access to safe sanitation in low-income, informal settlements of Sub-Saharan Africa has not significantly improved since 1990. The combination of a high faecal-related disease burden and inadequate infrastructure suggests that investment in expanding sanitation access in densely populated urban slums can yield important public health gains. No rigorous, controlled intervention studies have evaluated the health effects of decentralised (non-sewerage) sanitation in an informal urban setting, despite the role that such technologies will likely play in scaling up access.

METHODS AND ANALYSIS

We have designed a controlled, before-and-after (CBA) trial to estimate the health impacts of an urban sanitation intervention in informal neighbourhoods of Maputo, Mozambique, including an assessment of whether exposures and health outcomes vary by localised population density. The intervention consists of private pour-flush latrines (to septic tank) shared by multiple households in compounds or household clusters. We will measure objective health outcomes in approximately 760 children (380 children with household access to interventions, 380 matched controls using existing shared private latrines in poor sanitary conditions), at 2 time points: immediately before the intervention and at follow-up after 12 months. The primary outcome is combined prevalence of selected enteric infections among children under 5 years of age. Secondary outcome measures include soil-transmitted helminth (STH) reinfection in children following baseline deworming and prevalence of reported diarrhoeal disease. We will use exposure assessment, faecal source tracking, and microbial transmission modelling to examine whether and how routes of exposure for diarrhoeagenic pathogens and STHs change following introduction of effective sanitation.

ETHICS

Study protocols have been reviewed and approved by human subjects review boards at the London School of Hygiene and Tropical Medicine, the Georgia Institute of Technology, the University of North Carolina at Chapel Hill, and the Ministry of Health, Republic of Mozambique.

TRIAL REGISTRATION NUMBER

NCT02362932.

The relation between the prevalence of soil transmitted parasites in the soil and among school children in Zagazig district, Sharkyia Governorate, Egypt

Soil transmitted helminths are highly prevalent throughout the developing countries of the world and Egypt is categorized as one of the developing countries. This study aimed to detect the relation between the presence and prevalence of STH in the soil and their reflection on the prevalence among school-children living in rural and urban areas in Zagazig district, Egypt. The present study was carried out on (859) school-children aged 6-13 years in Zagazig district all over the year 2013. They were subjected to stool examination. Out of them 100 suspected children were serotested for anti-TES IgG antibodies Toxocara spp. Soil samples also were collected from their places and regions. The results showed overall prevalence of parasitic infections was 21.07 % for helminthic infection and 39.46 % for protozoa. The prevalence of parasitic infections was more among children in rural areas (28, 49.2, 11.1 %) than those who live in urban areas (6.4, 18, 2.2 %) for helminths, protozoa and Toxocara as the most prevalent helminth respectively. Highly significant association was found between soil-transmitted helminthic infections detected by stool examination of the studied children group and the prevalence of geohelminthes in the examined soil samples, taken from residency areas of those children. This association was missed regarding protozoal infections. According to the results, low level of education and consequently poor socio-economic and hygienic conditions of families appear to be powerful determinants of infection. Thus, improving environmental sanitation is imperative for the control of soil-transmitted helminths.

Schistosomiasis in Malawi: a systematic review

INTRODUCTION

Schistosomiasis remains an important public health problem that undermines social and economic development in tropical regions of the world, mainly Sub-Saharan Africa. We are not aware of any systematic review of the literature of the epidemiology and transmission of schistosomiasis in Malawi since 1985. Therefore, we reviewed the current state of knowledge of schistosomiasis epidemiology and transmission in this country and identified knowledge gaps and relevant areas for future research and research governance.

METHODS

We conducted computer-aided literature searches of Medline, SCOPUS and Google Scholar using the keywords: "schistosomiasis", "Bilharzia", "Bulinus" and "Biomphalaria" in combination with "Malawi". These searches were supplemented by iterative reviews of reference lists for relevant publications in peer reviewed international scientific journals or other media. The recovered documents were reviewed for their year of publication, location of field or laboratory work, authorship characteristics, ethics review, funding sources as well as their findings regarding parasite and intermediate host species, environmental aspects, geographical distribution, seasonality of transmission, and infection prevalence and intensities.

REVIEW

A total of 89 documents satisfied the inclusion criteria and were reviewed. Of these, 76 were published in international scientific journals, 68 were peer reviewed and 54 were original research studies. Most of the documents addressed urinary schistosomiasis and about two thirds of them dealt with the definitive host. Few documents addressed the parasites and the intermediate hosts. While urinary schistosomiasis occurs in most parts of Malawi, intestinal schistosomiasis mainly occurs in the central and southern highlands, Likoma Island and Lower Shire. Studies in selected communities estimated prevalence rates of up to 94.9% for Schistosoma haematobium and up to 67.0% for Schistosoma mansoni with considerable geographical variation. The main intermediate host species are Bulinus globosus and Bulinus nyassanus for urinary schistosomiasis and Biomphalaria pfeifferi for intestinal schistosomiasis. Seasonality of transmission tends to vary according to geographical, environmental, biological and behavioural factors.

