Prevalence distribution and risk factors for Schistosoma hematobium infection among school children in Blantyre, Malawi

Endemic status of urogenital schistosomiasis and the efficacy of a single-dose praziquantel treatment in unmapped rural farming communities in Oyo East Local Government Area, Oyo State, Nigeria

BACKGROUND

Schistosomiasis is endemic in Nigeria, and the treatment is largely concentrated on children enrolled in schools. Consequently, the coverage of non-enrolled school-aged children is often neglected. Ajagba and Awosan are two communities in Nigeria that have never had any control intervention. Hence, this survey was designed to determine the endemicity of urogenital schistosomiasis and to evaluate the efficacy of a single-dose praziquantel in the communities.

METHODS

Urine sample (10 mL) of each participant from Ajagba and Awosan communities was filtered through 12μm polycarbonate filter. The filter was placed on a microscope slide, and stained with a drop of 1% Lugol iodine solution. The stained slides were examined under the microscope and the numbers of S. haematobium eggs were counted. Water contact sites were searched for snail hosts and the snails collected were shed for Schistosoma cercariae. Data were analyzed using SPSS version 24.0 and the significance level was set at 95%.

RESULTS

The overall prevalence of infection in the Ajagba community was 45.6% with a mean intensity of 61.1 ± 144.5 eggs/10 mL of urine, while the prevalence of infection in the Awosan community was 5.7% with a mean intensity of 1.4 ± 6.8 eggs/10 mL of urine. The school-aged children had a prevalence and mean intensity of infection of 73.1% and 111.6 ± 177.9 eggs/10 mL of urine, respectively. Following treatment, women had a higher egg reduction rate than men (p = 0.0283). Bulinus globosus were found in Ajagba but not in Awosan, with 5.7% shedding Schistosoma spp, cercariae.

CONCLUSION

Urogenital schistosomiasis was hyperendemic in the Ajagba community, and hypoendemic in the Awosan community. The presence of Bulinus globosus supported the transmission of the schistosomiasis in the Ajagba community. Communities where schistosomiasis is still actively transmitted in Nigeria should be identified for effective intervention through the MDA programs.

Exploring the Role of Community Involvement in Reducing the Burden of Schistosomiasis and Other Neglected Tropical Diseases in Malawi: Where are We in the Fight Against Neglected Tropical Diseases?

Schistosomiasis has been endemic in Malawi since 1947. Despite the longevity of endemicity of the disease, it still maintains a high burden in Malawi. This could be attributed to insufficient coverage of preventive and therapeutic mass drug administration (MDA) which mainly targets school-aged children, leaving out adults who also bear a high burden of the disease. Additionally, despite well documented impact of community involvement in boosting up the effectiveness of health programmes, there is minimal community involvement in schistosomiasis control and prevention programmes. Therefore, this perspective seeks to discuss the historical background of schistosomiasis in Malawi, gaps in community engagement and participation and suggest ways of enhancing the role of the community in prevention and control programmes. Amongst other challenges, the control programmes are centralised, leading to minimal input at the district and community level as well as low awareness of schistosomiasis control and prevention methods at the community level. It is of utmost significance therefore to provide comprehensive schistosomiasis health education to the communities and devise a thorough outline of the specific roles and responsibilities of all stakeholders including community members in the fight against schistosomiasis and other neglected tropical diseases.

Have there been efforts to integrate malaria and schistosomiasis prevention and control programs? A scoping review of the literature

Malaria and schistosomiasis are two important parasitic diseases that are a particular threat to young children and pregnant women in sub-Saharan Africa. Malaria and schistosomiasis prevention and control strategies primarily focus on the distribution of long-lasting insecticidal nets and the delivery of praziquantel tablets to at-risk populations in high burden settings through mass drug administration, respectively. The objective of this scoping review was to identify previous efforts to integrate malaria and schistosomiasis prevention and control programs in the literature and to summarize the strategies and approaches used in these programs following the PRISMA-ScR guidelines. We reviewed published and grey literature using a combination of keywords and search terms following themes surrounding "malaria", "Plasmodium falciparum", "Anopheles", "schistosomiasis", "Schistosoma haematobium", "Schistosoma mansoni", and "snails". Neither a date limit nor relevant terms for prevention and control were used. Out of 6374, eight articles were included in the scoping review-three articles investigated the integration of mass drug administration for schistosomiasis with the administration of antimalarials, four articles investigated the effect of administering antimalarials on malaria, schistosomiasis, and their co-infection, and one article assessed the impact of an educational intervention on malaria and schistosomiasis knowledge and preventative behaviors. Our findings suggest that there is an opportunity to link disease control programs to increase access and coverage of interventions to improve outcomes for malaria, schistosomiasis, and their co-infection. Further research is needed on the potential benefits, feasibility, and cost-effectiveness of integrating malaria and schistosomiasis prevention and control programs.

Prevalence of Schistosomiasis and Soil-Transmitted Helminthiasis and Their Risk Factors: A Cross-Sectional Study in Itilima District, North-Western Tanzania

Schistosomiasis and soil-transmitted helminthiasis remain a public health concern in Tanzania. This study investigated the prevalence and intensities of Schistosoma haematobium, S. mansoni, and soil-transmitted helminths and associated factors in Itilima district, north-western Tanzania. A cross-sectional survey was conducted between August and September 2020 among 3779 primary schoolchildren in 62 primary schools and 1122 adults in 19 villages. Urine samples were obtained from each participant and examined visually for the presence of macrohaematuria, microhaematuria, and S. haematobium eggs using a urine dipstick and urine filtration test. A single stool sample was obtained from each participant and screened for S. mansoni and soil-transmitted helminths using the Kato Katz and formalin-ether concentration techniques. A questionnaire was administered to schoolchildren to elucidate the risk factors for schistosomiasis. The overall prevalence of S. haematobium in adults was 8.1% (95% confidence interval (CI), 6.6-9.8%). In total, 3779 schoolchildren had complete results from urine testing, and the overall prevalence of S. haematobium was 10.1% (95% CI, 9.1-11.1%). The prevalence of S. mansoni and soil-transmitted helminths was relatively low among both children and adults compared to S. haematobium. Factors associated with S. haematobium infection among schoolchildren were the mother's occupation, children aged 11-15 years, and water contact behaviour. The odds of having schistosomiasis infection among children aged 11-15 are 40% higher than those aged 5-10 (95% confidence interval (CI), 10-80%, p = 0.04). Children of parents who are livestock keepers have 12.3 times higher odds of having infection compared to those who have small-scale businesses (95% CI, 1.0-5.4, p = 0.03). Children who are in contact with infested water more than three times a week have 2.1 times higher odds of having an infection compared to those who do not (95% CI, 2.1; 1.6-2.8, p < 0.001). The findings provide updated geographical information on prevalence, yielding insights into the planning and implementation of mass drug administration in rural Tanzania.

SEROPREVALENCE TO SCHISTOSOMA SOLUBLE EGG ANTIGEN AMONG NOMADIC PASTORALISTS RESIDING IN NORTHERN SENEGAL

Urinary and intestinal schistosomiasis are endemic in Senegal, with prevalence heterogeneous throughout the country. Because of their way of life, nomadic pastoralists are not typically included in epidemiological surveys, and data on the prevalence of schistosomiasis in Senegalese nomadic populations are largely non-existent. The purpose of this study was to determine the seroprevalence of schistosomiasis in Senegalese nomadic pastoralists. A modified snowball sampling survey was conducted among 1,467 nomadic pastoralists aged 6 mo and older in 5 districts in northern Senegal. Dried blood spots from participants of all ages and data regarding demographics were collected to assess IgG antibody responses against Schistosoma mansoni soluble egg antigen (SEA) using a bead-based multiplex assay. Out of 1,467 study subjects, 1,464 (99.8%) provided IgG serological data that cleared quality assurance. Of the participants with appropriate data, 56.6% were male, the median age was 22 yr, and 31.6% were under 15 yr of age. The overall anti-SEA IgG seroprevalence was 19.1% (95% confidence interval [CI]: 17.1-21.1%) with the highest estimates observed in Dagana (35.9%) and the lowest observed in Podor nomadic groups (3.4%). Antibody responses increased significantly with age except for the oldest age groups (>40 yr of age), which saw lower levels of antibody response compared to younger adults. When controlling for age and location by multivariate regression, the male sex was associated with a 2-fold greater odds of anti-SEA IgG seropositivity (aPOR: 2.0; 95% CI: 1.5-2.7). Serosurveys for anti-SEA IgG among nomadic peoples in northern Senegal found a substantial percentage of individuals with evidence for current or previous Schistosoma spp. infection with the highest levels of exposure in the district adjacent to the Diama dam along the Senegal River. With IgG prevalence increased by age except in the older adults, and the male sex significantly associated with seropositivity, these data point toward sex-associated behavioral practices and human environmental modification as risk factors for Schistosoma exposure.

Urogenital schistosomiasis in three different water access in the Senegal river basin: prevalence and monitoring praziquantel efficacy and re-infection levels

BACKGROUND

Urogenital schistosomiasis is a neglected tropical disease most prevalent in sub-Saharan Africa. In the Senegal river basin, the construction of the Diama dam led to an increase and endemicity of schistosomiasis. Since 2009, praziquantel has frequently been used as preventive chemotherapy in the form of mass administration to Senegalese school-aged children without monitoring of the treatment efficacy and the prevalence after re-infection. This study aims to determine the current prevalence of urogenital schistosomiasis (caused by Schistosoma haematobium), the efficacy of praziquantel, and the re-infection rates in children from five villages with different water access.

METHODS

The baseline prevalence of S. haematobium was determined in August 2020 in 777 children between 5 and 11 years old and a single dose of praziquantel (40 mg/kg) was administered to those positive. The efficacy of praziquantel and the re-infection rates were monitored 4 weeks and 7 months after treatment, respectively, in 226 children with a high intensity of infection at baseline.

RESULTS

At the baseline, prevalence was low among children from the village of Mbane who live close to the Lac de Guiers (38%), moderate among those from the villages of Dioundou and Khodit, which neighbor the Doue river (46%), and very high at Khodit (90.6%) and Guia (91.2%) which mainly use an irrigation canal. After treatment, the observed cure rates confirmed the efficacy of praziquantel. The lowest cure rate (88.5%) was obtained in the village using the irrigation canal, while high cure rates were obtained in those using the lake (96.5%) and the river (98%). However, high egg reduction rates (between 96.7 and 99.7%) were obtained in all the villages. The re-infection was significantly higher in the village using the canal (42.5%) than in the villages accessing the Lac de Guiers (18.3%) and the Doue river (14.8%).

CONCLUSION

Praziquantel has an impact on reducing the prevalence and intensity of urogenital schistosomiasis. However, in the Senegal river basin, S. haematobium remains a real health problem for children living in the villages near the irrigation canals, despite regular treatment, while prevalence is declining from those frequenting the river and the Lac de Guiers. Trial registration ClinicalTrials.gov, NCT04635553. Registered 19 November 2020 retrospectively registered, https://www.

CLINICALTRIALS

gov/ct2/show/NCT04635553?cntry=SN&draw=2&rank=4.

