Soil-transmitted Helminths Research Articles

Surveillance of Soil-Transmitted Helminth Infection in Preschool Child Population: Do Changes in Behavior and Immunological Responses Affect Prevalence?

Soil-transmitted helminths (STHs) persist as a significant global public health issue among neglected tropical diseases (NTDs), particularly in children. STH infection can induce immune responses that affect the course of the disease; if treatment fails, chronic infection can lead to stunting, especially among children aged 24-59 months, which is a vulnerable period for growth and development. We conducted a correlational, cross-sectional data collection study to evaluate the characteristics and association of 25(OH)D, interleukin-5 (IL-5), and interleukin-13 (IL-13) with the prevalence of STH infection in children aged 24-59 months in Bandung District, Indonesia, in October 2019-January 2023. We recruited 694 subjects (401 stunted and 293 normal-height children). The prevalence of STH infection among the stunted and normal-height groups was 5.7% (95% CI: 3.85-8.46%) and 3.4% (95% CI; 1.86-6.17%) (p = 0.156), respectively. The probability of the prevalence of STH infection in children with levels of 25(OH)D, IL-5, and IL-13 below the cut-off point was 6,93 to 16.71 times higher. We found a relationship between IL-5, IL-13, and environmental factors and the prevalence of STH infection in stunted children.

Prevalence of Soil-Transmitted Helminth Infections in Malaysia: A Systematic Review and Meta-Analysis

BACKGROUND: Prevention and control of soil-transmitted helminth (STH) infections in Malaysia remain a challenge, especially among aborigine and rural population. Despite several community-based reports, there are lacking national data on the overall prevalence for STH infection. AIM: The study aimed to determine the prevalence, endemic species, and distribution and risk zones (RZs) for STH infections in Malaysia through a systematic review and meta-analysis of the data published between 1999 and 2019. METHODS: This study employed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The databases used in this review include SCOPUS, WEB OF SCIENCE, OVID MEDLINE, and PUBMED. The random-effects model determined the pooled prevalence estimate (PPE) while Cochran’s Q-test evaluated the heterogeneity. RESULTS: A total of 13240 samples were examined during the period under review with 6235 were infected with one or more species of STHs. The overall PPE for STH infections was 51% (95% Confidence interval [CI]: 34, 67). PPEs for sub-groups ranged between 13% (95% CI: 5, 22) and 69% (95% CI: 50, 87). Highest PPEs for STH infections were observed among aborigine children (69% 95% CI: 50, 87). Trichuris trichiura was the most prevalent species (46%, 95% CI: 27, 65). Over 46% (17/37) of the studies, especially among aborigine community and their area showed high-HRZ for STH infections. CONCLUSION: STH infections involving T. trichiura, Ascaris lumbricoides, hookworms and Strongyloides stercoralis are highly prevalent among aborigine community. Primary and secondary prevention such as the use of anthelmintic, health education, and adequate sanitation was essential in the control of these infections in Malaysia to improve individual and community health.

Prevalence of intestinal parasites and comparison of detection techniques for soil-transmitted helminths among newly arrived expatriate labors in Jeddah, Saudi Arabia.

Diversity in clinical signs and symptoms are associated with soil transmitted diseases (STD), which are spread to humans by intestinal worms and transmitted in a variety of ways. There is a need for the present study, which aimed to investigate the prevalence of intestinal parasites and to compare between the common detection techniques for soil-transmitted helminths (STHs) among newly arrived expatriate labors in Jeddah, Saudi Arabia. A total of 188 stool samples were analyzed by macroscopic examination, and microscopic examination using direct iodine smear and the formal ether sedimentation technique. Trichrome and modified Kinyoun's stains were used to confirm the morphology of any detected protozoa stages and oocyst of Cryptosporidium, respectively. A chromatographic immunoassay kit was used for Entamoeba histolytica, Giardia lamblia and Cryptosporidium. In addition, real-time PCR was employed only to identify various STHs. Out of 188, several types of parasites were detected in 35 samples (18.62%), of which some with multiple infections. Nine samples (4.79%) were positive for Entamoeba coli, seven samples (3.72%) for Trichuris trichiura, six samples (3.19%) for Necator americanus, four samples (2.13%) for Strongyloides stercoralis, four samples (2.13%) for Ascaris lumbricoides, four samples (2.13%) for E. histolytica, three samples (1.60%) for Blastocystis hominis and two samples (1.06%) for Ancylostoma duodenale. In comparison between laboratory techniques for STHs, real-time PCR was able to detect the DNA of 19 samples (10.1%) followed by Ritchie sedimentation technique (18, 9.6%), and direct smear (7, 3.7%) (p > 0.05). The high rate of newly arrived foreign workers infected with intestinal parasites could lead to a risk to society. Continuous and regular surveys are needed to deal with the occurrence of intestinal parasitic infections including STHs. To improve the identification of these infections, we recommend a supporting infrastructure for the application of concentration methods and molecular assays.

