Intensity Of Hookworm Infection Research Articles

Gastrointestinal parasites of wild Bornean orang-utans (Pongo pygmaeus) in a habitat affected by wildfire smoke

Wildfires are becoming increasingly frequent and severe in the tropical peatlands of Southern Borneo, with major consequences for both wildlife and people that inhabit them. Burning peat releases vast amounts of toxic smoke that, when inhaled, can cause a plethora of health-related issues. With some of the largest remaining populations of Bornean orang-utans (Pongo pygmaeus) being found in peatland forests, wildfires are becoming one of the greatest threats to this Critically Endangered ape, yet the effects of the toxic smoke on their health are unknown. Wildfire has long been known to influence wildlife disease by reducing populations of free-living parasites in the environment (thus altering host exposure), and there is a growing body of evidence to suggest that smoke may affect host susceptibility to such parasites by diminishing physiological condition and immune function. In this study, we investigated parasitic nematode infections in wild Bornean orang-utans inhabiting a drained peatland forest prone to fire and smoke. We identified four gastrointestinal nematode taxa that varied significantly in their prevalence and intensity. Overall prevalence of nematode infection was high, but intensity was relatively low. We present some evidence for an increase the prevalence and intensity of certain nematode taxa after the wildfire smoke event. Namely, an increase in the prevalence of Enterobius spp. and Trichuris spp., and an increase in the intensity of hookworm infections, after the smoke period. We identify the need for multi-year, multi-fire event research to increase sample sizes, along with measuring endocrinological markers of physiological condition, in tandem with parasitological monitoring, to gain a more comprehensive understanding of the impacts of environmental changes on orang-utan health.

The Relationship Between Soil-Transmitted Helminth Infections and Environmental Factors in Puerto Iguazú, Argentina: Cross-Sectional Study.

Soil-transmitted helminths (STHs) are widely distributed throughout the world. Various factors, including the environment, socioeconomic characteristics, and access to water and sanitation, play an important role in the spread and persistence of these parasites within communities. They, in turn, affect the growth and development of members of the community, especially children. Studies in the northern provinces of Argentina have shown variable prevalence of STHs, but the factors associated with their presence have not been completely elucidated. This cross-sectional study aimed to identify the socioeconomic and environmental factors related to STH infection in indigenous villages located in Puerto Iguazú (Misiones), Argentina. Between 2018 and 2019, stool samples were collected from individuals ≥1 year residing in 3 villages: Mini-Marangatú, Yriapú, and Fortín Mbororé. Standard parasitological methods were used to determine STH prevalence. Standardized questionnaires were used to assess participants' habits, customs, and household characteristics, and environmental data were obtained through satellite imagery. Multilinear regression with Akaike information criterion stepwise variables was used to explore relevant associations. A total of 342 individuals from the 3 villages participated in this study. The prevalence of STHs varied across villages: 89.6% (43/48), in Mini-Marangatú, 80.8% (101/125) in Yriapú, and 68.5% (115/169) in Fortín Mbororé. Notably, there was a significant difference in hookworm infection among the villages (P=.02). The analysis highlighted the significant influence of specific environmental factors on STH presence and spatial distribution, particularly in relation to hookworm infection. Vegetation patterns represented by the Vegetation Heterogeneity Index, created ad hoc for this study, emerged as a critical factor, with 2 significant predictors related to it (P=.002 and P=.004) alongside impervious surface density with a significant predictor (P<.001). The multilinear regression model yielded a high F test score (F108=4.75, P<.001), indicating a strong fit (R2=0.5465). Furthermore, socioeconomic factors, including walking barefoot in houses with dirt floors and overcrowding, were significantly correlated with hookworm infection intensity (P<.001 and P=.001, respectively). We also used the multilinear regression model to calculate hookworm infection intensity (F110=21.15, P<.001; R2=0.4971). Our study underscores the complexity of STH transmission, as villages with similar living conditions and environmental characteristics displayed varied STH prevalence and spatial distribution. Specific environmental factors, such as vegetation pattern and impervious surface density, played major roles in STH presence, demonstrating the crucial relationship between environmental factors and hookworm infection distribution. Moreover, our findings emphasize the significant influence of socioeconomic factors on hookworm infection intensity. By gaining insights into this complex interplay, our research contributes to a better understanding of STH transmission characteristics, thereby informing targeted public health interventions for effective control.

Interventions to improve water, sanitation, and hygiene for preventing soil-transmitted helminth infection.

