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

Prevalence and correlates of soil-transmitted helminths in schoolchildren aged 5 to 18 years in low- and middle-income countries: a systematic review and meta-analysis

Background

According to the Global Burden of Disease (GBD) 2019 report, up to 1.5 million disability-adjusted life years (DALYs) are lost due to soil-transmitted helminths (STHs), and 5.9 million people are at risk of acquiring STHs. Regions with the highest prevalence of STH infections include Sub-Saharan Africa, China, South America, and Asia. While there are numerous fragmented studies on STH, comprehensive information on the prevalence and geographic distribution of different species, as well as their regional variations in the context of STHs is limited. The present systematic review and meta-analysis study attempts to provide a summary of the prevalence, geographical variation, and determinants of STHs among schoolchildren aged 5 to 18 years.

Methods

An extensive literature search was carried out using PubMed, Embase, Cinhal, and Psychinfo for studies published between 1999 and 2022 that reported the rate of STH infection in school-going children aged 5-18 years. A random effects model was employed in this meta-analysis due to expected heterogeneity. Subgroup analysis was carried out based on sex and STH species because of expected geographical variation.

Results

A total of 19,725 of the 49,630 children examined were infected with STH, yielding an overall pooled prevalence of 37.16% (95% CI: 29.74-44.89). The prevalence was highest in the Western Pacific region at 50.41% (95% CI: 33.74-67.04) followed by Europe at 39.74% (95% CI: 20.40-61.0) and Africa at 37.10% (95% CI: 26.84-47.95). Ascaris lumbricoides was found to be the most prevalent helminth with a prevalence of 24.07% (95% CI: 17.07-31.83).

Conclusion

The Western Pacific region is classified as a High-risk Zone (HRZ), while Southeast Asia, Africa, Europe, and the Eastern Mediterranean are classified as moderate-risk zones (MRZs). We found a 12% reduction in the pooled prevalence of STH infection from 1999 to 2012. Ascaris lumbricoides was the predominant species among schoolchildren. Mass Drug Administration (MDA) of Albendazole tablets and improved water, sanitation, and hygiene (WASH) practices are effective in controlling and preventing STH. Ensuring their implementation and access is crucial to addressing the problem.

Systematic review registration

https://www.crd.york.ac.uk/prospero/#loginpage, CRD42022333341.

Prevalence and Risk Factors of Soil-Transmitted Helminthic Infections in the Pediatric Population in India: A Systematic Review and Meta-Analysis

Soil-transmitted helminths (STH) is a major healthcare challenge in the pediatric age group affecting poor and deprived parts of our community. The main species that infect people are roundworm (AL, Ascaris lumbricoides), whipworm (TT, Trichuris trichiura), and hookworms (HW, Ancylostoma duodenale and Necator americanus). We aimed to estimate the pooled prevalence of STH infections in India in the pediatric age group (< 18 years) and assess the risk factors associated with STH in this age group. Three databases were searched (PubMed, Scopus, and Embase) up to February 16, 2021 with deliberate and inclusive search terms for original research articles estimating the prevalence of either of the three STH in India. Data extracted included individual prevalence of the three STH, prevalence of double or triple infections, and associated risk factors.

We identified systematically 1,408 publications, of which 44 were included for the final analysis, including studies from 20 states covering 34,590 children. In our study, the prevalence of AL ranged from 0.8 to 91% with a pooled prevalence of 25%, prevalence of TT ranged from 0.3 to 72% with a pooled prevalence of 13%, and for HW prevalence ranged from 0.2 to 80% with pooled prevalence of 10%. Two most important risk factors with higher odds ratio were open defecation practices or open latrine (odds ratio: 5.2) and washing hands without soap using water only (odds ratio: 2.49). Knowledge of areas with high prevalence of STH and associated risk factors would help in designing effective control strategies in the high-risk groups to prevent infection and aid in a drastic reduction of morbidity in children.

Intestinal polyparasitism and levels of mucosal anthelmintic SIgA in children from endemic areas in Northeastern Brazil

Interactions between parasites during co-infections are often complex and can impact immunization and treatment programmes, as well as disease outcomes and morbidity. However, little is known about these interactions and the mechanisms involved. In this study, a coproparasitological survey was carried out in school-age children living in endemic areas of parasitic infection in the state of Sergipe, Northeastern Brazil. Anti-helminth-specific and total secretory immunoglobulin-A (SIgA) levels were measured in stool and saliva samples and were compared in children presenting monoparasitism, polyparasitism (helminths and/or intestinal protozoa) and no infections. The survey showed that protozoa were more prevalent than helminths, and that there was a high frequency of polyparasitism in the studied population, mainly from combinations of protozoan species. Although less frequent, combinations between species of protozoa and helminths were also observed. The levels of salivary SIgA in these co-infected individuals were lower than the average observed in infections with helminths alone. Although the children participating in this survey were asymptomatic, and it was, therefore, not possible to evaluate the impact of salivary SIgA reduction on the diseases, and the study highlights the need for further investigations of co-infections by intestinal parasites and the effects on immune response induced by the interactions between different parasites.

Prevalence and the factors influencing soil-transmitted helminths among school age children (5-14 years age) in a rural area of Coimbatore district

Context

Highest intensity of soil-transmitted helminthiasis (STH) is seen among school age children.

Aims

The aim of this study is to find out the prevalence and factors associated with soil-transmitted helminthic infection among school age children (5-14 years) in a rural area of Coimbatore district.

Settings and Design

The study was conducted in the field practice area of the Rural Health Training Centre (RHTC) Vedapatti, Coimbatore. RHTC caters to a total population of 23,841 distributed in 14 villages. After getting ethical clearance, five of the 14 villages of Vedapatti were selected by the cluster sampling method. Totally, 819 participated in the survey conducted between November 2015 and July 2016 in the field practice area.

Subjects and Methods

Structured questionnaire was used to collect the information. Consent from parents and assent from child were obtained. Totally, 610 gave one adequate stool sample. Early morning samples were collected and transported to the laboratory within four hours. Formal ether concentration method was performed, and examination was done.

Statistical Analysis Used

Data analysis was performed with the SPSS version 19 software. The prevalence is expressed in percentage with 95% confidence interval (CI). Univariate and multivariate analyses were performed. Strength of association was expressed in terms of odds ratio (OR) and adjusted OR with 95% CI. P < 0.05 was considered as statistically significant.