Urinary Schistosomiasis and Associated Risk Factors Among Primary School Students in the Zaki Local Government Area, Bauchi State, Nigeria

Urinary schistosomiasis, a water-based disease, is endemic to Nigeria. The infection is transmitted by trematodes known as Schistosoma haematobium. The goal of this study was to determine the occurrence of urinary schistosomiasis among primary school children in the Zaki Local Government Area, Bauchi State, Nigeria. A cross-sectional study involving 300 school pupils from three primary schools in Zaki was conducted between June and November of 2021. The urine samples were examined with the sedimentation technique to detect S. haematobium eggs. Data on socio-demographic characteristics and risk factors were obtained through a well-structured questionnaire. In SPSS version 24, the associations between the dependent and independent variables were evaluated with Chi-square, bivariate, and multiple logistic regression analyses. The strength of associations was determined with the odds ratio (OR) and 95% confidence interval. Urinary schistosomiasis was found in 29.7% of school-aged children in the three primary schools. Significantly higher prevalence was observed in the Almajiri (informal) school (59.6%) and one public primary school (31.5%), P = 0.001. Boys were four times more likely than girls to have schistosomiasis [AOR (95% CI): 4.38 (2.23–8.60)]. Children who played in shallow water had a higher risk of contracting schistosomiasis infection and were five times more likely to be infected [AOR (95% CI): 5.14 (1.97–13.37)]. Children who had blood in their urine (hematuria) were nearly nine times more likely to be infected [AOR (95% CI): 9.64 (4.79–20.66)]. The present study indicated that urinary schistosomiasis is endemic to the study area in the Zaki Local Government Area, with a moderate infection rate.

Prevalence and Molecular Identification of Schistosoma haematobium among Children in Lusaka and Siavonga Districts, Zambia

Schistosomiasis remains a public health concern in Zambia. Urinary schistosomiasis caused by Schistosoma haematobium is the most widely distributed infection. The aim of the current study was to determine the prevalence and risk factors of urinary schistosomiasis and identify the strain of S. haematobium among children in the Siavonga and Lusaka districts in Zambia. Urine samples were collected from 421 primary school children and S. haematobium eggs were examined under light microscopy. A semi-structured questionnaire was used to obtain information on the socio-demographic characteristics and the potential risk factors for urinary schistosomiasis. DNA of the parasite eggs was extracted from urine samples and the internal transcribed spacer gene was amplified, sequenced and phylogenetically analysed. The overall prevalence of S. haematobium was 9.7% (41/421) (95% CI: 7.16–13.08), male participants made up 6.2% (26/232) (95% CI: 4.15–9.03), having a higher burden of disease than female participants who made up 3.5% (15/421) (95% CI: 2.01–5.94). The age group of 11–15 years had the highest overall prevalence of 8.3% (35/421) (5.94–11.48). Participants that did not go fishing were 0.008 times less likely to be positive for schistosomiasis while participants whose urine was blood-tinged or cloudy on physical examination and those that lived close to water bodies were 9.98 and 11.66 times more likely to test positive for schistosomiasis, respectively. A phylogenetic tree analysis indicated that S. haematobium isolates were closely related to pure S. haematobium from Zimbabwe and hybrids of S. haematobium × S. bovis from Benin, Senegal and Malawi. The current study shows that urinary schistosomiasis is endemic in the study areas and is associated with water contact, and S. haematobium isolated is closely related to hybrids of S. bovis × S. haematobium strain, indicating the zoonotic potential of this parasite.

Burden and factors associated with schistosomiasis and soil-transmitted helminth infections among school-age children in Huambo, Uige and Zaire provinces, Angola

BACKGROUND

Schistosomiasis and soil-transmitted helminths (STHs) contribute high disease burdens amongst the neglected tropical diseases (NTDs) and are public health problems in Angola. This study reports the prevalence, intensity and risk factors for schistosomiasis and STH infection in Huambo, Uige and Zaire provinces, Angola, to inform a school-based preventive chemotherapy program.

METHODS

A two-stage cluster design was used to select schools and schoolchildren to participate in parasitological and water, sanitation and hygiene (WASH) surveys across Huambo, Uige, and Zaire provinces. Point-of-care circulating cathodic antigen and urinalysis rapid diagnostic tests (RDTs) were used to determine the prevalence of Schistosoma mansoni and S. haematobium, respectively. Kato-Katz was used to identify and quantify STH species and quantify and compare with RDTs for S. mansoni. Urine filtration was used to quantify and compare with RDTs for S. haematobium. Descriptive statistics were used for prevalence and infection intensity of schistosomiasis and STH infection. Performance of RDTs was assessed through specificity and Cohen's Kappa agreement with microscopy. A multivariate regression analysis was used to determine demographic and WASH factors associated with schistosomiasis and STH infection.

RESULTS

A total 575 schools and 17,093 schoolchildren participated in the schistosomiasis survey, of which 121 schools and 3649 schoolchildren participated in the STH survey. Overall prevalence of S. mansoni was 21.2% (municipality range 0.9-74.8%) and S. haematobium 13.6% (range 0-31.2%), with an overall prevalence of schistosomiasis of 31.4% (range 5.9-77.3%). Overall prevalence of Ascaris lumbricoides was 25.1% (range 0-89.7%), hookworm 5.2% (range 0-42.6%), and Trichuris trichiura 3.6% (range 0-24.2%), with an overall prevalence of STH infection of 29.5% (range 0.8-89.7%). Ecological zone and ethnicity were factors associated with schistosomiasis and STH infection, with older age and female sex additional risk factors for S. haematobium.

CONCLUSIONS

Most municipalities met World Health Organization defined prevalence thresholds for a schistosomiasis preventive chemotherapy program. A STH preventive chemotherapy program is indicated for nearly all municipalities in Uige and select municipalities in Huambo and Zaire. The association between ecological zone and ethnicity with schistosomiasis and STH infection necessitates further evaluation of home and school environmental, sociodemographic and behavioural factors to inform targeted control strategies to complement preventive chemotherapy programs.

A survey of urinary schistosomiasis among school aged children of ten communities in South-South, Nigeria

BACKGROUND & OBJECTIVES

Schistosomiasis is one of the major neglected tropical parasitic diseases caused by a group of blood-feeding worms in the genus Schistosoma. Nigeria ranks highest among all countries worldwide, however, there is a paucity of information on the prevalence of the disease in some parts of the country. Therefore, the research aims to augment available data on the prevalence of Schistosoma haematobium infection among schoolaged children in ten communities in Edo state, Nigeria.

METHODS

A cross-sectional survey involving 400 school-aged children was conducted in 10 randomly selected communities in Akoko-Edo Local Government Area, Edo State of Nigeria between November 2016 and April 2017. Demographic data of subjects was collected using a structured questionnaire. Urine samples were collected and examined for haematuria and ova of Schistosoma haematobium using a commercially prepared reagent strip (Medi-Test Combi9TM^R) and sedimentation technique respectively.

RESULTS

The prevalence of urinary schistosomiasis based on microscopic examination of the urine sediment for the ova of S. haematobium was 17.3%, while haematuria was 22.0%. Mean intensity of S. haematobium oval count ranged between 2.0-4.0/10ml of urine per community. Prevalence was higher among males (24.5%) than females (10.0%)(P<0.05), which was statistically significant. Overall, age group 7-9 years showed the highest prevalence of infection. Farming showed a strong correlation as a parent occupational risk factor in predisposing children to infection as it accounts for 73.9% of all infections.

INTERPRETATION & CONCLUSION

Findings indicate that urinary schistosomiasis is still prevalent among school-aged children in Akoko-Edo LGA, which hinders their growth, development and cognitive abilities. Although, mass drug administration is ongoing in some of the communities, re-infection still occurs due to ignorance, occupational factors, lack of portable water and sanitary toilets.

Sexual Dimorphism and Gender in Infectious Diseases

Epidemiological studies and clinical observations show evidence of sexual dimorphism in infectious diseases. Women are at less risk than men when it comes to developing most infectious diseases. However, understanding these observations requires a gender approach that takes into account an analysis of both biological and social factors. The host’s response to infection differs in males and females because sex differences have an impact on hormonal and chromosomal control of immunity. Estradiol appears to confer protective immunity, while progesterone and testosterone suppress anti-infectious responses. In addition, genetic factors, including those associated with sex chromosomes, also affect susceptibility to infections. Finally, differences in occupational activities, lifestyle, and comorbidities play major roles in exposure to pathogens and management of diseases. Hence, considering sexual dimorphism as a critical variable for infectious diseases should be one of the steps taken toward developing personalized therapeutic approaches.

Factors influencing uptake of schistosomiasis research findings in ingwavuma area, uMkhanyakude District, Kwazulu-Natal, South Africa

Background

Research uptake is concerned with spreading ideas across multiple levels of the community. Barriers such as poverty, lack of infrastructure, illiteracy and culture prevent information sharing in arid rural areas of sub-Saharan Africa.

Objective

This study explores the factors influencing schistosomiasis research uptake and the available channels for the uptake of research findings from a transdisciplinary and eco-health research project on schistosomiasis in Ingwavuma area, uMkhanyakude district, KwaZulu-Natal province in South Africa.

Methods

This case study conducted in 2017 involved 78 primary school children and 73 heads of household recruited through convenience and purposive sampling. Data were collected through focus group discussions, then transcribed and analysed by the researcher using thematic analysis.

Results

Factors such as poor knowledge, water and sanitation problems, and lack of sufficient health workers hindered the uptake of schistosomiasis research findings. Participants recommended several platforms to share schistosomiasis research findings with the community, including: door to door visits; social gatherings such as sports events, talent shows, and religious gatherings; mass media platforms such as radio and television; social media platforms such as WhatsApp, Facebook and Twitter; and printed media such as posters, booklets and pamphlets.

Conclusions

There is a need to train health workers and peer educators in this area of South Africa to educate people about schistosomiasis infection, screening and treatment through home visits or social events. Schistosomiasis research findings must be synthesised and packaged in different forms for dissemination via multimedia media-based communication channels.

Polyparasitism with Schistosoma haematobium, Plasmodium and soil-transmitted helminths in school-aged children in Muyuka-Cameroon following implementation of control measures: a cross sectional study

Background

Despite the ubiquity of polyparasitism, its health impacts have been inadequately studied. The aim of this study was to determine the prevalence and determinants of polyparasitism with Schistosoma haematobium, Plasmodium and soil-transmitted helminths (STH) following sustained control measures, as well as evaluate the outcomes and clinical correlates of infection in school-aged children (SAC) living in the schistosomiasis endemic focus of Muyuka-Cameroon.

Methods

In a cross-sectional study, urine, blood and stool samples were each collected from SAC (4–14 years) selected at random between March and June 2015. Microhaematuria in urine was detected using reagent strip and S. haematobium ova by filtration/microscopy methods. Plasmodium was detected using Giemsa-stained blood films and complete blood count was obtained using an auto-haematology analyser. STH in stool was detected by the Kato-Katz method. Categorical and continuous variables were compared as required, Kappa value estimated and the adjusted odds ratio (aOR) in the multivariate analysis was used to evaluate association of the risk factors with infection.

Results

Out of the 638 SAC examined, single infection was prevalent in 33.4% while polyparasitism was 19.9%. Prevalence of S. haematobium + Plasmodium was 7.8%; S. haematobium + STH was 0.8%; Plasmodium + STH was 0.8%; while S. haematobium + Plasmodium + STH was 0.9%. Higher preponderance of S. haematobium + Plasmodium infection occurred in females, those from Likoko, did not use potable water, practiced bathing in stream and carried out open defecation than their equivalents. However, being female (aOR = 2.38, P = 0.009) was the only significant risk factor identified. Anaemia was a common morbidity (74.3%) with a slight agreement with microscopy in predicting S. haematobium and Plasmodium infections. The sensitivity and specificity of haematuria (13.0%) in predicting S. haematobium infection was 46.5% and 100% with a moderate agreement with microscopy. Co-infection with S. haematobium and malaria parasite was significantly associated with threefold odds of history of fever in the last three days.