BackgroundIt is estimated that 1.5 billion people are infected with soil‐transmitted helminths (STHs) worldwide. Re‐infection occurs rapidly following deworming, and interruption of transmission is unlikely without complementary control efforts such as improvements in water, sanitation, and hygiene (WASH) access and behaviours.ObjectivesTo assess the effectiveness of WASH interventions to prevent STH infection.Search methodsWe used standard, extensive Cochrane search methods. The latest search date was 19 October 2021.Selection criteriaWe included interventions to improve WASH access or practices in communities where STHs are endemic. We included randomized controlled trials (RCTs), as well as trials with an external control group where participants (or clusters) were allocated to different interventions using a non‐random method (non‐RCTs). We did not include observational study designs. Our primary outcome was prevalence of any STH infection. Prevalence of individual worms was a secondary outcome, including for Ascaris lumbricoides, Trichuris trichiura, hookworm (Ancylostoma duodenale or Necator americanus), or Strongyloides stercoralis. Intensity of infection, measured as a count of eggs per gram of faeces for each species, was another secondary outcome.Data collection and analysisTwo review authors independently reviewed titles and abstracts and full‐text records for eligibility, performed data extraction, and assessed risk of bias using the Cochrane risk of bias assessment tool for RCTs and the EPOC tool for non‐RCTs. We used a random‐effects meta‐analysis to pool study estimates. We used Moran’s I² statistic to assess heterogeneity and conducted subgroup analyses to explore sources of heterogeneity. We assessed the certainty of the evidence using the GRADE approach.Main resultsWe included 32 studies (16 RCTs and 16 non‐RCTs) involving a total of 52,944 participants in the review. Twenty‐two studies (14 RCTs (16 estimates) and eight non‐RCTs (11 estimates)) reported on our primary outcome, prevalence of infection with at least one STH species. Twenty‐one studies reported on the prevalence of A lumbricoides (12 RCTs and 9 non‐RCTs); 17 on the prevalence of T trichiura (9 RCTs and 8 non‐RCTs); 18 on the prevalence of hookworm (10 RCTs and 8 non‐RCTs); and one on the prevalence of S stercoralis (1 non‐RCT). Sixteen studies measured the intensity of infection for an individual STH type. Ten RCTs and five non‐RCTs reported on the intensity of infection of A lumbricoides; eight RCTs and five non‐RCTs measured the intensity of infection of T trichiura; and eight RCTs and five non‐RCTs measured the intensity of hookworm infection. No studies reported on the intensity of infection of S stercoralis.The overall pooled effect estimates showed that the WASH interventions under study may result in a slight reduction of any STH infection, with an odds ratio (OR) of 0.86 amongst RCTs (95% confidence interval (CI) 0.74 to 1.01; moderate‐certainty evidence) and an OR of 0.71 amongst non‐RCTs (95% CI 0.54 to 0.94; low‐certainty evidence). All six of the meta‐analyses assessing individual worm infection amongst both RCTs and non‐RCTs had pooled estimates in the preventive direction, although all CIs encapsulated the null, leaving the possibility of the null or even harmful effects; the certainty of the evidence ranged from very low to moderate. Individual studies assessing intensity of infection showed mixed evidence supporting WASH. Subgroup analyses focusing on narrow specific subsets of water, sanitation, and hygiene interventions did very little to elucidate which interventions might be better than others. Data on intensity of infection (e.g. faecal egg count) were reported in a variety of ways across studies, precluding the pooling of results for this outcome.We did not find any studies reporting adverse events resulting from the WASH interventions under study or from mass drug administration (MDA).Authors' conclusionsWhilst the available evidence suggests that the WASH interventions under study may slightly protect against STH infection, WASH also serves as a broad preventive measure for many other diseases that have a faecal oral transmission route of transmission. As many of the studies were done in addition to MDA/deworming (i.e. MDA was ongoing in both the intervention and control arm), our data support WHO recommendations for implementation of improvements to basic sanitation and adequate access to safe water alongside MDA. The biological plausibility for improved access to WASH to interrupt transmission of STHs is clear, but WASH interventions as currently delivered have shown impacts that were lower than expected. There is a need for more rigorous and targeted implementation research and process evaluations in order that future WASH interventions can better provide benefit to users. Inconsistent reporting of the intensity of infection underscores the need to define the minimal, standard data that should be collected globally on STHs to enable pooled analyses and comparisons.

Assessment of Soil-Transmitted Helminth Infections among Pregnant Women in Western Kenya: A Cross-Sectional Study

Intestinal geo-helminths are among the common human infections in the developing world. Preschool and school-age children in Kenya have been targeted for deworming strategies through the National School-Based Deworming Program leaving out vulnerable groups including pregnant women. We conducted this study to assess the prevalence and intensity of worm infections and associated risk factors among pregnant women in Western Kenya. A cross-sectional study was carried out among 250 pregnant women seeking antenatal care services from selected health facilities in Vihiga County. Stool samples were collected and examined for soil transmitted helminths (STH) using the Kato-Katz technique and structured questionnaires were administered to determine associated risk factors. Statistical analysis was done using STATA version 14.1. Differences in proportions by age and health facility were assessed using Chi-square (χ2) test and differences in means using the student t-test. Prevalence of STHs was 12.4% (95%CI: 9.1%-16.9%). Infection caused by hookworm was 2.4% (95%CI: 1.2% - 4.7%), Ascaris lumbricoides 9.6% (95%CI: 6.3% - 14.6%), Trichuris trichiura 2.0% (95%CI: 0.8% - 5.3%). The mean intensity of hookworm infection was 101 (95%CI: 8 -1355), A. lumbricoides 375 (95%CI: 107 - 1308), and T. trichiura 3 (95%CI: 0 - 29). Univariable analysis of factors associated with infection did not reveal any significant associations. Participants with primary level of education had higher odds of T. trichiura infection compared to other participants (OR=2.58, p=0.400). Farming had higher odds of STH and A. lumbricoides infections (OR=3.47, p=0.076) and (OR=3.75, p=0.089) respectively compared to other occupations. Participants in the second trimester of pregnancy had higher odds of hookworm infection (OR=3.36, p=0.272) those with children under three years had higher odds of T. trichiura infection (OR=3.60, p=0.165). The study revealed that STH infection is prevalent among pregnant women in Vihiga although there were no significant risk factors associated with the infection. Therefore, health facilities should conduct deworming and testing for STH also they should provide health education on the risks of getting infected.