Results

The prevalence of STH was 7.70% (95% CI: 5.58-9.82). Ascaris lumbricoides was highly prevalent 6.9% (4.89%-8.91%) followed by Hook worm 0.7% (0.04%-1.36%), and Trichuris trichura 0.2% (0.15%-0.55%). Mulitivariate logistic regression analysis showed that pucca houses offered protection against STH.

Conclusions

The prevalence of STH in a rural area of Coimbatore is 7.7% (95% CI: 5.58-9.82), and is continuing as a public health problem.

Gastrointestinal Nematodes among Residents in Melong, Moungo Division, Littoral Region, Cameroon

BACKGROUND

Intestinal parasitic infections are among the most common infections worldwide. The present study was undertaken to provide baseline information on the status of gastrointestinal nematodes in Melong Subdivision, Moungo Division, Littoral Region, Cameroon. Material and Methods. Seven hundred and eighty-eight stool samples were collected in randomly selected quarters in the community of Melong. These stool samples were brought to the Laboratory of Applied Biology and Ecology in the University of Dschang for analysis using the qualitative (simple flotation) and quantitative (Mc Master count) technique.

RESULTS

The nematodes identified were Ascaris lumbricoides, hookworm, Trichuris trichiura, and Capillaria hepatica with respective prevalences and intensities of infection of 2.2% and 3691.12 ± 3898.47, 1.4% and 940.91 ± 1825.90, 1.0% and 193.75 ± 227.47, and 0.4%and 50 ± 00. The data on the prevalence of nematodes with respect to sex and age showed that females (6.0%) were more infected than males (2.76%) with no significant difference (P > 0.05). Furthermore, with respect to age, adults were more infected than children. The percentage of educational level showed a reduction in the number of parasites in the higher educational level. The prevalence of A. lumbricoides between localities showed a significant difference (P < 0.05) with "Quarter 1" harboring most of the nematodes. Cases of double (Ascaris lumbricoides + Trichuris trichiura) and triple (Ascaris lumbricoides + Trichuris trichiura + hookworm) parasitism were encountered with both having a prevalence of 0.3%. According to the fecal concentration of eggs, 63.89% of the infections were light, 5.56% moderate, and 30.56% heavy.

CONCLUSION

A relatively low overall prevalence was obtained in our study, showing that the national deworming campaign is proving effective, but more effort is needed to completely eradicate these parasites for a single infected individual can cause havoc.

Risk Factors Associated with Helminthic Intestinal Infection in Lurambi Subcounty, Kakamega, Kenya

Background

Soil-transmitted helminths (STHs) and schistosome infections have been known to be major causes of morbidity and mortality in sub-Saharan countries. School aged and preschool children are known to be at high risk of infection. Therefore, the aim of this study was to determine the prevalence and risk factors associated with soil-transmitted helminths among school-going children in Lurambi Subcounty, Kakamega, Kenya.

Method

A cross-sectional study was conducted from Jan 2020 to Feb 2020 among 392 randomly selected primary school-going children aged 5 to 14 years old in six primary schools. Risk factors associated with STH infection were obtained using a structured questionnaire answered by the children's caregivers. Stool samples were examined using the standard quantitative Kato-Katz technique. The data was analyzed using SPSS version 20 and Epi Info version 7.2.3.1.

Result

A total of 278 children provided stool samples for analysis. The overall prevalence of intestinal helminths was 14.4% (40/278). The prevalence of Ascaris lumbricoides was 11.5% (32/278), 0.4% (1/278) for hookworm, 0.4% (1/278) for Trichuris trichiura, and 2.1% (6/278) for Schistosoma mansoni; coinfection was detected in 0.4% (1/278). The intensity of infection ranged between light and moderate. Significant risk factors for STH infection included failure to wash hands before eating (OR: 3.529; P = 0.041), failure to wash fruits and vegetables before eating (OR: 2.3129; P = 0.005), and not washing hands after soil contact (OR: 2.1529; P = 0.005). Age (Z = 2.4006, P = 0.0164) was a risk factor only for infection with Schistosoma mansoni.

Conclusion

Preventive chemotherapy and proper hygienic and sanitation practices should be integrated to achieve elimination of STH and Schistosoma mansoni in Lurambi Subcounty and at large in Kenya.

Helminthiasis among School-Age Children and Hygiene Conditions of Selected Schools in Lafia, Nasarawa State, Nigeria

The burden of soil-transmitted helminths (STHs) infections in Nigeria is enormous with serious public health significance. This study, therefore, assessed helminthiasis among school-age children and the hygiene conditions of schools in Lafia, Nasarawa State, Nigeria between December 2015 and April 2016 from four randomly selected primary schools. Stool samples were collected from 200 primary school pupils including 80 males (40%) and 120 females (60%) between five and 16 years, using clean sample bottles and a standard parasitology examination technique at the central laboratory at the Federal University, Lafia. An overall prevalence of 33.5% (67/200) helminths infections was recorded. A checklist of Ascaris lumbricoides, hookworm, Trichuris trichiura, and Strongyloides stercoralis was generated from the pooled data of the four studied schools in which A. lumbricoides occurred highest with 13% (26/200) while S. stercoralis was the least prevalent at 2.50% (5/200). Among the schools sampled, St. James Pilot Science Primary School's children were the most infected at 44% (22/50). Multiple infections were observed in three of the four schools sampled. There was no significant difference (p > 0.05) in prevalence rates of different STHs infections in relation to age group and gender across schools. Our findings showed that the hygiene conditions in the studied schools were poor without water, hand washing materials, refuse bins, as well as poor sanitary conditions. This study also identified ova and larvae of STHs parasites in the analyzed soil samples from the studied schools. Most school-age children had knowledge about contamination but few among them washed their hands with water and soap. The obtained result indicated a negative association between the prevalence of STHs and the proportion of pupils that cleaned up with water after defection. We, therefore, advise that hygiene conditions in schools be improved and that the government should prioritize enrolling all primary schools in Nasarawa state for the school health program so as to reduce the burden of STHs among school-age children in the state.

