Exposure, hazard, and vulnerability all contribute to Schistosoma haematobium re-infection in northern Senegal.

BACKGROUND: Infectious disease risk is driven by three interrelated components: exposure, hazard, and vulnerability. For schistosomiasis, exposure occurs through contact with water, which is often tied to daily activities. Water contact, however, does not imply risk unless the environmental hazard of snails and parasites is also present in the water. By increasing reliance on hazardous activities and environments, socio-economic vulnerability can hinder reductions in exposure to a hazard. We aimed to quantify the contributions of exposure, hazard, and vulnerability to the presence and intensity of Schistosoma haematobium re-infection. METHODOLOGY/PRINCIPAL FINDINGS: In 13 villages along the Senegal River, we collected parasitological data from 821 school-aged children, survey data from 411 households where those children resided, and ecological data from all 24 village water access sites. We fit mixed-effects logistic and negative binomial regressions with indices of exposure, hazard, and vulnerability as explanatory variables of Schistosoma haematobium presence and intensity, respectively, controlling for demographic variables. Using multi-model inference to calculate the relative importance of each component of risk, we found that hazard (Æ©wi = 0.95) was the most important component of S. haematobium presence, followed by vulnerability (Æ©wi = 0.91). Exposure (Æ©wi = 1.00) was the most important component of S. haematobium intensity, followed by hazard (Æ©wi = 0.77). Model averaging quantified associations between each infection outcome and indices of exposure, hazard, and vulnerability, revealing a positive association between hazard and infection presence (OR = 1.49, 95% CI 1.12, 1.97), and a positive association between exposure and infection intensity (RR 2.59-3.86, depending on the category; all 95% CIs above 1). CONCLUSIONS/SIGNIFICANCE: Our findings underscore the linkages between social (exposure and vulnerability) and environmental (hazard) processes in the acquisition and accumulation of S. haematobium infection. This approach highlights the importance of implementing both social and environmental interventions to complement mass drug administration.

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

BACKGROUND: Knowledge of urogenital schistosomiasis can empower individuals to limit surface water contact and participate in mass drug administration campaigns, but nothing is currently known about the schistosomiasis knowledge that schoolchildren have in Ghana. We developed and implemented a survey tool aiming to assess the knowledge of urogenital schistosomiasis (treatment, transmission, prevention, symptoms) among science teaches and primary and junior high school students in the Eastern Region of Ghana. METHODS: We developed a 22-question knowledge survey tool and administered it to 875 primary and 938 junior high school students from 74 schools in 37 communities in the Eastern Region of Ghana. Teachers (n = 57) answered 20 questions matched to student questions. We compared knowledge scores (as percent of correct answers) across topics, gender, and class year and assessed associations with teacher's knowledge scores using t-tests, chi-squared tests, univariate, and multivariate linear regression, respectively. RESULTS: Students performed best when asked about symptoms (mean±SD: 76±21% correct) and prevention (mean±SD: 69±25% correct) compared with transmission (mean±SD: 50±15% correct) and treatment (mean±SD: 44±23% correct) (p<0.0005). Teachers performed best on prevention (mean±SD: 93±12% correct, p<0.0005) and poorest on treatment (mean±SD: 69±16% correct, p<0.001). When listing five facts about urogenital schistosomiasis, teachers averaged 2.9±1.2 correct. Multiple regression models suggest that gender, class year, teacher score, and town of residency explain ~27% of variability in student scores. On average, junior high school students outperformed primary school students by 10.2 percentage points (CI95%: 8.6-11.8); boys outperformed girls by 3.5 percentage points (CI95%: 2.3-4.7). CONCLUSIONS: Our survey parsed four components of student and teacher knowledge. We found strong knowledge in several realms, as well as knowledge gaps, especially on transmission and treatment. Addressing relevant gaps among students and science teachers in UGS-endemic areas may help high-risk groups recognize risky water contact activities, improve participation in mass drug administration, and spark interest in science by making it practical.

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.

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.

Epidemiological and clinical aspects of urogenital schistosomiasis in women, in Burkina Faso, West Africa.