Soil-transmitted helminth infections after mass drug administration for lymphatic filariasis in rural southern India.

Targeted deworming is the current strategy for control of morbidity associated with soil-transmitted helminths (STH) among at-risk populations: preschool-aged children, school-aged children and women of childbearing age. We report the prevalence and intensity of STH in a district after lymphatic filariasis (LF) mass drug administration (MDA) in southern India where albendazole was co-administered from 2001. Children aged 2 to 15years and adults (defined as ≥15years) in a rural administrative block of Tamil Nadu were recruited using a probability proportional to size method. Stool samples were screened and eggs per gram (EPG) determined by Kato-Katz method. Multilevel logistic regression (MLR) and multilevel negative binomial regression (MNBR) analyses were used to identify factors associated with infection and intensity, respectively. Of 862 participants who provided samples, 60 (7.0%; 95% confidence interval (CI): 5.3-8.7) were positive for STH with a predominance of hookworm infections (n= 57, 6.6%; 95% CI: 5.0-8.3). Increasing age (odds ratio (OR): 1.09; 95% CI: 1.04-1.15) and regular usage of the toilet (OR: 0.32; 95% CI: 0.12-0.88) were independently associated with hookworm infection and age was significantly associated with increasing intensity of hookworm infection (infection intensity ratio (IIR): 1.28; 95% CI: 1.19-1.37). A brief review of STH prevalence in endemic settings before and after the stoppage of LF MDA indicated that, in most settings, a substantial reduction in STH prevalence is seen. Community-wide MDA in all age groups in these post-LF MDA districts with low prevalence and light intensity infections could result in transmission interruption of STH.

Impact of hookworm infection and preventive chemotherapy on haemoglobin in non-pregnant populations.

To assess the impact of hookworm infection and preventive chemotherapy on haemoglobin levels in non-pregnant populations in endemic areas. Systematic review and meta-analysis searching PubMed and Web of Science for articles published since 2010 reporting either hookworm prevalence and Hb concentration (cross-sectional studies) or Hb concentration before and after the implementation of preventive chemotherapy (before-after studies and randomised controlled trials [RCTs]). For papers published before 2010, data were extracted from a previously published systematic review. Random effects meta-analyses were conducted to examine the relationship between Hb concentration and hookworm infection intensity (from cross-sectional studies) and the effect of preventive chemotherapy on Hb concentration (from before-after studies and RCTs). Sensitivity analyses investigated the impact of malaria endemicity and combined interventions for schistosomiasis and nutrition status on Hb concentration. Among cross-sectional studies, both light- and heavy-intensity hookworm infections were associated with lower Hb in school-aged children. School-aged children with heavy hookworm infection in settings of high malaria endemicity had lower mean Hb than those in settings of low malaria endemicity. In non-pregnant populations, deworming with albendazole was associated with an increase in Hb of 3.02g/L (95% CI 0.1, 6.0g/L). No additional benefit was seen with deworming using albendazole co-administered with praziquantel for schistosomiasis infection or iron supplementation for nutrition status. Our findings confirm the benefits of preventive chemotherapy as a public health intervention.

Detection of Hookworm (Necator Americanus) and Other Intestinal Parasitic Infection among Primary School Children in Sokoto Metropolis

Background: Hookworm is an intestinal parasite of human and is one of the major public health burdens in developing countries, particularly in Sub-Saharan Africa. It is estimated that about 3.5 billion people globally and 450 million people are thought to be ill as a result of such infections, the majority being children.&#x0D; Aims: The study aimed to determine the prevalence of Hookworm and other intestinal parasitic infection among primary school children&#x0D; Study Design: This was a cross-sectional, descriptive study&#x0D; Place and Duration of Study: This study was conducted in among patients attending Usmanu Danfodiyo University, Teaching Hospital, Sokoto, Sokoto state, between March to November, 2017.&#x0D; Methodology: A total of 224 participants were enrolled for the study. Standard parasitological examination was carried out on stool samples using microscopy followed by formal ether concentration methods&#x0D; Results: Finding revealed, an overall prevalence of 4.5% out of 224 samples examined recorded for both Hookworm and other intestinal parasitic infection. There was high prevalence rate of Hookworm and other intestinal parasitic infection among males (5.3%) than females (3.6%).29 (12%) were positive for intestinal parasitic infections. Males recorded higher prevalence than the females with 19 (11.9%) and 10 (11.8%) respectively&#x0D; Conclusion: The total low prevalence rate of Hookworm and other intestinal parasitic infection may be as a result of improved standard of living and awareness of the Hookworm and other intestinal parasites in the study area. The government, non-governmental agencies and private individuals should help in the provision of social amenities to ensure total eradication of these diseases. The teaching of health education in both private schools should be encouraged by the government which will go a long way in reducing prevalence and intensity of Hookworm infections among the study community.