CONCLUSION

Transmission of schistosomiasis in Malawi appears to be highly focal, with considerable variation in space and time. Many locations have not been covered by epidemiological investigations and, thus, information on the transmission of schistosomiasis in Malawi remains fragmented. Functional infection risk assessment systems based on systematic investigations and surveillance are required for developing informed prevention and control strategies.

Association between footwear use and neglected tropical diseases: a systematic review and meta-analysis

BACKGROUND

The control of neglected tropical diseases (NTDs) has primarily focused on preventive chemotherapy and case management. Less attention has been placed on the role of ensuring access to adequate water, sanitation, and hygiene and personal preventive measures in reducing exposure to infection. Our aim was to assess whether footwear use was associated with a lower risk of selected NTDs.

METHODOLOGY

We conducted a systematic review and meta-analysis to assess the association between footwear use and infection or disease for those NTDs for which the route of transmission or occurrence may be through the feet. We included Buruli ulcer, cutaneous larva migrans (CLM), leptospirosis, mycetoma, myiasis, podoconiosis, snakebite, tungiasis, and soil-transmitted helminth (STH) infections, particularly hookworm infection and strongyloidiasis. We searched Medline, Embase, Cochrane, Web of Science, CINAHL Plus, and Popline databases, contacted experts, and hand-searched reference lists for eligible studies. The search was conducted in English without language, publication status, or date restrictions up to January 2014. Studies were eligible for inclusion if they reported a measure of the association between footwear use and the risk of each NTD. Publication bias was assessed using funnel plots. Descriptive study characteristics and methodological quality of the included studies were summarized. For each study outcome, both outcome and exposure data were abstracted and crude and adjusted effect estimates presented. Individual and summary odds ratio (OR) estimates and corresponding 95% confidence intervals (CIs) were calculated as a measure of intervention effect, using random effects meta-analyses.

PRINCIPAL FINDINGS

Among the 427 studies screened, 53 met our inclusion criteria. Footwear use was significantly associated with a lower odds of infection of Buruli ulcer (OR=0.15; 95% CI: 0.08-0.29), CLM (OR=0.24; 95% CI: 0.06-0.96), tungiasis (OR=0.42; 95% CI: 0.26-0.70), hookworm infection (OR=0.48; 95% CI: 0.37-0.61), any STH infection (OR=0.57; 95% CI: 0.39-0.84), strongyloidiasis (OR=0.56; 95% CI: 0.38-0.83), and leptospirosis (OR=0.59; 95% CI: 0.37-0.94). No significant association between footwear use and podoconiosis (OR=0.63; 95% CI: 0.38-1.05) was found and no data were available for mycetoma, myiasis, and snakebite. The main limitations were evidence of heterogeneity and poor study quality inherent to the observational studies included.

CONCLUSIONS/SIGNIFICANCE

Our results show that footwear use was associated with a lower odds of several different NTDs. Access to footwear should be prioritized alongside existing NTD interventions to ensure a lasting reduction of multiple NTDs and to accelerate their control and elimination.

PROTOCOL REGISTRATION

PROSPERO International prospective register of systematic reviews CRD42012003338.

Geohelminths distribution as affected by soil properties, physicochemical factors and climate in Sharkyia governorate Egypt

Soil-transmitted helminths are mainly a group of parasitic nematodes causing human infection through contact with parasite eggs or larvae; they survive in the warm and moist soil of the tropical and subtropical countries. This study was carried out in Sharkyia governorate from October, 2011 to October, 2013, to correlate between the prevalence and distribution of these parasites in the soil and the physicochemical factors affecting the examined samples of the soil. One hundred and twenty samples of different types of soil (clay, silt, sand) from different localities were collected and examined. Diagnosis of geohelminths was confirmed by the recovery of their eggs and larvae with other protozoa by different parasitological methods. The modified baermann method was found to be more efficient in detection of geohelminths larvae than charcoal culture method. Among the examined sites geohelminths were much more numerous in the soil of rural areas especially in the spring and summer seasons, while the contamination of canal banks by geohelminths was the worst (80 %). An insignificant correlation was reported between the soil texture and the number of positive samples in the examined areas while the relationship was directly proportional among (moisture, PH, organic). It appeared that the most common geohelminthic stage was Toxocara spp. eggs besides other types of protozoa especially Balantidium coli cysts. This suggests that factors other than soil texture are important in the prevalence of geohelminths in the soil e.g. temperature, moisture, PH and organic matter. So, to change some of these factors in a trial to control geoparasites transmission but with keeping the environment should be tried. These results also open the way to further studies to highlight the mutual affection between inhabitants of these sites and the prevalence of these geoparasites.

Shared sanitation versus individual household latrines: a systematic review of health outcomes

BACKGROUND

More than 761 million people rely on shared sanitation facilities. These have historically been excluded from international sanitation targets, regardless of the service level, due to concerns about acceptability, hygiene and access. In connection with a proposed change in such policy, we undertook this review to identify and summarize existing evidence that compares health outcomes associated with shared sanitation versus individual household latrines.