Schistosoma mansoni infection and risk factors among the fishermen of Lake Hawassa, southern Ethiopia

Schistosomiasis is a neglected tropical parasitic disease caused by different species of genus Schistosoma. Schistosoma mansoni causes a severe intestinal parasitic infection of high public and medical importance in Ethiopia. This study aimed to determine the prevalence of, and risk factors for, S. mansoni infection among the fishermen of Lake Hawassa, southern Ethiopia, using a cross-sectional study design. A total of 243 fishermen were selected from the Hawassa Town Fishermen Association's list in 2013. Data on socio-demographic characteristics and risk factors were collected from the fishermen using semi-structured questionnaires. Stool samples were collected and processed using the Kato-Katz thick smear technique. The overall prevalence of S. mansoni among the fishermen was 29.21% and the mean intensity of infection was 158.88 eggs per gram (EPG). The overall prevalence of intestinal helminths, including S. mansoni, was 69.54%. Similar prevalences of S. mansoni were recorded in age groups 15-19, 20-24 and 25-29 years: 31.82%, 31.75% and 31.94%, respectively. Fishermen who swam a minimum of once a week in Lake Hawassa were 2.92 times (95% CI: 1.554, 5.502) more likely to have acquired S. mansoni infection than those who swam in the lake less than once a week. The results indicate moderate endemicity of S. mansoni infection among the fishermen of Lake Hawassa. These fishermen could be a potentially high-risk group for S. mansoni infection and might be responsible for the transmission of infection to other segments of the community visiting the lake for recreation. Moreover, a high prevalence of soil-transmitted helminths (STHs) was recorded among the fishermen. Integrated prevention and control strategies for schistosomiasis and STHs by different sectors are needed to tackle this problem.

A Cross-Sectional Study on Intestinal Parasitic Infections in Children in Suburban Public Primary Schools, Saraburi, the Central Region of Thailand

Intestinal parasitic infection rate among school-aged children in Thailand has been decreasing. However, certain intestinal parasites remain problematic in some regions. This cross-sectional study was conducted between February and September 2016 in three suburban government primary schools (KK, BR, and HK), Saraburi, Thailand. Stool was collected from 263 asymptomatic subjects (4-15 years old), using simple direct smear, formalin-ether concentration, Boeck and Drbohlav's Locke-Egg-Serum (LES) medium culture, and agar plate culture. A self-administered questionnaire was used to collect data about lifestyle and socioeconomic status. The overall rate of intestinal parasites was 22.1% (15.6% single infection and 6.5% multiple infections). The helminths involving the digestive system found were Strongyloides stercoralis (1.5%) and Opisthorchis viverrini (0.4%). For protozoan infection, the major cause was Blastocystis hominis (17.5%). The other protozoa included Endolimax nana (4.6%), Entamoeba coli (3.4%), Entamoeba histolytica/Entamoeba dispar (1.1%), and Giardia intestinalis (0.8%). The sensitivity for the detection of B. hominis increased with the LES culture technique. The infection rate of each organism was not significantly different among the three schools except for B. hominis which showed the highest prevalence in the HK school (P = 0.001). This was correlated with the questionnaire results in which the HK school showed the highest risk of drinking contaminated water (P = 0.004). The present study emphasized the persistent problems of protozoan infections among suburban school-aged children. Lifestyle was still an important factor for intestinal parasitic infections among suburban school-aged Thai children in this study. Health education as well as routine surveillance was necessary to control the infections.

Prevalence and distribution of soil-transmitted helminth infections in India

Background

Understanding the prevalence of soil-transmitted helminth infections is necessary to plan control strategies and focus on highly endemic regions for preventive chemotherapy and improved sanitation facilities. India is known to be endemic for soil-transmitted helminth infections.

Methods

To understand the prevalence, spatial distribution and identify high-risk zones, a systematic search of published literature was carried out based on PRISMA guidelines from the year 2000 to 2015.

Results

A careful screening of the identified literature yielded 39 studies that reported the prevalence of soil-transmitted helminth infections from 19 different states of India. Ascaris lumbricoides was the most prevalent parasite. Higher than 50% prevalence was reported from six states. Nearly 90% studies reported the prevalence of more than one parasite species in the same sample population.

Conclusion

This is the first study to comprehensively review the literature associated with soil-transmitted helminth infections from India giving a clear idea of its prevalence, distribution and high endemic areas.

Differential effect of mass deworming and targeted deworming for soil-transmitted helminth control in children: a systematic review and meta-analysis

BACKGROUND

Soil-transmitted helminth infections are a major global health issue, causing substantial morbidity in the world's poorest populations. Regular delivery of anthelmintic drugs is the mainstay for global soil-transmitted helminth control. Deworming campaigns are often targeted to school-aged children, who are at high risk of soil-transmitted-helminth-associated morbidity. However, findings from modelling studies suggest that deworming campaigns should be expanded community-wide for effective control of soil-transmitted helminth transmission. We aimed to do a systematic review and meta-analysis to compare the effect of mass (community-wide) and targeted (children only) anthelmintic delivery strategies on soil-transmitted helminth prevalence in school-aged children.

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, Embase, and Web of Science for articles published on or before Nov 5, 2015, reporting soil-transmitted helminth prevalence before and after distribution of albendazole or mebendazole, either targeted to children or delivered to the whole community. We excluded studies in which drug delivery was restricted to infected individuals or to a subset of the community or school, or if follow-up time was less than 3 months or greater than 18 months after drug delivery. We extracted data on study year, country, drug administration strategy, drug dose, number of deworming rounds, treatment coverage, diagnostic method, follow-up interval, and soil-transmitted helminth prevalence before and after treatment. We used inverse variance weighted generalised linear models, with prevalence reduction as the outcome variable, to examine the effect of mass versus targeted drug administration, as well as baseline prevalence, number of drug doses, and follow-up time. This study is registered with PROSPERO, number CRD42016026929.

FINDINGS

Of 10 538 studies identified, 56 studies were eligible for the systematic review and 38 of these were included in meta-analysis. Results of the regression models showed that mass deworming led to a significantly greater reduction in prevalence in children than targeted deworming, for both hookworm (odds ratio 4·6, 95% CI 1·8-11·6; p=0·0020) and Ascaris lumbricoides (16·4, 2·1-125·8; p=0·0092), with no effect seen for Trichuris trichiura. There was significant heterogeneity across studies; for targeted studies I² was 97% for A lumbricoides and hookworm, and 96% for T trichiura, and for mass studies, I² was 89% for A lumbricoides, 49% for hookworm, and 66% for T trichiura.

INTERPRETATION

The results of this meta-analysis suggest that expanding deworming programmes community-wide is likely to reduce the prevalence of soil-transmitted helminths in the high-risk group of school-aged children, which could lead to improved morbidity outcomes. These findings are in support of recent calls for re-evaluation of global soil-transmitted helminth control guidelines.

FUNDING

None.

