Prevalence Of Hookworm Infection Research Articles

Insights into hookworm prevalence in Asia: a systematic review and meta-analysis.

Hookworm infections are neglected tropical diseases of humans and animals worldwide. A meta-analysis and systematic review was designed to evaluate the prevalence of hookworm infection in animal and human hosts in Asia until July 2018. The available online articles of five English databases (PubMed, Scopus, Science Direct, Web of Science and Google Scholar) were explored. The most parasitized carnivores were jackal (48%, CI: 4 to 91%), followed by dog (41%, CI: 29 to 53%), cat (26%, CI: 14 to 38%) and the red fox (19%, CI: 13 to 24%). The weighted prevalence of Ancylostoma braziliensis, A. caninum, A. ceylanicum, A. tubaeforme and Uncinaria stenocephala isolated from different canids were found to be 27% (CI: 21 to 33%), 23% (CI: 7.0 to 53%), 24% (CI: 12 to 35%), 44% (CI: 37 to 51%) and 37% (CI: 18 to 55%), respectively. In total, 98 records were obtained for human hookworms from 3209 760 examined individuals and the calculated weighted prevalence in this population was 19% (CI: 17 to 20%). These findings highlight a desirable ecological milieu for parasite survival and transmission in such territories, which implicates revisiting control programs and public health infrastructures in those areas.

Semi-domesticated dogs as a potential reservoir for zoonotic hookworms in Bangkok, Thailand.

Background and Aim:Hookworms are parasitic nematodes that live in the small intestine of their mammalian hosts including humans, dogs, and cats. This study was conducted to determine the prevalence and perform genetic characterization of hookworms using molecular techniques and to elucidate the risk factors associated with hookworm infections among semi-domesticated dogs residing in temples in the Bangkok Metropolitan Area, Thailand.Materials and Methods:A total of 500 fecal samples were collected from semi-domesticated dogs from 91 temples in 48 districts of Bangkok. DNA was extracted and screened using internal transcribed spacer polymerase chain reaction-restriction fragment length polymorphism. In addition, samples positive for Ancylostoma ceylanicum were further characterized at the haplotype level based on the analysis of the mitochondrial cytochrome oxidase-1 gene (cox1).Results:The prevalence of hookworm infections in semi-domesticated dogs was 6.2% (31/500). Hookworm infections were detected in temple-community dogs in 12 of 48 districts (25.0%), with Bang Khen and Lak Si districts having the highest proportion of infected dogs (22.6%). Regarding molecular characterization of hookworm species, 21 positive samples (67.74%) were infected with A. ceylanicum and 10 (32.26%) with Ancylostoma caninum. Characterization of cox1 in A. ceylanicum isolates revealed the presence of a mixture of human and dog isolates.Conclusion:Semi-domesticated dogs act as a potential source of hookworm infections for human and animal populations in Bangkok, Thailand.

Domains of transmission and association of community, school, and household sanitation with soil-transmitted helminth infections among children in coastal Kenya.

IntroductionFew studies have simultaneously examined the role of sanitation conditions at the home, school, and community on soil-transmitted helminth (STH) infection. We examined the contribution of each domain that children inhabit (home, village, and school) to STH infection and estimated the association of STH infection with sanitation in each domain.MethodsUsing data from 4,104 children from Kwale County, Kenya, who reported attending school, we used logistic regression models with cross-classified random effects to calculate measures of general contextual effects and estimate associations of village sanitation coverage (percentage of households with reported access to sanitation), school sanitation coverage (number of usable toilets per enrolled pupil), and sanitation access at home with STH infection.FindingsWe found reported use of a sanitation facility by households was associated with reduced prevalence of hookworm infection but not with reduced prevalence of T. trichiura infection. School sanitation coverage > 3 toilets per 100 pupils was associated with lower prevalence of hookworm infection. School sanitation was not associated with T. trichiura infection. Village sanitation coverage > 81% was associated with reduced prevalence of T. trichiura infection, but no protective association was detected for hookworm infection. General contextual effects represented by residual heterogeneity between village and school domains had comparable impact upon likelihood of hookworm and T. trichiura infection as sanitation coverage in either of these domains.ConclusionFindings support the importance of providing good sanitation facilities to support mass drug administration in reducing the burden of STH infection in children.

