Detection of schistosome infection in the invasive snail Melanoides tuberculata (Gastropoda: Thiaridae) by polymerase chain reaction from Plateau State, Nigeria: a novel turning point in disease epidemiology and control?

BACKGROUND: Melanoides tuberculata is a freshwater snail that serves as an intermediate host for 11 parasitic flukes. This study was conducted with the aim of identifying and screening the snail intermediate hosts in the study site for schistosomiasis using the molecular technique. METHODS: DNA was extracted from the snails by the hexadecyl trimethyl ammonium bromide method and the Dra1 primer was used to amplify the Dra1 repeated sequence of Schistosoma haematobium. RESULTS: The presence of schistosome DNA in M. tuberculata by polymerase chain reaction was confirmed. CONCLUSIONS: Our findings show that M. tuberculata is a potential intermediate host of schistosomes.

Retraction Note: The epidemiology and chemotherapeutic approaches to the control of urinary schistosomiasis in school-age children (SAC): a systematic review.

The authors have retracted this article [1] because of methodological inaccuracies and incorrect use of the PRISMA/PROSPERO guidelines of systematic reviews and meta-analyses in the article.

The epidemiology and chemotherapeutic approaches to the control of urinary schistosomiasis in school-age children (SAC): a systematic review.

BACKGROUND: Human schistosomiases are acute and chronic infectious diseases of poverty. Currently, epidemiological data of urinary schistosomiasis (US) in school-age children (SAC) and adults are often reported together making it difficult to ascertain the true status of the disease. Based on this premise, we set out to carry out this review. METHOD: To achieve this aim, we carried out a computer-aided search of PubMed, Web of Science, Science Direct, African Journals OnLine (AJOL) and the database of World Health Organization. However, the information obtained from these sources was supplemented with additional literatures from Mendeley, Research Gate, and Google. RESULTS: The search yielded 183 literatures of which 93 full text research, review and online articles were deemed fit for inclusion. Our key findings showed that: (1) of all World Health Organization (WHO) Regions, Africa is the most endemic zone for US, with Kenya and Senegal recording the highest prevalence and mean intensity respectively; (2) SAC within the range of 5-16 years contribute most significantly to the transmission cycle of US globally; (3) gender is a factor to watch out for, with male often recording the highest prevalence and intensity of infection; (4) contact with open, potentially infested water sources contribute significantly to transmission; (5) parental factors (occupation and education status) predispose SAC to US; (6) economic vis a vis ecological factors play a key role in infection transmission; and (7) in the last decade, a treatment coverage of 45% was never achieved globally for SAC or non-SAC treatment category for urinary schistosomiasis. CONCLUSION: In view of the WHO strategic plan to eliminate schistosomiasis by 2020 and the findings from this review, it is obvious that this goal, in the face of realities, might not be achieved. It is imperative that annual control programmes be scaled up marginally, particularly in the African region of WHO. While US-based researches should be sponsored at the grass-root level to unveil hidden endemic foci, adequate facilities for Water, Sanitation, and Hygiene (WASH) should be put in place in all schools globally.

The current epidemiological status of urogenital schistosomiasis among primary school pupils in Katsina State, Nigeria: An imperative for a scale up of water and sanitation initiative and mass administration of medicines with Praziquantel.

INTRODUCTION: Human schistosomiasis, a debilitating and chronic disease, is among a set of 17 neglected tropical infectious diseases of poverty that is currently posing a threat to the wellbeing of 2 billion people in the world. The SHAWN/WASH and MAM programmes in the study area require epidemiological data to enhance their effectiveness. We therefore embarked on this cross-sectional study with the aim of investigating the prevalence, intensity and risk factors of urogenital schistosomiasis. METHODOLOGY/ PRINCIPAL FINDINGS: Interviewed 484 respondents produced terminal urine samples (between 10.00h - 14.00h) which were analyzed with Medi ─Test Combi 10 and centrifuged at 400 r.p.m for 4 minutes using C2 series Centurion Scientific Centrifuge. Eggs of S. haematobium were identified with their terminal spines using Motic Binocular Microscope. Data were analyzed with Epi Info 7. In this study, the overall prevalence and arithmetic mean intensity of the infection were 8.68% (6.39─ 11.64) and 80.09 (30.92─129.28) eggs per 10ml of urine respectively. Urogenital schistosomiasis was significantly associated with knowledge about the snail host (χ2 = 4.23; P = 0.0398); water contact activities (χ2 = 25.788; P = 0.0001), gender (χ2 = 16.722; P = 0.0001); age (χ2 = 9.589; P = 0.0019); economic status of school attended (χ2 = 4.869; P = 0.0273); residence distance from open water sources (χ2 = 10.546; P = 0.0012); mothers' occupational (χ2 = 6.081; P = 0.0137) and educational status (χ2 = 4.139; P = 0.0419). CONCLUSION/ SIGNIFICANCE: The overall prevalence obtained in this survey shows that the study area was at a low-risk degree of endemicity for urogenital schistosomiasis. Beneath this is a subtle, latent and deadly morbidity-inducing heavy mean intensity of infection, calling for urgent implementation of WHO recommendation that MAM with PZQ be carried out twice for School-Age Children (enrolled or not enrolled) during their primary schooling age (once each at the point of admission and graduation). The criteria for classifying endemic areas for schistosomiasis should also be reviewed to capture the magnitude of mean intensity of infection rather than prevalence only as this may underplay its epidemiological severity.