Conclusions

Polyparasitism is a public health problem in Muyuka with females most at risk. Anaemia prevalence is exacerbated in co- and triple-infections and together with a history of fever are of value in predicting polyparasitism.

Impact of seven years of mass drug administration and recrudescence of Schistosoma haematobium infections after one year of treatment gap in Zanzibar: Repeated cross-sectional studies

Background

Considerable progress towards the elimination of urogenital schistosomiasis was made by the Zanzibar Elimination of Schistosomiasis Transmission project from 2012 till 2016, when biannual praziquantel mass drug administration (MDA) alone or with additional snail control or behaviour change interventions were implemented. Annual MDA was continued in 2017 and 2018, but not in 2019, imposing a 16-month treatment gap. We monitored the Schistosoma haematobium prevalence from 2012 till 2020 and assessed recrudescence patterns with focus on 2020.

Methodology

Repeated cross-sectional surveys were conducted from 2011/12 till 2020 in 90 communities and 90 schools in Zanzibar. Annually, around 4,500 adults and up to 20,000 schoolchildren were surveyed. The S. haematobium prevalence was detected by urine filtration and reagent strips. In 2020, risk factors for infection were investigated using generalized estimated equation models.

Principal findings

In adults, the apparent S. haematobium prevalence was 3.9% in 2011 and 0.4% in 2020. In schoolchildren, the prevalence decreased from 6.6% in 2012 to 1.2% in 2019 with vicissitudes over the years. Prominent recrudescence of infection from 2.8% in 2019 to 9.1% (+225%) in 2020 was observed in 29 schools with historically moderate prevalences (≥10%). Compared with 2019, reinfection in 2020 was particularly striking in boys aged 9–16 years. Being male was a risk factor for infection in 2020 (adults: odds ratio (OR): 6.24, 95% confidence interval (95% CI): 1.96–19.60; schoolchildren: OR: 2.06, 95% CI: 1.52–2.78). Living near to a natural freshwater body significantly increased the odds of infection in adults (OR: 2.90, CI: 1.12–7.54).

Conclusions/Significance

After 11 rounds of MDA over 7 years and a 16-month treatment gap, the urogenital schistosomiasis prevalence considerably rebounded in hotspot areas. Future elimination efforts in Zanzibar should focus on re-intensifying MDA plus additional interventions in hotspot areas. In low-prevalence areas, the strategy might be adapted from MDA to targeted surveillance-response.

Schistosomiasis is a neglected tropical disease caused by parasitic blood flukes of the genus Schistosoma. On the Zanzibar islands, United Republic of Tanzania, interventions to eliminate urogenital schistosomiasis commenced in 2012. From 2012 to 2016, the population was treated biannually with praziquantel and, additionally, some areas received mollusciciding against the intermediate host snail, or educational measures for behavior change. Mass drug administration (MDA) with praziquantel was continued annually in 2017 and 2018, but not in 2019. As a result of the interventions, the overall S. haematobium prevalence was reduced to 0.4% in adults and 3.4% in schoolchildren in 2020. However, in some areas, the MDA gap in 2019 resulted in a considerable rebound of infections. The recrudescence in 2020 was particularly striking for boys aged 9–16 years. In general, in 2020, male participants had higher odds of infection than females. Adults living near to a natural freshwater body also showed an increased risk of S. haematobium infection. Future elimination efforts in Zanzibar should focus on re-intensifying elimination interventions, including MDA, snail control and behavior change in hotspot areas. In low-prevalence areas, the strategy might be adapted from MDA to targeted interventions, such as surveillance-response.

Urogenital Schistosomiasis among Primary School Children in Rural Communities in Obudu, Southern Nigeria

BACKGROUND

Schistosomiasis is a Neglected Tropical Disease (NTD) that constitutes a public health problem in Sub-Saharan Africa (SSA), including Nigeria. There is need for updated information on the extent of the disease burden at community level to facilitate effective prioritization and monitoring of the disease.

METHODS

A cross-sectional study was conducted among school-aged children in Obudu Local Government Area (LGA), one of the 18 LGAs in Cross River State, Southern Nigeria. Seven schools from seven communities were randomly selected for this study. A total of 1,113 urine samples obtained from school-aged children were screened for Schistosoma haematobium (S. haematobium) eggs using standard parasitological method of diagnosis. Proteinuria and hematuria were evaluated using reagent test strips.

RESULTS

In this study, 153 (13.7%) children were infected with S. haematobium. More males (86 or 14.7%) were infected than females (67 or 12.7%); the differences were not statistically significant. The overall geometric mean intensity of infection was 13.3 eggs/10ml of urine. Females (13.69 eggs/10ml of urine) had the highest intensity of infection than males (12.91eggs/10ml of urine). Prevalence of hematuria was 152 (13.7%) (95% C.I. = 10.649 - 18.751%) while the prevalence of proteinuria was 172 (15.5%) (95% C.I. = 5.162 - 38.712%). Prevalence of infection significantly (p<0.001) varied among the schools from 7.8% to 28.9%. Children aged 5-9 years old had the highest prevalence of infection 46 (17.1%). The prevalence of urogenital schistosomiasis was 28.9%, 20.5% and 13.2%, respectively, among Betukwel, Ibong, and Ohong communities.

CONCLUSION AND GLOBAL HEALTH IMPLICATIONS

Urinary schistosomiasis is still endemic in Obudu, Southern Nigeria but with decreased prevalence. Public health mitigation efforts such as mass chemotherapy, provision of safe water supply and sanitation facilities are recommended. Furthermore, health education should be encouraged within schools and communities.

The epidemiological status of urogenital schistosomiasis among reproductive aged individuals in the Tiko Health Area- a semi-urban setting in the Mount Cameroon area

BACKGROUND

Urogenital schistosomiasis (UGS) caused by S. haematobium has enormous reproductive health consequences including infertility. Reproductive aged individuals are a neglected group and not included in control programs in Cameroon. This study investigated the prevalence and severity of S. haematobium infection in the context of gender and socio-economic structures that shape behaviour among reproductive aged individuals living in Tiko, a semi-urban setting, Cameroon.

METHODOLOGY/PRINCIPAL FINDINGS

A cross-sectional study was carried out in the Tiko Health District (THD) between May to September 2019. Consenting individuals were enrolled using a convenient sampling technique and administered a semi-structured questionnaire to document data on socio-demographic and stream contact behaviour. A urine sample was collected and screened for the presence of S. haematobium ova using reagent strips, filtration and microscopy. The overall prevalence of S. haematobium infection was 22.8% (95% CL: 19.27-26.73) with geometric mean egg load of 18.74 (range: 1-1600) per 10ml of urine. Younger age group (15 - 20years) (OR: 5.13; 95% CL: 1.35-19.42), male (OR: 2.60 3.07; 95% CL: 1.54-4.40) and awareness of UGS (OR: 1.73; 95% CL: 1.02-2.95) were associated with higher odds of exposure to infection. Significantly higher intensity of infection was seen in males, singles and in the age group 15-30 years. It is worth noting that males carried out more activities which entailed longer duration in streams.

CONCLUSION/SIGNIFICANCE

The prevalence obtained shows that Tiko is a moderate-risk area for UGS with underlying morbidity-inducing infection intensity. The severity of the infection is more in males. Awareness of the disease is not enough to protect these communities from infection, but provision of public infrastructures and health education will limit contact with infested water and thus curtail the infection. There is an urgent need to involve all age groups in control programs.

Knowledge and perceptions of schistosomiasis, a water-borne disease, in two semi-arid rural areas of South Africa (Ndumo) and Zimbabwe (Ntalale)

Schistosomiasis is a serious water-borne disease of public health importance in southern Africa and is characterised by high morbidity and negative socio-economic repercussions. Limited knowledge on the mode of transmission and treatment contribute towards increase in the risk of infection. This study assessed community knowledge levels, perceptions and the co-constructed realities of social actors with regards to schistosomiasis in rural resource-poor communities of Ndumo in South Africa and Ntalale in Zimbabwe. We hypothesised that there was association between community knowledge level on schistosomiasis and location of residency and socio-demographic factors. Two-hundred and eight questionnaires were used to gather quantitative data on socio-demographics and knowledge levels while 18 focus group discussions were used to collect qualitative data on perceptions and social constructs. The Fisher's exact and Chi-square tests were used to determine the differences in community knowledge levels based on localities, gender, religion and age. Results showed that awareness level of schistosomiasis was assessed as ‘good’ in both Ndumo (91%) and Ntalale (81%). Majority of the respondents identified schistosomiasis as a water-borne disease with significantly higher proportion in Ndumo (89%) compared to Ntalale (68%) (p = 0.005). A significant proportion of participants in both localities were aware of the symptoms of schistosomiasis especially the passing of urine with blood (82.5% in Ndumo and 77.0% in Ntalale; p = 0.039). However, presence of schistosomiasis eggs in human stool apart from urine as a sign of infection was highly acknowledged in Ntalale (57.4%) compared to Ndumo (11.7%; p < 0.001). Knowledge on the body parts affected by the infection was low in both localities with 36.9% in Ntalale compared to 1.0% in Ndumo (p < 0.001). In both study areas, local understanding of schistosomiasis was limited to passing urine with blood, a symptom only seen in cases of urinary schistosomiasis. All the participants associated schistosomiasis with being water-borne, but had divergent perceptions on the symptoms, lifecycle and treatment of the infection. Trends of schistosomiasis and at-risk populations were perceived differently in Ndumo and Ntalale. Although respondents from the two localities acknowledged schistosomiasis as water-borne disease, the study showed lack of in-depth knowledge on the life cycle of the diseases. We therefore recommend that health education be implemented together with other strategies such as improvement in access to water and sanitation in the two study areas to achieve effective control and prevention of the disease.

