Neglected tropical diseases in sub-saharan Africa: review of their prevalence, distribution, and disease burden

The Geshiyaro Project: a study protocol for developing a scalable model of interventions for moving towards the interruption of the transmission of soil-transmitted helminths and schistosome infections in the Wolaita zone of Ethiopia

Background

National deworming programmes rely almost exclusively on mass drug administration (MDA) to children to control morbidity caused by these parasitic infections. The provision of other interventions, consisting of preventive chemotherapy at high population level coverage together with water, sanitation and hygiene (WaSH) and changes in risk behaviour, should enable sustainable control of soil-transmitted helminths (STH) and schistosomiasis and ultimately interrupt transmission.

Methods/Design

Two interventions will be implemented by the project: (i) community-wide biannual albendazole and annual praziquantel treatment with a target of 80–90% treatment coverage (“expanded MDA”); and (ii) provision of WaSH with behaviour change communication (BCC), within the Wolaita zone, Ethiopia. The project has three study arms: (i) expanded community-wide MDA, WaSH and BCC; (ii) expanded community-wide MDA only; and (iii) annual school-based MDA (the current National STH/schistosomiasis Control Programme). The impact of these interventions will be evaluated through prevalence mapping at baseline and endline (after four rounds of MDA), combined with annual longitudinal parasitological surveillance in defined cohorts of people to monitor trends in prevalence and reinfection throughout the project. Treatment coverage and individual compliance to treatment will be monitored by employing fingerprint biometric technology and barcoded identification cards at treatment. WaSH utilisation will be evaluated through school and household level observations and annual WaSH assessment survey. Complementary qualitative surveys will explore practices, cultural and social drivers of risk behaviours, uptake of WaSH and treatment, and assessing the impact of the BCC.

Discussion

The study has the potential to define an ‘End Game’ for STH and schistosomiasis programmes through provision of multiple interventions. Interrupting transmission of these infections would eliminate the need for long-term repeated MDA, lead to sustained health improvements in children and adults, thereby allowing health systems to focus on other disease control priorities.

Lipopeptide-Based Oral Vaccine Against Hookworm Infection

Background

The human hookworm, Necator americanus, is a parasite that infects almost half a billion people worldwide. Although treatment is available, vaccination is favorable to combat the spread of this parasite due to its wide distribution and continuous reinfection cycle in endemic communities.

Methods

We have designed a lipopeptide oral delivery system using a B-cell epitope derived from the aspartic protease Na-APR-1 from N americanus, attached to a T-helper epitope. Lipopeptides were self-assembled into nanoparticles or entrapped in liposomes that were electrostatically coated with alginate and trimethyl chitosan polymer shields. The adjuvant-free vaccine candidates were orally administered to mice and generated a humoral immune response against both peptide antigen, and the parent protein in the hookworm gut.

Results

The vaccine candidates were evaluated in a rodent hookworm challenge model, resulting in up to 98% and 99% decreases in mean intestinal worm and egg burdens in immunized mice, respectively.

Conclusions

Lipopeptide survived the gastrointestinal conditions, induced humoral immune responses and drived protection against parasite challenge infection.

Intestinal schistosomiasis of Ijinga Island, north-western Tanzania: prevalence, intensity of infection, hepatosplenic morbidities and their associated factors

Background

Intestinal schistosomiasis is highly endemic in Tanzania and mass drug administration (MDA) using praziquantel is the mainstay of the control program. However, the MDA program covers only school aged children and does not include neither adult individuals nor other public health measures. The Ijinga schistosomiasis project examines the impact of an intensified treatment protocol with praziquantel MDA in combination with additional public health interventions. It aims to investigate the feasibility of eliminating intestinal schistosomiasis in a highly endemic African setting using an integrated community-based approach. In preparation of this project, we report about baseline data on S.mansoni prevalence, intensity of infection, related hepatosplenic morbidities and their associated factors.

Methods

A cross sectional study was conducted among 930 individuals aged 1–95 years living at Ijinga Island, north-western Tanzania in September 2016. Single stool and urine samples were collected from each study participant and processed using Kato Katz (KK) technique and point-of-care Circulating Cathodic (POC-CCA) antigen test for detection of S.mansoni eggs and antigen respectively. Ultrasonographical examination for S.mansoni hepatosplenic morbidities was done to all participants. For statistical analyses Fisher’s exact test, chi-square test, student-t-test, ANOVA and linear regression were used where applicable.

Results

Overall based on KK technique and POC-CCA test, 68.9% (95%CI: 65.8–71.8) and 94.5% (95%CI: 92.8–95.8) were infected with S.mansoni. The overall geometrical mean eggs per gram (GMepg) of faeces was 85.7epg (95%CI: 77.5–94.8). A total of 27.1, 31.2 and 51.9% of the study participants had periportal fibrosis (PPF-grade C-F), splenomegaly and hepatomegaly. Risk factors for PPF were being male (aRR = 1.08, 95%CI: 1.02–1.16, P < 0.01), belong to the age group 16–25 years (aRR = 1.23, 95%CI: 105–1.44, P < 0.01), 26–35 years (aRR = 1.42, 95%CI: 1.21–1.67, P < 0.001), 36–45 years (aRR = 1.56, 95%CI:1.31–1.84, P < 0.001) and ≥ 46 years (aRR = 1.64, 95%CI:1.41–1.92, P < 0.001). The length of the left liver lobe was associated with being female (P < 0.03), belong to the age group 1–5 years (P < 0.013), 6–15 years (P < 0.04) and S.mansoni intensity of infection (P < 0.034). Male sex (aRR = 1.15, 95%CI:1.06–1.24, P < 0.001) and belonging to the age groups 16–25 years (aRR = 1.27, 95%CI:1.05–1.54, P < 0.02) or 26–35 years (aRR = 1.32, 95%CI:108–1.61, P < 0.01) were associated with splenomegaly.

Conclusion

Schistosoma mansoni infection and its related morbidities (hepatomegaly, splenomegaly, periportal fibrosis) are common in the study area. Age, sex and intensity of infection were associated with periportal fibrosis. The prevalence of S.mansoni was above 50% in each age group and based on the observed prevalence, we recommend MDA to the entire community.

Urogenital Schistosomiasis and Sexually Transmitted Coinfections among Pregnant Women in a Schistosome-Endemic Region of the Democratic Republic of Congo

Schistosomiasis afflicts an estimated 10 million pregnant women in Africa annually. With mounting evidence of adverse impacts to reproductive health resulting from urogenital schistosomiasis, including increased transmission of HIV, further research on prenatal disease epidemiology is warranted, with implications for maternal and fetal health. Between October 2016 and March 2017, we conducted a cross-sectional study examining the prevalence of urogenital schistosomiasis and its association with sexually transmitted infections (STIs) other than HIV among pregnant women visiting antenatal clinics in Kisantu health zone, Democratic Republic of Congo. An extensive sociodemographic and clinical survey was administered to consenting participants, with urine samples and vaginal swabs collected to deduce active schistosomiasis and STIs, respectively. In total, 17.4% of expectant mothers were infected with Schistosoma haematobium, 3.1% with Chlamydia trachomatis (CT), 1.4% with Neisseria gonorrhoeae (NG), and 14.6% with Trichomonas vaginalis (TV). Women infected with urogenital schistosomiasis were at significantly increased odds of harboring a CT, NG, or TV infection (adjusted odds ratio = 3.0, 95% CI: 1.5, 6.0), but reports of clinical symptoms were low, ranging from 17.2% of schistosomiasis to 30.8% of TV cases. Laboratory confirmation of schistosomiasis and STIs provided objective evidence of disease in a cohort with low symptomology where syndromic management may not suffice. Shedding light on local risk factors and associated coinfections of urogenital schistosomiasis can identify unique intervention opportunities for prenatal care in trematode-endemic regions and aid in reducing adverse pregnancy outcomes.

Risk Factors for Infectious Diseases in Urban Environments of Sub-Saharan Africa: A Systematic Review and Critical Appraisal of Evidence

Our world is rapidly urbanizing. According to the United Nations, between 1990 and 2015, the percent of the world's population living in urban areas grew from 43% to 54%. Estimates suggest that this trend will continue and that over 68% of the world's population will call cities home by 2050, with the majority of urbanization occurring in African countries. This urbanization is already having a profound effect on global health and could significantly impact the epidemiology of infectious diseases. A better understanding of infectious disease risk factors specific to urban settings is needed to plan for and mitigate against future urban outbreaks. We conducted a systematic literature review of the Web of Science and PubMed databases to assess the risk factors for infectious diseases in the urban environments of sub-Saharan Africa. A search combining keywords associated with cities, migration, African countries, infectious disease, and risk were used to identify relevant studies. Original research and meta-analyses published between 2004 and 2019 investigating geographical and behavioral risk factors, changing disease distributions, or control programs were included in the study. The search yielded 3610 papers, and 106 met the criteria for inclusion in the analysis. Papers were categorized according to risk factors, geographic area, and study type. The papers covered 31 countries in sub-Saharan Africa with East Africa being the most represented sub-region. Malaria and HIV were the most frequent disease focuses of the studies. The results of this work can inform public health policy as it relates to capacity building and health systems strengthening in rapidly urbanizing areas, as well as highlight knowledge gaps that warrant additional research.