METHODS AND FINDINGS

Shared sanitation included any type of facilities intended for the containment of human faeces and used by more than one household, but excluded public facilities. Health outcomes included diarrhoea, helminth infections, enteric fevers, other faecal-oral diseases, trachoma and adverse maternal or birth outcomes. Studies were included regardless of design, location, language or publication status. Studies were assessed for methodological quality using the STROBE guidelines. Twenty-two studies conducted in 21 countries met the inclusion criteria. Studies show a pattern of increased risk of adverse health outcomes associated with shared sanitation compared to individual household latrines. A meta-analysis of 12 studies reporting on diarrhoea found increased odds of disease associated with reliance on shared sanitation (odds ratio (OR) 1.44, 95% CI: 1.18-1.76).

CONCLUSION

Evidence to date does not support a change of existing policy of excluding shared sanitation from the definition of improved sanitation used in international monitoring and targets. However, such evidence is limited, does not adequately address likely confounding, and does not identify potentially important distinctions among types of shared facilities. As reliance on shared sanitation is increasing, further research is necessary to determine the circumstances, if any, under which shared sanitation can offer a safe, appropriate and acceptable alternative to individual household latrines.

Assessment of the prevalence of intestinal parasitosis and associated risk factors among primary school children in Chencha town, Southern Ethiopia

BACKGROUND

Parasitic infection is the most prevalent among rural communities in warm and humid regions and where water, hygiene and sanitation facilities are inadequate. Such infection occurs in rural areas where water supplies are not enough to drink and use, and in the absence of environmental sanitation, when the rubbish and other wastes increased, and sewage and waste water are not properly treated. Hence the aim of the study was to assess the prevalence of intestinal parasitosis and associated risk factors.

METHODS

This cross sectional study was conducted on children of the selected primary schools in Chencha town from March to May, 2012. Children were selected within age group 5-15 years. The socio-demographic, environmental and behavioral variables data were collected using structured questionnaire from the guardians of children and school teachers to assess the risk factors. Prevalence of intestinal parasitosis was determined using direct method and formol-ether concentration method. Participants' data were analyzed using SPSS version 16.0.

RESULTS

Of 422 selected school children, 400 participated in the study with full information for analysis. The overall prevalence of intestinal parasitosis was high (81.0%). Soil-transmitted helminths (STHs) infections (63.0%) were more prevalent than protozoa infections (23.5%). The predominant parasites were A. lumbricoides (60.5%), E. histolytica/dispar (16.25%), Giardia lamblia (11.7%) and T. trichuria (9.7%). The presence of Intestinal Parasitic Infections (IPIs) have statistically significant association with the educational status of the household heads, absence of washing facility, home cleanness condition and type of latrine used with (p < 0.05).

CONCLUSIONS

The prevalence of intestinal parasitic infections, especially soil-transmitted helminths (STHs) is very high in the school children. The high prevalence of parasitic infections in these children indicates that the protozoa and helminths concerned are very common in the environment of these villages and the results of the risk factors analysis suggests that the transmission is from several routes. Therefore, multiple intervention strategies should be implemented for the school children, households and the environment to reduce the disease burden.

Prevalence and risk factors of soil-transmitted helminth infection in Nepal

BACKGROUND

The purpose of this study is to evaluate the prevalence and intensity and examine the risk factors of soil transmitted helminth (STH; i.e., roundworm [Ascaris lumbricoides], hookworms [Ancylostoma duodenale and Necator americanus], and whipworm [Trichuris trichiura]) infections in Nepal.

METHODS

Five hundred and ninety-four adults (256 men and 338 women) were selected via convenience sampling from five communities in Nepal. The Kato-Katz method was used to assess the prevalence and intensity of STH infection in this population.

RESULTS

Prevalence of STH infection ranged from 3.3% in Birendranagar in Chitwan, 3.5% in Kuleshor in Kathmandu, 11.7% in Kanyam in Ilam, 17.0% in Dhikurpokhari in Kaski and 51.4% in Khokana in Lalitpur District [corrected]. Multivariable regression analysis revealed that not using soap for hand-washing was significantly associated with the prevalence and infection intensity of roundworm, hookworms and whipworm. Similarly, not wearing sandals or shoes outside was significantly associated with the prevalence and infection intensity of roundworm and hookworms, but not with infection intensity of whipworm. Literacy, being underweight or overweight, anemia and occupation were not associated with prevalence and intensity of roundworm and hookworms infection, but there was an association between occupation and the prevalence of whipworm infection.

CONCLUSION

STH infection was associated with individual hygiene behavior, but not with nutritional status or socio-demographic characteristics. Health policy focusing on changing individual hygiene behaviors might be useful in addressing STH infection in Nepal.

High malnutrition rate in Venezuelan Yanomami compared to Warao Amerindians and Creoles: significant associations with intestinal parasites and anemia

BACKGROUND

Children in rural areas experience the interrelated problems of poor growth, anemia and parasitic infections. We investigated the prevalence of and associations between intestinal helminth and protozoan infections, malnutrition and anemia in school-age Venezuelan children.