Prevalence, risk factors and health consequences of soil-transmitted helminth infection on the Bijagos Islands, Guinea Bissau: A community-wide cross-sectional study.

Soil-transmitted helminths (STH) are endemic and widespread across Sub-Saharan Africa. A community wide soil-transmitted helminth (STH) prevalence survey was performed on the island of Bubaque in Guinea-Bissau using both Kato-katz microscopy and qPCR methodology. Predictors of infection and morbidity indicators were identified using multivariable logistic regression, and diagnostic methods were compared using k statistics. Among 396 participants, prevalence of STH by microscopy was 23.2%, hookworm was the only species identified by this method and the mean infection intensity was 312 eggs per gram. qPCR analysis revealed an overall prevalence of any STH infection of 47.3%, with the majority A. duodenale (32.3%), followed by N. americanus (15.01%) and S. stercoralis (13.2%). A. lumbricoides, and T. trichiura infections were negligible, with a prevalence of 0.25% each. Agreement between diagnostic tests was k = 0.22, interpreted as fair agreement, and infection intensity measured by both methods was only minimally correlated (Rs = -0.03). STH infection overall was more common in females and adults aged 31–40. STH infection was associated with open defaecation, low socio-economic status and further distance to a water-source. The prevalence of anaemia (defined as a binary outcome by the WHO standards for age and sex) was 69.1%, and 44.2% of children were malnourished according to WHO child growth standards. Hookworm infection intensity by faecal egg count showed no statistically significant association with age (Rs 0.06) but S. Stercoralis infection intensity by qPCR cycle threshold was higher in pre-school aged children (Rs = 0.30, p-value 0.03) There was no statistically significant association between STH infection and anaemia (OR 1.0 p = 0.8), stunting (OR 1.9, p-value 0.5) and wasting (OR 2.0, p-value 0.2) in children. This study reveals a persistent reservoir of STH infection across the community, with high rates of anaemia and malnutrition, despite high-coverage of mebendazole mass-drug administration in pre-school children. This reflects the need for a new strategy to soil-transmitted helminth control, to reduce infections and ultimately eliminate transmission.

Impact of annual and semi-annual mass drug administration for Lymphatic Filariasis and Onchocerciasis on Hookworm Infection in Côte d'Ivoire.

Mass Drug Administration (MDA) programs to eliminate Lymphatic Filariasis (LF) in western Africa use the anthelminthics ivermectin plus albendazole. These drugs have the potential to impact also Soil-Transmitted Helminth (STH) infections, since the drugs have a broad range of anthelminthic activity. Integration of preventive chemotherapy efforts for LF, onchocerciasis and STH is recommended by the World Health Organization (WHO) in order to avoid duplication of MDA and to reduce costs. The objective of the current study was to determine whether five semi-annual rounds of community-wide MDA to eliminate LF and onchocerciasis have a greater impact on STH than three annual rounds of MDA with similar compliance. The effects of MDA using ivermectin (IVM, 0.2 mg/kg) combined with albendazole (ALB, 400 mg) on the prevalence and intensity of hookworm infection were evaluated in the Abengourou (annual MDA) and Akoupé (semi-annual MDA) health Districts in eastern Côte d’Ivoire from 2014 to 2017. A cross-sectional approach was used together with mixed logistic regression, and mixed linear models. Subjects were tested for STH using the Kato-Katz technique before the first round of MDA and 12, 24, and 36 months after the first round of MDA. The mean self-reported MDA compliance assessed during the survey was 65%, and no difference was observed between treatment areas. These results were confirmed by an independent coverage survey as recommended by WHO. Hookworm was the most prevalent STH species in both areas (23.9% vs 12.4%) and the prevalence of other STH species was less than 1%. The crude prevalence of hookworm dropped significantly, from 23.9% to 5.5% (p <0.001, 77% reduction) in the annual MDA treatment area and from 12.4% to 1.9% (p <0.001, 85% reduction) in the semi-annual treatment area. The average intensity of hookworm infection decreased in the annual MDA area (406.2 epg to 118.3 epg), but not in the semi-annual MDA area (804.9 epg to 875.0 epg). Moderate and heavy infections (1% and 1.3% at baseline) were reduced to 0% and 0.4% in the annual and semi-annual treatment areas, respectively. Using a mixed logistic regression model, and after adjusting for baseline prevalence, only the year 2 re-examination showed a difference in prevalence between treatments (OR: 2.26 [95% CI: 1.03, 4.98], p = 0.043). Analysis of intensity of hookworm infection indicated also that treatment differences varied by follow-up visit. In conclusion twelve months after the last treatment cycle, three annual and five semi-annual rounds of community-wide MDA with the combination of IVM and ALB showed strong, but similar impact on hookworm prevalence and intensity in eastern Côte d’Ivoire. Therefore, an annual MDA regimen seems to be an efficient strategy to control hookworm infection in endemic areas with low and moderate infection prevalence.Trial registration: The study was registered at ClinicalTrial.gov under the number NTC02032043.

Efficacy, safety and acceptability of a new chewable formulation versus the solid tablet of mebendazole against hookworm infections in children: An open-label, randomized controlled trial.