Genome-wide analysis of Anisakis simplex sensu lato: the role of carbohydrate metabolism genes in the parasite's development

Anisakis simplex sensu lato is a parasitic nematode which can cause gastric symptoms and/or allergic reactions in humans who consume raw and undercooked fish. Anisakiasis poses a growing health problem around the globe because it causes non-specific symptoms and is difficult to diagnose. This genome-wide study was undertaken to expand our knowledge of A. simplex s.l. at the molecular level and provide novel data for biological and biotechnological research into the analyzed species and related nematodes. A draft genome assembly of the L3 stage of A. simplex s.l. was analyzed in detail, and changes in the expression of carbohydrate metabolism genes during the parasite's life cycle were determined. To our knowledge, this is the first genome to be described for a parasitic nematode of the family Anisakidae to date. We identified genes involved in parasite-specific pathways, including carbohydrates metabolism, apoptosis and chemo signaling. A total of 7607 coding genes were predicted. The genome of A. simplex s.l. is highly similar to genomes of other parasitic nematodes. In particular, we described a valuable repository of genes encoding proteins of trehalose and glycogen metabolism, and we developed the most comprehensive data set relating to the conversion of both saccharides which play important roles during the parasite's life cycle in a host environment. We also confirmed that trehalose is synthesized at the expense of glycogen. Trehalose anabolism and glycogen catabolism were the predominant processes in stages L4 and L5, which could confirm our and other authors' previous reports that trehalose is synthesized at the expense of glycogen. The A. simplex s.l. genome provides essential data for post-genomic research into the biology of gastrointestinal and allergic anisakiasis in humans and the biology of other important parasitic helminths.

Comparison of the Impact of Different Mass Drug Administration Strategies on Infection with Schistosoma mansoni in Mwanza Region, Tanzania-A Cluster-Randomized Controlled Trial

Annual school-based mass drug administration with praziquantel has been widely implemented to control schistosomiasis, but other treatment strategies could have a different impact. The aim of this study was to investigate the impact of six different treatment strategies on Schistosoma mansoni infection in a cluster-randomized controlled trial in schoolchildren, in a high transmission area of the Mwanza Region, Tanzania. A total of 150 villages were randomized into six arms with 25 villages in each arm. In each village, approximately 100 schoolchildren aged 9-12 years were randomly selected each year and investigated for S. mansoni prevalence and intensity based on three consecutive stool samples using the duplicate Kato-Katz technique. Four years of community-wide treatment (CWT) was the most intensive treatment strategy, whereas 2 years of school-based treatment (SBT) combined with 2 years without treatment (holiday) was the least intensive treatment. The remaining strategies constituted different combinations of CWT, SBT, and holiday years. Baseline results on S. mansoni infection were obtained from 14,620 schoolchildren from 148 villages, and mean prevalence and mean intensity among infected were 48.6-60.6% and 130.5-229.8 eggs per gram, respectively. Over the years, mean prevalence and mean intensities declined in all arms, but when comparing year 5 mean prevalence and mean intensity, there were no statistically significant differences between treatment arms. Thus, measured in a random selection of schoolchildren aged 9-12 years, four times CWT was not superior to four times SBT, while 2 years of treatment holiday combined with 2 years of SBT had the same impact as 4 years of SBT.

Risk of Soil-Transmitted Helminthiasis among Agrarian Communities of Kogi State, Nigeria

Background:

Soil-transmitted helminths (STH) have remained a major threat to humans, especially children in developing countries, including Nigeria. Interventions have always been geared towards school-aged children, neglecting preschool-aged children and occupational risk adults. The Soil-Transmitted Helminthiasis Advisory Committee (STHAC) recently suggested incorporating other at-risk groups.

Objective:

This study assessed the associated risk of STH infection among agrarian communities of Kogi State, Nigeria.

Methods:

A total of 310 individuals of all ages participated in the cross-sectional survey. Stool samples were analyzed using standard Kato-Katz method.

Results:

A total of 106 (34.2%) individuals were infected with at least one STH. Hookworm was the most prevalent (18.1%); followed by Ascaris lumbricoides (16.8%). Worm intensity was generally light. Prevalence of infection was similar between four age groups considered (preschool, school, ‘women of reproductive age’ and older at-risk group). Poor socio-economic status (SES) was a major risk for STH infection. Using a 20-asset based criteria, 68 (23.1%) and 73 (24.7%) of 295 questionnaire respondents were classified into first (poorest) and fifth (richest) wealth quintiles respectively. Risk of infection with STH was 60% significantly lower in the richest wealth quintile compared to the poorest (Prevalence Ratio [PR] = 0.4843, 95% CI = 0.2704–0.8678, p = 0.015). Open defecators were more likely to harbour STH than those who did not (PR = 1.7878, 95% CI = 1.236–2.5846, p = 0.00201). Pit latrine and water closet toilets each approximately reduced STH infection by 50% (p < 0.05).

Conclusion:

Preventive chemotherapy for all age groups, health education and provision of basic amenities especially toilets are needed in order to achieve the goal toward the 2020 target of STH control.

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

Background

Hookworm infection is a common parasitic infection in sub-Saharan Africa. The prevalence of hookworm infection is influenced by different determinant factors. This study aimed to determine the prevalence of hookworm infection and determinant factors among school age children in North West Ethiopia.

Methods

A cross-sectional study was conducted from April 2016 to August 2016. Children were selected by systematic random sampling and Formoleether concentration technique was used to identify hookworm infection. We conducted descriptive and logistic regression analysis for categorical variables. The adjusted odds ratio was calculated at 95% confidence interval.

Results

Among 333 children, 49 (14.7%) were infected with hookworm parasites. Eating raw vegetables, not wearing shoes, absence of regular wearing of shoes and hand washing habit, absence of proper utilization of latrines, absence of deworming were significantly associated (p<0.05) with hookworm infection.

Conclusion

The prevalence of hookworm infection was high among school age children. Walking with bare foot, hand washing habit, and absence of proper latrine utilization are the major determinant factors for the high prevalence of hookworm infection. Therefore, community mobilization and health education should be done to decrease hookworm infection among school age children in Jawe district.

Visceral Leishmaniasis Treatment Outcome and Associated Factors in Northern Ethiopia

BACKGROUND

Visceral leishmaniasis (VL), one of the most neglected tropical diseases, is placing a huge burden on Ethiopia. Despite the introduction of antileishmanial drugs, treatment outcomes across regions are variable due to drug resistance and other factors. Thus, understanding of VL treatment outcomes and its contributing factors helps decisions on treatment. However, the magnitude and the risk factors of poor treatment outcome are not well studied in our setting. Therefore, our study was designed to assess treatment outcomes and associated factors in patients with VL.

MATERIALS AND METHODS

A cross-sectional study was conducted in VL patients admitted between June 2016 and April 2018 to Ayder Comprehensive Specialized Hospital, Tigray, Northern Ethiopia. Data was collected through chart review of patient records. Logistic regression analysis was used to identify factors associated with poor treatment outcome.

RESULTS

A total of 148 VL patients were included in the study. The mean age (SD) of the patients was 32.86 (11.9) years; most of them (94.6%) were male patients. The proportion of poor treatment outcome was 12.1%. Multivariable logistic regression analysis showed that long duration of illness (> four weeks) (adjusted odds ratio (AOR): 6.1 [95% confidence interval (CI); 1.3-28.6], p=0.02) and concomitant tuberculosis (TB) infection (AOR 4.6 [95% CI; 1.1-19.1], p=0.04) were the independent predictors of poor treatment outcome.

CONCLUSIONS

Poor treatment outcome was observed in a considerable proportion of VL patients. Long duration of illness and coinfection with TB were associated with poor VL treatment outcome. Hence, early diagnosis and effective prompt treatment are important to improve treatment outcomes among VL patients. Special attention should also be given in the treatment of VL/TB coinfected patients in our setting.

The prevalence of schistosomiasis in Uganda: A nationally representative population estimate to inform control programs and water and sanitation interventions

Background

To improve schistosomiasis control programs in Uganda, where intestinal schistosomiasis is a widespread public health problem, a country-wide assessment of the disease prevalence among all age ranges is needed. Few studies have aimed to quantify the relationships between disease prevalence and water and sanitation characteristics across Uganda to understand the potential to interrupt disease transmission with an integrated package of interventions.

Methodology/Principal findings

A nationally representative survey was undertaken that included a household and individual questionnaire followed by disease testing based on detection of worm antigens (circulating cathodic antigen–CCA), diagnosis and treatment. A comprehensive set of questions was asked of randomly sampled individuals, two years of age and above, to understand their water and sanitation infrastructure, open defecation behaviors, exposure to surface water bodies, and knowledge of schistosomiasis. From a set of 170 randomly sampled, geographically diverse enumeration areas, a total of 9,183 study participants were included. After adjustment with sample weights, the national prevalence of schistosomiasis was 25.6% (95% confidence interval (CI): 22.3, 29.0) with children ages two to four most at risk for the disease with 36.1% infected (95% CI: 30.1, 42.2). The defecation behaviors of an individual were more strongly associated with infection status than the household water and sanitation infrastructure, indicating the importance of incorporating behavior change into community-led total sanitation coverage.

Conclusions/Significance

Our results highlight the importance of incorporating monitoring and evaluation data into control programs in Uganda to understand the geographic distribution of schistosomiasis prevalence outside of communities where endemicity is known to be high. The high prevalence of schistosomiasis among the youngest age group, ineligible to receive drug treatment, shows the imperative to develop a child-appropriate drug protocol that can be safely administered to preschool-aged children. Water and sanitation interventions should be considered an essential investment for elimination alongside drug treatment.