A tale of two communities: intestinal polyparasitism among Orang Asli and Malay communities in rural Terengganu, Malaysia

Background

Intestinal parasitic infections (IPIs) are still major health problems in many developing countries including Malaysia, particularly in the poor and socioeconomically deprived rural and remote communities in Peninsular Malaysia. This study was conducted to determine the prevalence of IPIs and to identify the key factors associated with intestinal polyparasitism as well as to evaluate the knowledge, attitude and practices (KAP) on IPIs among rural Orang Asli and Malay communities in Terengganu, Malaysia.

Methods

A cross-sectional study was conducted among 340 participants (165 Orang Asli and 175 Malay) aged ≤ 15 years from the Hulu Terengganu and Kemaman districts of Terengganu. Faecal samples were examined for the presence of intestinal parasites by using direct smear, formalin-ether sedimentation, trichrome stain, modified Ziehl Neelsen stain, in vitro cultivation in Jones’ medium, Kato Katz and Harada Mori techniques. Demographic, socioeconomic, environmental and behavioural information of the participants and their KAP for IPIs were collected by using a pre-tested questionnaire.

Results

Overall, 149 (90.3 %) Orang Asli and 43 (24.6 %) Malay children were infected by at least one parasite species. The overall prevalences of intestinal polyparasitism among the Orang Asli and Malay were 68.5 % (113/165) and 14.3 % (25/175), respectively. Multiple logistic regression analysis showed that using unsafe water supply as a source for drinking water, the presence of domestic animals, not wearing shoes when outside, not washing vegetables before consumption, not washing hands after playing with soil, indiscriminate defecation and the low level of mother’s education were the key risk factors for intestinal polyparasitism among the Orang Asli, while working mothers and the presence of domestic animals were the risk factors among the Malay children. Almost all the Malays were well aware about the IPIs while Orang Asli respondents had a poor level of related awareness.

Conclusions

This study demonstrates that IPIs are highly prevalent in rural Terengganu, Malaysia. Community awareness about IPIs was found to be imperative in protecting Malay children from these infections. An integrated control programme for the prevention and control of IPIs is highly recommended for these communities, with a special emphasis on the Orang Asli population.

Soil-Transmitted Helminth Infections and Associated Risk Factors among Schoolchildren in Durbete Town, Northwestern Ethiopia

Identifying determinants of soil transmitted helminth infection is vital to design control strategy for the disease. This study assessed the prevalence of STH infections and associated factors among schoolchildren in Durbete town, northwestern Ethiopia. Data about the sociodemographic and socioeconomic status of the children were collected using a questionnaire and stool samples were diagnosed using thick Kato-Katz smear. STH infection was more common among school-age children in Durbete town. Hookworm was the most frequent helminth species detected. The prevalence of STH infection was more in children who did not practice wearing shoes and washing hands before eating and in those who were older in age. Deworming of school-age children in the study area would be important. In addition, provision of health education about helminths and the importance of wearing shoes and washing hands before eating would be important to reduce the burden of STH infection in the study area.

Soil transmitted helminths and associated factors among schoolchildren in government and private primary school in Jimma Town, Southwest Ethiopia

Background

Soil transmitted helminth infections are among the most common human infections. They are distributed throughout the world with high prevalence rates in tropical and sub-tropical countries mainly because of lack of adequate sanitary facilities, inappropriate waste disposal systems, lack of safe water supply, and low socio-economic status.

Methods

A comparative cross sectional study was conducted from December 2011 to June 2012 to determine and assess the prevalence of soil transmitted helminths and their associated factors among government and private primary school children. Stool samples were collected from 369 randomly selected children and examined microscopically for eggs of soil transmitted helminth following McMaster techniques. Soil samples were collected from different parts of the school compound and microscopic examination was performed for eggs of the helminths using sodium nitrate flotation technique.

Results

The overall prevalence rate of soil transmitted helminth infections in private and government schools was 20.9% and 53.5% respectively. T. trichiura was the most common soil transmitted helminth in both schools while hookworm infections were identified in government school students only. Type of school and sex were significantly associated with soil transmitted helminth. Soil contamination rate of the school compounds was 11.25% with predominant parasites of A. lumbricoides.

Conclusion

Higher prevalence of soil transmitted helminth infection was found among government school students. Thus, more focus, on personal hygiene and sanitary facilities, should be given to children going to government schools.

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

OBJECTIVE

To determine the prevalence of gastrointestinal helminthes and associated risk factors among schoolchildren in Tilili town, northwest Ethiopia.

METHODS

A cross-sectional study involving 385 schoolchildren was conducted between November 2011 to February 2012. Each student was selected using systematic random sampling method. Questionnaire and observation were used to identify socio-demographic and associated risk factors. Fresh stool samples were observed using formal-ether concentration technique. Data were analyzed using SPSS 16.0 statistical software.

RESULTS

Four species of intestinal helminthes were identified with an overall prevalence of 44.2% (170 of 385 schoolchildren). The predominant parasites were Ascaris lumbricoides (A. lumbricoides) 153 (39.7%) and Trichuris trichiura (T. trichiura) 30 (7.8%). One hundred thirty five (35.1%) had single infections and 35 (9.2%) were infected with more than one helminthic parasites in which 32 (8.4%) were double infections and 3 (0.8%) were triple infections. Significant associations were observed between intestinal helminth infection and those of age, grade level, and school variables. Prevalence of hookworm infection was significant in children who did not wear shoes regularly (P<0.05).

CONCLUSIONS

Intervention programs and education on personal and environmental hygiene should be implemented for the prevention and control of helminthic infections in the study area.

Epidemiology of intestinal polyparasitism among Orang Asli school children in rural Malaysia

Background

This cross-sectional study aimed to investigate the current prevalence and risk factors associated with intestinal polyparasitism (the concurrent infection with multiple intestinal parasite species) among Orang Asli school children in the Lipis district of Pahang state, Malaysia.

Methods/Principal findings

Fecal samples were collected from 498 school children (50.6% boys and 49.4% girls), and examined by using direct smear, formalin-ether sedimentation, trichrome stain, modified Ziehl Neelsen stain, Kato-Katz, and Harada Mori techniques. Demographic, socioeconomic, environmental, and personal hygiene information were collected by using a pre-tested questionnaire. Overall, 98.4% of the children were found to be infected by at least one parasite species. Of these, 71.4% had polyparasitism. The overall prevalence of Trichuris trichiura, Ascaris lumbricoides, hookworm, Giardia duodenalis, Entamoeba spp., and Cryptosporidium spp. infections were 95.6%, 47.8%, 28.3%, 28.3%, 14.1% and 5.2%, respectively. Univariate and multivariate analyses showed that using an unsafe water supply as a source for drinking water, presence of other family members infected with intestinal parasitic infections (IPI), not washing vegetables before consumption, absence of a toilet in the house, not wearing shoes when outside, not cutting nails periodically, and not washing hands before eating were significant risk factors associated with intestinal polyparasitism among these children.