Prevalence and determinant factors of hookworm infection among school age children in Jawe district, NorthWest Ethiopia.

Hookworm infection is a common parasitic infection in sub-Saharan Africa. The prevalence of hookworm infection is influenced by different determinant factors. This study aimed to determine the prevalence of hookworm infection and determinant factors among school age children in North West Ethiopia. A cross-sectional study was conducted from April 2016 to August 2016. Children were selected by systematic random sampling and Formoleether concentration technique was used to identify hookworm infection. We conducted descriptive and logistic regression analysis for categorical variables. The adjusted odds ratio was calculated at 95% confidence interval. Among 333 children, 49 (14.7%) were infected with hookworm parasites. Eating raw vegetables, not wearing shoes, absence of regular wearing of shoes and hand washing habit, absence of proper utilization of latrines, absence of deworming were significantly associated (p<0.05) with hookworm infection. The prevalence of hookworm infection was high among school age children. Walking with bare foot, hand washing habit, and absence of proper latrine utilization are the major determinant factors for the high prevalence of hookworm infection. Therefore, community mobilization and health education should be done to decrease hookworm infection among school age children in Jawe district.

Environmental Factors and Prevalence of Hookworm infection and Strongyloidiasis in Rural East Kalimantan, Indonesia

The prevalence of hookworm infection and strongyloidiasis is serious public health concern globally. In rural East Kalimantan, Indonesia has high-risk environmental factors of the prevalence of hookworm infection and strongyloidiasis. In this study would show the infection rates, correlation analysis between environmental risk factors and prevalence of hookworm infection with statistical analysis. We performed a cross-sectional study among 213 participants from rural community of East Kalimantan Province, Indonesia. In this study used two diagnostic methods: Kato Katz and Koga agar plate culture/KAP culture for diagnosing of hookworm and Strongyloides infections. Chi-square analysis was used for study correlation between environmental factors and hookworm infection. Hookworm, strongyloides, and ascaris infections were found in this study; 44.1%, 16.4%, and 7.5% respectively. Environmental risk factors such as; rainy season, quality of soil and infection hookworm and strongyloides in pet have significant correlation (p-value &lt; 0.05) with hookworm infection and strongyloidiasis. The prevalence of hookworm infection and strongyloidiasis has correlation with environmental factors, and the finding in this research could be contributed to decreasing program of hookworm infection and strongyloidiasis especially in rural community area.

Deworming in non-pregnant adolescent girls and adult women: a systematic review and meta-analysis