Schistosomiasis is a neglected tropical disease in sub-Saharan Africa that has remained intractable despite efforts to eliminate it through mass drug administration. The transmission cycle is perpetuated when sanitation infrastructure does not adequately capture infected urine or feces and local water bodies, with snail vectors, are contaminated. Schistosomiasis has been linked with stunting and cognitive deficits and there is particular concern for the most vulnerable age group under five years old who are undergoing critical intestinal development but are ineligible to receive drug treatment. Efforts to reduce the disease have focused on children and young adolescents in endemic areas, near water bodies where transmission is known to be high. In Uganda, where fresh water bodies are abundant and intestinal schistosomiasis is endemic, very little is understood about the disease prevalence at a national level. We conducted a large, nationally representative survey and found a national prevalence of 25.6% where the 2–4 year old children had the highest prevalence for schistosomiasis with 36.1% infected. The most significant risk-factor for the disease was an individual’s open defecation behaviors in surface waters. This emphasizes the need to include water and sanitation investments alongside drug treatment and behavior change to control schistosomiasis in Uganda.

A Qualitative Description of Community Participation in Water and Sanitation Activities in the Control of Schistosomiasis in Nyalenda B, an Informal Settlement in Kisumu City, Western Kenya

BACKGROUND

Community participation is central to the success of primary health care. However, over 30 years since the Alma Ata declaration, the absence of universal community participation remains a major obstacle to combating all types of diseases. This study investigated community participation in water and sanitation activities towards schistosomiasis control in Nyalenda B, an informal settlement in Kisumu City.

METHODS

Eight key informant interviews (KIIs) and 8 focus group discussions (FGDs) were conducted. Additionally, data on NGOs dealing with water and sanitation activities in Kisumu was collected from the local NGO registration Board. Qualitative data was organised into themes and concepts and analyzed using Atlas.ti.

RESULTS

Most participants felt that project implementers did not involve them in key levels of project implementation, leading to unsustainable projects and unacceptance from the community. Community structures identified that could be used as avenues of engaging the community in improving water and sanitation situation included the use of organised groups, such as youth, gender-based, farmers and HIV support groups, and merry-go-rounds. Factors mentioned that hindered community participation included negative attitude from community members, poor monitoring and evaluation strategies, limited disclosure of project details, and overdependence from the community.

CONCLUSION

Effective community participation in water and sanitation activities requires a multipronged paradigm that incorporates a change of attitude from the community, information sharing and consultation, improved monitoring and evaluation, transparency and accountability.

Toxoplasma papillitis without vitritis. A case report in an immunocompetent Congolese patient

Introduction

Unilateral papillitis and neuroretinitis are uncommon manifestations of ocular Toxoplasma gondii infection and pose particularly challenging diagnosis problems. Due to the limited accessibility of healthcare and poor socioeconomic status of a significant proportion of the population in Democratic Republic of the Congo, knowledge of seroprevalence rates for toxoplasmosis remains key to the health system. When Toxoplasma papillitis or neuroretinitis is suspected, vitreous inflammatory reaction is usually present at various degrees on the initial examination as a diagnosis clue.

Case report

We report the case of a 37-year-old Congolese man who was managed in the University Hospital of Kinshasa, DR Congo, between October 2017 and April 2019 (18 months). The patient's informed consent was obtained for publication of his data. The patient developed presumed Toxoplasma papillitis with complete absence of vitritis at presentation. He was in good general health and had a known contact with a cat. Ophthalmoscopic examination revealed unilateral inflammation in the left optic disc and peripapillary area coexisting with active juxtapapillary retinochoroiditis that could be confirmed in ocular coherence tomography. A retinochoroiditis scar was present in the right eye. Left visual field was severely altered in automated perimetry. Toxoplasma titer was positive. Anti-HIV (ELISA) antibodies were negative. Rapid and favorable response to appropriate antiparasitic agents was observed without recurrence. Absence of vitritis and retinochoroiditis scar were confirmed during all the follow-up period.

Conclusions

Papillary toxoplasmosis is rare and potentially serious. Its diagnosis must be sought, even in the absence of vitritis, before taking into account any unilateral papillary edema. Our case report highlights the importance of detailed history and clinical examination to improve diagnostic decision making such as the need for complementary investigations, especially serologic testing, in a country with relatively limited financial resources in public health.

Prevalence and intensity of Schistosoma mansoni infection in pediatric populations on antiretroviral therapy in north-western Tanzania: a cross-sectional study

BACKGROUND

In areas where HIV and intestinal schistosomiasis are highly endemic, co-infections of the two diseases in a single human host are frequent. Evidence in adult populations indicates that HIV and intestinal schistosomiasis are associated with negative health impacts. However, the topic of HIV and schistosomiasis in paediatric populations has received little attention. The present study determined the prevalence and intensity of Schistosoma mansoni infection in a paediatric population on antiretroviral therapy (ART) in north-western Tanzania.

DESIGN, SETTINGS AND PARTICIPANTS

A cross-sectional study was conducted among HIV-infected children aged 1-16 years on ART attending a Care and Treatment Clinic at Ukerewe Designated District Hospital, north-western Tanzania.

MAIN OUTCOME MEASURES

Single stool and urine samples were collected and screened for S. mansoni eggs and circulating cathodic antigen (CCA), using the Kato-Katz (KK) technique and point-of-care CCA (POC-CCA) rapid urine test, respectively.

RESULTS

A total of 134 children with a median age of 10 years (IQR 7-12 years) participated in the study. Of these, 44.8% (60/134) and 55.2% (74/134) were female and male, respectively. The overall prevalence of S. mansoni based on the KK technique and POC-CCA rapid test were 10.7% (95% CI 5.9% to 18.4%) and 33.8% (95% CI 26.2% to 42.4%), respectively. The overall geometrical mean eggs per gram of faeces was 293.9 GM-epg (95% CI 123.3 to 700.9). A small proportion of the children had moderate (4.9%, 5/103) and heavy (3.8%, 4/103) intensity of infection.

CONCLUSION

Paediatric populations on ART are co-infected with S. mansoni infection. Screening and treatment of intestinal schistosomiasis at initiation of ART is recommended to reduce the risk of developing hepatosplenic disease, schistosomiasis-related immune reconstitution inflammatory syndrome and the possible adverse effect of schistosomiasis on outcome of ART.

Reaching the last mile: main challenges relating to and recommendations to accelerate onchocerciasis elimination in Africa

BACKGROUND

Onchocerciasis (river blindness), caused by the filarial worm species Onchocerca volvulus, is a serious vector-borne neglected tropical disease (NTD) of public health and socioeconomic concern. It is transmitted through the bite of black flies of the genus Simulium, and manifested in dermal and ocular lesions. Ninety-nine percent of the total global risk and burden of onchocerciasis is in Africa. This scoping review examines the key challenges related to the elimination of onchocerciasis by 2020-2025 in Africa, and proposes recommendations to overcome the challenges and accelerate disease elimination. To find relevant articles published in peer-reviewed journals, a search of PubMed and Google Scholar databases was carried out.

MAIN TEXT

Rigorous regional interventions carried out to control and eliminate onchocerciasis in the past four decades in Africa have been effective in bringing the disease burden under control; it is currently not a public health problem in most endemic areas. Notably, transmission of the parasite is interrupted in some hyperendemic localities. Recently, there has been a policy shift from control to complete disease elimination by 2020 in selected countries and by 2025 in the majority of endemic African countries. The WHO has published guidelines for stopping mass drug administration (MDA) and verifying the interruption of transmission and elimination of human onchocerciasis. Therefore, countries have revised their plans, established a goal of disease elimination in line with an evidence based decision to stop MDA and verify elimination, and incorporated it into their NTDs national master plans. Nevertheless, challenges remain pertaining to the elimination of onchocerciasis in Africa. The challenge we review in this paper are: incomplete elimination mapping of all transmission zones, co-endemicity of onchocerciasis and loiasis, possible emergence of ivermectin resistance, uncoordinated cross-border elimination efforts, conflict and civil unrest, suboptimal program implementation, and technical and financial challenges. This paper also proposes recommendations to overcome the challenges and accelerate disease elimination. These are: a need for complete disease elimination mapping, a need for collaborative elimination activities between national programs, a need for a different drug distribution approach in conflict-affected areas, a need for routine monitoring and evaluation of MDA programs, a need for implementing alternative treatment strategies (ATSs) in areas with elimination anticipated beyond 2025, and a need for strong partnerships and continued funding.

CONCLUSIONS

National programs need to regularly monitor and evaluate the performance and progress of their interventions, while envisaging the complete elimination of onchocerciasis from their territory. Factors hindering the targeted goal of interruption of parasite transmission need to be identified and remedial actions should be taken. If possible and appropriate, ATSs need to be implemented to accelerate disease elimination by 2025.

Soil-transmitted helminth infection in school age children in Sierra Leone after a decade of preventive chemotherapy interventions

BACKGROUND

Baseline mapping of soil-transmitted helminth (STH) infections among school age children (SAC) in 2008-2009 found high or moderate prevalence in 13 of the 14 districts in Sierra Leone. Following these surveys, mass drug administration (MDA) of mebendazole/albendazole was conducted biannually at national level targeting pre-school children (PSC) aged 12-59 months and intermittently at sub-national level targeting SAC. In addition, MDA with ivermectin and albendazole for eliminating lymphatic filariasis (LF) has been conducted nationwide since 2010 targeting individuals over 5 years of age. Each MDA achieved high coverage, except in 2014 when all but one round of MDA for PSC was cancelled due to the Ebola emergency. The objective of the current study was to determine the prevalence and intensity of STH infections among SAC after a decade of these deworming campaigns.