Conclusions/Significance

Intestinal polyparasitism is highly prevalent among children in the peninsular Malaysian Aboriginal communities. Hence, effective and sustainable control measures, including school-based periodic chemotherapy, providing adequate health education focused on good personal hygiene practices and proper sanitation, as well as safe drinking water supply should be implemented to reduce the prevalence and consequences of these infections in this population.

Intestinal parasitic infections (IPI) are still a major public health problem worldwide, with more than 2 billion people infected with at least one parasite species. Despite efforts to improve the quality of life of the Orang Asli population in rural Malaysia, IPI are still highly prevalent and of serious concern in this population, especially among children. We screened 498 school children in Lipis district, Pahang, Malaysia for the prevalence and risk factors of polyparasitism (concurrent infection with multiple parasite species). Overall, 98.4% of the children were found to be infected by at least one parasite species, with 71.4% of them having polyparasitism. Using an unsafe water supply as a source for drinking water, presence of another family member infected with IPI, not washing vegetables before consumption, absence of a toilet in the house, not wearing shoes when outside, not cutting nails periodically, and not washing hands before eating were significantly associated with intestinal polyparasitism among these children. Our findings revealed an urgent need to implement an effective and integrated control program to reduce the prevalence of IPI as a part of the efforts to improve the quality of life in Orang Asli communities.

School hygiene and deworming are key protective factors for reduced transmission of soil-transmitted helminths among schoolchildren in Honduras

BACKGROUND

Among many neglected tropical diseases endemic in Honduras, soil-transmitted helminth (STH) infections are of particular importance. However, knowledge gaps remain in terms of risk factors involved in infection transmission. The aim of this study was to investigate risk factors associated with STH infections in schoolchildren living in rural Honduras.

METHODS

A cross-sectional study was conducted among Honduran rural schoolchildren in 2011. Demographic, socio-economic, and epidemiological data were obtained through a standardized questionnaire and STH infections were determined by the Kato-Katz method. Logistic regression models accounting for school clustering were used to assess putative risk factors for infection.

RESULTS

A total of 320 children completed the study. Prevalences for any STH and for Ascaris lumbricoides, Trichuris trichiura and hookworms were: 72.5%, 30.3%, 66.9% and 15.9%, respectively. A number of risk factors were identified at the individual, household, and school level. Boys were at increased odds of infection with hookworms (OR 2.33, 95% CI = 1.23-4.42). Higher socio-economic status in the family had a protective effect against infections by A. lumbricoides (OR 0.80, 95% CI = 0.65-0.99) and T. trichiura (OR 0.77, 95% CI = 0.63-0.94).Low school hygiene conditions significantly increased the odds for ascariasis (OR 14.85, 95% CI = 7.29-30.24), trichuriasis (OR 7.32, 95% CI = 3.71-14.45), mixed infections (OR 9.02, 95% CI = 4.66-17.46), and ascariasis intensity of infection (OR 3.32, 95% CI = 1.05 -10.52).Children attending schools not providing deworming treatment or that had provided it only once a year were at increased odds of ascariasis (OR 10.40, 95% CI = 4.39-24.65), hookworm (OR 2.92, 95% CI = 1.09-7.85) and mixed infections (OR 10.57, 95% CI = 4.53-24.66).

CONCLUSIONS

Poverty-reduction strategies will ultimately lead to sustainable control of STH infections in Honduras, but as shorter-term measures, uninterrupted bi-annual deworming treatment paired with improvements in school sanitary conditions may result in significant reductions of STH prevalence among Honduran schoolchildren.

A cross-sectional study on intestinal parasitic infections in rural communities, northeast Thailand

Despite the existence of effective anthelmintics, parasitic infections remain a major public health problem in Southeast Asia, including Thailand. In rural communities, continuing infection is often reinforced by dietary habits that have a strong cultural basis and by poor personal hygiene and sanitation. This study presents a survey of the prevalence of intestinal parasitic infections among the people in rural Thailand. The community-based cross-sectional study was conducted in villages in Khon Kaen Province, northeastern Thailand, from March to August 2013. A total of 253 stool samples from 102 males and 140 females, aged 2-80 years, were prepared using formalin-ethyl acetate concentration methods and examined using light microscopy. Ninety-four individuals (37.2%) were infected with 1 or more parasite species. Presence of parasitic infection was significantly correlated with gender (P=0.001); nearly half of males in this survey (49.0%) were infected. Older people had a higher prevalence than younger members of the population. The most common parasite found was Opisthorchis viverrini (26.9%), followed by Strongyloides stercoralis (9.5%), Taenia spp. (1.6%), echinostomes (0.4%), and hookworms (0.4%). The prevalence of intestinal protozoa was Blastocystis hominis 1.6%, Entamoeba histolytica 0.8%, Entamoeba coli 0.8%, Balantidium coli 0.4%, Iodamoeba bütschlii 0.4%, and Sarcocystis hominis 0.4%. Co-infections of various helminths and protozoa were present in 15.9% of the people. The present results show that the prevalence of parasitic infections in this region is still high. Proactive education about dietary habits, personal hygiene, and sanitation should be provided to the people in this community to reduce the prevalence of intestinal parasite infections. Moreover, development of policies and programs to control parasites is needed.

Regional, household and individual factors that influence soil transmitted helminth reinfection dynamics in preschool children from rural indigenous Panamá

Background

Few studies have investigated the relative influence of individual susceptibility versus household exposure factors versus regional clustering of infection on soil transmitted helminth (STH) transmission. The present study examined reinfection dynamics and spatial clustering of Ascaris lumbricoides, Trichuris trichiura and hookworm in an extremely impoverished indigenous setting in rural Panamá over a 16 month period that included two treatment and reinfection cycles in preschool children.

Methodology/Principle Findings

Spatial cluster analyses were used to identify high prevalence clusters for each nematode. Multivariate models were then used (1) to identify factors that differentiated households within and outside the cluster, and (2) to examine the relative contribution of regional (presence in a high prevalence cluster), household (household density, asset-based household wealth, household crowding, maternal education) and individual (age, sex, pre-treatment eggs per gram (epg) feces, height-for-age, latrine use) factors on preschool child reinfection epgs for each STH. High prevalence spatial clusters were detected for Trichuris and hookworm but not for Ascaris. These clusters were characterized by low household density and low household wealth indices (HWI). Reinfection epg of both hookworm and Ascaris was positively associated with pre-treatment epg and was higher in stunted children. Additional individual (latrine use) as well as household variables (HWI, maternal education) entered the reinfection models for Ascaris but not for hookworm.