Rapid mapping of urinary schistosomiasis: An appraisal of the diagnostic efficacy of some questionnaire-based indices among high school students in Katsina State, northwestern Nigeria.

BACKGROUND: In sub-Saharan Africa, over 200 million individuals are estimated to be infected with urinary and intestinal schistosomiasis. In a bid to lay a foundation for effective future control programme, this study was carried out with the aim of assessing the diagnostic efficacy of some questionnaire-based rapid assessment indices of urinary schistosomiasis. METHODOLOGY: A total number of 1,363 subjects were enrolled for the study. Questionnaires were administered basically in English and Hausa languages by trained personnel. Following informed consent, terminal urine samples were collected between 09:40 AM and 2:00 PM using clean 20 ml capacity universal bottles. 10µl of each urine residue was examined for the eggs of S. haematobium using x10 objective nose of Motic Binocular Light Microscope (China). PRINCIPAL FINDINGS: The average age ± Standard Deviation (SD) of school children examined was 15.30 ± 2.30 years and 40.87% were females. The overall prevalence and geometric mean intensity of S. haematobium infection were 26.41% (24.10─28.85) and 6.59 (5.59─7.75) eggs / 10 ml of urine respectively. Interestingly, a questionnaire equivalence of the prevalence obtained in this survey was 26.41% (24.10─28.85) for Rapid Assessment Procedure based on self-reported blood in urine. The results of correlation analyses demonstrated significant associations between the prevalence of S. haematobium infection and contact with potentially infested open water sources (r = 0.741; P = 0.006). By regression model, cases of respondents with self-reported blood in urine are expected to rise to 24.75% if prevalence of the infection shoots up to 26.5%. CONCLUSIONS/SIGNIFICANCE: The best RAP performance was obtained with self-reported blood in urine. Based on the overall prevalence value, the study area was at a "moderate-risk" of endemicity for urinary schistosomiasis. Chemotherapeutic intervention with Praziquantel, the rationale behind rapid assessment procedure for schistosomiasis, has been recommended to be carried out once in every 2 years for such communities.

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 (X (2) = 29.031, P = 0.0000), sex (male) [X (2) = 109.82; P<0.0001], location (Dutsin─Ma) [X (2) = 7.19; P = 0.0073], age group 18-20 (X (2) = 4.819, P = 0.0281), altitude (531─560 m) [X (2) = 6.84, p = 0.0089], fathers doing other brown─collar jobs (X (2) = 8.449, P = 0.0037) and mothers' occupation (X (2) = 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.

Prevalence and intensity of genito-urinary schistosomiasis and associated risk factors among junior high school students in two local government areas around Zobe Dam in Katsina State, Nigeria.

BACKGROUND: The national burden of genito-urinary schistosomiasis in Nigeria has been expressed by an estimate of 101.3 million people at risk with an alarming figure of 29 million infected. Report obtained from respondents about Praziquantel® distribution and the obviously prevalent haematuria without any control programme in place justified the need for data on the prevalence, intensity of infection and associated risk factors which were the objectives this cross-sectional survey sought to address. METHODS: A total of 718 students aged 10-23 years from the study area were surveyed between May and August, 2015. Data on socio-demographic and risk factors were obtained using structured questionnaires. Clean universal bottles with corresponding labels were offered for sample collection between 10:00 am and 13:30 pm. Centrifuged samples were microscopically examined and intensity of infection was recorded per 10 ml of each sample. RESULTS: Prevalence of genito-urinary schistosomiasis was 22.7 % with a mean intensity of 25.05 (± standard deviation, ± 71.51) eggs/10 ml of urine. Higher prevalence (19.5 %) and mean intensity (28.7 eggs/10 ml of urine) was recorded among boys. Sex (χ (2) = 77.065, P < 0.0001), age group 16-18 (χ (2) = 5.396, P = 0.0202), altitude (χ (2) = 8.083, P = 0.0045), unwholesome water sources (χ (2) = 27.148, P < 0.0001), human recreational activities (χ (2) = 122.437, P < 0.0001), mothers' occupation (χ (2) = 6.359, P = 0.0117), farming (χ (2) = 6.201, P = 0.0128) and other brown collar jobs (χ (2) = 4.842, P = 0.0278) in fathers' occupational category were found to be significantly associated with urogenital schistosomiasis. Boys were seven times more likely to be infected compared to girls [AOR (95 % CI): 7.3 (4.26-12.4)]. Age group 16-18 years was four times more likely to be infected compared to age group 10-12 years [AOR (95 % CI): 4.43 (2.62-7.49)]. Similarly, respondents with farming as fathers' occupation were twice more likely to be infected than those whose fathers were civil servants [AOR (95 % CI): 2.08 (1.2-3.59)]. CONCLUSIONS: Dutsin-Ma and Safana were classified as moderate-risk Local Government Areas (LGA). Sex, altitude, unwholesome water sources and mothers' occupation were identified as the determining epidemiological factors in the prevalence of the disease. Sustainable chemotherapeutic intervention with Praziquantel®, good network of treated pipe-borne water, health education and waste disposal facilities are highly recommended to reduce its prevalence below the threshold of public health significance.