Status of Soil-transmitted Helminth after Implementation of School-based Deworming Programmes in Five Districts, South Kalimantan Province, Indonesia

Status of Soil-transmitted Helminth after Implementation of School-based Deworming Programmes in Five Districts, South Kalimantan Province, Indonesia

Reduced efficacy of single-dose albendazole against Ascaris lumbricoides, and Trichuris trichiura, and high reinfection rate after cure among school children in southern Ethiopia: a prospective cohort study

BackgroundMass drug administration (MDA) program of albendazole to at-risk populations as preventive chemotherapy is the core public health intervention to control soil-transmitted helminths (STHs). Achieving this goal relies on drug effectiveness in reducing the parasite reservoirs in the community and preventing reinfection. We assessed the efficacy of albendazole against STH parasite infection and reinfection status after cure.MethodsA total of 984 schoolchildren infected with at least one type of STH parasite (hookworm, Ascaris lumbricoides, Trichuris trichiura) in southern Ethiopia were enrolled and received albendazole and praziquantel in MDA campaign conducted from January to March 2019. Stool exams at week-4 and at week-8 of post-MDA were done using Kato Katz technique. The primary outcome was efficacy assessed by cure rate (CR) and fecal egg reduction rates (ERRs) at four weeks of post-MDA. The secondary outcome was reinfection status defined as parasite egg positivity at eight weeks among those who were cured at 4 weeks of post-MDA. Group comparisons in CR and related factors were assessed with chi-square or Fisher’s exact tests. Predictors of CR were examined through univariate and multivariate regression analyses.ResultsThe overall CR and ERR for hookworm infection were 97.2% (95% CI 94.6–99.4) and 97.02%, respectively. The overall CR and ERR for A. lumbricoides were 71.5% (95% CI 68.3–74.6) and 84.5% respectively. The overall CR and ERR and for T. trichiura were 49.5% (95% CI 44.8–54.2) and 68.3%, respectively. The CR among moderate T. trichiura infection intensity was 28.6%. Among children cured of hookworm, A. lumbricoides and T. trichiura at week 4 post-MDA, 4.6%, 18.3% and 52.4% became reinfected at week-8 post-MDA, respectively. Significantly lower CR (36.6%) and higher reinfection after cure (60.6%) among A. lumbricoides and T. trichiura coinfected children than A. lumbricoides only (CR = 69.6%, reinfection rate = 15.1%) or T. trichiura only infected children (CR = 55.6%, reinfection rate = 47.1%) was observed. Pre-treatment coinfection with ≥ two types of STH parasites was significantly associated with re-infection after cure.ConclusionAlbendazole MDA is efficacious against hookworm but has reduced efficacy against A. lumbricoides and is not effective against T. trichiura. The low drug efficacy and high reinfection rate after cure underscore the need for alternative treatment and integration of other preventive measures to achieve the target of eliminating STHs as a public health problem by 2030.Graphical

Association between arterial stiffness and Loa loa microfilaremia in a rural area of the Republic of Congo: A population-based cross-sectional study (the MorLo project).