Conclusions/Significance

Even within the context of extreme poverty in this remote rural setting, the distinct transmission patterns for hookworm, Trichuris and Ascaris highlight the need for multi-pronged intervention strategies. In addition to poverty reduction, improved sanitation and attention to chronic malnutrition will be key to reducing Ascaris and hookworm transmission.

Control of soil transmitted helminth (STH) infections is of central importance to improving preschool child health because these infections can have long lasting consequences on growth and development. Our study in indigenous Ngäbe preschool children in western Panama was conducted over a period of 16 months. We monitored reinfection dynamics of three STH infections (Ascaris, Trichuris and hookworm) over two reinfection cycles to gain an understanding of regional, household and individual factors that influenced transmission of these infections among preschool children. Despite the rural setting, where virtually all households live under conditions of extreme poverty, we identified spatial clusters of high prevalence of Trichuris and hookworm in the most remote and poorest area, whereas Ascaris was present throughout the study area. Preschool children who were chronically malnourished (low height-for-age) had a higher reinfection burden of Ascaris and hookworm. Household poverty (low relative household wealth and maternal education) and infrequent latrine use were also influential in Ascaris reinfection. This cross-disciplinary analysis of preschool child STH transmission in a poor rural setting provides pertinent information for STH control programs that aim to break the cycle of poverty and infection.

Towards an effective control programme of soil-transmitted helminth infections among Orang Asli in rural Malaysia. Part 1: prevalence and associated key factors

Background

Despite the continuous efforts to improve the quality of life of Orang Asli (Aborigines) communities, these communities are still plagued with a wide range of health problems including parasitic infections. The first part of this study aimed at determining the prevalence of soil-transmitted helminth (STH) infections and identifying their associated factors among rural Orang Asli children.

Methods

A cross-sectional study was carried out among 484 Orang Asli children aged ≤ 15 years (235 females and 249 males) belonging to 215 households from 13 villages in Lipis district, Pahang, Malaysia. Faecal samples were collected and examined by using formalin-ether sedimentation, Kato Katz and Harada Mori techniques. Demographic, socioeconomic, environmental and behavioural information were collected by using a pre-tested questionnaire.

Results

Overall, 78.1% of the children were found to be infected with one or more STH species. The prevalence of trichuriasis, ascariasis and hookworm infections were 71.7%, 37.4% and 17.6%, respectively. Almost all, three quarters and one fifth of trichuriasis, ascariasis and hookworm infections, respectively, were of moderate-to-heavy intensities. Multiple logistic regression analysis showed that age of ≥ 6 years (school-age), using unsafe water supply as a source for drinking water, absence of a toilet in the house, large family size (≥ 7 members), not washing hands before eating, and not washing hands after defecation were the key factors significantly associated with STH among these children.

Conclusion

This study reveals an alarmingly high prevalence of STH among Orang Asli children and clearly brings out an urgent need to implement school-based de-worming programmes and other control measures like providing a proper sanitation, as well as a treated drinking water supply and proper health education regarding good personal hygiene practices. Such an integrated control program will help significantly in reducing the prevalence and intensity of STH in Orang Asli communities.

The role of co-infections in mother-to-child transmission of HIV

In HIV-infected women, co-infections that target the placenta, fetal membranes, genital tract, and breast tissue, as well as systemic maternal and infant infections, have been shown to increase the risk for mother-to-child transmission of HIV (MTCT). Active co-infection stimulates the release of cytokines and inflammatory agents that enhance HIV replication locally or systemically and increase tissue permeability, which weakens natural defenses to MTCT. Many maternal or infant co-infections can affect MTCT of HIV, and particular ones, such as genital tract infection with herpes simplex virus, or systemic infections such as hepatitis B, can have substantial epidemiologic impact on MTCT. Screening and treatment for co-infections that can make infants susceptible to MTCT in utero, peripartum, or postpartum can help reduce the incidence of HIV infection among infants and improve the health of mothers and infants worldwide.

Prevalence and risk factors of intestinal helminth infection among rural malay children

Background:

Soil-transmitted intestinal helminth infection is prevalent in rural communities of Malaysia. Risk factors contributing to helminth infections are largely unknown in the country.

Aim:

To determine the prevalence and risk factors of intestinal helminth infections among children in Beris Lalang, a rural Muslim community of Malaysia.

Settings and Design

In this cross-sectional study, children aged 7-9 years were recruited during the mass Friday prayer at Beris Lalang mosque by trained imams (religious leaders). A standardized questionnaire was used to obtain information on socio-demographic profile, daily hygienic practices, and history of helminth infection.

Results:

Out of 79 samples, 29 (37%) were positive for helminthic ova, of which 24 were ova of Trichuris trichiura. Poor education of the mother (primary education or less) (P=0.015), eating raw salad (P=0.03), and no physical activities (P=0.03) were found independent risk factors for the child's helminth infections in univariate analysis. A higher proportion of children with helminth infections complained of tiredness and fatigue compared to those without such infections (36% vs. 12%, P=0.019). In a multivariate analysis of predictors of helminth infection, poor education of the mother (P=0.02) and eating raw salad (P=0.04) remained statistically significant, after controlling for several other potential risk factors.

Conclusions

T. trichiura was the most prevalent intestinal helminth infection in children in rural Malaysia. Risk factors of helminth infection included mother's poor education and eating raw salad and vegetables.