BACKGROUND: Because infections with Schistosoma Haematobium usually peak in childhood, the majority of studies on schistosomiasis have focused on school-aged children. This study aimed to assess the epidemiological and clinical aspects of urogenital schistosomiasis in women in Burkina Faso, West Africa. METHODS: A cross-sectional study was conducted in a mesoendemic region (Kombissiri) and a hyperendemic region (Dori) for schistosomiasis in Burkina Faso. A total of 287 females aged 5 to 50 years were included in the study. S. haematobium infection was assessed using the urine filtration method and dipsticks were used for the detection of hematuria. Interviews were conducted to identify clinical aspects and risk factors related to urogenital schistosomiasis. RESULTS: The overall prevalence of S. haematobium infection in Dori was 21.3 %, where as Kombissiri was less affected with a prevalence of 4.6 %. The most affected age group was the 10- to 14-year-olds (41.2 %), followed by the 15- to 19-year-olds (26.3 %). Risk factors significantly associated with schistosomiasis (P <0.05) were place of residence, age, contact with open water in the past year, and distance of home to open water. The percentage of participants who had contact with open water was significantly higher among the women living in Dori compared to Kombissiri. Females over 15 years of age showed a significant higher rate of water contact compared to the 5- to 15-year-olds. A significant correlation between schistosomiasis and hematuria was established. Microhematuria showed a sensitivity of 80.6 %, a specificity of 92.7 %, and a positive predictive value of 61.7 %, whereas macrohematuria had a sensitivity of 47.2 %, a specificity of 99.2 %, and a positive predictive value of 89.5 %. The mass distribution of praziquantel in Burkina Faso is well established. However, over half of the participants with schistosomiasis in this study said they took praziquantel in the past 6 months, which indicates a high reinfection rate. This may be associated with a lack of knowledge about the transmission of schistosomiasis. Only 6 % of the participants in Kombissiri and 1.5 % in Dori knew about the correct mode of transmission. CONCLUSIONS: The results of our study indicate that distribution campaigns should be extended from school-aged children to young women. Our data also demonstrate the necessity of combining already established mass distribution campaigns with information campaigns, so that long-term elimination, or at least reduction, of schistosomiasis can be achieved.

Evaluation of the health-related quality of life of children in Schistosoma haematobium-endemic communities in Kenya: a cross-sectional study.

BACKGROUND: Schistosomiasis remains a global public health challenge, with 93% of the ~237 million infections occurring in sub-Saharan Africa. Though rarely fatal, its recurring nature makes it a lifetime disorder with significant chronic health burdens. Much of its negative health impact is due to non-specific conditions such as anemia, undernutrition, pain, exercise intolerance, poor school performance, and decreased work capacity. This makes it difficult to estimate the disease burden specific to schistosomiasis using the standard DALY metric. METHODOLOGY/PRINCIPAL FINDINGS: In our study, we used Pediatric Quality of Life Inventory (PedsQL), a modular instrument available for ages 2-18 years, to assess health-related quality of life (HrQoL) among children living in a Schistosoma haematobium-endemic area in coastal Kenya. The PedsQL questionnaires were administered by interview to children aged 5-18 years (and their parents) in five villages spread across three districts. HrQoL (total score) was significantly lower in villages with high prevalence of S. haematobium (-4.0%, p<0.001) and among the lower socioeconomic quartiles (-2.0%, p<0.05). A greater effect was seen in the psychosocial scales as compared to the physical function scale. In moderate prevalence villages, detection of any parasite eggs in the urine was associated with a significant 2.1% (p<0.05) reduction in total score. The PedsQL reliabilities were generally high (Cronbach alphas ≥0.70), floor effects were acceptable, and identification of children from low socioeconomic standing was valid. CONCLUSIONS/SIGNIFICANCE: We conclude that exposure to urogenital schistosomiasis is associated with a 2-4% reduction in HrQoL. Further research is warranted to determine the reproducibility and responsiveness properties of QoL testing in relation to schistosomiasis. We anticipate that a case definition based on more sensitive parasitological diagnosis among younger children will better define the immediate and long-term HrQoL impact of Schistosoma infection.

Exploring the feasibility and possible efficacy of mass treatment and education of young females as schistosomiasis influences the HIV epidemic.