•

Community awareness level of schistosomiasis as a water-borne disease was good

•

Knowledge levels of the cause and risk factors of schistosomiasis was relatively low

•

Communities from the two study localities were aware of the symptoms of Schistosoma haematobium and not the mode of transmission

•

Knowledge on S. mansoni was poor in both areas

•

In Ndumo, the understanding of schistosomiasis had changed over time

Schistosoma haematobium infection and environmental factors in Southwestern Tanzania: A cross-sectional, population-based study

Schistosomiasis is a leading cause of morbidity in Africa. Understanding the disease ecology and environmental factors that influence its distribution is important to guide control efforts. Geographic information systems have increasingly been used in the field of schistosomiasis environmental epidemiology. This study reports prevalences of Schistosoma haematobium infection and uses remotely sensed and questionnaire data from over 17000 participants to identify environmental and socio-demographic factors that are associated with this parasitic infection. Data regarding socio-demographic status and S. haematobium infection were obtained between May 2006 and May 2007 from 17280 participants (53% females, median age = 17 years) in the Mbeya Region, Tanzania. Combined with remotely sensed environmental data (vegetation cover, altitude, rainfall etc.) this data was analyzed to identify environmental and socio-demographic factors associated with S. haematobium infection, using mixed effects logistic regression and geostatistical modelling. The overall prevalence of S. haematobium infection was 5.3% (95% confidence interval (CI): 5.0-5.6%). Multivariable analysis revealed increased odds of infection for school-aged children (5-15 years, odds ratio (OR) = 7.8, CI: 5.9-10.4) and the age groups 15-25 and 25-35 years (15-25 years: OR = 5.8, CI: 4.3-8.0, 25-35 years: OR = 1.6, CI: 1.1-2.4) compared to persons above 35 years of age, for increasing distance to water courses (OR = 1.4, CI: 1.2-1.6 per km) and for proximity to Lake Nyasa (<1 km, OR = 4.5, CI: 1.8-11.4; 1-2 km, OR = 3.5, CI: 1.7-7.5; 2-4 km; OR = 3.3, CI: 1.7-6.6), when compared to distances >4 km. Odds of infection decreased with higher altitude (OR = 0.7, CI: 0.6-0.8 per 100 m increase) and with increasing enhanced vegetation index EVI (OR = 0.2, CI: 0.1-0.4 per 0.1 units). When additionally adjusting for spatial correlation population density became a significant predictor of schistosomiasis infection (OR = 1.3, CI: 1.1-1.5 per 1000 persons/km2) and altitude turned non-significant. We found highly focal geographical patterns of S. haematobium infection in Mbeya Region in Southwestern Tanzania. Despite low overall prevalence our spatially heterogeneous results show that some of the study sites suffer from a considerable burden of S. haematobium infection, which is related to various socio-demographic and environmental factors. Our results could help to design more effective control strategies in the future, especially targeting school-aged children living in low altitude sites and/or crowded areas as the persons at highest need for preventive chemotherapy.

Antibody response to Schistosoma haematobium and other helminth species in malaria-exposed populations from Burkina Faso

Infection with helminths in sub-Saharan Africa could modulate the immune response towards Plasmodium falciparum as well as susceptibility to malaria infection and disease. The aim of this study is to assess the antibody responses to helminths species in malaria-exposed populations from Burkina Faso. Plasma samples were collected in rural villages inhabited by Fulani, Mossi and Rimaibe communities, and IgG against parasitic helminths were measured by ELISA. The prevalence of IgG against antigens of Strongyloides stercoralis, Wuchereria bancrofti and Schistosoma haematobium (Soluble Egg Antigen, SEA) was 5%, 16% and 63% respectively, in line with estimates of infection prevalence in the region for the three parasites. Anti-SEA IgG prevalence was highest at 10-20 years of age, higher in males than females, and did not show differences between ethnic groups. However, the Fulani showed lower levels of anti-SEA IgG suggesting that lighter S. haematobium infections may occur in the ethnic group known for a marked lower susceptibility to P. falciparum. The present data support the use of serological methods for integrated surveillance of neglected tropical diseases such as soil-transmitted helminths, lymphatic filariasis and bilharzia. Furthermore, as helminth infections might promote downregulation of immune responses against intracellular pathogens, the observation of lower anti-SEA IgG levels in the malaria resistant Fulani population warrants further investigation into the immunological cross-talk between S. haematobium and P. falciparum in this geographical region.

T. F, Olusi TA. Will Nigerians Win the War Against Urinary Schistosomiasis? Prevalence, Intensity, Risk Factors and Knowledge Assessment among Some Rural Communities in Southwestern Nigeria

Urinary schistosomiasis is a devastating parasitic disease in Nigeria. This study was carried out to investigate the current prevalence, intensity, risk factors and knowledge assessment among some rural communities in southwestern Nigeria. A cross-sectional study was carried out in which a standard urine filtrations technique was used to determine the prevalence and intensity of infection. A well-designed questionnaire was used to collect subject's data on demographic and socioeconomic characteristics. Of the total 620 urine samples examined, overall 346 (55.81%) were positive with a mean egg intensity (S.D) of 65.60 (59.33) egg/10 mL of urine. Significant differences occurred in the analysis. Males had the highest prevalence and intensity of 224 (61.9%) and 69.20 egg/10 mL of urine, respectively. The 10-14 years age group had the highest prevalence of 65.9% while mean intensity of infection among the age group decreases with increasing age, with the highest mean intensity of infection (80.14 egg/10 mL) recorded among the age group ≤ 4 years. Bivariate logistic regression analysis showed that being age group 10-14 (COR 0.27, 95% CI: 0.09-0.79) and dependent on river (COR 0.67, 95% CI: 0.33-1.33) increased the odd of contracting an infection. Similarly, the knowledge of respondents on urinary schistosomiasis was low. Conclusively, urinary schistosomiasis is still persistent at a very high rate in the study area and appropriate control measure should be deployed.

The association between child Schistosoma spp. infections and morbidity in an irrigated rice region in Mali: A localized study

Background

Schistosomiasis is one of the neglected tropical diseases endemic to Mali. There has been insufficient investigation of the morbidity burden in highly endemic irrigated rice areas with the ongoing mass drug administration with praziquantel. In February 2005, a year after an initial mass drug administration in 2004, we performed the first cross-sectional survey of schistosomiasis in the Kokry-Bozo village in the Office du Niger rice irrigation region. In the fourteen years since this survey, there has been almost no research into schistosomiasis morbidity in Mali due to lack of funding. Therefore, the 2005 survey supplies near-baseline data for any future research into the treatment impacts in the area.

Methods

One hundred and ninety-four children aged 6–14 years from two schools were assessed for bladder pathology by ultrasound, and for anaemia and micro-haematuria by laboratory tests. Schistosoma eggs were examined microscopically in fresh stool and urine samples. Multivariate logistic regression analysis quantified the association of Schistosoma infections with anaemia, bladder pathology and micro-haematuria. Akaike’s information criterion was used to test the assumption of linear effects of infection intensity classes and used to compare across models.

Results

The overall prevalence of schistosomiasis in 189 school children was 97%; 17% (33/189) had a single infection (S. mansoni,13%, or S. haematobium, 4%) and 80% (156/189) were co-infected with S. mansoni and S. haematobium. The overall prevalence of S. mansoni with light infection was 27% (53/194), moderate infection was 24% (47/194) and heavy infection was 42% (81/194). Of the 194 of children investigated for S. haematobium 59% (114/194) had light infection and 26% (50/194) had heavy infection. No hookworm eggs were detected.

The level of abnormal bladder pathology was 18% (35/189) with the highest found in 10–14 year old children. The prevalence of anaemia was 91% (172/189) and was twice as likely to be associated (OR 2.0, 95% CI 1.1–3.9) with S. mansoni infections than in children without infection. As infection intensity with S. mansoni increased the risk of anaemia (OR 2.0, 95% CI 1.1–3.9) also increased. As infection intensity with S. haematobium increased bladder pathology (OR 2.4, 95%CI 1.3–4.5), haematuria (OR 6.7, 95%CI 3.3–13.6) and micro-haematuria increased (OR 2.4, 95%CI 1.3–4.5).

Conclusion

Our research contributes an important micro-geographical assessment of the heavy burden of schistosomiasis and associated morbidity in children who live in the rice irrigation regions. Our literature review found that there has been very limited research conducted on the impact of the treatment to control morbidity in the ON. Therefore, there is a need to do a comparable, but more extensive, study to identify any changes in morbidity and to indicate current requirements for the control programme. Our results from 2005 called for routine integration of iron supplementation, food fortification and diet diversification into the deworming program.

Prevalence and risk factors of schistosomiasis and soil-transmitted helminthiases among preschool aged children (1-5 years) in rural KwaZulu-Natal, South Africa: a cross-sectional study

Background

Despite efforts to control neglected tropical diseases (NTDs), schistosomiasis and soil-transmitted helminthiases remain widely prevalent in sub-Saharan Africa. Recent data suggest that these infections are prevalent among preschool aged children (PSAC) in poor communities. Evidence of schistosomiasis and soil-transmitted helminths (STH) infection patterns and prevalence among PSAC is essential for effective treatment and control programmes. The aim of the study was to determine the prevalence, intensity and risk factors of schistosomiasis and STH infection among PSAC in the Ingwavuma area of uMkhanyakude District, South Africa.

Methods

A cross-sectional study was conducted among 1143 PSAC aged 1–5 years in 34 preschools and early childhood development (ECD) centres. Data on risk factors was collected using a semi-structured questionnaire. A Kruskal–Wallis test was used to compare the differences in infection intensity with age. Pearson Chi-square test and multivariate logistic regression were performed to assess the association between PSAC infection status, sociodemographic, household, water and sanitation variables and hygiene practices of PSAC and their caregivers.

Results

We observed a low prevalence of Schistosoma haematobium (1.0%) and S. mansoni (0.9%). The prevalence of Ascaris lumbricoides (18.3%) was high compared to Trichuris trichiura (1.2%), hookworms (1.6%) and Taenia (6.4%). The odds of schistosome infection were lowest among PSAC under younger (15–24 years) caregivers (0.1, 95% CI: 0.02–0.54) and those who used tap water (0.3, 95% CI: 0.09–0.78) for domestic purposes. Schistosome infection was however higher among PSAC who bathed in river water (17.4, 95% CI: 5.96–51.04). STH infection on the other hand was lowest among PSAC who did not play in soil (0.1, 95% CI: 0.51–0.28), were from households that used tap water for domestic purposes (0.5, 95% CI: 0.27–0.80) and PSAC under the care of younger (25–35 years) caregivers (0.3, 95% CI: 0.10–0.75). The risk of STH infection was highest among PSAC who did not wash their hands with soap (3.5, 95% CI: 1.04–11.67) and PSAC whose nails were not trimmed (3.6, 95% CI: 1.75–7.26).

Conclusions

The findings show low prevalence and infection intensity of schistosomiasis and STH infection except A. lumbricoides among PSAC. Factors predicting schistosomiasis and STH infection among PSAC were related to caregivers’ age, educational status, water and hygiene practices. STH infection was exclusively associated with PSAC playing and handwashing habits. These findings highlight the need to include PSAC caregivers in schistosomiasis and STH prevention and control programmes.

Electronic supplementary material

The online version of this article (10.1186/s40249-019-0561-5) contains supplementary material, which is available to authorized users.

Community knowledge, perceptions and water contact practices associated with transmission of urinary schistosomiasis in an endemic region: a qualitative cross-sectional study

BACKGROUND

In an effort to complement the current chemotherapy based schistosomiasis control interventions in Shinyanga district, community knowledge, perceptions and water contact practices were qualitatively assessed using focus group discussions and semi structured interviews involving 271 participants in one S. haematobium prevalent community of Ikingwamanoti village, Shinyanga district, Northwestern, Tanzania.

METHODS

In October, 2016 we conducted 29 parent semi structured interviews and 16 focus group discussions with a total of 168 parent informants. Adult participants were conveniently selected from three sub-villages of Butini, Miyu, and Bomani of Ikingwamanoti village, Shinyanga district. In March, 2017, a total of 103 children informants participated in 10 focus group discussions and 20 semi structured interviews, administered to children from standard four, five, six and seven attending Ikingwamanoti Primary School. Note taking and digital recorders were used to collect narrative data for thematic analysis of emergent themes.

RESULTS

Among participants, 75% parents and 50% children considered urinary schistosomiasis as a low priority health problem. Of the informants, 70% children and 48.3% parents had misconceptions about the cause, modes of transmission and control of schistosomiasis demonstrating gaps in their biomedical knowledge of the disease. Assessment of treatment seeking behavior for urinary schistosomiasis revealed a combination of traditional and modern health care sectors. However, modern medicines were considered effective in the treatment of urinary schistosomiasis. Lack of alternative sources of water for domestic and recreational activities and unhygienic water use habits exposed community members to high risk of acquiring urinary schistosomiasis.