METHODS

Seventy-three schools in 14 districts were purposefully selected, including 39 schools from the baseline surveys, with approximately two sites from each of low, moderate and high prevalence categories at baseline per district. Fresh stool samples were collected from 3632 children aged 9-14 years (male 51%, female 49%) and examined using the Kato Katz technique.

RESULTS

The prevalence of STH infections in Sierra Leone decreased in 2016 compared to 2008: Ascaris lumbricoides 4.4% (95% confidence interval [CI]: 3.7-5.1%) versus 6.6% (95% CI: 0-25%), Trichuris trichiura 0.7% (95% CI: 0.5-1.1%) versus 1.8% (95% CI: 0-30.2%), hookworm 14.9% (95% CI: 13.8-16.1) versus 38.5% (95% CI: 5.4-95.1%), and any STH 18.3% (95% CI:17.0-19.5%) versus 48.3% (CI: 5.4-96.3%), respectively. In 2016, no district had high hookworm prevalence and four districts had moderate prevalence, compared with eight and four districts respectively in 2008. In 2016, the arithmetic mean hookworm egg count in all children examined was light: 45.5 eggs per gram (EPG) of faeces, (95% CI:\ 35.96-55.07 EPG); three (0.08%) children had heavy infections and nine (0.25%) children had moderate infections.

CONCLUSIONS

Sierra Leone has made considerable progress toward controlling STH as a public health problem among SAC. As LF MDA phases out (between 2017 and 2021), transition of deworming to other platforms and water and sanitation strategies need to be strengthened to maintain STH control and ultimately interrupt transmission.

The Prevalence of Intestinal Parasite Infection in El Behara Schoolchildren

This study was conducted to evaluate the prevalence of intestinal parasite in schoolchildren in Damanhur, Egypt and some of its villages. The pathogenic enteric protozoa have been progressively involved in bargaining the soundness of a great many individuals, for the most part in creating nations. Mediations are being set up to control the dreariness and mortality because of these protozoan contaminations. A portion of these mediations target school going kids with regards to class based wellbeing intercession. The present examination concentrated on exploring the commonness of intestinal protozoan contaminations among younger students chose networks comprising of urban, urban-poor and per urban settlements in the Damanhour and a few towns. In the present work Giardia lamblia was the second usually identified protozoan with a diseases rate 10.4% among the analyzed cases. In the present examination generally speaking level of parasitic contaminations among the kids was 57.3%. It's viewed as Enterobius vermicularis was the most usually identified protozoan as it spoke to 4.1% of the parasitic diseases in the considered cases pursued by Ascaris lumbricoides; 1.4% and Giardia lamblia contaminations as they spoke to 0.6%; separately. The protozoa like Giardia and Cryptosporidium are regularly present in surface waters and cause episodes in this manner legitimately affecting human wellbeing.

Assessment of urogenital schistosomiasis knowledge among primary and junior high school students in the Eastern Region of Ghana: A cross-sectional study

Background

Knowledge of urogenital schistosomiasis can empower individuals to limit surface water contact and participate in mass drug administration campaigns, but nothing is currently known about the schistosomiasis knowledge that schoolchildren have in Ghana. We developed and implemented a survey tool aiming to assess the knowledge of urogenital schistosomiasis (treatment, transmission, prevention, symptoms) among science teaches and primary and junior high school students in the Eastern Region of Ghana.

Methods

We developed a 22-question knowledge survey tool and administered it to 875 primary and 938 junior high school students from 74 schools in 37 communities in the Eastern Region of Ghana. Teachers (n = 57) answered 20 questions matched to student questions. We compared knowledge scores (as percent of correct answers) across topics, gender, and class year and assessed associations with teacher’s knowledge scores using t-tests, chi-squared tests, univariate, and multivariate linear regression, respectively.

Results

Students performed best when asked about symptoms (mean±SD: 76±21% correct) and prevention (mean±SD: 69±25% correct) compared with transmission (mean±SD: 50±15% correct) and treatment (mean±SD: 44±23% correct) (p<0.0005). Teachers performed best on prevention (mean±SD: 93±12% correct, p<0.0005) and poorest on treatment (mean±SD: 69±16% correct, p<0.001). When listing five facts about urogenital schistosomiasis, teachers averaged 2.9±1.2 correct. Multiple regression models suggest that gender, class year, teacher score, and town of residency explain ~27% of variability in student scores. On average, junior high school students outperformed primary school students by 10.2 percentage points (CI_95%: 8.6–11.8); boys outperformed girls by 3.5 percentage points (CI_95%: 2.3–4.7).

Conclusions

Our survey parsed four components of student and teacher knowledge. We found strong knowledge in several realms, as well as knowledge gaps, especially on transmission and treatment. Addressing relevant gaps among students and science teachers in UGS-endemic areas may help high-risk groups recognize risky water contact activities, improve participation in mass drug administration, and spark interest in science by making it practical.

Larval species diversity, seasonal occurrence and larval habitat preference of mosquitoes transmitting Rift Valley fever and malaria in Baringo County, Kenya

Background

Baseline information that is essential for determining the areas to target with larval control includes estimates of vector diversity and larval habitat preferences. Due to a lack of such information in Baringo County, Kenya, this study assessed species diversity and larval habitat preference of potential mosquito vectors of Rift Valley fever (RVF) and malaria.

Methods

Mosquito larvae were sampled from nine types of larval habitats and were identified morphologically. Species diversity was estimated by the Shannon’s diversity index while larval habitat preference by RVF and malaria vectors was determined by ANOVA.

Results

A total of 7724 immature mosquitoes comprising 17 species belonging to four genera, namely Anopheles, Culex, Aedes and Mansonia, were identified. Among the 17 species, three Anopheles species are responsible for malaria transmission: An. gambiae (s.l.), An. funestus (s.l.) and An. pharoensis. Rift Valley fever vectors included Mansonia spp. and Culex spp. The highest Shannon's diversity index was observed during the cold dry season (H = 2.487) and in the highland zone (H = 2.539) while the lowest diversity was recorded during the long rain season (H = 2.354) and in the riverine zone (H = 2.085). Ditches had the highest mean number of Anopheles larvae (16.6 larvae per sample) followed by swamp (12.4) and seasonal riverbed (10.7). Water pit and water pan had low mean numbers of Anopheles larvae (1.4 and 1.8, respectively) but relatively high mean numbers of culicines (16.9 and 13.7, respectively). Concrete tank was the least sampled type of habitat but had highest mean number of culicine larvae (333.7 l) followed distantly by water spring (38.9) and swamp (23.5). Overall, larval habitats were significantly different in terms of larval density (F_(8,334) = 2.090, P = 0.036).

Conclusions

To our knowledge, the present study reports culicine larval species diversity in Baringo for the first time and the most preferred habitats were concrete tanks, water springs and swamps. Habitats preferred by Anopheles were mainly riverbed pools, ditches and swamps. Environmental management targeting the habitats most preferred by potential vectors can be part of integrated vector control in Baringo, especially during dry seasons.

Climate Change-Induced Impacts on Smallholder Farmers in Selected Districts of Sidama, Southern Ethiopia

Different factors control the types of adaptive strategies and likelihoods of experiencing climate change-induced impacts by smallholder farmers. By using a mixed research method, this study examines the types and determinants of climate change-induced impacts on smallholder rural farmers in drought-prone low lands of Sidama, Southern Ethiopia. Randomly selected (401) households were surveyed on climate change-induced impacts. Longitudinal climatic data were also collected from the Ethiopian National Meteorological Agency to assess the trend of rainfall (RF), temperature and drought incidents. The analyses of the data revealed that RF and temperature had shown decreasing and increasing trends, respectively, during the three decades under consideration (1983–2014). These changes in RF and temperature exposed farmers to climate-related epidemics, drought, harvest loss, and hunger. The logit model results revealed that different factors control the likelihood of exposure to climate change-induced impacts. The findings revealed that literacy level, involving women in family decisions and farmers’ involvement in adaptation planning, reduces the likelihood of exposure to climate change-induced hunger. Therefore, there is a need to work on human capital of the farmers through expanding education, strengthening women’s participation in family decision-making, and by improving public participation in climate change adaptation undertakings to minimize climate change-induced impacts.

Ivermectin: From theory to clinical application

Approximately 250 million people have been using ivermectin (IVM) annually to combat many parasitic diseases including filariasis, onchocerciasis, strongyloidiasis, scabies and pediculosis. Many clinical studies have proven its efficacy against these diseases and have reported the optimum dose and duration of treatment. Moreover, its antiparasitic range has increased to cover more parasitic infections, but it still requires further exploration, e.g. for trichinosis and myiasis. Furthermore, IVM showed high efficacy in killing vectors of disease-causing parasites such as mosquitoes, sandflies and tsetse flies. The World Health Organization (WHO) has managed many control programmes involving the use of IVM to achieve elimination of onchocerciasis and lymphatic filariasis and to reduce malaria transmission. However, IVM is not exempt from the possibility of resistance and, certainly, its intensive use has led to the emergence of resistance in some parasites. Recent research is investigating the possibility of novel drug delivery systems for IVM that increase its potential to treat a new range of diseases and to overcome the possibility of drug resistance. This review highlights the most common human uses of IVM, with special reference to the new and promising properties of IVM.