BackgroundThe impact of deworming on parasite load, nutritional status and other health outcomes of non-pregnant adolescent girls and adult women is uncertain.MethodsMEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials, the WHO International Clinical Trials Registry Platform, the Cochrane Database of Systematic Reviews and Food and Technology s databases were searched until 24 September 2018. Studies were included if they were randomised controlled trials (RCTs), controlled before and after studies or interrupted time studies comparing deworming with no intervention or placebo in non-pregnant adolescent girls and women 10 to 49 years old. Outcomes of interest included parasite load, reinfection, anaemia, severe anaemia, iron deficiency, diarrhoea or all-cause morbidity. Risk of bias was assessed using the Cochrane risk of bias tool.ResultsWe included four RCTs of mass deworming involving 1086 participants, in the analyses. Mass deworming probably reduces the prevalence of roundworm infection (RR 0.29; 95% CI 0.14 to 0.62; 2 trials; 1498 participants, moderate certainty evidence), prevalence of hookworm infection (RR 0.32; 95% CI 0.18 to 0.59; 2 trials; 1498 participants, moderate certainty evidence), prevalence of whipworm infection (RR 0.77; 95% CI 0.65 to 0.91; 2 trials; 1498 participants, moderate certainty evidence) compared to the control group. Deworming may make little or no difference in prevalence of anaemia (RR 0.82; 95% CI 0.60 to 1.11, 3 studies, 683 participants, low certainty evidence) and prevalence of iron-deficiency (RR 0.89; 95% CI 0.64 to 1.23, 1 study, 186 participants, low certainty evidence) compared to control. We are uncertain whether deworming reduces the prevalence of severe anaemia compared to control as the certainty of evidence was very low. None of the included studies assessed screen and treat deworming or reported reinfection, diarrhoea or adverse events.ConclusionsMass deworming probably reduces the prevalence of soil-transmitted helminth infections but may have little or no effect on anaemia and iron-deficiency in adolescent girls and non-pregnant women in comparison to no intervention or placebo. We are uncertain about the effect on severe anaemia. These results are limited by sparse data and the moderate to very low quality of evidence available.Systematic review registrationThe protocol was registered in PROSPERO (registration number: CRD42016039557). Primary source of funding: Evidence and Programme Guidance unit, Department of Nutrition for Health and Development, World Health Organization (WHO).

Focal persistence of soil-transmitted helminthiases in impoverished areas in the State of Piaui, Northeastern Brazil.

ABSTRACTThis study aims to describe the prevalence, distribution, and factors associated with soil-transmitted helminthiases (STHs) in rural localities in Piaui, Brazil. Two cross-sectional surveys (n=605 subjects; 172 families) were carried out in order to obtain socio-demographic, anthropometric, spatial and parasitological data. Parasites were evaluated using Kato-Katz and centrifugal sedimentation techniques. Eggs were measured to assess infection with zoonotic Strongylida parasites. Kernel maps were constructed with Q-GIS. The prevalence of hookworm infection was 12.4% (75/605). Other helminthes found were Trichuris trichiura (n=1; 0.2%) and Hymenolepis nana (n=1; 0.2%). The hookworm positivity rate was significantly lower among subjects who had used albendazole when compared with individuals who had not used anthelmintics or had used antiprotozoal drugs in the last 6 months (8/134 [6.0%] vs. 59/415 [14.2%]; p=0.009). A total of 39/172 (22.7%) families had at least one infected member. The association between the number of dwellers and hookworm positivity in the family was present in a logistic regression multivariate model. Assessment of worm burdens showed 92.2% light, 6.2% moderate, and 1.6% heavy infections. Hookworm eggs (n=34) measured 57.2 - 75.4 µm in length and 36.4 - 44.2 µm in width (mean ± SD = 65.86 ± 4.66 µm L and 40.05 ± 1.99 µm W), commensurate with human hookworms. Hotspots suggest that transmission has a focal pattern. STHs persist in impoverished rural areas in Northeastern Brazil where currently available control strategies (mass drug administration) apparently do not allow the elimination of the infection.

Prevalence of Hookworm infection and Strongyloidiasis in Cats and Potential Risk Factor of Human Diseases

Hookworm infection and Stronyloidiasis are public health problem in the worldwide which both of them could infective in human by penetrated on skin and they have potential risk from Gastrointestinal zoonotic helminths of pets, including cats. We investigated the prevalence soil transmitted helminths infection in human and cats used modified Formal-Ether Concentration and agar plate culture. Fecal samples of 23 cats and human from Naitung and Subua Villages (area study 1), and fecal samples of 15 cats and 17 humans from Thasala Beach villages (area study 2) were collected. Result of study in area study 1 showed prevalence of infection in human was not hookworm and strongyloidiasis but 10% humans have infected Ascaris and Tricuris, and in cats have infected by hookworm 75.2% and S. strercoralis 8.5%, toxocara 13%, spirometra 13% and overall prevalence 82.5%. In area study 2 showed in human has infected by Trichuris 100% and S. stercoralis 29.4% and in cats have infected by hookworm 100% and S. strercoralis 40%, toxocora 20%, and spirometra 20%. Helminth infection found in both humans in two areas study are S. strercoralis. Hookworms were the most common helminth in cats but did not connection with infection in human, while S. strercoralis was helminth infection in cats which has potential zoonotic disease to human.