CONCLUSION

Use of Schistosoma haematobium contaminated water sources for daily domestic and recreational use facilitated contraction of urinary schistosomiasis among community members in Shinyanga district. People's perceptions of urinary schistosomiasis as a less priority health problem promoted persistence of the disease. Future efforts to control urinary schistosomiasis should take into account integrated approaches combining water, sanitation and hygiene, health education, alternative sources of clean and safe water to facilitate behavior change.

Epidemiological Survey on Schistosomiasis and Intestinal Helminthiasis among Village Residents of the Rural River Basin Area in White Nile State, Sudan

There have been some reports on schistosomiasis of school children in Sudan’s Nile River basin area; however, information about the infection status of Schistosoma species and intestinal helminths among village residents of this area is very limited. Urine and stool samples were collected from the 1,138 residents of the Al Hidaib and Khour Ajwal villages of White Nile State, Sudan in 2014. The prevalence of overall schistosomiasis and intestinal helminthiasis was 36.3% and 7.7%, respectively. Egg positive rates were 35.6% for Schistosoma haematobium, 2.6% for S. mansoni, and 1.4% were mixed. The prevalence of schistosomiasis was significantly higher in men (45.6%) than in women (32.0%), in Khou Ajwal villagers (39.4%) than in Al Hidaib villagers (19.2%), and for age groups ≤15 years old (51.5%) than for age groups >15 years old (13.2%). The average number of eggs per 10 ml urine (EP10) of S. haematobium infections was 18.9, with 22.2 eggs in men vs 17.0 in women and 20.4 in Khou Ajwal villagers vs 8.1 in Al Hidaib villagers. In addition to S. mansoni eggs, 4 different species of intestinal helminths were found in the stool, including Hymenolepis nana (6.6%) and H. diminuta (1.0%). Collectively, urinary schistosomiasis is still prevalent among village residents in Sudan’s White Nile River basin and was especially high in men, children ≤15 years, and in the village without a clean water system. H. nana was the most frequently detected intestinal helminths in the 2 villages.

Urogenital schistosomiasis is associated with signatures of microbiome dysbiosis in Nigerian adolescents

Urogenital schistosomiasis is a neglected tropical disease caused by the parasite Schistosoma haematobium, which resides in the vasculature surrounding the urogenital system. Previous work has suggested that helminthic infections can affect the intestinal microbiome, and we hypothesized that S. haematobium infection could result in an alteration of immune system-microbiota homeostasis and impact the composition of the gut microbiota. To address this question, we compared the fecal microbiomes of infected and uninfected schoolchildren from the Argungu Local Government Area of Kebbi State, Nigeria, detecting significant differences in community composition between the two groups. Most remarkably, we observed a decreased abundance of Firmicutes and increased abundance of Proteobacteria - a shift in community structure which has been previously associated with dysbiosis. More specifically, we detected a number of changes in lower taxa reminiscent of inflammation-associated dysbiosis, including decreases in Clostridiales and increases in Moraxellaceae, Veillonellaceae, Pasteurellaceae, and Desulfovibrionaceae. Functional potential analysis also revealed an enrichment in orthologs of urease, which has been linked to dysbiosis and inflammation. Overall, our analysis indicates that S. haematobium infection is associated with perturbations in the gut microbiota and may point to microbiome disruption as an additional consequence of schistosome infection.

Transmission of Schistosoma mansoni in Yachi areas, southwestern Ethiopia: new foci

Background

Schistosoma mansoni, causing intestinal schistosomiasis, is widely distributed in Ethiopia and new transmission foci are continually reported. Here we report new transmission sites and prevalence of S.mansoni infection among school children in Yachi areas, southwestern Ethiopia.

Methods

A cross-sectional survey was conducted among school children of Yachi Yisa and Yachi Efo elementary schools, southwestern Ethiopia, from April 2017 to June 2017. Three hundred seventeen school children aged six to 15 years were randomly selected to provide stool specimens for helminth infection examination by Kato-Katz and formol-ether concentration techniques. Snail survey was carried out to assess schistosome infection in Biomphalaria pfeifferi. Laboratory bred mice were also exposed to schistosome cercariae shed by B. pfeifferi en masse for definite identification of Schistosoma species.

Results

From the 317 stool specimens examined using double Kato-Katz thick smear and single formol-ether concentration techniques, 224 (70.7%) were found positive for at least one intestinal helminth species. The most prevalent parasite was S. mansoni (42.9%) followed by Trichuris trichiura (34.1%) and Ascaris lumbricoides (14.2%). The prevalence of S. mansoni infection was significantly higher among the children attending Yachi Yisa School (49.4%) than those in Yachi Efo School (35.6%) (P = 0.002). The study also revealed that there was a significantly higher prevalence of S.mansoni infection among males (51.2%) than females (33.1%) (P < 0.001). However, the prevalence of S.mansoni infection was not significantly associated with age categories (P = 0.839). B. pfeifferi snails infected with schistosomes were collected from the water bodies found in the study area. After six weeks post exposure, adult S. mansoni worms were harvested from the mesenteric veins of laboratory bred mice.

Conclusions

The study revealed establishment of new S. mansoni transmission foci and moderate prevalence of schistosomiasis in Yachi areas. Hence, treatment of all school-age children once every two years is recommended. Snail control and non-specific control approaches including provision of clean water supply and health education should also complement mass drug administration of praziquantel.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0513-5) contains supplementary material, which is available to authorized users.

Prevalence of schistosomiasis and associated risk factors among school children in Um-Asher Area, Khartoum, Sudan

Objective

Schistosomiasis remains one of the most common parasitic diseases worldwide. This is a cross-sectional study aimed to determine the prevalence of schistosomiasis and its associated risk factors among primary school children in Um-Asher area. The study was conducted among 170 primary school students in Um-Asher area from November 2017 to February 2018. Urine and stool samples were collected and examined for schistosomiasis infections. Moreover, data on sociodemographic characteristics and associated risk factors were obtained using a questionnaire.

Results

The overall prevalence of Schistosoma haematobium was 12.9%, whereas that of Schistosoma mansoni was 2.95%. Additionally, the males had higher prevalence (60%) of S. mansoni than females (40%). However, both gender were equally infected with S. haematobium (50%). With regard to risk factors, distance of residence from water source and source of drinking water are relatively associated with the infection.

Schistosoma haematobium effects on Plasmodium falciparum infection modified by soil-transmitted helminths in school-age children living in rural areas of Gabon

BACKGROUND

Malaria burden remains high in the sub-Saharan region where helminths are prevalent and where children are often infected with both types of parasites. Although the effect of helminths on malaria infection is evident, the impact of these co-infections is not clearly elucidated yet and the scarce findings are conflicting. In this study, we investigated the effect of schistosomiasis, considering soil-transmitted helminths (STH), on prevalence and incidence of Plasmodium falciparum infection.

METHODOLOGY

This longitudinal survey was conducted in school-age children living in two rural communities in the vicinity of Lambaréné, Gabon. Thick blood smear light microscopy, urine filtration and the Kato-Katz technique were performed to detect malaria parasites, S. haematobium eggs and, STH eggs, respectively. P. falciparum carriage was assessed at inclusion, and incidence of malaria and time to the first malaria event were recorded in correlation with Schistosoma carriage status. Stratified multivariate analysis using generalized linear model was used to assess the risk of plasmodium infection considering interaction with STH, and survival analysis to assess time to malaria.

MAIN FINDINGS

The overall prevalence on subject enrolment was 30%, 23% and 9% for S. haematobium, P. falciparum infections and co-infection with both parasites, respectively. Our results showed that schistosomiasis in children tends to increase the risk of plasmodium infection but a combined effect with Trichuris trichiura or hookworm infection clearly increase the risk (aOR = 3.9 [95%CI: 1.7-9.2]). The incidence of malaria over time was 0.51[95%CI: 0.45-0.57] per person-year and was higher in the Schistosoma-infected group compared to the non-infected group (0.61 vs 0.43, p = 0.02), with a significant delay of time-to first-malaria event only in children aged from 6 to 10-years-old infected with Schistosoma haematobium.

CONCLUSIONS

Our results suggest that STH enhance the risk for P. falciparum infection in schistosomiasis-positive children, and when infected, that schistosomiasis enhances susceptibility to developing malaria in young children but not in older children.

Infection status and risk factors associated with urinary schistosomiasis among school-going children in the Ndumo area of uMkhanyakude District in KwaZulu-Natal, South Africa two years post-treatment

OBJECTIVES

To assess the efficacy of praziquantel in children infected with Schistosoma haematobium over a 2-year period in the Ndumo area of uMkhanyakude District, South Africa.

METHODS

This cohort study enrolled 173 school-going children in September 2017 who had participated in a baseline survey conducted in 2015 in the Ndumo area. Questionnaire interviews were conducted to collect information on the risk factors related to the transmission of schistosomiasis. The filtration technique was performed to detect Schistosoma haematobium eggs in urine. Infection intensity was classified as light or heavy. The Chi-square test was used to assess the associations between variables at the 95% confidence level, and p=0.05 was considered significant.

RESULTS

Of the 173 participants screened 2 years post-treatment, 10 were infected. Six of these were new infection cases, while four were cases of re-infection. The intensity of infection had decreased significantly (p=0.001) at the time of the follow-up survey compared to the baseline survey. However, no significant difference was found among the risk factors for schistosomiasis 2 years later.

CONCLUSIONS

The prevalence of S. haematobium had decreased significantly in the cohort at 2 years post praziquantel treatment, during a period of persistent drought in the area. Risk factors that were significantly associated with schistosomiasis at baseline were no longer significantly associated at 2 years following treatment.

Schistosoma haematobium, Plasmodium falciparum infection and anaemia in children in Accra, Ghana

Background

Urinary Schistosomiasis and malaria are endemic in Sub-Saharan Africa. There are public health concerns and implications of these parasites. This study sought to assess the prevalence of malaria, urinary schistosomiasis, and anaemia in children of school going age in two municipalities in Ghana.

Methods

A cross-sectional study design was used to investigate the prevalence of S. haematobium, P. falciparum infection and the haemoglobin concentration of respondents. A total of 404 (231 males and 173 females) school children between ages 9 - 14 years (mean age 11.8 ± 1.4 years) were recruited for the survey. Urine and blood samples were collected using standard operating procedures for urinary schistosomiasis and malaria diagnosis. Haemoglobin concentration was measured using a Hemocue® Hb 201 m.

Results

The prevalence of mono-infection was 4.7 and 12.9% for S. haematobium and P. falciparum respectively with a small proportion (0.9%) of the respondents infected with both parasites. The prevalence of anaemia in the study population was 59.9%. The risk of developing anaemia was not associated with being infected with any of the parasites. All co-infected children had anaemia.

Conclusion

High prevalence of anaemia was observed within the study population. Prevalence of malaria was higher compared to schistosomiasis. Interventions to address the high levels of anaemia is required within the community.

Electronic supplementary material

The online version of this article (10.1186/s40794-018-0063-7) contains supplementary material, which is available to authorized users.