Anthelmintic activity of ripe fruit extract of Solanum myriacanthum Dunal (Solanaceae) against experimentally induced Hymenolepis diminuta (Cestoda) infections in rats

Although there are many effective drugs available to treat intestinal worms, the fact remains that they remain out of reach to a majority of the population in many areas of the world. On the other hand, traditional plant-based remedies continue to be an important therapeutic aid for treating worm infections throughout the world, especially in the developing nations. Solanum myriacanthum Dunal is a perennial shrub that is used in the folk medicine of Tangkhul Naga tribe of India for treating intestinal worms. This study evaluates the anthelmintic activity of its ripe fruit extract using experimental Hymenolepis diminuta (a zoonotic tapeworm) infections in albino rats. The efficacy of extract was adjudged by monitoring the eggs per gram (EPG) count of parasite as well as by the direct count of surviving worms in the intestine following treatment with methanol fruit extract of this plant to different groups of rats harbouring H. diminuta infections. The plant extract showed a dose-dependent reduction of both EPG as well as worm counts for all the developmental stages of H. diminuta in rats. However, the effects of the extract were more apparent on the adult stages than larval or immature stages of the parasite. Against the adult stage, a single oral dose of 800 mg/kg of extract, given for 3 days, showed 60.49% reduction in the EPG counts and 56.60% reduction in the worm counts in the extract-treated group as compared to untreated control. In comparison, the reference drug praziquantel (5 mg/kg) showed 51.81% and 70.00% reduction in the EPG and worm counts, respectively. The LD50 (oral) of the extract was determined to be 3,093.24 mg/kg in rats, and no significant changes were observed in the values of serum glutamate oxalate transaminase, serum glutamate pyruvate transaminase, cholesterol and total protein between the extract-treated and control groups of animals. These findings indicate that ripe fruits of S. myriacanthum possess significant anthelmintic property, without any adverse effects to the experimental animals. This may provide a scientific rationale for the traditional use of this plant against intestinal worms.

Helminthic infections in school children in Puducherry, South India

BACKGROUND/PURPOSE

Intestinal parasites are widely prevalent in developing countries, probably due to poor sanitation and inadequate personal hygiene. It is estimated that as much as 60% of the world's population is infected with intestinal parasites, which may play a significant role in morbidity due to intestinal infections. This study was designed to estimate the prevalence of helminthic infections among school children in Puducherry, South India.

METHODS

The prevalence of helminthic infections was studied in 1,172 children in public schools in Puducherry (Pondicherry), South India, between March and September 2006. The stools collected were concentrated using the formol-ether sedimentation technique, screened using conventional iodine and saline wet mounts, and examined by direct microscopy.

RESULTS

The prevalence of helminthic infection was found to be 34.56% in school children; Ascaris lumbricoides constituted 43.21% of total infections; Ancylostoma duodenale (hookworm), 28.89%; Trichuris trichiura, 10.87%; Hymenolepis nana, 7.66%; Taenia spp., 7.41%; and Enterobius vermicularis, 1.98%. Co-infections were also common; dual infections accounted for 8.40% and multiple infections for 2.47%, respectively, of total infection. The stool samples found to be positive for hookworm ova were further processed for culture using the Harada-Mori culture technique. Sixty-five (55.56%) hookworm ova-positive stools were found to be culture positive.

CONCLUSION

The infection prevalent in school children in this area is Ascariasis.

The epidemiology of soil-transmitted helminth and protozoan infections in south-west Cameroon

A cross-sectional study of the prevalence, intensity and effects of soil-transmitted helminth and protozoan infections was undertaken among patients at the Buea Hospital Annex located in Buea sub-division of Cameroon. Stool samples from 356 subjects (174 males and 182 females) were collected and processed using standard concentration methods. Our results showed that 31.0% of subjects were infected with intestinal helminths and the prevalence was higher in females (32.4%) than in males (30.5%). A significantly higher prevalence was observed in rural (47.2%) than in urban areas (21.0%); significance < 0.1%. Prevalence was highest among those aged between 6 and 12 years (41.4%). The total prevalence of intestinal helminth infections were 19.3% for Ascaris lumbricoides, 14.0% for hookworm and 11.8% for Trichuris trichiura. The intensity of infection was unevenly distributed, with very heavy loads concentrated in a few individuals. Data also showed that 28.1% (100/356) of the subjects were infected with protozoans. Females showed a higher prevalence (28.6%; 52/182) than males (20.7%; 36/174). Also, there was a significantly higher prevalence in rural (34.0%; 49/144) than urban areas (18.4%; 39/212); significance < 0.1%. The age group 6–12 years again had a higher prevalence (37.1%; 26/70). The total prevalence of intestinal protozoans was: Entamoeba histolytica (24.4%), Entamoeba coli (11.2%) and Giardia lamblia (0.6%). These relatively heavy prevalences in patients may be reduced by appropriate medication and maintaining strict personal hygiene. Health education, clean water supply, good sewage management and a congenial environment will all help to minimize infection.

Immune-based approaches to the prevention of mother-to-child transmission of HIV-1: active and passive immunization

Despite more than 2 decades of research, an effective vaccine that can prevent HIV-1 infection in populations exposed to the virus remains elusive. In the pursuit of an HIV-1 vaccine, does prevention of exposure to maternal HIV-1 in utero, at birth or in early life through breast milk require special consideration? This article reviews what is known about the immune mechanisms of susceptibility and resistance to mother-to-child transmission (MTCT) of HIV-1 and summarizes studies that have used passive or active immunization strategies to interrupt MTCT of HIV-1. Potentially modifiable infectious cofactors that may enhance transmission and/or disease progression (especially in the developing world) are described. An effective prophylactic vaccine against HIV-1 infection needs to be deployed as part of the Extended Program of Immunization recommended by the World Health Organization for use in developing countries, so it is important to understand how the infant immune system responds to HIV-1 antigens, both in natural infection and presented by candidate vaccines.

Social science implications for control of helminth infections in Southeast Asia

Social science perspectives can inform helminth disease control in Southeast Asia. The social science literature offers theoretical and conceptual models; research methods; recommendations for training and capacity building, health education and health care professional training; and practice guidelines, including implementation of evidence-based interventions. Priority themes include poverty, gender differences, health inequities and access to social resources. Implications for helminth control include broadening disease monitoring and surveillance to include social and economic variables and subjective measures of well-being; training for health professionals and researchers in the social determinants of health; and application of social science models, specifically the expanded 'Chronic Care Model', to the planning and evaluation of interventions. The chapter posits that helminth diseases meet the World Health Organization's expanded definition of chronic conditions, and that integrated delivery of multiple interventions is needed to address the full range of risks and outcomes due to helminth infection.