Combination of five diagnostic tests to estimate the prevalence of hookworm infection among school-aged children from a rural area of colombia

BackgroundPublic health programs for the control of soil-transmitted helminthiases require valid diagnostic tests for surveillance and parasitic control evaluation. However, there is currently no agreement about what test should be used as a gold standard for the diagnosis of hookworm infection. Still, in presence of concurrent data for multiple tests it is possible to use statistical models to estimate measures of test performance and prevalence. The aim of this study was to estimate the diagnostic accuracy of five parallel tests (direct microscopic examination, Kato-Katz, Harada-Mori, modified Ritchie-Frick, and culture in agar plate) to detect hookworm infections in a sample of school-aged children from a rural area in Colombia. Methods and resultsWe used both, a frequentist approach, and Bayesian latent class models to estimate the sensitivity and specificity of five tests for hookworm detection, and to estimate the prevalence of hookworm infection in absence of a Gold Standard. The Kato-Katz and agar plate methods had an overall agreement of 95% and kappa coefficient of 0.76. Different models estimated a sensitivity between 76% and 92% for the agar plate technique, and 52% to 87% for the Kato-Katz technique. The other tests had lower sensitivity. All tests had specificity between 95% and 98%. The prevalence estimated by the Kato-Katz and Agar plate methods for different subpopulations varied between 10% and 14%, and was consistent with the prevalence estimated from the combination of all tests. The Harada-Mori, Ritchie-Frick and direct examination techniques resulted in lower and disparate prevalence estimates. Bayesian approaches assuming imperfect specificity resulted in lower prevalence estimates than the frequentist approach.

Hookworm infections among migrant workers in Malaysia: Molecular identification of Necator americanus and Ancylostoma duodenale

Ongoing urbanisation of the working population as well as cross-border migration of workers particularly into large cities has contributed to the development and growth of urban slums. These deprived areas are conducive for the transmission of intestinal pathogens including hookworm. The aim of this study was to determine both the prevalence and species identity of hookworm infections among the migrant worker community in Malaysia. A total of 388 faecal samples were collected from migrant workers between September 2014 and August 2015, representing workers from five employment sectors: construction, manufacturing, agriculture and plantations, food services and domestic services. Faecal samples were examined by microscopy and positive samples were subjected to molecular analysis. A total of 51 samples (13.1%) were positive by microscopy for hookworm infections. A two-step PCR based method amplifying a fragment of the 28S rRNA-ITS2 region was used to identify infections by Necator americanus and Ancylostoma spp. PCR products positive for Ancylostoma spp. were sequenced bidirectionally, and sequences analysed through BLAST and phylogenetic analysis. Samples containing Ancylostoma duodenale were further characterized by amplification and sequencing a fragment of cytochrome c oxidase subunit 1 (cox1) gene. PCR amplicons were successfully obtained from 42 (82.4%) of 51 samples, with 81.0% (34 of 42) identified as Necator americanus, 16.7% (7 of 42) as Ancylostoma spp. and 2.4% (1 of 42) as mixed infections of both species. All eight Ancylostoma spp. were confirmed to be Ancylostoma duodenale and this is the first time A. duodenale was reported in Malaysia. Samples containing A. duodenale from Nepalese and Indonesian workers shared high-similarity and were distinct compared to sequences from other countries. This study highlights the prevalence of hookworm infections among migrant workers living in Malaysia. Our findings underscore the necessity of screening migrant workers for hookworm infections, particularly those working in food-related services and industries.