METHODS

This cross-sectional study was conducted in 390 children aged 4-16 years from three rural areas of Venezuela: the Amazon Region, Orinoco Delta and Carabobo State. Stool samples were collected for direct parasitic examinations. Anthropometric indicators of chronic (height-for-age Z score) and acute (weight-for-height and Body Mass Index (BMI)-for-age Z score in respectively children under 5 years of age and children aged 5 years and above) malnutrition were calculated. Multivariate linear and logistic regression models were built to determine factors associated with nutritional status and polyparasitism.

RESULTS

Hookworm and Strongyloides stercoralis prevalences were highest in children from the Amazon rainforest (respectively 72% and 18%) while children from the Orinoco Delta and Carabobo State showed higher rates of Ascaris lumbricoides (respectively 28% and 37%) and Trichuris trichiura (40% in both regions). The prevalence of Giardia lamblia infection was not significantly different between regions (average: 18%). Anemia prevalence was highest in the Amazon Region (24%). Hemoglobin levels were significantly decreased in children with a hookworm infection. Malnutrition was present in respectively 84%, 30% and 13% of children from the Amazon Region, Orinoco Delta and Carabobo State. In multivariate analysis including all regions, G. lamblia and helminth infections were significantly and negatively associated with respectively height-for-age and weight-for-height/BMI-for-age Z scores. Furthermore, hemoglobin levels were positively associated with the height-for-age Z score (0.11, 95% CI 0.02 - 0.20).

CONCLUSIONS

In rural populations in Venezuela helminthiasis and giardiasis were associated with acute and chronic nutritional status respectively. These data highlight the need for an integrated approach to control transmission of parasites and improve the health status of rural Venezuelan children.

Socioeconomic determinants of haemoglobin levels of African women are less important in areas with more health facilities: a multilevel analysis

BACKGROUND

The prevalence of anaemia in Africa is the highest in the world. Especially women are at risk because of blood loss during menstruation and increased iron requirements during pregnancy. This study examined determinants of the haemoglobin (Hb) level of African women at individual/household, cluster, district, and national level. Special attention was paid to socioeconomic factors and the presence of health facilities.

METHODS

Data were derived from Demographic and Health Surveys conducted between 2003 and 2010 in 21 African countries. We included all women aged 15-49 who participated in a women's survey and had a Hb measurement. Multilevel models were used to examine the influence of various factors at different hierarchical levels simultaneously.

RESULTS

104 899 women were included in the study, of which 23.1% were anaemic (Hb<110 g/L). Socioeconomic factors were strongly related to the Hb level of women. Wealth, education, having a job, occupation of the partner, presence of a toilet facility, context educational level and preventive health measures were positively associated with the Hb level. Interaction analysis indicated that socioeconomic differences in the Hb level of women were reduced by the presence of health facilities.

CONCLUSIONS

Interventions aimed at improving the Hb level of African women should take socioeconomic and contextual aspects into account. Increasing availability of health facilities might be a tool for reducing socioeconomic differences.

Prevalence of intestinal parasitic infections among highland and lowland dwellers in Gamo area, South Ethiopia

Background

Epidemiological information on the prevalence of intestinal parasitic infections in different regions is a prerequisite to develop appropriate control strategies. Therefore, this present study was conducted to assess the magnitude and pattern of intestinal parasitism in highland and lowland dwellers in Gamo area, South Ethiopia.

Methods

Community-based cross-sectional study was conducted between September 2010 and July 2011 at Lante, Kolla Shelle, Dorze and Geressie kebeles of Gamo Gofa Zone, South Ethiopia. The study sites and study participants were selected using multistage sampling method. Data were gathered through house-to-house survey. A total of 858 stool specimens were collected and processed using direct wet mount and formol-ether concentration techniques for the presence of parasite.

Results

Out of the total examined subjects, 342(39.9%) were found positive for at least one intestinal parasite. The prevalence of Entamoeba histolytica/dispar was the highest 98(11.4%), followed by Giardia lamblia 91(10.6%), Ascaris lumbricoides 67(7.8%), Strongyloides stercoralis 51(5.9%), hookworm 42(4.9%), Trichuris trichiura 24(2.8%), Taenia species 18(2.1%), Hymenolepis nana 7(0.6%) and Schistosoma mansoni 1(0.12%). No statistically significant difference was observed in the prevalence of intestinal parasitic infections among lowland (37.9%) and highland dwellers (42.3%) (P = 0.185). The prevalence of intestinal parasitic infection was not significantly different among the study sites but it was relatively higher in Geressie (42.8%) than other kebeles. Sex was not associated with parasitic infections (P = 0.481). No statistically significant difference of infection was observed among the age groups (P = 0.228) but it was higher in reproductive age group.

Conclusions

The high prevalence of intestinal parasitic infections among the lowland and highland dwellers in Gamo area indicated that parasitic infections are important public health problems. Thus, infection control measures and the development of awareness strategies to improve sanitation and health education should be considered.

