Geographical information system and predictive risk maps of urinary schistosomiasis in Ogun State, Nigeria

<p>Abstract</p> <p>Background</p> <p>The control of urinary schistosomiasis in Ogun State, Nigeria remains inert due to lack of reliable data on the geographical distribution of the disease and the population at risk. To help in developing a control programme, delineating areas of risk, geographical information system and remotely sensed environmental images were used to developed predictive risk maps of the probability of occurrence of the disease and quantify the risk for infection in Ogun State, Nigeria.</p> <p>Methods</p> <p>Infection data used were derived from carefully validated morbidity questionnaires among primary school children in 2001–2002, in which school children were asked among other questions if they have experienced "blood in urine" or urinary schistosomiasis. The infection data from 1,092 schools together with remotely sensed environmental data such as rainfall, vegetation, temperature, soil-types, altitude and land cover were analysis using binary logistic regression models to identify environmental features that influence the spatial distribution of the disease. The final regression equations were then used in Arc View 3.2a GIS software to generate predictive risk maps of the distribution of the disease and population at risk in the state.</p> <p>Results</p> <p>Logistic regression analysis shows that the only significant environmental variable in predicting the presence and absence of urinary schistosomiasis in any area of the State was Land Surface Temperature (LST) (B = 0.308, p = 0.013). While LST (B = -0.478, p = 0.035), rainfall (B = -0.006, p = 0.0005), ferric luvisols (B = 0.539, p = 0.274), dystric nitosols (B = 0.133, p = 0.769) and pellic vertisols (B = 1.386, p = 0.008) soils types were the final variables in the model for predicting the probability of an area having an infection prevalence equivalent to or more than 50%. The two predictive risk maps suggest that urinary schistosomiasis is widely distributed and occurring in all the Local Government Areas (LGAs) in State. The high-risk areas (≥ 50% prevalence) however, are confined to scatter foci in the north western part of the State. The model also estimated that 98.99% of schools aged children (5–14 years) are living in areas suitable for urinary schistosomiasis transmission and are at risk of infection.</p> <p>Conclusion</p> <p>The risk maps developed will hopefully be useful to the state health officials, by providing them with detailed distribution of urinary schistosomiasis, help to delineate areas for intervention, assesses population at risk thereby helping in optimizing scarce resources.</p

Oral Delivery of the Sj23LHD-GST Antigen by Salmonella typhimurium Type III Secretion System Protects against Schistosoma japonicum Infection in Mice

Schistosomiasis japonica is a zoonotic parasitic disease and occurs predominantly in Southeast Asia and China. Using a simple, cheap, yet efficient oral method to deliver the vaccine antigen would benefit to control its transmission in that the oral vaccine could be made into a preparation and mixed with feedstuffs of livestock hosts. In this study, we used an attenuated S. typhimurium strain VNP20009, whose safety has been demonstrated in phase I clinical trial, to express the bivalent Schistosoma japonicum antigen Sj23LHD-GST by an intracellular activated promoter (nirB) and deliver it to host cells through type III secretion system. After oral vaccination of this recombinant strain, efficient protection against S. japonicum challenge was induced in mice. Mean while, granuloma formation in the liver was improved significantly in the immunized mice. This protective immune response was Th1 specific type as evidenced by increase in the production of IL-12 and IFN-γ. This work provides an alternative S. japonicum vaccine for livestock and humans

Host Determinants of Reinfection with Schistosomes in Humans: A Systematic Review and Meta-analysis