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.

Sustained effectiveness of weekly iron-folic acid supplementation and regular deworming over 6 years in women in rural Vietnam

BackgroundWeekly iron-folic acid (IFA) supplementation and regular deworming is effective for the prevention of iron deficiency and anaemia in women of child-bearing age. Between 2006 and 2013, a program of weekly IFA and biannual deworming was implemented in Yen Bai province, Vietnam. In this study we aimed to determine the effectiveness of the program in reducing anaemia and the prevalence of hookworm infection after 72 months (six years).MethodsThis prospective cohort study followed up a cohort of 389 women of child-bearing age from baseline until six years after the introduction of the weekly IFA (one tablet containing 200 mg ferrous sulphate, 0.4mg folic acid) and deworming (one 400mg tablet of albendazole given twice yearly) program (May 2006 to 2012). In each of the six surveys (baseline and five follow-up surveys) we measured haemoglobin and ferritin, and the burden of soil transmitted helminth (STH) infections, and in the 72 month survey we also administered a questionnaire to assess adherence and possible impediments to participating in the program.ResultsTwo hundred and fifty six (65.8%) of the original 389 women enrolled in the cohort attended the final 72 month survey. Haemoglobin levels were 122 g/L [95% C.I. 120, 124] at baseline and increased to 135g/L [95% C.I. 133, 138] after 72 months. The prevalence of anaemia was 37.8% [95% C.I. 31.0, 44.7] at baseline and reduced to 14.3% [95% C.I. 9.5, 19.1]. Hookworm infection prevalence, 75.9% [95% C.I. 68.1, 83.8] at baseline, reduced to 10.2% [95% C.I. 5.4, 15.0] with no moderate or heavy intensity infections. Seventy-two percent of participants reported still taking at least 75% of the weekly supplements, and 85.0% had taken the most recent deworming treatment.DiscussionAnaemia rates fell significantly during the six-year program, and STH infections were eliminated as a public health risk. Adherence was well maintained but long-term sustainability is challenging in the absence of ongoing external support.

Evaluation of hookworm infections and some haematological parameters amongst primary and secondary schools children in Aba Metropolis, Abia State, Nigeria

Hookworm infections and some haematological parameter among children were assessed in five different schools in Aba metropolis, Abia State, Nigeria. Blood and Stool samples were collected and analysed, following ethical approval and consent from parents and teachers of the subjects. Stool samples were analyzed using standard parasitological technique, from the blood samples, Haemoglobin (Hb) levels, Esinophils and white blood cell counts (WBC) were determined. Out of 1500 samples examined, 120 (8.0%) were positive for Hookworm infection. There was variation in infection rate by school and there is significant difference in the prevalence of Hookworm infection within the schools (P<0.05). Sex related prevalence showed that infection was higher in females 8.17% than in males 7.89%. It was observed that hookworm infection is dependent on sex and age (P<0.05). There was a negative correlation between hookworm infection and Haemoglobin levels both in female and male subjects. Eosinophil count and hookworm infection by sex and age revealed that there is a correlation between hookworm infection and eosinophilia counts. There was an increase in eosinophilia with high rate of hookworm infection in the age group of 10 – 13 years. This result showed that there is higher value of eosinophilia in female children than in male children (P <0.05). White blood cell counts (WBC) showed a proportional variation with hookworm infection in both male and female (P<0.05). In conclusion, Hookworm infection is relatively high among the children in Aba metropolis and the relationships between hookworm infection and Haemoglobin, Eosinophil and white blood cells were established. Keywords : Hookworm infections, Haemoglobin, Eosinophils, Leucocytes, School Children, Aba Metropolis

Prevalence of Hookworm Infection Related Anaemia Among Okeh Memorial Junior and Senior Secondary Commercial School Students in Elele Rivers-State Nigeria