Loa loa filariasis (loiasis) is still considered a relatively benign disease. However, recent epidemiologic data suggest increased mortality and morbidity in L. loa infected individuals. We aimed to examine whether the density of L. loa microfilariae (mfs) in the blood is associated with cardiovascular disease. Using a point-of-care device (pOpmètre), we conducted a cross-sectional study to assess arterial stiffness and peripheral arterial disease (PAD) in 991 individuals living in a loiasis-endemic rural area in the Republic of the Congo. Microfilaremic individuals were matched for age, sex and village of residence with 2 amicrofilaremic subjects. We analyzed markers of arterial stiffness (Pulse-Wave Velocity, PWV), PAD (Ankle-Brachial Index, ABI) and cardiovascular health (Pulse Pressure, PP). The analysis considered parasitological results (L. loa microfilarial density [MFD], soil-transmitted helminths infection, asymptomatic malaria and onchocerciasis), sociodemographic characteristics and known cardiovascular risk factors (body mass index, smoking status, creatininemia, blood pressure). Among the individuals included in the analysis, 192/982 (19.5%) and 137/976 (14.0%) had a PWV or an ABI considered out of range, respectively. Out of range PWV was associated with younger age, high mean arterial pressure and high L. loa MFD. Compared to amicrofilaremic subjects, those with more than 10,000 mfs/mL were 2.17 times more likely to have an out of range PWV (p = 0.00). Factors significantly associated with PAD were older age, low pulse rate, low body mass index, smoking, and L. loa microfilaremia. Factors significantly associated with an elevation of PP were older age, female sex, high average blood pressure, low pulse rate and L. loa microfilaremia. A potential link between high L. loa microfilaremia and cardiovascular health deterioration is suggested. Further studies are required to confirm and explore this association.

Participatory development of a target policy profile to support soil-transmitted helminth elimination.

Soil-transmitted helminths (STH) are parasitic worms that infect nearly a quarter of the world's population, particularly those living in communities without access to adequate water, sanitation, and housing. Emerging evidence suggests that it may be possible to interrupt transmission of STH by deworming individuals of all ages via community-wide MDA (cMDA), as opposed to only treating children and other focal populations. Transitioning from a policy of STH control to STH elimination in targeted areas would require a fundamental shift in STH policy and programming. This policy change would require updated guidance to support countries as they adapt their current approaches for STH surveillance, supply chain management, community mobilization, and core programmatic activities in pursuit of STH elimination. There is an opportunity to engage with key stakeholders, such as program implementers and implementation partners, to understand what evidence they need to confidently adopt a new policy guideline and to deliver guideline adherent management at scale. We aimed to engage with STH stakeholders to develop a Target Policy Profile (TPoP), a single document that describes optimal characteristics and evidence requirements that STH stakeholders prioritized in future potential STH transmission interruption efforts. Steps in TPoP development included a scoping review and key informant interviews (KIIs), which were used to design a two-stage Delphi technique to identify and verify TPoP components. The scoping review resulted in 25 articles, and 8 experts participated in KII's. Twenty respondents completed the first Delphi survey and 10 respondents completed the second. This systematic effort resulted in a net of 3 key information domains (background/context, clinical considerations, and implementation considerations) encompassing 24 evidence categories (examples include evidence regarding safety and adverse events, implementation feasibility, or evidence dissemination). For each evidence category, STH stakeholders reviewed, endorsed, or revised a range of options for how the evidence could be presented. This information can be used by guideline committees or global policy makers prior to convening guideline advisory groups. The TPoP tool may also speed the process of stakeholder consensus building around guidelines, accelerating progress towards implementing evidence-based policy at scale.

Identification of eggs of soil transmitted helminthes (STH) intestinal nemathodes in children by flotation method in Tengket village, Arosbaya district, Bangkalan regency

Background: Worm infections can occur in humans throughout the world regardless of age and attack children's health. This statement encouraged researchers to do this in Tengket Village, where most guardians ignore their children's PBHS and latrines in rivers around residents' houses cause worm infections. More than 1.5billion people, or 24% of the world's population, are infected with soil-borne worms. That are transmitted through the soil are also called nematodes of the STH class. Objectives: The study aimed to identify STH intestinal nematode eggs in children in Tengket Village, Arosbaya, Bangkalan. Materials and Methods: The method used is flotation using NaCl reagent with the principle of different specific gravity so the parasites in the feces will be floated on the surface. The floatation method is able to produce a clean field of view and an easy procedure, thereby minimizing false positives and false negatives. Results: The research was carried out in February 2023 and the results obtained were that 9 out of 30 children's feces samples tested positive for worms. The positive results in the samples could be due to river latrines still being used and the spread occurring due to lack of attention to PHBS. Conclusions: Based on the research results, the percentage of worms has increased.