BackgroundSoil-transmitted helminths (STHs) infect almost 1·5 billion people worldwide. The control of STH infections is based on preventive chemotherapy using either albendazole or mebendazole. Before being widely used, a sufficient body of evidence on efficacy, safety and acceptability is warranted for the new chewable child-friendly formulation of mebendazole that was recently developed.MethodsWe conducted a randomised controlled superiority trial in four primary schools and kindergartens on Pemba Island, Tanzania. We considered eligible children aged 3 to 12 years with a hookworm infection intensity of at least 50 eggs per gram (EPG) of stool and no chronic diseases. Participants were allocated to treatment arms (ratio 1:1) using a computer generated random sequence. Our primary outcome was geometric mean based egg reduction rate (ERR) against hookworm assessed 14–21 days post-treatment. This trial complete and is registered with ClinicalTrials.gov, number NCT03995680 (June 24, 2019).Findings397 children were eligible and randomised into the solid (198) or chewable (199) tablet arms, of whom 393 were analysed. We found no significant difference between both formulations in terms of ERR (solid 70·8% versus chewable 68·5%, difference in ERRgeometric mean 2·3%-points, 95% CI -7·8 to 12·6, p = 0.65) and CR (11·2 versus 12·7%, 95% CI -4·9 to 7·9, p = 0.65) against hookworm infections. Adverse events were mild in both treatment arms.InterpretationsThough we could not demonstrate superiority in terms of efficacy of the new formulation, the difference between arms was small and therefore, the chewable formulation could be safely used as an alternative to swallowable tablets, in particular in young children who may have swallowing difficulties. This might help increase compliance and, consequently, enhance the effect of preventive chemotherapy.

Prevalence and intensity of hookworm infection in relation to anaemia among primary school pupils in Lafia rural areas

The study was carried out between March to September 2020 to determine the prevalence and intensity of hookworm infection in relation to anaemia among primary school children in Lafia rural areas of Nasarawa State namely Musha, Alawagana, Duglu and Azuba. Four primary schools were randomly selected from the locality and a total of 560 faecal and 69 blood samples were collected and analysed. Out of the 560 faecal samples analysed, 115(20.5%) were infected with hookworm with a Geometric Mean Intensity (GMI) of 436.2 eggs per gram of faeces (epgf). Meanwhile, the prevalence and GMI of hookworm infection were higher in females (21.5%, 76.3 epgf) than in males (19.6%, 71.1 epgf), though no significant difference (p&gt;0.05) in the prevalence between males and females. Age group 10 12 years old had the highest prevalence rate of hookworm infection (26.3%), followed by 13 15 (22.9%), 7 9 (19.2%) and 4 6 (9.0%). There was a strong inverse correlation (r = -0.99) between the intensity of hookworm infection and haemoglobin value. Haemoglobin value decreased with an increase in the intensity of hookworm infection in terms of eggs per gram of faeces. Hookworm infection is therefore associated with anaemia in the study area.

Community-level epidemiology of soil-transmitted helminths in the context of school-based deworming: Baseline results of a cluster randomised trial on the coast of Kenya.

Most epidemiological studies of soil-transmitted helminth (STH) infections focus on school-going children. The majority of large-scale cross-sectional and longitudinal community-based studies have been conducted prior to the implementation of wide-scale mass drug administration (MDA). This study investigates age-related patterns in prevalence and intensity of STH infection, and associated risk factors, in a region of south coastal Kenya that had previously received three consecutive years of school-based deworming (2012–14) and four rounds of community-based MDA for lymphatic filariasis between 2003 and 2014. Between March and May 2015, a cross-sectional survey was conducted in 120 community clusters as a baseline for a cluster randomised trial. Individuals aged two years and above were randomly selected during household surveys and requested to provide stool samples, which were assessed for presence and intensity of STH using the duplicate Kato-Katz thick smear method. Species-specific predictors of presence and intensity were investigated through multilevel logistic regression and zero-inflated negative binomial regression models. Of the 19,684 individuals who provided a stool sample, 21.5% were infected with at least one STH. Hookworm was the predominant species, with an overall prevalence of 19.1%; Trichuris trichiura prevalence was 3.6% and Ascaris lumbricoides was negligible (0.4% prevalence). The vast majority were light intensity infections. Prevalence and intensity of hookworm infection were significantly higher in adults and males, and were associated with environmental conditions, low socio-economic status, household flooring, individual and household water, sanitation and hygiene (WASH) characteristics and behaviours, previous treatment, lack of shoe-wearing and not attending school. In contrast, T. trichiura was more commonly found in school-aged boys and those living in communities close to the coast, with reduced infection in the least poor individuals with private latrine access. Overall, results show that despite several years of school-based deworming, hookworm infection remains common among untreated adults in this population, suggesting that this strategy alone is insufficient to reduce community-wide hookworm infection and in the longer term to eliminate transmission.Trial registrationClinicalTrials.gov NCT02397772

Status of hookworm infection in junior secondary students, Bwari Area Council, Abuja, Nigeria