PURPOSE: Genital schistosomiasis may be a risk factor for HIV, but chronic lesions in adults may be refractory to standard treatment. We aimed to investigate young girls' risk factors for gynaecological schistosomiasis, possible protective factors and possibilities for behavioural change and mass treatment in rural Tanzania. METHODS: A standardised questionnaire was used to interview females between 5 and 20 years of age in a small cross-sectional study. RESULTS: One third of the girls were found to be at risk of acquiring schistosomal infection. Younger and older girls were engaged in more risk behaviour than the 10-14-year-olds. Knowledge of the parasite was associated with less risky water contact, and most of the girls had acquired this knowledge through primary school education. CONCLUSION: Mass treatment for gynaecological schistosomiasis should be done in collaboration with the school system as a joint venture with the health system in order to reach non-enrolled girls who may be at particular risk. Research is still needed to assess the preventive effect of treatment on genital lesions and on HIV incidence.

The perception, beliefs and practices toward genitourinary schistosomiasis by inhabitants of selected endemic areas (Edo/Delta States) in south-eastern Nigeria.

Well-structured questionnaire on the perception, impression and response to genitourinary bilharziasis (Genitourinary schistosomiasis) was administered and explained in local languages: 'Igbo' 'Esan' 'Ezon' Itshekiri and Bini to 33815 inhabitants of selected endemic areas in south-eastern Nigeria from January, 1999 to December, 2001. Out of this number, 3815 (11.3%) were properly filled and returned. About 42.0% of the inhabitants admitted knowledge of the disease, while 14 (0.4%) knew about the aetiologic agent. About 181 (5.0%) who responded, admitted procuring treatment, while 100 (5.0%) declined to seek treatment of any sort. The relationships between water-bodies and human activities, and infection were well discussed. Amongst those who admitted knowledge of the disease but no knowledge of its etiologic agent, declined seeking treatment of any kind, but believe the disease is a natural phenomenon in ones developmental stage and therefore of no morbidity and mortality. Laboratory analysis of urine, faeces, semen and HVS was employed to assess questionnaire responses, and in some cases, physical examination was utilized to augment laboratory analysis in confirming urinal diagnosis. Haematuria was only directly related to egg count in the early part of life. Females were significantly haematuric and excreted more ova than males (p < 0.05). Headache (43.0%) and fever (31.0%) were major clinical signs while sexual pains (22.0%) were the least.

Determinants of health-seeking behaviour for schistosomiasis-related symptoms in the context of integrating schistosomiasis control within the regular health services in Ghana.

Morbidity control of schistosomiasis through integration within existing health care delivery systems is considered a potentially sustainable and cost-effective approach. We conducted a questionnaire-based field study in a Ghanaian village endemic for both urinary and intestinal schistosomiasis to determine whether infected individuals self-reported to health centres or clinics and to identify factors that influenced their decision to seek health care. A total of 317 subjects were interviewed about having signs and symptoms suggestive of schistosomiasis: blood in urine, painful urination, blood in stool/bloody diarrhoea, abdominal pain, diarrhoea, swollen abdomen and fatigue within 1 month of the day of the interview. Fever (for malaria) was included as a disease of high debility for comparison. Around 70% with blood in urine or painful urination did not seek health care, whilst diarrhoea, blood in stool, abdominal pain and fever usually led to action (mainly self-medication, with allopathic drugs being used four to five times more often than herbal treatment). On average 20% of schistosomiasis-related signs and symptoms were reported to health facilities either as the first option or second and third alternative by some of those that self-medicated. A few of those who visited a clinic or health centre as first option still self-medicated afterwards. Children under 10 years and adults were more likely to seek health care than teenagers. Also, females were more likely to visit a health facility than males of the same age groups. Socio-economic status and duration of symptoms did not appear to affect health-seeking behaviour. 'Do not have the money' (43%) and 'Not serious enough' (41%) were the commonest reasons for not visiting a clinic, reported more frequently by lower and higher socio-economic classes, respectively, for both urinary or intestinal schistosomiasis. The regular health service shows some potential in passive control of schistosomiasis as some, but far too few, people visit a health facility as first or second option.

Schistosomiasis-related perceptions, attitudes and treatment-seeking practices in Magu district, Tanzania: public health implications.

A study on perceptions, attitudes and treatment-seeking practices related to schistosomiasis was conducted among the Wasukuma in the rural Magu district of Tanzania at the shore of Lake Victoria where Schistosoma haematobium and mansoni infections are endemic. The study applied in-depth interviews, focus group discussions and a questionnaire survey among adults and primary school children. The perceived symptoms and causes were incongruous with the biomedical perspective and a number of respondents found schistosomiasis to be a shameful disease. Lack of diagnostic and curative services at the government health care facilities was common, but there was a willingness from the biomedical health care services to collaborate with the traditional healers. Recommendations to the District Health Management Team were: that collaboration between biomedical and traditional health care providers should be strengthened and that the government facilities' diagnostic and curative capacity with regard to schistosomiasis should be upgraded. Culturally compatible health education programmes should be developed in collaboration with the local community.