Effectiveness of a School Intervention Based on Knowledge, Attitude, and Practice of Soil-Transmitted Helminths.

More than 1.5 billion people are infected by soil-transmitted helminths (STHs) worldwide, comprising one of the world's most serious public health problems. School-age children are the most affected as a result of precarious hygienic habits, especially in economically poor areas that lack appropriate sanitation. Therefore, this study aimed to evaluate a didactic method via a health education approach as a complement to the school curriculum of the sixth-grade students of public schools, distributed among six cities in the state of São Paulo, Brazil. For this, a didactic booklet was elaborated with educational explanatory activities about worms, their life cycle, and how to avoid infections. The intervention was measured by the change caused by knowledge, attitude, and practice (KAP), in students before and after using the notebook, through a questionnaire with high validity and internal consistency. Schools were assigned randomly into intervention and control groups, receiving both the didactic material and the questionnaires, versus the questionnaires only, respectively. The results were submitted to an analysis of covariance that revealed a significant difference pre- and postintervention for knowledge (P < 0.001), with greater means (0.54) compared with the control group (0.44); attitude (P < 0.005), with respective means of 0.56 versus 0.48; and practice (P < 0.001), with means of 0.75 versus 0.57. These findings set the didactic material as a potential tool to complement the school curriculum through KAP without disrupting the teaching system, in addition to assisting teachers in health education at schools aiming to prevent children's infections by STHs.

The burden of intestinal parasitic infections in Antioquia, Colombia: impact in childhood growth development and nutritional status

Gastrointestinal protist (GP) and soil-transmitted helminth (STH) infections cause significant morbidity among children in poor-resource settings of tropical and sub-tropical countries including Colombia. Few prospective transversal studies investigating how GP and STH infections affect growth development and nutritional status during childhood have been conducted in this country, none of them in the Antioquia Department. This microscopy-based study estimated the prevalence of GP and helminth (including STH) infections in faecal samples from schoolchildren (n=384) collected during April-May 2019 in three municipalities of the Antioquia Department. Demographic, epidemiological, and household data were elicited through face-to-face interviews. Parasite detection was carried out by direct microscopic examination of both fresh smears and concentrated faecal material. Children (aged 6-15 years) also had their haemoglobin (Hb) levels, height and weight data collected, and BMI estimated. Data were analysed using bivariate and multivariate logistic regression analysis. Overall, 60.7% (233/384) of schoolchildren were infected by at least one intestinal parasitic species. Among GPs, Blastocystis sp. was the most common species found (47.7%, 95% CI: 42.6-52.8), followed by G. duodenalis (15.9%, 95% CI: 12.4-19.9). Cryptosporidium spp. and Cyclospora cayetanensis were sporadically identified (0.3%, 95% CI: 0.1-1.4 each). Among helminths, the most prevalent species found were Trichuris trichiura (6.0%, 95% CI: 3.8-8.9) and Enterobius vermicularis (1.0%, 95% CI: 0.3-2.6). Hookworms, Ascaris lumbricoides, and Strongyloides stercoralis were found at prevalence rates <1%. Underweight, overweigh, or obese schoolchildren had 1.2 times greater chance of being infected with intestinal parasites than their counterparts with a healthy weight (P-value: 0.015). Variables significantly associated with an increased likelihood of being infected by intestinal parasites include living in a household with unfinished flouring, not wearing shoes, being in close proximity to rodents, and having improper waste disposal. Relatively simple interventional measures directed towards the improvement of household conditions, access to sanitary toilets, and promoting shoe wearing can significantly reduce childhood infections by GP and helminths in the Antioquia Department.

Anemia among malaria patients with and without soil-transmitted helminths in Arba Minch town health facilities: A comparative cross-sectional study.