Hookworm infection has long been classified as the second most common parasitic helminth disease of the tropic and sub-tropic most especially because besides its grievous public health implications, some of which are due to the pathological damage it causes in the human host’s tissue and organs, the disease also has negative impacts on both human and socio-economic developments in communities where it is endemic. This study aims to verify the prevalence and intensity of hookworm infection in secondary school students in Bwari Area Council, FCT, Abuja. Four secondary schools namely, Government Secondary School, Law School Road, St. Theresa’s Catholic Schools, Government Secondary School, Kuduru and Government Secondary School, Zuma II, were selected randomly as case study. Four hundred and eighty (480) stool specimens (i.e., 120 from each school) were collected exclusively from the Junior Secondary School students of these schools, ensuring that both sexes were equally represented in those to supply the stool specimens. Microscopic examination of the stool specimens was carried out using saline and iodine wet mounts, brine floatation and centrifugation/sedimentation methods to check for presence of ova of hookworm. Result obtained showed that only 167(34.8%) stool specimens contained ova of hookworm of which 107(64.1%) were those from male students and 60(35.9%) were from females. 67(62.6%) were from those within the age bracket of 9-13 years while the other 40(37.4%) were those from 14-18 years age bracket. Similarly, 33(55%) of the infected females were within 9-13 years’ age bracket while the rest 27(45%) were between 14-18 years. Further classification of the result revealed JSS 2 and JSS3 students as having the highest prevalence with 67(40.1%) and 57(34.8%), respectively, while JSS 1 had low infection with 43(25.7%). When infections amongst the schools were compared, it was found that Government Secondary School, Zuma II, had the highest with 48(40%) while the rest Government Secondary School, Law School Road, St. Theresa’s Catholic Schools and Government Secondary School, Kuduru, had 40(33.3%), 36(30%) and 43(35.3%), respectively. the study has confirmed that hookworm exist in Bwari Area Council. The observed high prevalence of infection amongst male students between the 9-13 years age bracket cannot therefore be unconnected with their active engagement in farming, hunting, sports (such as football, athletics, etc.) and other extra-curricular activities that make them expose themselves to unprotected and hookworm-infested soils. Prompt treatment of known cases beside adequate and regular health education campaign in primary, secondary, work places and public markets on the need for proper hygiene practices and regular environmental sanitation and avoidance indiscriminate human faecal disposal.Keywords: Hookworm; prevalence; intensity; secondary school; students; Bwari.

Prevalence of intestinal parasitic infections and associated risk factors for hookworm infections among primary schoolchildren in rural areas of Nakhon Si Thammarat, southern Thailand

BackgroundSoil-transmitted helminth (STH) infections are among the most common type of infections worldwide and are widely distributed in tropical areas. In rural areas of southern Thailand where most land is used for agriculture, children are at risk of acquiring parasites, especially STHs. Assessing the current situation regarding parasitic infection in these areas is a prerequisite for developing appropriate control measures. This study is aimed at determining the prevalence of intestinal parasitic infections, the intensity of STH infections and the associated risk factors among primary schoolchildren in Nopphitam District, Nakhon Si Thammarat Province, Thailand.MethodsA cross-sectional study involving 299 schoolchildren between 7 and 12 years of age was conducted between January and March 2016. A questionnaire administered by direct interviews was used to collect sociodemographic information and data on associated risk factors. Stool samples were processed using direct wet smears, formalin-ethyl acetate sedimentation concentration, and the modified Kato-Katz technique.ResultsThe overall prevalence of intestinal parasites among the 299 children was 16% (48 of 299), with 32 children infected with hookworms (10.7%), 10 with Blastocystis hominis (3.3%), seven with Giardia intestinalis (1.6%), one with Enterobius vermicularis (0.3%), and one with Trichuris trichiura (0.3%). The hookworm infection intensity, measured by the median eggs per gram (EPG) of stool, was 1200 EPG (Interquartile range (IQR): 360–3200). Most children had light-intensity hookworm infections, but two had heavy-intensity infections. When participants included in the sample were classified by age, children 10–12 years old demonstrated higher intestinal parasite prevalence than those aged 7–9 years (adjusted odds ratio (AOR) = 2.3, 95% CI: 1.1–4.9, P = 0.030). Inadequate handwashing before meals was statistically associated with hookworm infections (AOR = 2.3; 95% CI: 1.1–4.8, P = 0.037).ConclusionsThis study highlights that hookworms are the most prevalent STH infection in the study area. Older age group (10–12 years) and inadequate handwashing before meals were statistically associated with hookworm infections. Accordingly, appropriate strategies and education on personal and environmental hygiene should be implemented. Moreover, the cost-effectiveness of mass drug administration in this area should be further investigated.

Prevalence of soil-transmitted helminths and Schistosoma mansoni among a population-based sample of school-age children in Amhara region, Ethiopia