Paediatric schistosomiasis: What we know and what we need to know

Schistosomiasis affects over 200 million people worldwide, most of whom are children. Research and control strategies directed at preschool-aged children (PSAC), i.e., ≤5 years old, have lagged behind those in older children and adults. With the recent WHO revision of the schistosomiasis treatment guidelines to include PSAC, and the recognition of gaps in our current knowledge on the disease and its treatment in this age group, there is now a concerted effort to address these shortcomings. Global and national schistosome control strategies are yet to include PSAC in treatment schedules. Maximum impact of schistosome treatment programmes will be realised through effective treatment of PSAC. In this review, we (i) discuss the current knowledge on the dynamics and consequences of paediatric schistosomiasis and (ii) identify knowledge and policy gaps relevant to these areas and to the successful control of schistosome infection and disease in this age group. Herein, we highlight risk factors, immune mechanisms, pathology, and optimal timing for screening, diagnosis, and treatment of paediatric schistosomiasis. We also discuss the tools required for treating schistosomiasis in PSAC and strategies for accessing them for treatment.

Biosocial Determinants of Persistent Schistosomiasis among Schoolchildren in Tanzania despite Repeated Treatment

Schistosomiasis is a parasitic disease endemic to Tanzania and other countries of the global south, which is currently being addressed through preventive chemotherapy campaigns. However, there is growing recognition that chemotherapy strategies will need to be supplemented to sustainably control and eventually eliminate the disease. There remains a need to understand the factors contributing to continued transmission in order to ensure the effective configuration and implementation of supplemented programs. We conducted a cross-sectional questionnaire, to evaluate the biosocial determinants facilitating the persistence of schistosomiasis, among 1704 Tanzanian schoolchildren residing in two districts undergoing a preventive chemotherapeutic program: Rufiji and Mkuranga. A meta-analysis was carried out to select the diagnostic questions that provided a likelihood for predicting infection status. We found that self-reported schistosomiasis continues to persist among the schoolchildren, despite multiple rounds of drug administration.Using mixed effects logistic regression modeling, we found biosocial factors, including gender, socio-economic status, and water, sanitation, and hygiene (WASH)-related variables, were associated with this continued schistosomiasis presence. These findings highlight the significant role that social factors may play in the persistence of disease transmission despite multiple treatments, and support the need not only for including integrated technical measures, such as WASH, but also addressing issues of poverty and gender when designing effective and sustainable schistosomiasis control programs.

Maternal urogenital schistosomiasis; monitoring disease morbidity by simple reagent strips

Background

Urine analysis is one of the recommended antenatal guidelines for early diagnosis of pregnancy-associated complications. While in practice, urine analysis by dipstick had been used to provide useful information on other urinary tract infections, its applications for early detection of urogenital schistosomiasis in pregnant women is often times not given due attention in most endemic areas. Our study therefore assessed the performance of some common urinalysis parameters in the diagnosis of maternal urogenital schistosomiasis in endemic rural communities of Nigeria.

Methodology/Principal findings

The cross-sectional epidemiologic survey of urogenital schistosomiasis was conducted among pregnant women in Yewa North Local Government, Ogun State, Nigeria. The women were microscopically examined for infection with Schistosoma haematobium, visually observed for macrohematuria, and screened for microhematuria and proteinuria using standard urine chemical reagent strips. Of 261 volunteered participants, 19.9% tested positive for S. haematobium infection. The proportion of microhematuria (23.8%) was significantly higher than that of macrohematuria (3.8%) and proteinuria (16.8%) (P<0.05). Microhematuria with sensitivity (82.7%) and specificity (89.0%) was the best diagnostic indicator of urogenital schistosomiasis. Macrohematuria with the least sensitivity (11.8%) was however the most specific (98.1%) for diagnosing urogenital schistosomiasis in pregnant women. Maximum microhematuria sensitivity (100.0%) was observed in women between 15–19 years but sensitivity was consistently low in older age groups. Maximum sensitivity, specificity and predictive values (100.0%) were recorded for microhematuria in first trimester women. Diagnostic efficiency of proteinuria and macrohematuria was also better in the first trimester women except the 25.0% specificity recorded for proteinuria. The overall diagnostic performance of microhematuria and proteinuria was better in secundigravidae.

Conclusions/Significance

Microhematuria can be used for early detection of urogenital schistosomiasis in endemic areas especially in younger women. However because microhematuria is a condition that occurs during pregnancy and in several other diseases, it is necessary to compliment the diagnosis with other diagnostic tools such as microscopy and serology. Treatment with praziquantel is recommended for the women in their late trimesters after follow up test in order to avert associated adverse pregnancy outcomes.

Urinary schistosomiasis among preschool children in Malengachanzi, Nkhotakota District, Malawi: Prevalence and risk factors

AIM

This study was designed to determine the prevalence of and risk factors for schistosomiasis among a group of preschool children in Malawi. Schistosomiasis burden among preschoolers in Malawi is not well documented in the literature.

METHODS

This study used field research (in the form of a snail survey), laboratory work (urinalysis and microscopy for parasite identification), and questionnaire-guided interviews to determine the prevalence of and risk factors for urinary schistosomiasis among children, aged between 6 and 60 months, in Malengachanzi, Nkhotakota District, Malawi.

RESULTS

Urinary schistosomiasis prevalence among preschool children was 13%. Of the factors evaluated, only age (P = 0.027) was statistically significantly associated with urinary schistosomiasis risk. Four-year-old preschool children were five times more likely to contract urinary schistosomiasis than twoyear-old children (odds ratio [OR] = 5.255; 95% confidence interval [CI] = 1.014-27.237; P = 0.048). Increased contact with infested water among older children likely explains much of their increased risk. Infestation was evidenced by the presence of infected Bulinus globosus snails in the water contact points surveyed. Multiple regression analysis showed that visiting water contact sites daily (OR = 0.898, 95% CI = 0.185-4.350, P = 0.894), bathing in these sites (OR = 9.462, 95% CI = 0.036-0.00, P = 0.430) and lack of knowledge, among caregivers, regarding the causes of urinary schistosomiasis (OR = 0.235, 95% CI = 0.005-1.102, P = 0.066) posed statistically insignificant risk increases for preschoolers contracting urinary schistosomiasis.

CONCLUSIONS

Urinary schistosomiasis was prevalent among preschool children in Malengachanzi, Nkhotakota District. Contact with infested water puts these children and the general population at risk of infection and reinfection. Inclusion of preschool children in treatment programmes should be considered imperative, along with safe treatment guidelines. To prevent infection, the population in the area should be provided with health education and safe alternative water sources.

Detection of Schistosoma Antibodies and exploration of associated factors among local residents around Inlay Lake, Southern Shan State, Myanmar

Background

Schistosomiasis is a chronic parasitic disease caused by blood flukes (trematode worms) of the genus Schistosoma. Its transmission has been reported in 78 countries affecting at least 258 million people world-wide. It was documented that S. japonicum species was prevalent in Shan State, Myanmar, but the serological study was not conducted yet. General objective of the present study was to detect schistosoma antibodies and explore associated factors among local residents living around Inlay Lake, Nyaung Shwe Township, and Southern Shan State, Myanmar.

Methods

An exploratory and cross-sectional analytic study was conducted among local residents (n = 315) in selected rural health center (RHC) areas from December 2012 through June 2013. The participants were interviewed with pretested semi-structured questionnaires and their blood samples (serum) were tested using Schistosomiasis Serology Microwell ELISA test kits (sensitivity 100% and specificity 85%) which detected IgG antibodies but could not distinguish between a new and past infection. Data collected were analysed by SPSS software 16.0 and associations of variables were determined by Chi-squared test with a significant level set at 0.05.

Results

Schistosoma seroprevalence (IgG) in study area was found to be 23.8% (95% CI: 18.8–28.8%). The present study is the first and foremost study producing serological evidence of schistosoma infection—one of the neglected tropical diseases—in local people of Myanmar. The factors significantly associated with seropositivity were being male [OR = 2.6 (95% CI: 1.5–4.49), P < 0.001], residence [OR = 3.41 (95% CI: 1.6-7.3), P < 0.05 for Khaung Daing vs. Min Chaung] and education levels [OR = 4.5 (95% CI: 1.18–17.16),

P < 0.05 for illiterate/3Rs level vs. high/graduate and OR = 3.16 (95% CI: 1.26–7.93),

P < 0.05 for primary/middle level vs. high/graduate] all factors classically associated with risk of schistosoma infection. None of the behavioural factors tested were significantly associated with seropositivity.

Conclusion

Schistosoma infection serologically detected was most probably present at some time in this location of Myanmar, and this should be further confirmed parasitologically and kept under surveillance. Proper trainings on diagnosis, treatment, prevention and control of schistosomiasis should be provided to the healthcare providers.

Trial registration

ISRCTN ISRCTN73824458. Registered 28 September 2014, retrospectively registered.

PREVALENCE AND RISK FACTORS OF SCHISTOSOMIASIS AMONG HAUSA COMMUNITIES IN KANO STATE, NIGERIA

Schistosomiasis remains one of the most prevalent neglected tropical diseases especially in Nigeria which has the greatest number of infected people worldwide. A cross-sectional study was conducted among 551 participants from Kano State, North Central Nigeria. Fecal samples were examined for the presence of Schistosoma mansoni eggs using the formalin-ether sedimentation method while the urine samples were examined using the filtration technique for the presence of S. haematobium eggs. Demographic, socioeconomic and environmental information was collected using a pre-validated questionnaire. The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium, respectively and 0.5% presenting co-infection with both species. The multiple logistic regression analysis revealed that age < 18 years (OR = 2.13; 95% CI; 1.34- 3.41), presence of infected family members (OR = 3.98; 95% CI; 2.13-7.46), and history of infection (OR = 2.87; 95% CI; 1.87- 4.56) were the significant risk factors associated with schistosomiasis in these communities. In conclusion, this study revealed that schistosomiasis is still prevalent among Hausa communities in Nigeria. Mass drug administration, health education and community mobilization are imperative strategies to significantly reduce the prevalence and morbidity of schistosomiasis in these communities.

Prevalence and distribution of Schistosoma haematobium infection among school children living in southwestern shores of Lake Malawi

BACKGROUND

The prevalence of Schistosoma haematobium infection has been shown to be about 23.7% among children living in the lakeshore areas of Malawi, with reinfection rates of about 30% to 40%. This study aimed to determine the current prevalence and distribution of S. haematobium infection in school children along the southwestern shores of Lake Malawi and examine the control interventions present in the area.

METHODS

This prospective cross-sectional study was conducted in primary schools. School children were enrolled, demographic data were collected, and urine samples were submitted for analysis on macrohaematuria, microhaematuria, and S. haematobium eggs. A questionnaire was administered to 3 health facilities on diagnosis and treatment of schistosomiasis, as well as the control interventions against it.

RESULTS

Four hundred children (174 males and 226 females) were enrolled from 7 primary schools. Mean participant age was 9.57 years (range 7 to 12 years). Fifty children (12.5%) had S. haematobium eggs detected in their urine, with the mean egg count being 15/10 mL. The highest infection intensity category (≥ 50 eggs/10mL) was seen in 10 children (2.5%). Prevalence varied significantly between the schools, with rates ranging from 0% to 20%. Schools with higher prevalence rates were located farther away from the nearest public hospital that provides treatment free of charge. Prevalence correlated with previous history of mass chemotherapy in schools. Mass chemotherapy, health education, and improved water supply and sanitation were some of the interventions that contributed to lower prevalence rates in some areas.