Anemia is one of the severe clinical outcomes associated with concomitant infection of malaria and soil-transmitted helminths (STH). Since STH infections mostly share similar geographical areas with malaria, the influence of co-infections on the epidemiology and course of Anemia deserves greater consideration to assess the impact of interventions, the adequacy of strategies implemented, and the progress made in the fight against Anemia. So, this study was done to investigate Anemia among STH-negative malaria patients and malaria patients co-infected with single or multiple STHs, in 3 health facilities of Arba Minch, 2020 to 2021. An institutional-based comparative cross-sectional study was conducted at 3 Governmental Health Institutions, Arba Minch, and southern Ethiopia from November 2020 to February 2021 on a total of 321 malaria-positive study participants. Thick and thin blood films were prepared for microscopic examination of malaria parasites and identification of species. A malaria parasite count was done to determine the intensity of the infection. A stool wet mount was done to identify STHs. Kato-Katz was done for microscopic quantitative examination of STHs. A complete blood cell count was done to determine hemoglobin level. Socio-demographic data were collected using a questionnaire. Data were analyzed using SPSS version 25. Independent samples t test and one-way analysis of variance were done. Anemia magnitude in this study was 38.3% and it was higher in malaria with multiple STH co-infection groups (55.1%). Malaria parasite density was significantly higher in malaria with multiple STHs co-infected study participants F (2, 318) = 20.075. It increased with the increasing intensity of hookworm, Trichuris trichiura, and several co-infecting helminth species. But it decreased with increasing intensity of Ascaris lumbricoides. The mean hemoglobin concentration of malaria with multiple STHs co-infection study participants was significantly lower than mono malaria-infected and malaria with single STHs co-infection study participants. The management of malaria should take account of STH infections and optimal modalities of treatment should be devised. Anti-helminthic treatments of malaria patients through regular, inexpensive, single-dose, and highly effective drugs must be seriously considered to protect the population from exacerbation of Anemia by intestinal helminth infections.

Community views on mass drug administration for soil-transmitted helminths: a qualitative evidence synthesis

Community views on mass drug administration for soil-transmitted helminths: a qualitative evidence synthesis

Identifying opportunities to optimize mass drug administration for soil-transmitted helminths: A visualization and descriptive analysis using process mapping.

The control of soil-transmitted helminths (STH) is achieved through mass drug administration (MDA) with deworming medications targeting children and other high-risk groups. Recent evidence suggests that it may be possible to interrupt STH transmission by deworming individuals of all ages via community-wide MDA (cMDA). However, a change in delivery platforms will require altering implementation processes. We used process mapping, an operational research methodology, to describe the activities required for effective implementation of school-based and cMDA in 18 heterogenous areas and over three years in Benin, India, and Malawi. Planned activities were identified during workshops prior to initiation of a large cMDA trial (the DeWorm3 trial). The process maps were updated annually post-implementation, including adding or removing activities (e.g., adaptations) and determining whether activities occurred according to plan. Descriptive analyses were performed to quantify differences and similarities at baseline and over three implementation years. Comparative analyses were also conducted between study sites and areas implementing school-based vs. cMDA. Digitized process maps were developed to provide a visualization of MDA processes and inspected to identify implementation bottlenecks and inefficient activity flows. Across three years and all clusters, implementation of cMDA required an average of 13 additional distinct activities and was adapted more often (5.2 adaptations per year) than school-based MDA. An average of 41% of activities across both MDA platforms did not occur according to planned timelines; however, deviations were often purposeful to improve implementation efficiency or effectiveness. Visualized process maps demonstrated that receipt of drugs at the local level may be an implementation bottleneck. Many activities rely on the effective setting of MDA dates and estimating quantity of drugs, suggesting that the timing of these activities is important to meet planned programmatic outcomes. Implementation processes were heterogenous across settings, suggesting that MDA is highly context and resource dependent and that there are many viable ways to implement MDA. Process mapping could be deployed to support a transition from a school-based control program to community-wide STH transmission interruption program and potentially to enable integration with other community-based campaigns. NCT03014167.

Decreased Weight-for-Age Associated with Mass Deworming among Young Ethiopian Schoolchildren in Jimma Town, Southwest Ethiopia: A School-Based Cross-Sectional Study.