A total of 750 stool and finger prick blood samples each were collected randomly from Okeh Memorial Junior Secondary Commercial School (OMJSCS) students and also from OKeh Memorial Senior Secondary Commercial School (OMSSCS) students in Elele to determine the presence of Hookworm and level of packed cell volume (PCV). Standard diagnostic methods were used for the analysis. Out of 750 stool samples analysed, 39(5.2%) were positive for the ova of Hookworm. Age group 10-11 years had the highest percentage of occurrence 17(14.4%), while no case of infection was recorded from 18 years and above. Female students were more infected 21(7.7%) than male students 18(3.8%), and OMJSCS had more infected cases 32(8.5%) than OMSSCS 7(1.9%). Packed cell volume reduced with high parasitemia level. Improvement of sanitation and provision of health care facilities are required to control and eliminate all intestinal parasitic infections in the area after preventive measures.

Two thirds of hookworm infected children were anemic at the outpatient department in Jimma Health Center, Jimma, Southwest Ethiopia

ObjectiveTo assess the prevalence of hookworm infections and anemia and also measure their association among children. MethodsA cross-sectional parasitological and hematological study was conducted on 130 children at Jimma Health Center, Jimma, Southwest Ethiopia. Stool samples were collected and processed for direct microscopic examination. Blood samples were examined by using hematocrit to determine the hemoglobin level. Data were collected using a semi-structured questionnaire from every study participant. ResultsThe overall prevalence of hookworm infection and anemia was found to be 18 (13.48%) and 43 (33.07%), respectively. Anemia prevalences were 66.67% (12/18) among hookworm infected children and 33.07% (43/130) among all study participants. Hookworm had a statistically significant association with anemia and predisposing factors such as shoes wearing habits and methods of excreta disposal (P < 0.05). ConclusionsPrevalences of hookworm infection and anemia were low among children. But the prevalence of anemia as compared to hookworm was too high. Attention should be given to contributing factors accordingly to reduce hookworm infection and anemia.

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

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. 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. 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. 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.

Human anthelminthic vaccines: Rationale and challenges

Helminth infections are the most common afflictions of humankind, affecting almost every single person living in profound poverty. Through mass drug administration (MDA) we have seen sharp declines in the global prevalence of some helminth infections, including lymphatic filariasis, onchocerciasis, and ascariasis. However, since 1990, there has been no appreciable decrease in the global prevalence of hookworm infection, schistosomiasis, or food-borne trematodiases. Through the activities of a non-profit product development partnerships and two research institutes, a total of five human anthelmintic vaccines for hookworm infection (two) and schistosomiasis (three) have advanced from discovery through manufacture and are now in Phase 1 clinical testing. At least three additional antigens, including two for onchocerciasis and one for schistosomiasis, are also advancing through preclinical development with the intention of moving into the clinic soon. These preventive human anthelmintic vaccines could be used as stand-alone technologies administered to infants as part of the Expanded Program on Immunization (EPI), or together with anthelmintic drugs in programs linked to MDA. Significant hurdles though could hinder the advancement of these vaccines into later-stage clinical and product development and licensure. They include the absence of a major pharma partner (and the resultant access to adjuvants and industrial scale manufacturing expertise), an uncharted roadmap for how to introduce anthelmintic vaccines into appropriate health systems, uncertain global access and regulatory strategies that might need to rely on developing country vaccine manufacturers and national regulatory authorities, and the lack of innovative financing schemes. However, the public health and economic benefits of introducing these vaccines could be massive and therefore deserve international attention and support.

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.

Interrupting transmission of soil-transmitted helminths: a study protocol for cluster randomised trials evaluating alternative treatment strategies and delivery systems in Kenya

IntroductionIn recent years, an unprecedented emphasis has been given to the control of neglected tropical diseases, including soil-transmitted helminths (STHs). The mainstay of STH control is school-based deworming (SBD), but...

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.