BackgroundFrom 2011 to 2015, seven trachoma impact surveys in 150 districts across Amhara, Ethiopia, included in their design a nested study to estimate the zonal prevalence of intestinal parasite infections including soil-transmitted helminths (STH) and Schistosoma mansoni.MethodsA multi-stage cluster random sampling approach was used to achieve a population-based sample of children between the ages of 6 and 15 years. Stool samples of approximately 1 g were collected from assenting children, preserved in 10 ml of a sodium acetate-acetic acid-formalin solution, and transported to the Amhara Public Health Research Institute for processing with the ether concentration method and microscopic identification of parasites. Bivariate logistic and negative binomial regression were used to explore associations with parasite prevalence and intensity, respectively.ResultsA total of 16,955 children were selected within 768 villages covering 150 districts representing all ten zones of the Amhara region. The final sample included 15,455 children of whom 52% were female and 75% reported regularly attending school. The regional prevalence among children of 6 to 15 years of age was 36.4% (95% confidence interval, CI: 34.9–38.0%) for any STH and 6.9% (95% CI: 5.9–8.1%) for S. mansoni. The zonal prevalence of any STH ranged from 12.1 to 58.3%, while S. mansoni ranged from 0.5 to 40.1%. Categories of risk defined by World Health Organization guidelines would indicate that 107 districts (71.3%) warranted preventive chemotherapy (PC) for STH and 57 districts (38.0%) warranted PC for schistosomiasis based solely on S. mansoni. No statistical differences in the prevalence of these parasites were observed among boys and girls, but age and school attendance were both associated with hookworm infection (prevalence odds ratio, POR: 1.02, P = 0.03 per 1 year, and POR: 0.81, P = 0.001, respectively) and age was associated with infection by any STH (POR: 1.02, P = 0.03). Age was also associated with reduced intensity of Ascaris lumbricoides infection (unadjusted rate ratio: 0.96, P = 0.02) and increased intensity of hookworm infection (unadjusted rate ratio: 1.07, P < 0.001).ConclusionsThese surveys determined that between 2011 and 2015, STH and Schistosoma mansoni were present throughout the region, and accordingly, these results were used to guide PC distribution to school-age children in Amhara.

Prevalence of intestinal parasitic infection and associated risk factors among village health volunteers in rural communities of southern Thailand

BackgroundIntestinal parasitic infections remain prevalent and constitute a public health problem in certain rural areas of Thailand. Village health volunteers (VHVs), who are members of a Thai healthcare alliance, function as key providers of health prevention measures, disease control, and health education and share national health promotion campaigns with community members. This study is aimed at evaluating the prevalence, intensity, and risk factors for intestinal parasitic infection in VHVs in order to design community awareness and health education campaigns for the target population.MethodsThis cross-sectional study was conducted between January to April 2016 among village health volunteers (VHVs) from four sub-districts of Nopphitam District, Nakhon Si Thammarat Province, southern Thailand. Subjects for the study were selected using a simple random sampling method. Socio-demographic variables and risk factors were collected by a structured questionnaire. Stool specimens were collected and processed using direct wet mount and formol-ether concentration techniques to determine the presence of parasites and modified Kato-Katz thick smear to determine the intensity of infection.ResultsA total of 324 VHVs were enrolled. The overall prevalence of intestinal helminths was 9.3% (95% confidence interval [CI]: 6.3–13.0). The prevalence of hookworm, Strongyloides stercoralis, and Trichuris trichiura were 8.0% (95% CI: 5.3–11.5), 0.9% (95% CI: 0.2–2.7), and 0.3% (95% CI: 0–1.7), respectively. Mean intensity of hookworm infection was 1732 eggs per gram of stool. The prevalence was lower for protozoan infection than for helminth infection. Blastocystis hominis accounted for the highest percentage of intestinal protozoan infections 4.0% (95% CI: 2.2–6.8), followed by Giardia intestinalis 0.6% (95% CI: 0–2.2). No statistically significant difference was observed in the prevalence of intestinal parasitic infection among sub-districts (p > 0.05). Having dogs at home was associated with soil-transmitted helminth (STH) infection in study participants (Crude prevalence ratio [CPR]: 2.3; 95% CI: 1.0–5.2).ConclusionsThis study is the first to describe the prevalence of intestinal parasitic infection VHVs from southern Thailand. Hookworm infection is more prevalent than other types of STH infection. The development of community awareness campaigns and appropriate control measures should be considered to reduce the prevalence of hookworm infection, especially among VHVs who are the key persons providing health education to the community.

Cognitive Performance and Iron Status are Negatively Associated with Hookworm Infection in Cambodian Schoolchildren.

Soil-transmitted helminth (STH) infection has been associated with lower cognitive performance of schoolchildren. To identify pathways through which STH infection might affect school performance, baseline data from a large rice-fortification trial in Cambodian schoolchildren were used to investigate associations between STH infection, micronutrient status, anemia, and cognitive performance. Complete data on anthropometry, cognitive performance, and micronutrient status were available for 1,760 schoolchildren, 6-16 years of age. STH infection was identified using Kato-Katz, whereas cognitive performance was assessed using Raven's Colored Progressive Matrices (RCPM), block design, and picture completion. STH infection was found in 18% of the children; almost exclusively hookwork infection. After adjusting for age and gender, raw cognitive test scores were significantly lower in hookworm-infected children (-0.65; -0.78; -2.03 points for picture completion, RCPM, and block design, respectively; P < 0.05 for all). Hookworm infection was associated with iron status (total body iron), but not with vitamin A and zinc status, nor with inflammation or anthropometry. Body iron was negatively associated with increased intensity of hookworm infection (R = 0.22, P < 0.001). Hookworm infection in Cambodian schoolchildren was associated with lower cognitive performance, an effect most likely mediated through lower body iron. Interventions that are more effective against hookworm infection are needed to contribute to better health and improvement of cognitive performance.