Modification of behaviour and attitude in the control of schistosomiasis. 1. Observations on water-contact patterns and perception of infection.

Observations on the water-contact patterns of 2136 residents of Admin community in Nigeria were conducted at four streams between February 1993 and January 1994. Urine samples collected from those observed were used to estimate the prevalence and intensity of Schistosoma haematobium infection. A questionnaire was also completed for each of the subjects, to test their perception of urinary schistosomiasis and its transmission. Infection was detected in 1076 (50.4%) of the subjects, with peak prevalence among those aged 10-14 years. Intensity of infection was more closely correlated with the number of water contacts (r = 0.97) than with the total duration of the exposure (r = 0.77), emphasising the importance of specific/multiple activities, and of the surface area of the body submerged, in transmission. One stream (Culvet) was identified as the main transmission point, with bathing/swimming and fishing as the main activities predisposing people to infection. The awareness of urinary schistosomiasis and its symptom (blood in urine) were high but specific knowledge about the parasite, its vector and the interaction between the parasite and vector in the parasite's life-cycle were extremely low. Activities that require behaviour and attitude modification have been identified and encouraged as components in the control of schistosome-attributable morbidity (in the absence of pipe-borne water).

The relationship between Schistosoma haematobium infection and school performance and attendance in Bamako, Mali.

Schistosomiasis due to Schistosoma haematobium was the most common helminth infection in school-age children from a poor area in Bamako, Mali. Almost half (47%) of the boys and 40% of the girls were infected, 18% of the children being heavily infected. There was a significant decline in academic performance and in school attendance with increasing intensity of infection. When all sources of variation were taken into consideration, absenteeism was the main factor explaining the variation in academic performance, although a significant effect of infection remained. School-based delivery of chemotherapeutic interventions is currently promoted by several international organizations. However, rates of school attendance are low in some areas and it is the absentees who appear to be at relatively high risk of ill health. Novel ways of reaching this elusive subset of the population are required.

Effect of Schistosoma haematobium infection on the physical growth and school performance of Nigerian children.

A cross-sectional study of urinary schistosomiasis among 510 primary school children in Ijiman community in south eastern Nigeria was undertaken in May 1992. Schistosoma prevalence and intensity of infection including the impact of the disease on the physical growth and school performance of the subjects aged 5-15 years was assessed. Prevalence of Schistosoma haematobium was 44 pc with the rate rising progressively with age, with a peak prevalence at 10-15. The ova burden was of light intensity (1-49 ova/10 ml) in a majority (73 pc) of the cases. No significant impact of the disease could be demonstrated regarding anthropometric parameters, school attendance and academic performance among the infected children compared with the controls. The lack of discernable effect of S. haematobium infection on these parameters is similar to the general pattern in the west African sub region and is attributed to the generally light ova burden among these children. It is also suggested that differences in the strains of the parasite between regions may be important determinants of morbidity.

Effects of Schistosoma haematobium infection on mental test scores of Kenyan school children.

Adverse effects of Schistosoma haematobium infection on mental activities were studied at a primary school in rural Kenya, where the intensity of infection was light (the average egg count: < 50/10 ml of urine). The school children received three kinds of mental tests, which examine attentiveness and concentration, before and a month after treatment with a single dose of praziquantel. A pretreatment analysis showed that test scores became worse as egg counts of children increased. The praziquantel treatment improved the scores of all three tests among children who got high scores in the first tests. The study showed that even the light infection caused adverse effects on mental activities, which were detectable using simple mental tests.

The effects of Schistosomiasis haematobium on the activity of school children.

Schistosomiasis haematobium is prevalent in many parts of Africa, especially among school-age children. It is thought to cause lethargy, but the effect may be masked by the selective exposure of more active children to the disease. Infected children at a primary school in an endemic area in South Africa were used as their own controls in a before-and-after treatment study. Energetic activity was monitored by means of electronic meters before treatment, and at 3 and 6 months after treatment with an antischistosomal drug. Results indicated that the scores of treated children had increased significantly relative to the untreated controls, and that there were differences between the sexes in the change of activity level.