CONCLUSIONS

Schistosomiasis prevalence around southwestern Lake Malawi was lower than previously reported, owing to control interventions focusing on health education, improved water supply, sanitation, and mass chemotherapy. Consistent and uniform interventions can reduce prevalence further and sustain control. As prevalence falls, diagnostics can identify high transmission areas, monitor disease trends, and guide evidence-based control strategies.

Coinfection with Schistosoma haematobium and Plasmodium falciparum and Anaemia Severity among Pregnant Women in Munyenge, Mount Cameroon Area: A Cross-Sectional Study

Background. Malaria and urogenital schistosomiasis are coendemic in Mount Cameroon Area. This study investigated the prevalence of S. haematobium, P. falciparum, and coinfections and their effect on anaemia in pregnancy. Methods. Pregnant women reporting for antenatal care (ANC) clinic visit in Munyenge were enrolled. S. haematobium and P. falciparum infections were determined by urine filtration and microscopy, respectively. Haemoglobin (Hb) levels were measured using haemoglobinometer. Of 250 women, 46.8%, 39.2%, and 15.2% had S. haematobium, P. falciparum, and coinfections, respectively. Schistosomes infection was higher in younger women (≤25 years) and those who bathe in and had domestic contact with stream compared with older age (>25 years) women and those who had only domestic contact with stream. Lower infection rate was associated with less water contact (≤2 times/day) compared with more water contact (>2 times/day). Compared with no sulphadoxine-pyrimethamine (SP) usage, malaria parasitaemia was less among women who used SP. Stream usage increased risk of coinfection while less water contact and SP usage decreased its risk. All coinfected cases were anaemic and coinfection accounted for 93.8% of severe anaemia. Conclusion. Coinfection contributes to anaemia severity. Less water contact and SP usage will reduce coinfection in pregnancy in Munyenge.

Urogenital schistosomiasis and associated determinant factors among senior high school students in the Dutsin-Ma and Safana Local Government Areas of Katsina State, Nigeria

Background

Human schistosomiasis is a chronic parasitic disease of poverty caused by the cercariae of digenetic trematodes of the genus Schistosoma. The disease is a major source of morbidity and mortality in 77 low- and middle-income countries in the tropics where 700 million people are at risk. In a bid to provide relevant epidemiological information to boost control of urogenital schistosomiasis at the state level in Nigeria, we conducted this study with the aim of investigating the disease’s prevalence and intensity, and the determinant factors responsible for its endemicity.

Methods

Data on risk factors were obtained from a total of 645 students aged 12─25 years using well- designed questionnaires. Samples were collected between 09:45 and 14:00 in universal bottles. Each10μl centrifuged sample was examined for the eggs of S. haematobium using Motic® (Binocular) Light Microscope (model S-10-P) with a x10 objective. Average infection intensity was recorded as number of eggs per 10 ml of urine sample. Survey data were entered into Microsoft Excel 2010 and analyzed using Epi Info™ 7. Associations among variables were determined using the chi square test and bivariate and multivariate logistic regressions.

Results

Prevalence of urogenital schistosomiasis was 30.54 % among the study population, with a mean infection intensity of 30.27 eggs/10 ml of urine. Prevalence and average intensity were higher in males (28.37 % and 32.21 eggs/10 ml of urine respectively) than in females (2.17 % and 5 eggs/10 ml of urine respectively). Water contact activities (X²  = 29.031, P = 0.0000), sex (male) [X²  = 109.82; P<0.0001], location (Dutsin─Ma) [X²  = 7.19; P = 0.0073], age group 18-20 (X²  = 4.819, P = 0.0281), altitude (531─560 m) [X²  = 6.84, p = 0.0089], fathers doing other brown─collar jobs (X²  = 8.449, P = 0.0037) and mothers’ occupation (X²  = 9.470, P = 0.0021) were found to be significantly associated with urogenital schistosomiasis. Boys were six times more likely to be infected with the cercariae of S. haematobium compared to girls [AOR (95 % CI): 6.34 (4.89─8.22)].

Conclusions

Dutsin-Ma and Safana were classified as moderate-risk Local Government Areas for urogenital schistosomiasis. The strong association between the disease and mother’s occupation is of utmost importance and suggests a promising control measure: that is, directing health education as well as grassroots mass chemotherapeutic intervention with praziquantel at mothers. A good network including treated pipe-borne water, drainage system, and sewage disposal facilities available should be improved upon. Molluscicides should be provided at highly subsidized rate to help control the disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0158-1) contains supplementary material, which is available to authorized users.

Risk factors and micro-geographical heterogeneity of Schistosoma haematobium in Ndumo area, uMkhanyakude district, KwaZulu-Natal, South Africa

Schistosomiasis is a snail-transmitted parasitic disease endemic in most rural areas of sub-Saharan Africa. However, the currently used prediction models fail to capture the focal nature of its transmission due to the macro-geographical levels considered and paucity of data at local levels. This study determined the spatial distribution of Schistosoma haematobium and related risk factors in Ndumo area, uMkhanyakude District, KwaZulu-Natal province in South Africa. A sample of 435 schoolchildren between 10 to 15 years old from 10 primary schools was screened for S. haematobium using the filtration method. Getis-Ord Gi* and Bernoulli model were used to determine the hotspots of S. haematobium infection intensity based on their spatial distribution. Semiparametric-Geographically Weighted Regression (s-GWR) model was used to predict and analyse the spatial distribution of S. haematobium in relation to environmental and socio-economic factors. We confirmed that schistosomiasis transmission is focal in nature as indicated by significant S. haematobium cases and infection intensity clusters (p<0.05) in the study area. The s-GWR model performance was low (R(2)=0.45) and its residuals did not show autocorrelation (Moran's I=-0.001; z-score=0.003 and p-value=0.997) indicating that the model was correctly spelled. The s-GWR model also indicated that the coefficients for some of the socio-economic variables such as distances of households from operational piped water collection points, distance from open water sources, religion, toilet use, household head and places of bath and laundry significantly (t-values+/-1.96) varied across the landscape thereby determining the variation of S. haematobium infection intensity. This evidence may be used for control and management of the disease at micro scale. However, there is need for further research into more factors that may improve the performance of the s-GWR models in determining the local variation of S. haematobium infection intensity.

Natural and human induced factors influencing the abundance of Schistosoma host snails in Zambia

Schistosomiasis remains a global public health problem affecting about 240 million people. In Zambia, 2 million are infected while 3 million live with the risk of getting infected. Research and interventions relating to schistosomiasis are mainly linked to disease epidemiology. Malacological and ecological aspects of the disease are superficially understood. Developing effective control measures requires an understanding of interacting environmental and socioeconomic factors of host snails vis-a-vis schistosomiasis. Therefore, the present work involved collecting social and environmental data in a large field study in two zones in Zambia that are different in terms of temperature and rainfall amounts. Social data collected through questionnaires included demographic, educational and knowledge of schistosomiasis disease dynamics. Environmental data included physicochemical factors, aquatic plants and snails. Gender (P < 0.001) significantly influences livelihood strategies, while age (P = 0.069) and level of education (P = 0.086) have a moderate influence in zone I. In zone III, none of these factors (age, P = 0.378; gender, P = 0.311; education, P = 0.553) play a significant role. Environmental parameters explained 43 and 41 % variation in species composition for zones I and III, respectively. Most respondents' (52 %, 87 %) perception is that there are more cases of bilharzia in hot season than in other seasons (rainy season 23 %, 7 %; cold season 8 %, 0 % and year round 17 %, 6 %) for zone I and zone III, respectively.

Knowledge, attitude, and practices towards schistosomiasis among rural population in Yemen

Background

Schistosomiasis is highly prevalent in Yemen, with an estimated 3 million cases, particularly among rural communities. This community-based study aims to evaluate the knowledge, attitude and practices (KAP) on schistosomiasis among rural communities in Yemen.

Methods

A cross-sectional study was carried out among 250 households from ten rural districts in Yemen. Overall, 400 children were screened for urogenital and intestinal schistosomiasis. Moreover, parents were interviewed using a pre-tested questionnaire to collect information about the demographic and socioeconomic information and their KAP concerning schistosomiasis.

Results

A total of 127 (31.8 %) children were found to be excreting schistosome eggs in either their urine or faeces (22.5 % S. haematobium and 8.0 % S. mansoni). Although 92.4 % of the respondents had heard about schistosomiasis, 49.8 %, 68.0 % and 47.2 % had knowledge concerning the transmission, signs and symptoms, and prevention, respectively. In addition, 77.1 % considered schistosomiasis as harmful while 48.5 % believed that schistosomiasis could be prevented, albeit their practices to prevent infections were still inadequate. Significant associations between the KAP and age, education, employment status and household monthly income were reported (P < 0.05). Moreover, a significantly higher level of knowledge was reported among the respondents who had infected children compared to those with no infected family members (P < 0.05). Multiple logistic regression analysis revealed that the level of education and the history of schistosomiasis were the most important factors associated with the KAP concerning schistosomiasis among this population.

Conclusion

This study reveals that knowledge about the cause, transmission, symptoms and prevention of schistosomiasis among the rural population in Yemen was inadequate, and that this could be a challenging obstacle to the elimination of schistosomiasis in these communities. Besides the current mass drug administration, school and community-based health education regarding schistosomiasis is imperative among these communities to significantly reduce the transmission and morbidity of schistosomiasis.

Extent of morbidity associated with schistosomiasis infection in Malawi: a review paper

Data on the extent of the burden due to schistosomiasis is sparse in most Sub-Saharan African countries. However, this data is crucial for triggering medical attention. A review of extent of morbidity and determinants associated with schistosomiasis in Malawi was therefore conducted to quantify the infection in order to concretise the need for medical intervention. A systematic and traditional search strategy was used to find literature for the review, whilst exclusion and inclusion criteria were used to identify appropriate articles. Logistic regression curves of epidemiological model Y = (a + bx (c) )/(1 + bx (c) ) and the recommendation that schistosomiasis prevalence can be used to estimate morbidity were employed to quantify morbidity at various infection stages. Morbidity was quantified as a direct proportion of the population and the respective national schistosomiasis prevalence. Findings showed that both S. mansoni and S. haematobium are present in Malawi with the latter highly prevalent (50%). Furthermore, out of the estimated population of 16,829 million, approximately 8.4 million have schistosomiasis, with about 4.4 million of these aged 18 years and below. The most frequent manifestation is Katayama syndrome, while ascites is the lowest, impacting about 3.0 million and 960 individuals, respectively. Localised studies on association of schistosomiasis infection to risk factors such as occupation, age and gender found odds ratio (OR) ranging from 1.29 to 5.37. Morbidity due to schistosomiasis is high in Malawi. It is therefore recommended that a more detailed study on the determinants of high schistosomiasis and re-evaluation of the current control measures be conducted if the current morbidity statistics are to be remarkably reduced.