Fatores associados à ocorrência de parasitoses intestinais em uma população de crianças e adolescentes

OBJETIVOS: Analisar a prevalência de infecções por parasitos intestinais em crianças e adolescentes matriculados em escolas de ensino fundamental no município de São João del-Rei, Minas Gerais, e os fatores associados à infecção. MÉTODOS: Estudo epidemiológico seccional, realizado entre março/2008 e julho/2009. Foram realizados exames coproscópicos por sedimentação espontânea e Kato-Katz em 1.172 escolares. Foram ajustados modelos de regressão logística múltipla para o estudo dos fatores associados às infecções em geral e, separadamente, por helmintos e por protozoários. RESULTADOS: A prevalência de infecções foi de 29%, havendo uma variação de 7 a 83%, respectivamente, entre as escolas de menor e maior ocorrência. A presença de instalação sanitária no domicílio foi associada a uma ocorrência menor de helmintos; o aumento na idade dos escolares associou-se a uma maior ocorrência de protozoários e de parasitos em geral; enquanto a presença de filtro de água e a localização do domicílio em área urbana mostraram-se associadas a uma ocorrência menor dos três desfechos analisados. Em todas as regiões, foi registrado o consumo de medicação preventiva contra helmintos. CONCLUSÕES: Desigualdades nas condições de vida tornaram as prevalências diferenciadas entre as regiões do estudo. O estudo ressalta a necessidade de promover o uso de filtros de água nas residências de áreas endêmicas e de avaliar o consumo preventivo de medicamentos anti-helmínticos na dinâmica e na saúde dos indivíduos. Medidas de controle que levem em conta os fatores descritos devem ser prioritárias em nível de Saúde Pública.

The global limits and population at risk of soil-transmitted helminth infections in 2010

BACKGROUND

Understanding the global limits of transmission of soil-transmitted helminth (STH) species is essential for quantifying the population at-risk and the burden of disease. This paper aims to define these limits on the basis of environmental and socioeconomic factors, and additionally seeks to investigate the effects of urbanisation and economic development on STH transmission, and estimate numbers at-risk of infection with Ascaris lumbricoides, Trichuris trichiura and hookworm in 2010.

METHODS

A total of 4,840 geo-referenced estimates of infection prevalence were abstracted from the Global Atlas of Helminth Infection and related to a range of environmental factors to delineate the biological limits of transmission. The relationship between STH transmission and urbanisation and economic development was investigated using high resolution population surfaces and country-level socioeconomic indicators, respectively. Based on the identified limits, the global population at risk of STH transmission in 2010 was estimated.

RESULTS

High and low land surface temperature and extremely arid environments were found to limit STH transmission, with differential limits identified for each species. There was evidence that the prevalence of A. lumbricoides and of T. trichiura infection was statistically greater in peri-urban areas compared to urban and rural areas, whilst the prevalence of hookworm was highest in rural areas. At national levels, no clear socioeconomic correlates of transmission were identified, with the exception that little or no infection was observed for countries with a per capita gross domestic product greater than US$ 20,000. Globally in 2010, an estimated 5.3 billion people, including 1.0 billion school-aged children, lived in areas stable for transmission of at least one STH species, with 69% of these individuals living in Asia. A further 143 million (31.1 million school-aged children) lived in areas of unstable transmission for at least one STH species.

CONCLUSIONS

These limits provide the most contemporary, plausible representation of the extent of STH risk globally, and provide an essential basis for estimating the global disease burden due to STH infection.

Utilizing environmental, socioeconomic data and GIS techniques to estimate the risk for ascariasis and trichuriasis in Minas Gerais, Brazil

The impact of intestinal helminths on human health is well known among the population and health authorities because of their wide geographic distribution and the serious problems they cause. Geohelminths are highly prevalent and have a big impact on public health, mainly in underdeveloped and developing countries. Geohelminths are responsible for the high levels of debility found in the younger population and are often related to cases of chronic diarrhea and malnutrition, which put the physical and intellectual development of children at risk. These geohelminths have not been sufficiently studied. One obstacle in implementing a control program is the lack of knowledge of the prevalence and geographical distribution. Geographical information systems (GIS) and remote sensing (RS) have been utilized to improve understanding of infectious disease distribution and climatic patterns. In this study, GIS and RS technologies, as well as meteorological, social, and environmental variables were utilized for the modeling and prediction of ascariasis and trichuriasis. The GIS and RS technologies specifically used were those produced by orbital sensing including the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Shuttle Radar Topography Mission (SRTM). The results of this study demonstrated important factors related to the transmission of ascariasis and trichuriasis and confirmed the key association between environmental variables and the poverty index, which enabled us to identify priority areas for intervention planning in the state of Minas Gerais in Brazil.

Intestinal parasitic infestation among children in a semi-urban Indian population

BACKGROUND

Survey on the prevalence of various intestinal parasitic infestations in different geographic regions is a prerequisite to obtain an accurate understanding of the burden and cause of intestinal parasitic infestations in a particular area. The aim of the present study was to determine the intestinal parasitic infestation among children in a semi-urban area.

MATERIALS AND METHODS

A total of 335 stool samples were collected, processed, and microscopically examined for intestinal parasites.

RESULTS

One hundred twenty-eight (38%) stool samples showed presence of ova/cysts. Multiple parasites were seen in 42 (32.8%) samples. Among the protozoans, Entamoeba histolytica (55.3%) was the most common followed by Giardia lamblia (40.4%). Ascaris lumbricoides and Hymenolepis nana (24.2%) were the most common helminths detected.