Geohelminth infection and re-infection after chemotherapy among slum-dwelling children in Durban, South Africa

The prevalences and intensities of Ascaris lumbricoides, Trichuris trichiura and hookworm (probably Necator americanus) infection were measured in the young children (aged 2-10 years) living in 10 urban slums in Durban, South Africa. Re-infection was assessed at 4-6 and 12 months post-treatment. The baseline prevalences of A. lumbricoides and T. trichiura were 81.7%-96.3% and 54.5%-86.2%, respectively, and the corresponding geometric mean intensities were 960 and 91 eggs/g faeces. Most (85%) of the children found infected with A. lumbricoides and 23% of those found infected with T. trichiura had moderate-heavy infections. A few of the children investigated had intensities of Ascaris and Trichuris infection that were considerably higher than those previously recorded in South Africa. The baseline prevalences of hookworm infection (0%-20% in individual slums, with a mean of 4.7%) and intensities of such infection (geometric mean=17 eggs/g) were relatively low. Albendazole proved very effective against A. lumbricoides and hookworm but less so against T. trichiura. Re-infection by A. lumbricoides and T. trichiura reached pre-treatment prevalences by 4-6 months post-treatment in some of the slums and by 12 months in all the other slums. By 12 months post-treatment, the intensities of A. lumbricoides infection had reached their pre-treatment levels while those of T. trichiura infection were higher than at baseline. Approximately 50% of children had moderate-heavy T. trichiura infections at 12 months post-treatment compared with approximately 23% at baseline. Hookworm infections did not re-appear after treatment. The results show clearly that urban slums should be included in any future helminth-control programmes in South Africa.

Soil-transmitted helminth infections in Nigerian children aged 0-25 months

The objective of this cross-sectional study was to determine the prevalence and intensity of soil-transmitted helminths (STHs) in children aged 0-25 months and to identify the associated risk factors for Ascaris lumbricoides infections. The study was conducted in three villages outside Ile-Ife, Osun state, Nigeria in May/June 2005. Stool samples (369) were processed by formol-ether concentration. Ascaris lumbricoides (12.2%) was the dominant infection. Age, father's occupation and dog ownership were identified as the significant risk factors in the minimal adequate model for A. lumbricoides. The odds of being infected with A. lumbricoides increased as the children got older. Children aged 12-17 months and 18-25 months were 8.8 and 12.4 times, respectively, more likely to harbour Ascaris than those aged 7-11 months. The odds of harbouring Ascaris for children whose families owned a dog were 3.5 times that of children whose families did not own a dog. Children whose fathers were businessmen were 0.4 times less likely to be infected with Ascaris than those whose fathers were farmers. The findings from this study suggest that many of these young children, who are at a critical stage of development, are infected with Ascaris and that the prevalence of infection with this parasite increases with age. This study has highlighted the need to incorporate preschool children into deworming programmes in endemic regions and to investigate innovative ways of delivering cost-effective deworming treatment to this high-risk age group.

Prevalence and factors associated with intestinal parasitic infection among children in an urban slum of Karachi

Background

Intestinal parasitic infections are endemic worldwide and have been described as constituting the greatest single worldwide cause of illness and disease. Poverty, illiteracy, poor hygiene, lack of access to potable water and hot and humid tropical climate are the factors associated with intestinal parasitic infections. The study aimed to estimate prevalence and identify factors associated with intestinal parasitic infections among 1 to 5 years old children residing in an urban slum of Karachi Pakistan.

Methods and Principal Findings

A cross sectional survey was conducted from February to June 2006 in Ghosia Colony Gulshan Town Karachi, Pakistan. A simple random sample of 350 children aged 1–5 years was collected. The study used structured pre-tested questionnaire, anthropometric tools and stool tests to obtain epidemiological and disease data. Data were analyzed using appropriate descriptive, univariate and multivariable logistic regression methods. The mean age of participants was 2.8 years and 53% were male. The proportions of wasted, stunted and underweight children were 10.4%, 58.9% and 32.7% respectively. The prevalence of Intestinal parasitic infections was estimated to be 52.8% (95% CI: 46.1; 59.4). Giardia lamblia was the most common parasite followed by Ascaris lumbricoides, Blastocystis hominis and Hymenolepis nana. About 43% children were infected with single parasite and 10% with multiple parasites. Age {Adjusted Odds Ratio (aOR) = 1.5; 95% CI: 1.1; 1.9}, living in rented households (aOR = 2.0; 95% CI: 1.0; 3.9) and history of excessive crying (aOR = 1.9; 95% CI: 1.0; 3.4) were significantly associated with intestinal parasitic infections.

Conclusions

Intestinal parasites are highly prevalent in this setting and poverty was implicated as an important risk factor for infection. Effective poverty reduction programmes and promotion of deworming could reduce intestinal parasite carriage. There is a need for mass scale campaigns to create awareness about health and hygiene.

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

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

A 6 year Geohelminth infection profile of children at high altitude in Western Nepal

BACKGROUND

Geohelminth infections are a major problem of children from the developing countries. Children with these infections suffer from developmental impairments and other serious illnesses. This study aimed to measure the prevalence of geohelminth infection, infection intensity as well as the change in the intensity in children from Western Nepal over years.

METHODS

This 6-year hospital based prospective study at the Manipal Teaching Hospital, Pokhara included children (< 15 years) visiting the hospital from Kaski and 7 surrounding districts. Samples were also collected from children in the community from different medical camps. Three stool samples from every child were processed using direct and concentration methods. The Kato-Katz technique was used for measuring the intensity of infection.

RESULTS

The overall prevalence in hospital - attending children was 9.2% with 7.6% in preschool (0 - 5 y) and 11.0% in school-age (6 - 15 y) children, and in community 17.7% with 14.8% in pre-school and 20.5% in school-age children. Ascaris lumbricoides, Trichuris trichiura, Ancylostoma deodenale and Strongyloides stercoralis were the common geohelminths with a gradual decrease in worm load over the years. School-age children were found to be significantly more prone to geohelminth infection as compared to preschool children, but no statistical difference was detected by gender, district as well as season.

CONCLUSION

This heavy infection of geohelminths in children should be corrected by appropriate medication and maintaining strict personal hygiene. Health education, clean water, good sewage management and a congenial environment should be ensured to minimise infection.

Hookworm vaccines

Hookworm infection caused by the soil-transmitted nematodes Necator americanus and Ancylostoma duodenale is one of the most common parasitic infections worldwide. Although not directly responsible for substantial mortality, it causes significant morbidity in the form of chronic anemia and protein malnutrition. Current global control efforts based on periodic mass anthelmintic administration are unsustainable, and new control strategies must be developed. This review describes progress in the development of vaccines against hookworm infection, including the preclinical and initial clinical testing of the N. americanus Ancylostoma Secreted Protein-2 Hookworm Vaccine. Plans call for eventual development of a vaccine that will combine at least 2 hookworm antigens--one targeting the larval stage of the life cycle and another targeting the adult worm living in the gastrointestinal tract.