Prevalence and intensity of Schistosoma mansoni and hookworm infections among pre-school and school-aged children in Ilemela District, north-western Tanzania

Background: World Health Organization have recently recommended the inclusion of pre-school children in the Mass Drug Administration (MDA) against schistosomiasis and soil-transmitted helminths in endemic areas. This study was conducted to determine the prevalence and intensity of Schistosoma mansoni and hookworm infections among pre- and school going children in Ilemela District, north-western Tanzania.Methods: This cross-sectional study included pre- and school going children aged 4-14 years. A single stool sample was collected from each child and processed using Kato Katz thick smears and examined microscopically for presence of S. mansoni and hookworm eggs. A questionnaire was used to collect demographic information of the study participants.Results: Overall, prevalence of S. mansoni was 80.0%; with pre-school children aged 4-6 years having the point prevalence of 60.6%. The overall prevalence of hookworm infection was 18.7%; with age group 4-6 years having the prevalence of 14.1%. The intensity of hookworm infection was light in all age groups. The intensity of infection of S. mansoni increased with age. Using lake water for domestic purposes (OR=3.09, 95% CI: 1.93-4.95, p&lt;0.001), for bathing (OR=2.65, 95% CI: 1.66-4.23, p&lt;0.0001), and for washing purposes (OR=3.08, 95% CI: 1.90-4.97, p&lt;0.0001) remained independently associated with S. mansoni infection. Children who reported to swim in the lake and involved in paddy farming had 1.84 and 1.95 times odds of being infected than those who did not, respectively.Conclusion: These findings indicate that S. mansoni and hookworm infections are common among pre-school children as well as in school going children. These findings call for the need to urgently include the pre-school age children the MDSA programme.

Schistosoma haematobium and soil-transmitted Helminths in Tana Delta District of Kenya: infection and morbidity patterns in primary schoolchildren from two isolated villages.

BackgroundSchistosomes and soil-transmitted helminths (STH) (hookworm, Trichuris trichiura and Ascaris lumbricoides) are widely distributed in developing countries where they infect over 230 million and 1.5 billion people, respectively. The parasites are frequently co-endemic and many individuals are co-infected with two or more of the species, but information on how the parasites interact in co-infected individuals is scarce. The present study assessed Schistosoma haematobium and STH infection and morbidity patterns among school children in a hyper-endemic focus in the Tana River delta of coastal Kenya.MethodsTwo hundred and sixty-two children aged 5–12 years from two primary schools were enrolled in the study. For each child, urine was examined for S. haematobium eggs and haematuria, stool was examined for STH eggs, peripheral blood was examined for eosinophilia and haemoglobin level, the urinary tract was ultrasound-examined for S. haematobium-related pathology, and the height and weight was measured and used to calculate the body mass index (BMI).ResultsPrevalences of S. haematobium, hookworm, T. trichiura and A. lumbricoides infection were 94, 81, 88 and 46 %, respectively. There was no significant association between S. haematobium and STH infection but intensity of hookworm infection significantly increased with that of T. trichiura. Lower BMI scores were associated with high intensity of S. haematobium (difference =−0.48, p > 0.05) and A. lumbricoides (difference =−0.67, p < 0.05). Haematuria (both macro and micro) was common and associated with S. haematobium infection, while anaemia was associated with high intensity of S. haematobium (OR = 2.08, p < 0.05) and high hookworm infections OR = 4.75; p < 0.001). The majority of children had eosinophilia, which was significantly associated with high intensity of hookworm infection (OR = 5.34, p < 0.05). Overall 38 % of the children had ultrasound-detectable urinary tract morbidity, which was associated with high intensity of S. haematobium infection (OR = 3.13, p < 0.05).ConclusionPrevalences of S. haematobium and STH infections among the primary school children were high and the parasites were responsible for significant morbidity. A clear synergistic interaction was observed between hookworm and T. trichiura infections. Increased coverage in administration of praziquantel and albendazole in the area is recommended to control morbidity due to these infections.

Understanding Heterogeneity in the Impact of National Neglected Tropical Disease Control Programmes: Evidence from School-Based Deworming in Kenya.

BackgroundThe implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be influenced by factors that affect the reduction in the prevalence and intensity of infections following treatment, as well as the subsequent rate of reinfection. To better understand the heterogeneity of programme impact and its underlying reasons, we investigated the influence of contextual factors on reduction in STH infection as part of the national school based deworming (SBD) programme in Kenya.Materials and MethodsData on the prevalence and intensity of infection were collected within the monitoring and evaluation component of the SBD programme at baseline and after delivery of two annual treatment rounds in 153 schools in western Kenya. Using a framework that considers STH epidemiology and transmission dynamics, capacity to deliver treatment, operational feasibility and financial capacity, data were assembled at both school and district (county) levels. Geographic heterogeneity of programme impact was assessed by descriptive and spatial analyses. Factors associated with absolute reductions of Ascaris lumbricoides and hookworm infection prevalence and intensity were identified using mixed effects linear regression modelling adjusting for baseline infection levels.Principal FindingsThe reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school. Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community. Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores.ConclusionsThe study identifies factors associated with the impact of school-based deworming and in particular highlights how access to water, sanitation and hygiene and environmental conditions influence the impact of deworming programmes.