CONCLUSIONS

In most of the cases, intestinal parasitic infestation spreads due to low standards of personal hygiene, poor sanitation, non-usage of toilets and an illiterate population, thus suggesting regular surveys to help in devising optimum methods of control.

Geographical distribution of schistosomiasis and soil-transmitted helminths among school children in informal settlements in Kisumu City, Western Kenya

This cross-sectional study determined the prevalence and distribution of schistosome and soil-transmitted helminth (STH) infections among 1,308 children aged 10-18 years in 34 primary schools in 8 informal urban settlements in Kisumu City, western Kenya. Stool samples were collected and examined for eggs of Schistosoma mansoni and STH (Hookworms, Ascaris lumbricoides and Trichuris trichiura) using the Kato-Katz technique. Haematuria was used as a proxy indicator of urinary schistosomiasis. Schools and water bodies were mapped using a geographical information system. Overall, 34% of children were infected with one or more helminth species whereas 16·2% of children were infected with one or more STH species. Schools in closest proximity to Lake Victoria and River Nyamasaria had the highest S. mansoni prevalence while schools with STH were more homogenously distributed. Mean school prevalence of S. mansoni infection was 21% (range=0-69·7%), S. haematobium 3·6% (range=0-12%), hookworms 6·1% (range=0-20%), A. lumbricoides 4·9% (range=0-18·4%), and T. trichiura 7·7% (range=0-18·6%). Helminth-related morbidities were not associated with infection. Our study demonstrates that schistosomiasis and STH are important health priorities among schools in informal settlements of Kisumu City, and highlights the need for routine deworming in similar settings.

How do we sell the hygiene message? With dollars, dong or excreta?

In North and Central Vietnam it is common among farmers to use excreta from the family double vault composting latrine (DVC) as fertilizer in the fields. The official Vietnamese health guidelines stipulate a six-month period of composting before applying excreta to two of their three annual crops. However, farmers in this region cannot afford to follow these guidelines and this paper presents the reasons why.In their efforts to ensure optimal hygienic conditions, by providing a guideline, the Vietnamese health authorities have not put sufficient attention to the 'excreta economy' in relation to farmers' livelihoods. The free fertilizer in the household DVC represents a value of approximately US$ 15.5 per year--or the equivalent of 15 percent of the annual household income for the poorest 20 percent of farmers. For this reason, the economic benefits derived from free fertilizer outweigh the hygiene message for most Vietnamese farmers. Even at national level the excreta economy has an impact. If Vietnam were to replace human excreta with imported fertilizer, it would involve an extra national expenditure of at least US$ 83 million a year.In order to convince Vietnamese farmers to adopt different fertilizing methods when reusing human excreta, it is necessary for the Vietnamese health authorities to change their hygiene message. They need to replace their current health sector-specific approach with a holistic one that takes the premises of farmers' livelihoods into account. If they do not the hygiene message will simply be lost.

Spatial and genetic epidemiology of hookworm in a rural community in Uganda

There are remarkably few contemporary, population-based studies of intestinal nematode infection for sub-Saharan Africa. This paper presents a comprehensive epidemiological analysis of hookworm infection intensity in a rural Ugandan community. Demographic, kinship, socioeconomic and environmental data were collected for 1,803 individuals aged six months to 85 years in 341 households in a cross-sectional community survey. Hookworm infection was assessed by faecal egg count. Spatial variation in the intensity of infection was assessed using a Bayesian negative binomial spatial regression model and the proportion of variation explained by host additive genetics (heritability) and common domestic environment was estimated using genetic variance component analysis. Overall, the prevalence of hookworm was 39.3%, with the majority of infections (87.7%) of light intensity ( Collapse

Key Words Collapse

MESH Headings

• Adolescent
• Analysis of Variance
• Ancylostomatoidea
• Animals
• Bayes Theorem
• Child
• Child, Preschool
• Cluster Analysis
• Female
• Genetic Predisposition to Disease
• Geography
• Hookworm Infections/epidemiology
• Hookworm Infections/genetics
• Humans
• Infant
• Male
• Regression Analysis
• Risk Factors
• Rural Population/statistics & numerical data
• Sex Distribution
• Surveys and Questionnaires
• Uganda/epidemiology

Collapse

Grants

• Wellcome Trust
• 081673 Wellcome Trust
• Medical Research Council

Collapse

Affiliation(s)

Rachel L Pullan Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.
Narcis B Kabatereine
Rupert J Quinnell
Simon Brooker

Collapse

Intestinal helminthiasis in children of gurez valley of jammu and kashmir state, India

INTRODUCTION

This paper is a part of the helminthological studies carried out on school-going children of the Kashmir Valley and deals with the status of intestinal helminths in the children of Gurez Valley and to assess epidemiological factors associated with the extent of endemic disease so that control measures are adopted.

MATERIAL AND METHODS

Stool samples were collected from 352 children from Gurez Valley. The samples were processed using Kato-Katz thick smear technique, and microscopically examined for intestinal parasites.