Prevalence, infection intensity and associated factors of soil transmitted helminths among primary school children in Gurage zone, South Central Ethiopia: a cross-sectional study design

Objective

The aim of this study was to determine the prevalence of soil transmitted helminthes among primary school children. School based cross-sectional study design was employed. A total of six hundred study subjects were selected by a multistage sampling method. Fresh stool specimens were collected using clean, dry and wide mouthed labeled stool cups. It was processed by Kato-Katz technique. The data were analyzed using SPSS version 20 and p-value < 0.05 was considered statistically significant.

Result

The overall prevalence of soil transmitted helminthes was 57 (9.5%). Hookworm was the most prevalent helminthes species isolated (4.2%) followed by A. lumbricoide (3%). The prevalence of Taenia species, T. trichiura, H. nana and E. vermicularis were; 1.2%, 0.5%, 0.7% and 0.8% respectively. The prevalence of the Soil transmitted helminthes infection was low and all cases of Soil transmitted infections in this study were with low infection intensity. This might be due to the preventive chemotherapy given to the school children.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4254-8) contains supplementary material, which is available to authorized users.

Urinary schistosomiasis in Nigeria: a 50 year review of prevalence, distribution and disease burden

We reviewed survey data deposited in the Global Neglected Tropical Diseases database and many other articles on the prevalence and distribution of Schistosoma haematobium in Nigeria. Schistosoma haematobium surveys conducted over the period of 50 years under review using different diagnostic tools revealed that Ogun State has the highest prevalence, followed by Ekiti state, while the lowest prevalence was recorded in Adamawa. No incidence of Schistosoma haematobium was recorded for states such as Akwa Ibom, Bayelsa, Nasarawa, Jigawa and Gombe. In terms of endemicity, this review has shown that Nigeria is divided into four zones: hyperendemic, moderately endemic, low endemic, and no endemic zones. A survey of 47 (15%) of the 323 dams in Nigeria revealed that 45 out of the 47 dams are located in the hyperendemic zone, while the remaining two are located in the moderately endemic zone. Twenty (43%) of the total surveyed dams harboured Bulinus globosus and/or Biomphalaria pfeifferi, the local intermediate hosts of schistosomes, and 18 of these are located in the hyperendemic zone, while the other two are in the moderately endemic zone. We conclude that there is an urgent need to carry out a nationwide survey to help in planning, coordinating, and evaluating schistosomiasis control activities.

Chromatographic and computational studies of ligands associated with bilharziasis

OBJECTIVE

Rapid diagnostic techniques that do not depend on microscopic analysis are urgently needed for rapid diagnosis and management of bilharziasis. Specific ligands that are excreted through urine in bilharziasis may serve as rapid diagnostic biomarkers to replace microscopy, which is cumbersome and time-consuming. The aim of this study was to identify ligands associated with bilharziasis.

METHODS

Microscopy was employed to detect ova of Schistosoma haematobium in urine specimens obtained from 1032 subjects. Pooled positive urine samples and pooled normal urine samples were separately prepared in triplicates and analyzed by gas chromatography-mass spectrophotometry (GC-MS). Ligands identified in each pool were noted. Computational analysis was performed between the schistosome receptors and ligands.

RESULTS

GC-MS revealed that the level of indole in bilharziasis sample was higher than that in normal urine. Indole was the ligand with the highest (28.63%) concentration in the pooled positive urine sample, while ethyl phenazone level was the highest (69.64%) in the pooled normal sample. Computational analysis depicted perfect docking with indole and all other ligands identified in positive urine samples.

CONCLUSION

This study identified some ligands associated with bilharziasis some unique to normal (negative) urine samples.

Prevalence, Intensity of Soil-Transmitted Helminths, and Factors Associated with Infection: Importance in Control Program with Ivermectin and Albendazole in Eastern Côte d'Ivoire

Evaluation of soil-transmitted helminths (STHs) and implementation of additional interventions are required in the region of a filariasis control program, given that antifilariasis drugs also have a beneficial effect on STHs. Thus, this study determines the extensive epidemiology of STHs to improve their successful control. Stool samples were analyzed using the Kato-Katz method. Chi-squared and Kruskal-Wallis tests were used to measure differences in infection rates and intensities, respectively, and logistic regression identified the risks of infection. The main intestinal helminths (A. lumbricoides, hookworm [N. americanus], S. mansoni, and T. trichiura) were found in the population. The overall prevalence of STHs was 19.5%. The prevalence of hookworm, the predominant species, ranged from 2% (n=6) to 28% (n=97). The overall prevalence of the other intestinal helminths was less than 6% (n=18). Intensity of hookworm was mostly light with a range from 1.6% (n=5) to 25.9% (n=90). However, the intensity of the species was significantly greater in Soribadougou compared to the other localities. Heavy infection was found in old children and adults but not in young children. Open defecation (OR=3.23, p≤0.05), dog/cat raising (OR=1.94, p≤0.05), farming (OR=14.10, p≤0.05), and irrigated culture (OR=3.23, p≤0.05) were positively associated with hookworm. It was observed that the participants missed the follow-up examinations due to trip (32.7%) or misunderstanding (15%) and lack of information (11.8%) of the purpose of the survey. Thus, to sustain the control of STHs, the MDA program should target the entire community and add education about the use of toilets, best practices of farming, and dog/cat raising.

Decrease in Mycobacterium ulcerans disease (Buruli ulcer) in the Lalo District of Bénin (West Africa)

BACKGROUND

Buruli ulcer (BU) is a chronic, necrotizing infectious skin disease caused by Mycobacterium ulcerans. In recent years, there has been a decrease in the number of new cases detected. This study aimed to show the evolution of its distribution in the Lalo District in Bénin from 2006 to 2017.

METHODS

The database of the BU Detection and Treatment Center of Lalo allowed us to identify 1017 new cases in the Lalo District from 2006 to 2017. The annual prevalence was calculated with subdistricts and villages. The trends of the demographic variables and those related to the clinical and treatment features were analysed using Microsoft Excel® 2007 and Epi Info® 7. Arc View version® 3.4 was used for mapping.

RESULTS

From 2006 to 2017, the case prevalence of BU in the Lalo District decreased by 95%. The spatial distribution of BU cases confirmed the foci of the distribution, as described in the literature. The most endemic subdistricts were Ahomadégbé, Adoukandji, Gnizounmè and Tchito, with a cumulative prevalence of 315, 225, 215 and 213 cases per 10,000 inhabitants, respectively. The least endemic subdistricts were Zalli, Banigbé, Lalo-Centre and Lokogba, with 16, 16, 10, and 5 cases per 10,000 inhabitants, respectively. A significant decrease in the number of patients with ulcerative lesions (p = 0.002), as well as those with category 3 lesions (p < 0.001) and those treated surgically (p < 0.001), was observed. The patients confirmed by PCR increased (from 40.42% in 2006 to 84.62% in 2017), and joint limitation decreased (from 13.41% in 2006 to 0.0% in 2017).

CONCLUSION

This study confirmed the general decrease in BU prevalence rates in Lalo District at the subdistrict and village levels, as also observed at the country level. This decrease is a result of the success of the BU control strategies implemented in Bénin, especially in the Lalo District.

A colonial legacy of HIV/AIDS, NTD, and STI super-syndemics: Eugenicist foreign aid and intertwined health burdens in Nigeria

Syndemics theory has been applied to the structurally shaped, biologically facilitated co-occurrence of HIV/AIDS with Neglected Tropical Diseases (NTDs) and with sexually transmitted infections (STIs). The biological and social pathways of interaction between all three ailments have not yet been analysed together. The effects of these diseases are often exacerbated by structural factors including access to care and socioeconomic status. We explore the interrelated biological pathways and structural factors that have further heightened the risk for HIV/AIDS, NTDs, and STIs. Furthermore, we argue women in rural areas are at an increased risk for all three diseases due to biological and social factors including increased distance to quality care and lower reproductive autonomy. This paper integrates the established syndemics of HIV/NTDs and HIV/STIs within the historical and modern contexts of colonisation and neo-colonisation in Nigeria. We explore the effects of colonisation on women's health by evaluating the influence of foreign aid policies, structural programmes, and shifting gender norms. Applying a syndemic approach, juxtaposed by historical contextualisation, offers important implications for the prevention and treatment of HIV/AIDS, STIs, and NTDs. Our analysis suggests a perspective through which to view health of regions with a history of colonisation.

Prevalence and burden of epilepsy in Nigeria: A systematic review and meta-analysis of community-based door-to-door surveys

BACKGROUND

Studies on prevalence of epilepsy in Nigeria yielded figures ranging between 3.1 and 37 per 1000, giving one of the widest variations in prevalence of epilepsy world over. In order to accurately estimate clinical and public health impacts of epilepsy in Nigeria, robust and reliable epidemiological data are required for an appropriate estimation of logistical, economical, and social impacts of epilepsy.

OBJECTIVE

The objectives of the study were to determine, using meta-analysis, the prevalence of epilepsy by pooling data from community-based door-to-door surveys conducted in various parts of Nigeria, explore the existing variation in prevalence of epilepsy in Nigeria along geopolitical regions and settlement setting of the country, and then evaluate the burden of epilepsy in Nigeria.

METHODS

Prevalence estimates were derived from a random effects meta-analysis of observational studies reporting the prevalence of epilepsy in Nigeria. The derived estimate for the prevalence of epilepsy was applied to the total populations in Nigeria to give an estimated burden of epilepsy in Nigeria.

RESULT

Nine community-based door-to-door surveys, with quality data from different regions in Nigeria, were included. I-squared (I²) heterogeneity was 88.5%. Random effects model (REM) estimate of overall prevalence of epilepsy from the studies was 8 per 1000 (95% confidence interval (95% CI): 6-10). The prevalence was highest (11 per 1000) in the south western part of the country. It was also higher among the rural (15 per 1000 people) than the urban (6 per 1000) dwellers. The burden of epilepsy in Nigeria, based on the prevalence estimate was 1,280,000 persons (95% CI: 960,000-1,600,000 persons).