Background: Schistosomiasis is still a major public health burden in the tropics and subtropics. Although there is an effective chemotherapy (Praziquantel) for this disease, reinfection occurs rapidly after mass drug administration (MDA). Because the entire population do not get reinfected at the same rate, it is possible that host factors may play a dominant role in determining resistance or susceptibility to reinfection with schistosomes. Here, we systematically reviewed and meta-analyzed studies that reported associations between reinfection with the principal human-infecting species (S. mansoni, S. japonicum and S. haematobium) and host socio-demographic, epidemiological, immunological and genetic factors.Methodology/Principal Findings: PubMed, Scopus, Google Scholar, Cochrane Review Library and African Journals Online public databases were searched in October 2013 to retrieve studies assessing association of host factors with reinfection with schistosomes. Meta-analysis was performed to generate pooled odds ratios and standardized mean differences as overall effect estimates for dichotomous and continuous variables, respectively. Quality assessment of included studies, heterogeneity between studies and publication bias were also assessed. Out of the initial 2739 records, 109 studies were included in the analyses, of which only 32 studies with 37 data sets were eligible for quantitative data synthesis. Among several host factors identified, strong positive association was found with age and pre-treatment intensity, and only slightly for gender. These factors are major determinants of exposure and disease transmission. Significant positive association was found with anti-SWA IgG4 level, and a negative overall effect for association with IgE levels. This reconfirmed the concept that IgE/IgG4 balance is a major determinant of protective immunity against schistosomiasis. Other identified determinants were reported by a small number of studies to enable interpretation.Conclusions: Our data contribute to the understanding of host-parasite interaction as it affects reinfection, and is a potential tool to guide planning and tailoring of community interventions to target high-risk groups

Impact of industrial cassava effluent discharge on the water quality of Ogbese river, Ayede-Ogbese, Ondo state, Nigeria

Impacts of cassava effluent discharge on physicochemical parameters of water quality were assessed using standard procedure. Results showed TDS ranged (108.00 ± 28.2 – 110.50±27.5 mg/L), 123.50 ± 31.82-310.50 ±184.56 mg/L) and (114.00 ±31.11 - 115.50 ±30.41 mg/L) for UWS, DPWS and DWS respectively. TSS in the effluent samples were 1287.50 ±137.89 mg/L and 19942.00 ±2791.08 mg/L during wet season and 1925.00 ±0.00, 21942.00 ±0.00 mg/L in dry season respectively. Highest BOD (61.5±6.36 mg/L) was at discharge point during wet season and lowest (0.35±0.07 mg/L) was downstream during dry season. In wet season, the BOD ranged (2.00±0.5 - 3.20±1.13 mg/L) upstream was lower relative to downstream range (26.00±5.66 -36.00±21.21 mg/L). pH of water ranged (7.43±0.46 -7.85 ± 0.78) and (6.55±0.78 - 7.05±0.21) upstream and downstream respectively during wet season while pH ranged (7.15± 0.21- 7.35± 0.21) and 6.70 ± 0.00 – 6.90± 0.00) upstream and downstream respectively in dry season. At discharge points pH ranged (5.90±0.00 – 6.50 ± 0.42). Electrical conductivity (E.C.) in wet season has lowest value 191.50±54.45 - 192.50 ±50.20 µScm upstream and also lowest compared with all locations in dry season. Acidity of water ranged (30.00±8.49 - 45.00±26.87, 15.00±1.41 - 16.00±2.83 and 80.00±8.49 – 4,320.00 ± 4.24 mg/L) respectively for downstream, upstream and discharge point in wet season. However range of acidity values in dry season were (30.00±0.00 - 43.00± 1.41, 20.00 ± 70.00 – 32.50 ± 0.71 and 47.50 ± 13.44 – 5750.00 ± 70.71 mg/L) for downstream, upstream and discharge point respectively. Results indicated that water quality of downstream was impaired compared to upstream and season dependent, suggesting significant pollution from cassava effluent discharges. The effluent instilled unsightly, nauseating and undesirable effects on biotic community and rendered water useless for any domestic usage. Continuous monitoring of Ogbese River is imperative for future sustainability of the river.Key Words: Water quality, Effluent, Physiochemical parameters, Permissible limit

Chitosan Grafted Modified Maize Cob for Removal of Lead And Chromium from Wastewater

No abstract