RESULTS

Of the 352 children surveyed, 75.28% had one or more types of intestinal helminthes. Prevalence of Ascaris lumbricoides was highest (71.18%), followed by Trichuris trichiura (26.42%), Enterobius vermicularis (13.92) and Taenia saginata (5.39%). Conditions most frequently associated with infection included the water source, defecation site, personal hygiene, and the extent of maternal education.

CONCLUSION

The study shows a relatively high prevalence of intestinal helminths and suggests an imperative for the implementation of control measures.

Survival of Ascaris eggs and hygienic quality of human excreta in Vietnamese composting latrines

BACKGROUND

For centuries farmers in Vietnam have fertilized their fields with human excreta collected directly from their household latrines. Contrary to the official guideline of six-month storage, the households usually only store human excreta for three to four months before use, since this is the length of time that farmers have available to produce fertilizer between two cropping seasons. This study aimed to investigate whether hygienically safe fertilizer could be produced in the latrines within this period of time.

METHODS

By inoculating eggs of the helminth parasite indicator Ascaris suum into heaps of human excreta, a die-off experiment was conducted under conditions similar to those commonly used in Vietnamese latrines. Half a ton of human excreta was divided into five heaps containing increasing concentrations of lime from 0% to 11%.

RESULTS

Regardless of the starting pH, which varied from 9.4 to 11.6, a >99% die-off of eggs was obtained after 105 to 117 days of storage for all lime concentrations and 97% of eggs were non-viable after 88 days of storage. The most critical parameter found to determine the die-off process was the amount of ammonia (urine) in the excreta which indicates that longer storage periods are needed for parasite egg die-off if urine is separated from the excreta.

CONCLUSION

By inactivating >99% of all A. suum eggs in human excreta during a storage period of only three months the commonly used Double Vault Composting (DVC) latrine, in which urine is not separated, could therefore potentially provide a hygienic acceptable fertilizer.

Intestinal parasitic infections among inhabitants of Karaj City, Tehran province, Iran in 2006-2008

Karaj is an area with large influx of refugee people in Iran. To increase knowledge about parasitic infections, we carried out this research during 2006-2008. We recorded the stool examination results and some of their personal characteristics. A total of 13,915 human stools were examined, and 649 (4.7%) were positive for intestinal parasites. Among them, 13 (0.09%) had worm and 636 (4.6%) had protozoan infections. Maximum infections belonged to Giardia intestinalis, and 534 (3.8%) samples had this infection. Other parasitic infections included Entamoeba coli (0.39%), Entamoeba histolytica (0.021%), Blastocystis hominis (0.08%), Trichomonas hominis (0.1%), Iodamoeba butschlii (0.06%), Chilomastix mesnili (0.007%), Endolimax nana (0.05%), Enterobius spp. eggs (0.028%), Taenia proglottids (0.028%), and Strongyloides stercoralis larvae (0.03%). The maximum numbers of referred people to laboratories were in July and the maximum percentage of infections was in August. There is a point that all 5 Strongyloides stercoralis infections were pertained to 2008. With attention to the rate of parasitic infections (4.7%), it seems that we should take additional educational information to wide spectrum of people living in this city.

Global epidemiology, ecology and control of soil-transmitted helminth infections

Soil-transmitted helminth (STH) infections are among the most prevalent of chronic human infections worldwide. Based on the demonstrable impact on child development, there is a global commitment to finance and implement control strategies with a focus on school-based chemotherapy programmes. The major obstacle to the implementation of cost-effective control is the lack of accurate descriptions of the geographical distribution of infection. In recent years, considerable progress has been made in the use of geographical information systems (GIS) and remote sensing (RS) to better understand helminth ecology and epidemiology, and to develop low-cost ways to identify target populations for treatment. This review explores how this information has been used practically to guide large-scale control programmes. The use of satellite-derived environmental data has yielded new insights into the ecology of infection at a geographical scale that has proven impossible to address using more traditional approaches, and has in turn allowed spatial distributions of infection prevalence to be predicted robustly by statistical approaches. GIS/RS have increasingly been used in the context of large-scale helminth control programmes, including not only STH infections but also those focusing on schistosomiasis, filariasis and onchocerciasis. The experience indicates that GIS/RS provides a cost-effective approach to designing and monitoring programmes at realistic scales. Importantly, the use of this approach has begun to transition from being a specialist approach of international vertical programmes to becoming a routine tool in developing public sector control programmes. GIS/RS is used here to describe the global distribution of STH infections and to estimate the number of infections in school-age children in sub-Saharan Africa (89.9 million) and the annual cost of providing a single anthelmintic treatment using a school-based approach (US$5.0-7.6 million). These are the first estimates at a continental scale to explicitly include the fine spatial distribution of infection prevalence and population, and suggest that traditional methods have overestimated the situation. The results suggest that continent-wide control of parasites is, from a financial perspective, an attainable goal.

Physical trauma experience among school children in periurban Blantyre, Malawi

Background

Physical trauma is an important cause of childhood morbidity and mortality in Africa. There are however, few community-based reports on the subject on the continent. The present study was conducted to explore school children's experience of physical trauma in a disadvantaged periurban area of Blantyre, in Malawi.