CONCLUSION

In Nigeria, the estimated prevalence of epilepsy is 8 per 1000 people indicating a substantial burden of the disease in the country.

Human schistosomiasis in Benin: Countrywide evidence of Schistosoma haematobium predominance

BACKGROUND

A national mapping of human schistosomiasis was conducted in Benin to provide the baseline epidemiological data required to implement the national strategy for schistosomiasis control and elimination to achieve the WHO's goal of reaching at least 75% of school-age children in endemic areas by 2020.

METHODS

Parasitological surveys were conducted from 2013 to 2015, among 19,250 children aged 8-14 years randomly sampled in 385 units (schools/villages) across all districts. Urine and stool samples were examined using parasite-egg filtration for urine samples and the Kato-Katz technique for stool specimens.

RESULTS

Human schistosome eggs from two major species (S. haematobium and S. mansoni) were detected in the surveyed population with variable prevalence and parasite intensity. Urinary schistosomiasis due to S. haematobium was widely distributed and detected in 76/77 districts with a national average prevalence of 17.56% (95 °CI:16.80%- 18.32%), compared to S. mansoni detected in 28/77 districts with a national prevalence of 2.45% (95 °CI:2.14%-2.76%). The combined national prevalence of schistosomiasis, defined by infections with either or both schistosome species was 19.78% (95% CI:18.90% -20.49%), and was detected in 76/77 districts. Based on our findings, 31 districts were classified as low-risk (>0% and <10%); 37 as moderate-risk (≥10% and <50%); and 8 as high-risk (≥50%) of schistosome infection. No infection was detected in Kpomassè district in this study. In several districts where the two species were endemic with prevalence ≥10%, S. haematobium was the most prevalent schistosome species. Boys were relatively more infected than girls (18.29% v 16.82%, p = 0.007). Of note, heavy infections with S. haematobium (>50 eggs/10 mL) were detected in several districts of Atacora, Donga, Borgou, Collines, Ouémé and Atlantique departments.

CONCLUSIONS

The schistosomiasis mapping reported here clearly present a nationwide view of the epidemiological pattern of Schistosoma infections and the baseline data for implementing an effective control strategy by preventive chemotherapy (PCT). Although PCT might not be required in 32/77 districts, a yearly and bi-annual deworming is needed in 2 and 43 districts, respectively. If no environmental change occurs, and no mass treatment is delivered, prevalence is likely to remain stable for many years owing to poor hygiene and sanitation.

Prevalence of Schistosomiasis in a neglected community, South western Nigeria at two points in time, spaced three years apart

BACKGROUND

In recent years, the prevalence of schistosomiasis, a neglected tropical infection, has increased in underprivileged rural communities characterized by poverty.

OBJECTIVE

This cross-sectional community-based study was carried out to determine the prevalence of urinary schistosomiasis in a neglected community of Apojola community, South-Western Nigeria at two points in time, spaced three years apart.

METHOD AND RESULTS

A total of 145 participants were screened and 44.1% were diagnosed to have urinary Schistosoma haematobium infection after sedimentation and microscopy. The prevalence of schistosomiasis among females was higher (45.3%) than that among males (42.4%) but not significantly different (0.723). The prevalence of participants with light infection (26%) was significantly higher than those with heavy infection (11.0%). The predisposing factors with statistically significant association with Schistosoma haematobium infection were age (0.000), level of education (0.002), eating/selling of snails (0.037), occupation (0.000), drinking water (0.001), swimming (0.008), and washing in a river (0.019).

CONCLUSION

These findings indicate that the study area is still endemic to urinary schistosomiasis after three years of research and school-age children and teenagers are the populations at risk of urinary schistosomiasis. Community health education on the cause, mode of transmission, prevention, and prompt treatment of schistosomiasis is recommended.

Cross-Domain and Viral Interactions in the Microbiome

The importance of the microbiome to human health is increasingly recognized and has become a major focus of recent research. However, much of the work has focused on a few aspects, particularly the bacterial component of the microbiome, most frequently in the gastrointestinal tract. Yet humans and other animals can be colonized by a wide array of organisms spanning all domains of life, including bacteria and archaea, unicellular eukaryotes such as fungi, multicellular eukaryotes such as helminths, and viruses. As they share the same host niches, they can compete with, synergize with, and antagonize each other, with potential impacts on their host. Here, we discuss these major groups making up the human microbiome, with a focus on how they interact with each other and their multicellular host.

Molecular identification of hookworm isolates from stray dogs, humans and selected wildlife from South Africa

There is a paucity of information on hookworm species in humans, domestic animals and wildlife in southern Africa. Our study aimed to identify hookworm species from stray dogs, humans, and selected wildlife from South Africa. A total of 356 faecal samples were screened for the presence of hookworm-like eggs and subsequently coproculture from the positive samples was carried out to obtain larvae. Hookworm-like eggs were detected in 23.03% (82/356) of samples. Of these samples, 78/296 were from dogs, 3/50 from humans and 1/10 from wildlife. DNA was then isolated from the larvae of 55 positive samples, which were subjected to polymerase chain reaction (PCR), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing of the nuclear ribosomal internal transcribed spacer (ITS1) and 5.8S rRNA region. Presence of Ancylostoma caninum, A. braziliense and A. ceylanicum-like species was recorded in stray dogs and A. caninum was recorded in wildlife and humans, using PCR-RFLP. Although PCR-RFLP results pointed to the presence of A. ceylanicum, we did not get a sequence that matched with A. ceylanicum from GenBank. This may have been due to the low proportion of A. ceylanicum larvae in our samples. Twenty-two of the 27 positive amplicons from stray dogs matched with A. caninum, three with A. braziliense and two had mixed infections of A. braziliense and A. caninum. Sequences from a lion and three humans matched with A. caninum. This is the first confirmation of a patent A. caninum infection in humans as evidenced by the presence of eggs in faeces, with the subsequent larvae from coproculture being identified as A. caninum.

Prime-Boost Vaccine Regimen for SjTPI and SjC23 Schistosome Vaccines, Increases Efficacy in Water Buffalo in a Field Trial in China

Schistosomiasis remains a serious zoonotic disease in China and the Philippines. Water buffalo and cattle account for the majority of transmission. Vaccination of water buffalo is considered a key strategy to reduce disease prevalence. Previously, we showed that vaccination of water buffalo with SjC23 or SjCTPI plasmid DNA vaccines, induced 50% efficacy to challenge infection. Here, we evaluated several parameters to determine if we can develop a two dose vaccine that maintains the efficacy of the three dose vaccine. We performed four trials evaluating: (1) lab produced vs. GLP grade vaccines, (2) varying the time between prime and boost, (3) the influence of an IL-12 adjuvant, and (4) a two dose heterologous (DNA-protein) prime-boost. We found the source of the DNA vaccines did not matter, nor did increasing the interval between prime and boost. Elimination of the IL-12 plasmid lowered homologous DNA-DNA vaccine efficacy. A major finding was that the heterologous prime boost improved vaccine efficacy, with the prime-boost regimen incorporating both antigens providing a 55% reduction in adult worms and 53% reduction in liver eggs. Vaccinated buffalo produced vaccine-specific antibody responses. These trials suggest that highly effective vaccination against schistosomes can be achieved using a two dose regimen. No adjuvants were used with the protein boost, and the potential that addition of adjuvant to the protein boost to further increase efficacy should be evaluated. These results suggest that use of these two schistosome vaccines can be part of an integrated control strategy to reduce transmission of schistosomiasis in Asia.

Neglected tropical diseases in children: An assessment of gaps in research prioritization

BACKGROUND

Despite the known burden of neglected tropical diseases (NTDs) on child health, there is limited information on current efforts to increase pediatric therapeutic options. Our objective was to quantify and characterize research activity and treatment availability for NTDs in children in order to inform the prioritization of future research efforts.

METHODOLOGY/PRINCIPAL FINDINGS

We conducted a review of the World Health Organization's (WHO) International Clinical Trials Registry Platform to assess research activity for NTDs. The burden of disease of each NTD was measured in terms of disability adjusted life years (DALYs), which was extracted from the Global Health Data Exchange. First- and second-line medications for each NTD were identified from WHO guidelines. We reviewed FDA drug labels for each medication to determine whether they were adequately labeled for use in children. Descriptive statistics, binomial tests, and Spearman's rank order correlations were calculated to assess research activity compared to burden of disease. Children comprised 34% of the 20 million DALYs resulting from NTDs, but pediatric trials contributed just 17% (63/369) of trials studying these conditions (p<0.001 for binomial test). Conditions that were particularly under-represented in pediatric populations compared to adults included rabies, leishmaniasis, scabies, and dengue. Pediatric drug trial activity was poorly correlated with pediatric burden of disease across NTDs (Spearman's rho = 0.41, p = 0.12). There were 47 medications recommended by the WHO for the treatment of NTDs, of which only 47% (n = 22) were adequately labeled for use in children. Of the 25 medications lacking adequate pediatric labeling, three were under study in pediatric trials.

CONCLUSIONS/SIGNIFICANCE

There is a substantial gap between the burden of disease for NTDs in children and research devoted to this population. Most medications lack adequate pediatric prescribing information, highlighting the urgency to increase pediatric research activity for NTDs with high burden of disease and limited treatment options.