School-based mass deworming programs are implemented to reduce soil-transmitted helminth (STH) infection prevalence and intensity among school-aged children. However, previous studies debate the impact of deworming beyond the removal of worms. Hence, this study aimed to examine the effect of mass deworming on nutritional indicators in young Ethiopian schoolchildren. A school-based cross-sectional study was conducted among 1,036 participants from April to May 2020 in Jimma Town, Ethiopia. An interviewer-based questionnaire was administered to the children to gather data on sociodemographic, lifestyle variables, and deworming status. Anthropometric measurements were taken for the height and weight of the children. Stool samples were collected and analyzed for STH infection using direct wet mount microscopy and the Kato-Katz technique. In multivariate logistic regression analysis, deworming within the past 6 months or 1 year was not significantly associated with underweight, stunting, and thinning. However, deworming within the past year was significantly associated with decreased weight-for-age z-score (adjusted mean difference = -0.245; 95% CI: -0.413 to -0.076; P = 0.004). Deworming in the past 6 months demonstrated a nonsignificant trend toward increased stunting (adjusted odds ratio = 1.258; 95% CI: 0.923-1.714; P = 0.145). This study provides evidence that deworming in the past 6 months or 1 year was not significantly associated with underweight, stunting, and thinning. However, deworming within the past year was associated with a significantly decreased weight-for-age z-score in young Ethiopian schoolchildren of Jimma Town after adjustment for confounding variables.

Clonorchiasis and opisthorchiasis: epidemiology, transmission, clinical features, morbidity, diagnosis, treatment, and control.

Clonorchis sinensis, Opisthorchis viverrini, and Opisthorchis felineus are important liver flukes that cause a considerable public health burden in eastern Asia, southeastern Asia, and eastern Europe, respectively. The life cycles are complex, involving humans, animal reservoirs, and two kinds of intermediate hosts. An interplay of biological, cultural, ecological, economic, and social factors drives transmission. Chronic infections are associated with liver and biliary complications, most importantly cholangiocarcinoma. With regard to diagnosis, stool microscopy is widely used in epidemiologic surveys and for individual diagnosis. Immunologic techniques are employed for screening purposes, and molecular techniques facilitate species differentiation in reference laboratories. The mainstay of control is preventive chemotherapy with praziquantel, usually combined with behavioral change through information, education and communication, and environmental control. Tribendimidine, a drug registered in the People's Republic of China for soil-transmitted helminth infections, shows potential against both C. sinensis and O. viverrini and, hence, warrants further clinical development. Novel control approaches include fish vaccine and biological control. Considerable advances have been made using multi-omics which may trigger the development of new interventions. Pressing research needs include mapping the current distribution, disentangling the transmission, accurately estimating the disease burden, and developing new diagnostic and treatment tools, which would aid to optimize control and elimination measures.

Mass drug administration campaigns: comparing two approaches for schistosomiasis and soil-transmitted helminths prevention and control in selected Southern Malawi districts

BackgroundMass drug administration is one of the key interventions recommended by WHO to control certain NTDs. With most support from donors, health workers distribute antihelminthic drugs annually in Malawi. Mean community coverage of MDA from 2018 to 2020 was high at 87% for praziquantel and 82% for albendazole. However, once donor support diminishes sustaining these levels will be challenging. This study intended to compare the use of the community-directed intervention approach with the standard practice of using health workers in delivery of MDA campaigns.MethodsThis was a controlled implementation study carried out in three districts, where four health centres and 16 villages in each district were selected and randomly assigned to intervention and control arms which implemented MDA campaigns using the CDI approach and the standard practice, respectively. Cross-sectional and mixed methods approach to data collection was used focusing on quantitative data for coverage and knowledge levels and qualitative data to assess perceptions of health providers and beneficiaries at baseline and follow-up assessments. Quantitative and qualitative data were analyzed using IBM SPSS software version 26 and NVivo 12 for Windows, respectively.ResultsAt follow-up, knowledge levels increased, majority of the respondents were more knowledgeable about what schistosomiasis was (41%-44%), its causes (41%-44%) and what STH were (48%-64%), while knowledge on intermediate host for schistosomiasis (19%-22%), its types (9%-13%) and what causes STH (15%-16%) were less known both in intervention and control arm communities. High coverage rates for praziquantel were registered in intervention (83%-89%) and control (86%-89%) communities, intervention (59%-79) and control (53%-86%) schools. Costs for implementation of the study indicated that the intervention arm used more resources than the control arm. Health workers and community members perceived the use of the CDI approach as a good initiative and more favorable over the standard practice.ConclusionsThe use of the CDI in delivery of MDA campaigns against schistosomiasis and STH appears feasible, retains high coverages and is acceptable in intervention communities. Despite the initial high costs incurred, embedding into community delivery platforms could be considered as a possible way forward addressing the sustainability concern when current donor support wanes.Trial registrationPan-African Clinical Trials Registry PACTR202102477794401, date: 25/02/2021.