Methods

A cross sectional questionnaire study was carried out among school children in Ndirande-Blantyre, Malawi in 2004. Data were obtained to describe the following aspects of trauma experience: being a victim or observer of motor vehicular accidents involving pedestrians; history of falls from heights; and knowledge about road safety. Sex differences were determined for some of the variables in order to gain insights as to whether there is a difference in trauma experience between boys and girls.

Results

A total of 217 school children, 99 (45.6%) boys and 118 (54.4%) girls participated in the study. Eight of them reported to have ever been hit by a motor vehicle, 87 (40.1%) had witnessed a road accident where a pedestrian had been hit and 83 (38.2%) had witnessed a pedestrian they knew having been hit by a motor vehicle. Of those that reported to have ever been hit by motor vehicle, 2 (25%) reported that they had been hospitalized as a result of injury. With regard to falling from heights, 86 reported to have ever fallen from tree, 44 of these (51.2%) were injured from the fall and 14 (16.3%) were hospitalized as a result of injury sustained from the fall. Girls were more likely to fall from trees and getting injured as compared to males (p = 0.04 for both situations). Just under half (41.9%) of the study participants were able to report the correct procedure of crossing the road despite the fact that the majority (80%) reported having been taught road safety at home or school.

Conclusion

Many school children in Blantyre, Malawi have been exposed to trauma either involving themselves or someone they observed. Prevention, including education, supervision and management of trauma must receive the necessary attention they deserve in terms of resources, surveillance and impact mitigation.

Concurrent infections and socioeconomic determinants of geohelminth infection: a community study of schoolchildren in periurban Guinea-Bissau

We explored the association between subclinical intestinal helminth infections and other gastrointestinal pathogens in 706 schoolchildren from a poor semirural area while adjusting for socioeconomic risk factors. The study was carried out in two neighbouring areas in the capital of Guinea-Bissau in West Africa. Children aged 4-12 years were visited and one child per mother was invited to participate in the study. Among the 706 children included in the study, helminths were detected in 44.2%, enteropathogenic bacteria in 13.7%, protozoans in 51.1% and rotavirus in 5.9%. A total of 76.1% had an infection of some sort and 41.8% were concomitantly infected with more than one and up to five gastrointestinal pathogens. After adjustment for possible confounding factors, infection with helminths and Entamoeba histolytica/E. dispar remained associated. Other risk factors for helminths included increasing age, male gender, small mid-upper arm circumference and chicken husbandry. Maternal school attendance and belonging to a Muslim family were associated with a lower prevalence of helminths. Investigations of concomitant infections are valuable as they may have implications for control and treatment strategies.

Prevalence of intestinal parasites in a population in south of Tehran, Iran

The aim of this study was to describe epidemiologic characteristics of intestinal parasites in a population in south of Tehran, Iran. A retrospective cross-sectional study of patients with suspicious intestinal parasitic infections referred to the Zakaria Razi Laboratory in Shahre-Ray, southern Tehran, Iran, was conducted from April 21, 2004 to October 20, 2005. All stool samples were examined and socio-demographic informations were retrieved. Of 4,371 referred patients, 466 (239 males and 227 females) were laboratory diagnosed with intestinal parasites, with a period prevalence of 10.7%. Blastocystis hominis (B. hominis) and Giardia lamblia (G. lamblia) were the most frequent intestinal parasites. More than half of patients aged (3) 18 years had a low level of educational attainment (e.g. illiterate, primary school, high school) (170/331, 54.1%). Further, majority of patients were homemakers (42.3%, 140/331) or workers (28.1%, 93/331) employed in various business settings such as food industry and construction. Findings of this study showed that intestinal parasitic infections are still a major public health challenge in Iran that needs to be addressed. We believe that public education, improving sanitation conditions of underdeveloped areas/communities, community involvement, and supporting evidence-based practice/programs are the major keys to success in preventing the spread of intestinal parasitic infections in Iran.

Intestinal helminths in a population of children from the Kashmir valley, India

In any geographical area, surveys of the prevalence of intestinal helminths are necessary to suggest appropriate control measures. The aim of this study was to determine the prevalence of intestinal helminth infections in children of the Kashmir valley and to identify the risk factors. Stool samples were collected from 2256 children from rural as well as urban areas of the Kashmir valley. The samples were examined by simple smear and zinc sulphate concentration methods. Intensity of the infection was quantified by Stoll's egg-counting technique. Infection by at least one intestinal helminth was found in 71.18% of the sampled population. The prevalence of Ascaris lumbricoides was highest (68.30%), followed by Trichuris trichiura (27.92%), Enterobius vermicularis (12.67%) and Taenia saginata (4.60%). Light (57.1%) to moderate (42.8%) intensity of infection was observed for A. lumbricoides, while the majority of the infected children (92.3%) harboured a light intensity of infection for T. trichiura. The age group, rural or urban residence, type of water source, boiled or unboiled water, type of defecation site, level of personal hygiene and maternal education were associated with helminth infection. Adequate control measures are urgently needed to combat the high prevalence of intestinal helminths and risk factors in the children of Kashmir valley.