Community based cross sectional study of podoconiosis and associated factors in Dano district, Central Ethiopia

Background

Podoconiosis, affects lower limb, is an entirely preventable non-communicable tropical disease common in low income countries. Globally it is estimated that there are 4 million peoples with podoconiosis and nationally it is estimated that there are 1.56 million cases of podoconiosis. Even though nationwide mapping has been conducted including the current district under investigation, there are no studies conducted to identify factors associated with podoconiosis in the district. Hence, this study was aimed to determine the prevalence of podoconiosis and associated factors in the west Shewa of Dano district community.

Method

A community based cross sectional study was conducted from March 1 to 26, 2018. Seven kebeles out of the total of twenty-three kebeles found in the district were selected randomly. The total sample size was allocated by probability proportional to size to each kebele based on the number of households they had. Then, systematic random sampling was employed to select 652 study participants from the seven kebeles. Data was collected using interviewer administered structured questionnaire and observation. In addition, a blood sample was collected from the study subjects who had leg swelling for ruling out lymphedema due to lymphatic filarasis by using Immunochromatographic test card. Podoconiosis case was defined as bilateral but asymmetric swelling which develop first in the foot often confined to the lower leg and negative result for immune-chromatographic test (ICT card). The prevalence of podoconiosis was determined and multiple logistic regression model was fitted using SPSS version 23 to identify factors associated with podoconiosis.

Result

The prevalence of podoconiosis in Dano district was found to be 6.3% (95%CI: 5.8, 6.8). Age at first shoe wearing (AOR = 1.08,95% CI = 1.06–1.11), washing practice of feet by water only (AOR = 3.68, 95% CI = 1.47–9.24) and not wearing shoe daily (AOR = 9.32, 95% CI = 4.27–20.4) were found to be significantly associated with increased odds of podoconiosis.

Conclusion

This study revealed that there was significant burden of podoconiosis in the study area. Age at first shoe wearing, washing practice and frequency of shoe wearing were associated with the development of podoconiosis disease. Modalities to enhance the shoe wearing behaviour of the communities should be planned by high level decision makers working in the area of Health. Moreover, collaboration between local government and non-government stakeholders, and integration with existing programs addressing foot hygiene which involves washing feet with soap and water needs to be addressed.

Podoconiosis (endemic non-filarial elephantiasis) is one of a disabling and stigmatizing neglected tropical disease (NTD) which affects the lower limb found mostly in low income countries. Even though there were mostly prevalence studies and disease mapping, there was no report, especially on factors associated with the disease, from the study area. Hence, community based cross sectional study was conducted to determine its prevalence and factors associated with it in the west Shewa Zone of Dano district community. Data were collected from a total of 652 randomly selected peoples using interviewer administered structured questionnaire and observation. In addition, a blood sample was collected from the study subjects who had leg swelling for ruling out lymphedema due to lymphatic filarasis by using Immunochromatographic test card. Podoconiosis case was defined as bilateral but asymmetric swelling which develop first in the foot often confined to the lower leg and negative result for immune-chromatographic test (ICT card). Accordingly, the prevalence of podoconiosis in the district was found to be 6.3%. Age at first shoe wearing, washing practice of feet by water only and not wearing shoe daily were found to be the risk factors for the development of podoconiosis. Hence, this study revealed that there was significant burden of the disease in the study area. Thus, collaboration between local government and non-government stakeholders, and integration with existing programs addressing foot hygiene which involves washing feet with soap and water needs to be addressed.

Neglected zoonotic diseases in Nigeria: role of the public health veterinarian

Zoonotic diseases accounts for about 75% of emerging infectious disease and can be devastating to both human and animal health globally. A subset of zoonotic diseases is referred to as "neglected zoonotic diseases - NZDs" as they mainly affect poor populations who live in close proximity to domestic or wild animals often in areas where access to health and adequate sanitary facilities are not available. Furthermore, underestimation of the burden of NZD has continually led to its further neglect in least developed countries such as Nigeria. Controlling zoonotic infections including NZDs in animals is crucial in reducing human infections. Veterinarians provides an understanding of the epidemiology of infectious diseases in animal population and are therefore integral for the overall reduction in global burden of NZDs worldwide. Due to the current lack of and in some cases weak involvement of Veterinarians in policy issues related to zoonotic diseases, there is need to elucidate their importance in NZDs control in Nigeria. This review therefore summarises the neglected zoonotic diseases so far documented in Nigeria and also highlight the important role of the Veterinarian in their prevention and control within both human and animal population. Important recommendations to strengthen the role of the public health Veterinarian for sustainable control of NZDs were made.

Analysis of Schistosomiasis and soil-transmitted helminths mixed infections among pupils in Enugu State, Nigeria: Implications for control

BACKGROUND

Schistosomiasis and Soil-transmitted helminthiasis cause considerable morbidity and mortality in developing countries, especially among children. To this end it, a cross-sectional survey to determine the pattern of Schistosomiasis and Soil-transmitted helminthiasis co-infection was undertaken among primary school pupils in Oduma Community in Enugu State, Nigeria.

METHODS

Fresh urine and stool samples were collected from pupils. The urine and stool samples were examined using sedimentation and Kat-Katz techniques respectively.

RESULTS

Of the 236 pupils examined, 137 (58.1%) were found positive for at least one helminth infection. Ascaris lumbricoides was the most prevalent soil-transmitted helminth (STH), with a prevalence rate of 40.3%, followed by Trichuris trichiura (15.3%) and hookworm (8.9%). Infection with Schistosoma haematobium was detected in 13.6% of the pupils while Schistosoma mansoni infection prevalence was 7.2%. Age group 4 -7 years recorded the highest prevalence for S. haematobium, A. lumbricoides, T. Trichiura and hookworm infections. Multiple infections were also recorded, with 22.9% having double infections and 2.5% having triple infections. The most common double infection was A. lumbricoides with T. trichiura (8.9%), while the most common triple infection was A. lumbricoides, S. haematobium and hookworm (1.7%).

CONCLUSION

The results from the present study revealed an evident need for the systematic and sustained administration of school-based chemotherapy program targeting the control of STH infection and Schistosomiasis using Albendazole and Praziquantel respectively in the community, instead of a one-off approach that was carried out.

Earth Observation: Investigating Noncommunicable Diseases from Space

The United Nations has called on all nations to take immediate actions to fight noncommunicable diseases (NCDs), which have become an increasingly significant burden to public health systems around the world. NCDs tend to be more common in developed countries but are also becoming of growing concern in low- and middle-income countries. Earth observation (EO) technologies have been used in many infectious disease studies but have been less commonly employed in NCD studies. This review discusses the roles that EO data and technologies can play in NCD research, including ( a) integrating natural and built environment factors into NCD research, ( b) explaining individual-environment interactions, ( c) scaling up local studies and interventions, ( d) providing repeated measurements for longitudinal studies including cohorts, and ( e) advancing methodologies in NCD research. Such extensions hold great potential for overcoming the challenges of inaccurate and infrequent measurements of environmental exposure at the level of both the individual and the population, which is of great importance to NCD research, practice, and policy.

Urinary circulating DNA and circulating antigen for diagnosis of schistosomiasis mansoni: a field study

OBJECTIVE

To evaluate three non-invasive assays for the diagnosis of schistosomiasis mansoni in an Egyptian village.

METHODS

Urine was collected for the detection of circulating cathodic antigen (CCA) and cell-free parasite DNA (cfpd) by Point-of-contact (POC)-cassette assay and PCR, respectively. These tests were compared to Kato-Katz (KK) faecal thick smear for detection of Schistosoma mansoni eggs.

RESULTS

Disease prevalence by POC-CCA assay was 86%; by PCR it was 39% vs. 27% by KK. Compared to KK, the sensitivity of POC-CCA reached 100%, but its specificity was only 19.2% with 41% accuracy. Sensitivity of the PCR assay for cfpd was 55.56%, and specificity was 67.12% with 64% accuracy. A new end point was calculated for combined analysis of KK, POC-CCA assay and PCR. Sensitivity for the three tests was 52.94%, 90.2% and 76.47%; specificity was 100% for KK and PCR and 18.37% for POC-CCA. The accuracy calculated for the three tests at the end point was 76% for KK, 55% for POC-CCA assay and 88% for PCR.

CONCLUSION

Conventional PCR assay for detection of cfpd provides a potential screening tool for intestinal schistosomiasis with reliable specificity, reasonable accuracy and affordable financial and technical cost.

Acute paraplegia due to schistosomiasis: an uncommon cause in developed countries

We present a case of a young African migrant from Guinea-Conakry presented to a French emergency department with burning pain in both feet for 2 days. The symptoms progressed to limb paraparesis with sphincter disorders. A magnetic resonance imaging (MRI) scan showed a hyperintense spinal cord lesion without contrast enhancement extending from the T6 vertebrae to the conus medullaris. Cerebrospinal fluid exam (CFE) showed an isolated hyperproteinorachia (0.61 g/l). Schistosomiasiss serology was positive and a rectal biopsy showed a schistosoma egg surrounded by an inflammatory reaction with granulomatosis. After steroid and antihelminthic therapy, accompanied by intensive physical therapy, the patient had an improved neurological neurological outcome.

Assessment of seasonality in soil-transmitted helminth infections across 14 schools in Jimma Town, Ethiopia

Introduction

Up to date, the frequency of preventive chemotherapy based on the prevalence is the only strategy in the control programmes of soil-transmitted helminths (STHs). However, prevalence of STHs may be affected by climatic and/or seasonal changes, particularly when these are important determinants of transmission of STH infections. Our objective was to describe the prevalence and infection intensity and seasonal variation (mainly dry vs rainy season) of any STHs among school age children.