Epidemiology of soil-transmitted helminth infections and the differential effect of treatment on the distribution of helminth species in rural areas of Gabon

BackgroundSoil-transmitted helminth (STH) infections are a public health concern in endemic areas. For efficient control, the epidemiology of the disease needs to be monitored. This report assesses the prevalence, incidence, post-treatment infection (PTI) rate, and risk factors for STH infections in two rural areas of Gabon.MethodIn this longitudinal and prospective study, participants aged six to 30 years from the vicinity of Lambaréné and selected households using a simple randomization process were included and followed in two consecutive periods of six and nine months. Stool samples were obtained at the beginning and the end of each follow-up phase (FUP). The Kato-Katz technique was used for the detection of STH eggs, while the Harada-Mori technique and coproculture were used for the detection of larvae in stool processed within a maximum of four hours of collection. Prevalence was determined at the three main time points of the study, incidence was assessed during the two study phases, and PTI was defined as an infection detected nine months post-treatment.ResultsA total of 262 participants were included. The overall prevalence of STH infections was 42% (95%CI: 34–50) and 44% (95%CI: 37–51) at baseline for the six and nine month FUPs, respectively. Trichuris trichiura was the most prevalent species at each time point of assessment. The cumulative incidence of STH at the 6- and 9-month follow-ups was 18% (95%CI: 12–27) and 35% (95%CI: 27–43), respectively, while the incidence rates were 41 (95%CI: 28–55) and 56 (95%CI: 46–67) per 100 person-years, respectively. The PTI rates at the 9-month follow-up for T. trichiura, hookworm, and Ascaris lumbricoides were 58% (95%CI: 41–74), 31% (95%CI: 11–59) and 18% (95%CI: 5–40), respectively. The STH infection intensity was generally light.ConclusionThe prevalence level of STH infection is moderate in the vicinity of Lambaréné, with T. trichiura being the most prevalent species. Our results reveal a rapid spread of the disease in the population mainly following intervention, particularly for trichuriasis, and therefore call for the full implementation of the World Health Organization’s recommendations in the area.Trial registration clinicaltrials.gov Identifier NCT02769013. Registered 21 April 2016, https://clinicaltrials.gov/study/NCT02769013

Estimation of the Parasitic Burden of Soil-Transmitted Helminths Among Pregnant Women in the Maharashtra State of India Using qPCR: A Community-Based Study.

Soil-transmitted helminth (STH) infections are widespread in developing countries with inadequate sanitation facilities. These infections can lead to malnutrition, anemia, and other complications that can negatively impact both the mother's and fetus's health during pregnancy. This study aimed to estimate the burden of STH by Kato-Katz microscopy and quantitative polymerase chain reaction (qPCR) in pregnant women from rural India. The diagnostic accuracy of these two methods was also compared. A community-based cross-sectional study was conducted in rural areas of Wardha district of Maharashtra state. We randomly selected and interviewed 688 pregnant women. A total of 534 (77.61%) participants gave stool samples. Two containers (60 mL) labeled with a unique identification number were given to pregnant women to collect stool samples for Kato-Katz microscopy and qPCR. Stool specimens were transported to an accredited lab and examined within 24 hours. Suitable examinations were conducted to compare sensitivity between two tests. The results are presented for 534 participants who gave stool samples. The prevalence of any STH by Kato-Katz stool microscopy was 6.55% (95%CI 4.46-12.19), and that by qPCR was 20.41 (95%CI 17.53-29.40). The sensitivity of Kato-Katz microscopy was 29.17% compared to sensitivity of 90.83% by qPCR (P = 0.001). Pregnant women with STH infection have a significantly lower weight gain during pregnancy, and the majority were either mild or moderate anemic compared to those without STH. The study highlighted significant differences in prevalence of STH among pregnant women by Kato-Katz microscopy and qPCR. The sensitivity of qPCR for detecting STH was higher than that of Kato-Katz microscopy.