Impact of human schistosomiasis in sub-Saharan Africa

Schistosomiasis, a neglected tropical disease of poverty ranks second among the most widespread parasitic disease in various nations in sub-Saharan Africa. Neglected tropical diseases are causes of about 534,000 deaths annually in sub-Saharan Africa and an estimated 57 million disability-adjusted life-years are lost annually due to the neglected tropical diseases. The neglected tropical diseases exert great health, social and financial burden on economies of households and governments. Schistosomiasis has profound negative effects on child development, outcome of pregnancy, and agricultural productivity, thus a key reason why the “bottom 500 million” inhabitants of sub-Saharan Africa continue to live in poverty. In 2008, 17.5 million people were treated globally for schistosomiasis, 11.7 million of those treated were from sub-Saharan Africa. This enervating disease has been successfully eradicated in Japan, as well as in Tunisia. Morocco and some Caribbean Island countries have made significant progress on control and management of this disease. Brazil, China and Egypt are taking steps towards elimination of the disease, while most sub-Saharan countries are still groaning under the burden of the disease. Various factors are responsible for the continuous and persistent transmission of schistosomiasis in sub-Saharan Africa. These include climatic changes and global warming, proximity to water bodies, irrigation and dam construction as well as socio-economic factors such as occupational activities and poverty. The morbidity and mortality caused by this disease cannot be overemphasized. This review is an exposition of human schistosomiasis as it affects the inhabitants of various communities in sub-Sahara African countries. It is hoped this will bring a re-awakening towards efforts to combat this impoverishing disease in terms of vaccines development, alternative drug design, as well as new point-of-care diagnostics.

Schistosomiasis in Malawi: a systematic review

INTRODUCTION

Schistosomiasis remains an important public health problem that undermines social and economic development in tropical regions of the world, mainly Sub-Saharan Africa. We are not aware of any systematic review of the literature of the epidemiology and transmission of schistosomiasis in Malawi since 1985. Therefore, we reviewed the current state of knowledge of schistosomiasis epidemiology and transmission in this country and identified knowledge gaps and relevant areas for future research and research governance.

METHODS

We conducted computer-aided literature searches of Medline, SCOPUS and Google Scholar using the keywords: "schistosomiasis", "Bilharzia", "Bulinus" and "Biomphalaria" in combination with "Malawi". These searches were supplemented by iterative reviews of reference lists for relevant publications in peer reviewed international scientific journals or other media. The recovered documents were reviewed for their year of publication, location of field or laboratory work, authorship characteristics, ethics review, funding sources as well as their findings regarding parasite and intermediate host species, environmental aspects, geographical distribution, seasonality of transmission, and infection prevalence and intensities.

REVIEW

A total of 89 documents satisfied the inclusion criteria and were reviewed. Of these, 76 were published in international scientific journals, 68 were peer reviewed and 54 were original research studies. Most of the documents addressed urinary schistosomiasis and about two thirds of them dealt with the definitive host. Few documents addressed the parasites and the intermediate hosts. While urinary schistosomiasis occurs in most parts of Malawi, intestinal schistosomiasis mainly occurs in the central and southern highlands, Likoma Island and Lower Shire. Studies in selected communities estimated prevalence rates of up to 94.9% for Schistosoma haematobium and up to 67.0% for Schistosoma mansoni with considerable geographical variation. The main intermediate host species are Bulinus globosus and Bulinus nyassanus for urinary schistosomiasis and Biomphalaria pfeifferi for intestinal schistosomiasis. Seasonality of transmission tends to vary according to geographical, environmental, biological and behavioural factors.

CONCLUSION

Transmission of schistosomiasis in Malawi appears to be highly focal, with considerable variation in space and time. Many locations have not been covered by epidemiological investigations and, thus, information on the transmission of schistosomiasis in Malawi remains fragmented. Functional infection risk assessment systems based on systematic investigations and surveillance are required for developing informed prevention and control strategies.

Prevalence, risk factors, and clinical manifestations of schistosomiasis among school children in the White Nile River basin, Sudan

Background

We investigated the prevalence, risk factors, and clinical manifestations of schistosomiasis in White Nile State, Sudan, to determine the local characteristics of schistosomiasis in the White Nile River basin.

Methods

Urine and stool samples were collected from 338 students (176 boys, 162 girls) at three primary schools and were examined using the urine filtration method and the Kato-Katz technique, respectively. Of the students, 200 were interviewed using a semi-structured questionnaire to assess water-contact patterns and health conditions related with urinary schistosomiasis.

Results

Of the 338 students, egg-positive rates for S. haematobium and S. mansoni were 45.0% and 5.9%, respectively, and 4.4% were mixed. The intensities of S. haematobium and S. mansoni infection were 1.091 ± 0.744 log EP10 (eggs per 10 mL of urine, mean ± SD = 57 ± 172 EP10) and 1.787 ± 0.844 log EPG (eggs per gram of stool, mean ± SD = 156 ± 176 EPG), respectively. The prevalence and intensity of S. haematobium infection differed significantly among the three schools, but not by gender or age. Urinary schistosomiasis was significantly associated with the frequencies of contaminated water contact, taking baths, swimming, and wading the stream; however, frequencies of these events were not significantly correlated with infection intensity. Self-reported hematuria and dysuria also correlated significantly with urinary schistosomiasis.

Conclusions

The overall prevalence of schistosomiasis, especially urinary schistosomiasis, is high in the White Nile River basin, Sudan, and is closely associated with frequencies of water contact, taking baths, swimming, and wading the stream. We strongly recommend implementation of an integrated schistosomiasis control program in this area.

Bacteriuria and urinary schistosomiasis in primary school children in rural communities in Enugu State, Nigeria, 2012

INTRODUCTION

According to a study conducted in1989, Enugu State has an estimated urinary schistosomiasis prevalence of 79%. Recently, studies have implicated bacteriuria co-infection in bladder cancer. These bacteria accelerate the multi-stage process of bladder carcinogenesis. Knowledge about the prevalence of this co-infection is not available in Enugu and the information provided by the 1989 study is too old to be used for current decision making.

METHODS

We carried out a cross-sectional survey of primary school children aged 5-15 years, who were randomly selected through a multi stage sampling method using guidelines recommended by WHO for schistosomiasis surveys. An interviewer administered questionnaire was used to collect data on demography, socioeconomic variables and clinical presentations. Urine samples were collected between 10.00am and 2.00pm. Each sample was divided into two: (A) for prevalence and intensity using syringe filtration technique and (B) for culture. Intensity was categorized as heavy (>50ova/10mls urine) and light (<50ova/10mls urine). Significant bacteriuria was bacteria count ≥ 105 colony forming units/ml of urine.

RESULTS

Of the 842 pupils, 50.6% were females. The prevalence of urinary schistosomiasis was 34.1%. Infection rate was higher(52.8%) among 13-15 years(Prevalence Ratio = 2.45, 95% Confidence Interval 1.63-3.69). Heavy infections wad 62.7% and egg count/10mls urine ranged from 21-1138. Significant bacteriuria among pupils with urinary schistosomiasis was 53.7% compared to 3.6% in the uninfected(PR = 30.8,95% CI 18.91- 52.09). The commonest implicated organism was Escherchia coli.

CONCLUSION

We found high prevalence of bacteriuria co-infection among children with urinary schistosomiasis in Enugu State. This underscores the need for concurrent antibiotics administration and follow-up to avert later complications.

Micro-geographical heterogeneity in Schistosoma mansoni and S. haematobium infection and morbidity in a co-endemic community in northern Senegal

BACKGROUND

Schistosoma mansoni and S. haematobium are co-endemic in many areas in Africa. Yet, little is known about the micro-geographical distribution of these two infections or associated disease within such foci. Such knowledge could give important insights into the drivers of infection and disease and as such better tailor schistosomiasis control and elimination efforts.

METHODOLOGY

In a co-endemic farming community in northern Senegal (346 children (0-19 y) and 253 adults (20-85 y); n = 599 in total), we studied the spatial distribution of S. mansoni and S. haematobium single and mixed infections (by microscopy), S. mansoni-specific hepatic fibrosis, S. haematobium-specific urinary tract morbidity (by ultrasound) and water contact behavior (by questionnaire). The Kulldorff's scan statistic was used to detect spatial clusters of infection and morbidity, adjusted for the spatial distribution of gender and age.

PRINCIPAL FINDINGS

Schistosoma mansoni and S. haematobium infection densities clustered in different sections of the community (p = 0.002 and p = 0.023, respectively), possibly related to heterogeneities in the use of different water contact sites. While the distribution of urinary tract morbidity was homogeneous, a strong geospatial cluster was found for severe hepatic fibrosis (p = 0.001). Particularly those people living adjacent to the most frequently used water contact site were more at risk for more advanced morbidity (RR = 6.3; p = 0.043).

CONCLUSIONS/SIGNIFICANCE

Schistosoma infection and associated disease showed important micro-geographical heterogeneities with divergent patterns for S. mansoni and S. haematobium in this Senegalese community. Further in depth investigations are needed to confirm and explain our observations. The present study indicates that local geospatial patterns should be taken into account in both research and control of schistosomiasis. The observed extreme focality of schistosomiasis even at community level, suggests that current strategies may not suffice to move from morbidity control to elimination of schistosomiasis, and calls for less uniform measures at a finer scale.

Prevalence and associated factors of Schistosomiasis among children in Yemen: implications for an effective control programme

Background

Schistosomiasis, one of the most prevalent neglected tropical diseases, is a life-threatening public health problem in Yemen especially in rural communities. This cross-sectional study aims to determine the prevalence and associated risk factors of schistosomiasis among children in rural Yemen.

Methods/Findings

Urine and faecal samples were collected from 400 children. Urine samples were examined using filtration technique for the presence of Schistosoma haematobium eggs while faecal samples were examined using formalin-ether concentration and Kato Katz techniques for the presence of S. mansoni. Demographic, socioeconomic and environmental information were collected via a validated questionnaire. Overall, 31.8% of the participants were found to be positive for schistosomiasis; 23.8% were infected with S. haematobium and 9.3% were infected with S. mansoni. Moreover, 39.5% of the participants were anaemic whereas 9.5% had hepatosplenomegaly. The prevalence of schistosomiasis was significantly higher among children aged >10 years compared to those aged ≤10 years (P<0.05). Multivariate analysis confirmed that presence of other infected family member (P<0.001), low household monthly income (P = 0.003), using unsafe sources for drinking water (P = 0.003), living nearby stream/spring (P = 0.006) and living nearby pool/pond (P = 0.002) were the key factors significantly associated with schistosomiasis among these children.

Conclusions/Significance

This study reveals that schistosomiasis is still highly prevalent in Yemen. These findings support an urgent need to start an integrated, targeted and effective schistosomiasis control programme with a mission to move towards the elimination phase. Besides periodic drug distribution, health education and community mobilisation, provision of clean and safe drinking water, introduction of proper sanitation are imperative among these communities in order to curtail the transmission and morbidity caused by schistosomiasis. Screening and treating other infected family members should also be adopted by the public health authorities in combating this infection in these communities.

Schistosomiasis remains one of the most serious and prevalent diseases worldwide. Despite intensive control efforts by the government and international bodies, schistosomiasis is the second cause of death, after malaria, in Yemen, with an estimated 3 million cases. We screened 400 children in rural areas of five provinces in Yemen for the presence of schistosomiasis. Overall, 31.8% of the children were found to be positive for schistosomiasis; 23.8% were infected by Schistosoma haematobium, and 9.3% were infected by S. mansoni. The study identified the presence of other family members infected with schistosomiasis, low household monthly income, using unsafe water supply as a source for drinking water, living nearby stream/spring and/or pool/pond as the key factors significantly associated with schistosomiasis in these communities. Innovative and integrated control measures to control this infection should be implemented among this population. Periodic school-based and community-based drug distribution, health education, provision of clean and safe drinking water, introduction of proper sanitation will help to reduce the prevalence and morbidity of schistosomiasis among these communities.