Methods

Assessment of infection intensity and prevalence of STHs was carried out during dry season (February-March, 2012) and end of rainy season (September-October, 2012) across 14 primary schools in Jimma Town, Jimma, Ethiopia. A total of 1,680 school children (840 in each season) were included. All stool samples were processed by the McMaster egg counting method. Odds of infection and intensity was performed to assess any differences in prevalence and infection intensity between the schools and the two seasons. The pooled odd ratio and their 95% confidence interval was also computed and presented using the "metafor" package of the statistical software R. The level of significance was declared at p < 0.05.

Results

Infections with any STH were observed in 824/1,680 (49.0%) subjects. T. trichiura was the most prevalent (35.5%), followed by A. lumbricoides (23.4%) and hookworms (9.9%). Among the schools there were a huge variation in prevalence, ranging from 16.7% to 68.3% for any STH, 6.7% to 39.2% for A. lumbricoides, 10.8% to 55.0% for T. trichiura and 0 % to 28.3% for hookworms. A significant difference in prevalence (for T. trichiura) and in infection intensity (for A. lumbricoides and T. trichiura) across seasons was observed. Generally, STH infections were more prevalent in the dry season (52.4%) compared to the rainy season (45.7%) and as well intensity of all three STH infections was higher in the dry season.

Conclusion

Our data suggested that there were huge variation in STH prevalence among schools and a significant difference in infection intensity and prevalence across seasons. This in turn might limits how national governments and international organizations define and target resources to combat the disease burden due to STH infection. Long term studies are needed to confirm the influence of seasonal factors and related ecological, environmental and socio-economic factors.

Schistosomiasis

Schistosomiasis is a major cause of morbidity in the world; it is second only to malaria as a major infectious disease. Globally, it is estimated that the disease affects over 250 million people in 78 countries of the world and is responsible for some 280,000 deaths each year. The three major schistosomes infecting humans are Schistosoma mansoni, S. japonicum, and S. haematobium. This chapter covers a wide range of aspects of schistosomiasis, including basic biology of the parasites, epidemiology, immunopathology, treatment, control, vaccines, and genomics/proteomics. In this chapter, the reader will understand the significant toll this disease takes in terms of mortality and morbidity. A description of the various life stages of schistosomes is presented, which will be informative for both those unfamiliar with the disease and experienced scientists. Clinical and public health aspects are addressed that cover acute and chronic disease, diagnosis, current treatment regimens and alternative drugs, and schistosomiasis control programs. A brief overview of genomics and proteomics is included that details recent advances in the field that will help scientists investigate the molecular biology of schistosomes. The reader will take away an appreciation for general aspects of schistosomiasis and research advances.

Identification of novel multi-stage histone deacetylase (HDAC) inhibitors that impair Schistosoma mansoni viability and egg production

Background

Novel anti-schistosomal multi-stage drugs are needed because only a single drug, praziquantel, is available for the treatment of schistosomiasis and is poorly effective on larval and juvenile stages of the parasite. Schistosomes have a complex life-cycle and multiple developmental stages in the intermediate and definitive hosts. Acetylation and deacetylation of histones play pivotal roles in chromatin structure and in the regulation of transcription in eukaryotic cells. Histone deacetylase (HDAC) inhibitors modulate acetylation of several other proteins localized both in the nucleus and in the cytoplasm and therefore impact on many signaling networks and biological processes. Histone post-translational modifications may provide parasites with the ability to readily adapt to changes in gene expression required for their development and adaptation to the host environment. The aim of the present study was to screen a HDAC class I inhibitor library in order to identify and characterize novel multi-stage hit compounds.

Methods

We used a high-throughput assay based on the quantitation of ATP in the Schistosoma mansoni larval stage (schistosomula) and screened a library of 1500 class I HDAC inhibitors. Subsequently, a few hits were selected and further characterized by viability assays and phenotypic analyses on adult parasites by carmine red and confocal microscopy.

Results

Three compounds (SmI-124, SmI-148 and SmI-558) that had an effect on the viability of both the schistosomula larval stage and the adult worm were identified. Treatment with sub-lethal doses of SmI-148 and SmI-558 also decreased egg production. Moreover, treatment of adult parasites with SmI-148, and to a lesser extent Sm-124, was associated with histone hyperacetylation. Finally, SmI-148 and SmI-558 treatments of worm pairs caused a phenotype characterized by defects in the parasite reproductive system, with peculiar features in the ovary. In addition, SmI-558 induced oocyte- and vitelline cell-engulfment and signs of degeneration in the uterus and/or oviduct.

Conclusions

We report the screening of a small HDAC inhibitor library and the identification of three novel compounds which impair viability of the S. mansoni larval stage and adult pairs. These compounds are useful tools for studying deacetylase activity during parasite development and for interfering with egg production. Characterization of their specificity for selected S. mansoni versus human HDAC could provide insights that can be used in optimization and compound design.

Snakebite burden in Sub-Saharan Africa: estimates from 41 countries

There is no reliable estimate of burden of snakebite-envenoming (SBE) in Sub-Saharan Africa (SSA). We derived from a meta-analysis the burden of SBE related deaths, amputations and Post-Traumatic Stress Disorder (PTSD) in 41 countries in SSA. The annual burden was estimated at 1.03 million DALYs (95% Confidence Interval: 0.80-1.28 million DALYs). This is similar to or higher than the burden of many Neglected Tropical Diseases (NTDs) and the finding advocates for a commensurate resources allocation towards control of SBE.

High Efficacy of Praziquantel in Schistosoma haematobium-Infected Children in Taraba State, Northeast Nigeria: A follow-up study

Objectives

This study aimed to assess the efficacy of praziquantel in reducing urinary schistosomiasis prevalence, parasite burden and morbidity rates among a previously reported sample of Schistosoma haematobium-infected children. In addition, predisposing factors for reinfection one year post-treatment were also determined.

Methods

This prospective follow-up study was conducted between March 2014 and February 2015 among 675 previously reported children with urinary schistosomiasis in the Murbai and Surbai communities of Ardo Kola, Taraba State, Nigeria. A single dose of 40 mg/kg of praziquantel was administered to each infected child, with a second dose administered one month later if necessary. The number of S. haematobium eggs in urine samples was calculated at baseline and post-treatment.

Results

At four weeks post-treatment, the overall cure rate was 98.1%. Among children with low and heavy parasite burdens at baseline, egg reduction rates (ERRs) were 100% and 96.5%, respectively. The vast majority of children with microhaematuria (98.7%) and proteinuria (98.6%) at baseline were cured at follow-up. Following a second dose, the ERR, overall and morbidity cure rates increased to 100%. At one year post-treatment, 272 infected children (40.3%) were re-assessed; of these, 51 children (18.8%) were reinfected. Close proximity to bodies of water (odds ratio [OR] = 1.23, 95% confidence interval [CI]: 0.998-1.530; P = 0.05) and fishing (OR = 2.23, 95% CI: 0.828-6.040; P = 0.01) were significant factors that predisposed children to reinfection.

Conclusion

A moderate rate of reinfection was noted. Governmental and nongovernmental organisations in Nigeria should collaborate on mass treatment and health education campaigns to reduce the incidence of urinary schistosomiasis reinfections.

Repeated doses of Praziquantel in Schistosomiasis Treatment (RePST) - single versus multiple praziquantel treatments in school-aged children in Côte d'Ivoire: a study protocol for an open-label, randomised controlled trial

Background

Large scale administration of the anthelminthic drug praziquantel (PZQ) to at-risk populations is the cornerstone of schistosomiasis control, although persisting high prevalence of infections in some areas and growing concerns of PZQ resistance have revealed the limitations of this strategy. Most studies assessing PZQ efficacy have used relatively insensitive parasitological diagnostics, such as the Kato-Katz (KK) and urine-filtration methods, thereby overestimating cure rates (CRs). This study aims to determine the efficacy of repeated PZQ treatments against Schistosoma mansoni infection in school-aged children in Côte d’Ivoire using the traditional KK technique, as well as more sensitive antigen- and DNA-detection methods.

Methods

An open-label, randomised controlled trial will be conducted in school-aged children (5 to 18 years) from the region of Taabo, Côte d’Ivoire, an area endemic for S. mansoni. This 8-week trial includes four two-weekly standard doses of PZQ in the “intense treatment” intervention group and one standard dose of PZQ in the “standard treatment” control group. The efficacy of PZQ will be evaluated in stool samples using the KK technique and real-time PCR as well as in urine using the point-of-care circulating cathodic antigen test and the up-converting phosphor, lateral flow, circulating anodic antigen assay. The primary outcome of the study will be the difference in CR of intense versus standard treatment with PZQ on individuals with a confirmed S. mansoni infection measured by KK. Secondary outcomes include the difference in CR and intensity reduction rate between the intense and standard treatment groups as measured by the other diagnostic tests, as well as the accuracy of the different diagnostic tests, and the safety of PZQ.

Discussion

This study will provide data on the efficacy of repeated PZQ treatment on the clearance of S. mansoni as measured by several diagnostic techniques. These findings will inform future mass drug administration policy and shed light on position of novel diagnostic tools to evaluate schistosomiasis control strategies.

Trial registration

The study is registered at EudraCT (2016–003017-10, date of registration: 22 July 2016) and (NCT02868385, date of registration: 16 August 2016).

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3554-2) contains supplementary material, which is available to authorized users.