Zoonotic Parasites and Their Association With Human Activities in Northern Tanzania: An Integrated Ecosystem Approach for One Health.

The community's awareness of the prevalence and impact of zoonotic diseases has been significantly underestimated, leading to insufficient implementation of control measures. This study was carried out in Northern Tanzania between 2019 and 2023 to investigate zoonotic parasites and the risks associated with human activities that contribute to zoonotic diseases. Cross-sectional surveys were conducted in 12 villages, including nine in Loliondo Division and three in Babati District. Focus Group Discussions and Key Informant Interviews were conducted to assess the community's knowledge and practices regarding the risks associated with zoonotic diseases in the surveyed areas. A total of 255 samples were collected from various sources, including latrines, households, livestock enclosures, domestic dogs, and chickens. Out of these samples, 152 tested positive for identifiable parasite eggs and oocysts. These parasites included hookworms (21.7%), Trichuris sp. (14.5%), Strongyloides sp. (13.8%), Eimeria sp. (19.7%), Taeniids (5.9%), Hymenolepis sp. (3.3%), Spirometra sp. (2.6%), and Dipylidium sp. (0.7%). Taeniids and Spirometra species were predominantly found in villages near protected areas such as Arash Sokoni, Oloipiri, Sukenya, Wasso, Orkuyiene, Haytemba, and Loliondo. Hookworms were most commonly detected in Arash Sokoni, Loliondo, Isuguro, and Hyatemba, while Strongyloides sp. was prevalent in Wasso, Sukenya, and Olobo villages. The quantitative analysis reveals significant associations between hygiene practices, proximity to livestock enclosures, ecological factors, and human-animal interaction, highlighting their pivotal roles in determining soil-transmitted helminth (STH) prevalence across different villages. This study reveals that there was a generally low level of awareness regarding zoonotic diseases and STHs. The detection of STH samples, combined with the limited understanding of zoonotic diseases, emphasizes the importance of taking proactive measures to reduce transmission risks. Prioritizing education and promoting awareness along with implementing comprehensive strategies are essential steps to effectively tackle the problems linked to STH infections and substantially lessen the public health burden caused by zoonotic diseases.

Soil-Transmitted Helminths in Kindergarten Children: Prevalence, Intensity and Associated Factors in Bule Hora Town.

Background: Soil-transmitted helminth (STH) infections are a common problem in Ethiopia. This parasite affects the physical and mental development of children, causing malnutrition and iron deficiency anaemia. However, there are inadequate studies that demonstrate the extent of STHs and associated factors among kindergarten children in South Ethiopia, particularly in the study area. Objective: The aim of this study is to determine the prevalence, intensity, and associated factors of STH infection among kindergarten students in Bule Hora town. Methods: An institution-based cross-sectional study was conducted among randomly selected 235 kindergarten children in Bule Hora town from January to February 2023. A pretested questionnaire was used to collect information on associated factors. EpiData and SPSS were used for data entry and analysis, respectively. Binary logistic regression analyses were performed to identify risk factors. Results: In the present study, the prevalence of STH was 28.5% (95% CI: 22.7%-34.3%). A. lumbricoides 26 (11.1%) was the most common parasite identified. The arithmetic mean (+SD) of the egg counts for each species of STHs was as follows: A. Lumbricoides 1886.9 (+2103.2), T. Trichiura 299.2 (+305.8), and hookworms 756.1 (+739.4). Factors that showed significant association in the current study were hand washing after the toilet (AOR: 2.992, 95% CI: 1.299-6.891,), fingernail trimming (AOR: 3.646, 95% CI: 1.704-7.798,), and shoe wearing habit (AOR: 2.143, 95% CI: 1.170-3.924,). Conclusion: STH infection is a health problem among kindergarten children in Bule Hora town. Comprehensive health education on the value of hygienic habits, improved sanitation, and routine deworming of kindergarten children should be included in prevention and control efforts.