Akinola Stephen Oluwole

Urinary schistosomiasis among preschool children in a rural community near Abeokuta, Nigeria.

BackgroundThe control of schistosomiasis in Nigeria is mainly by mass treatment with praziquantel through the school system, with an absence of any provision for pre-school children. We therefore determined the prevalence and intensity of urinary schistosomiasis in pre-school children between the ages of 1-6 years in Ilewo-Orile a rural and endemic community, near Abeokuta, Nigeria as part of providing information on the neglected tropical diseases among this age group. Two urine samples were collected from each pre-school child. The samples were tested for microhaematuria using reagent strips and then processed and examined with a microscope for Schistosoma haematobium ova.ResultsOf the 167 children examined 97 (58.1%) had infection, with no significant difference (P = 0.809) in infection rates between boys (57.1%) and girls (59.2%). Both prevalence and intensity of infection did not increase significantly with age (P = 0.732). The overall geometric mean egg count was 1.17 eggs/10 ml urine. There was no significant association (P = 0.387) between intensity in boys (1.16 eggs/10 ml urine) and girls (1.19 eggs/10 ml urine). 47.4% of the children had microhaematuria which did not increase significantly with age (P = 0.526). Focus group discussions with guardians and caregivers revealed that infection of pre-school children early in life was due to exposures through bathing in the stream by their mothers, while the older children would visit the stream for washing, fetching of water, bathing and swimming.ConclusionCommunity participatory health education is needed in this community as a first step in reducing infection and transmission of the disease, while the rehabilitation and repair of the existing water borehole system in the community should be effected. The results of this study have shown that pre-school children also harbour infection and are a source of transmission of schistosomiasis in endemic communities. Planning and provision for their treatment should be considered in control programmes.

Bayesian Geostatistical Model-Based Estimates of Soil-Transmitted Helminth Infection in Nigeria, Including Annual Deworming Requirements

Background The acceleration of the control of soil-transmitted helminth (STH) infections in Nigeria, emphasizing preventive chemotherapy, has become imperative in light of the global fight against neglected tropical diseases. Predictive risk maps are an important tool to guide and support control activities. Methodology STH infection prevalence data were obtained from surveys carried out in 2011 using standard protocols. Data were geo-referenced and collated in a nationwide, geographic information system database. Bayesian geostatistical models with remotely sensed environmental covariates and variable selection procedures were utilized to predict the spatial distribution of STH infections in Nigeria. Principal Findings We found that hookworm, Ascaris lumbricoides, and Trichuris trichiura infections are endemic in 482 (86.8%), 305 (55.0%), and 55 (9.9%) locations, respectively. Hookworm and A. lumbricoides infection co-exist in 16 states, while the three species are co-endemic in 12 states. Overall, STHs are endemic in 20 of the 36 states of Nigeria, including the Federal Capital Territory of Abuja. The observed prevalence at endemic locations ranged from 1.7% to 51.7% for hookworm, from 1.6% to 77.8% for A. lumbricoides, and from 1.0% to 25.5% for T. trichiura. Model-based predictions ranged from 0.7% to 51.0% for hookworm, from 0.1% to 82.6% for A. lumbricoides, and from 0.0% to 18.5% for T. trichiura. Our models suggest that day land surface temperature and dense vegetation are important predictors of the spatial distribution of STH infection in Nigeria. In 2011, a total of 5.7 million (13.8%) school-aged children were predicted to be infected with STHs in Nigeria. Mass treatment at the local government area level for annual or bi-annual treatment of the school-aged population in Nigeria in 2011, based on World Health Organization prevalence thresholds, were estimated at 10.2 million tablets. Conclusions/Significance The predictive risk maps and estimated deworming needs presented here will be helpful for escalating the control and spatial targeting of interventions against STH infections in Nigeria.

Schistosoma haematobium infections in preschool children from two rural communities in Ijebu East, south-western Nigeria

There is an urgent need for information on schistosomiasis in preschool children, who are often excluded in mass treatment programmes. The prevalence and intensity of Schistosoma haematobium infection were determined in preschool children aged ≤ 6 years in two rural communities in Ijebu East, south-western Nigeria. Two urine samples each were collected from 83 preschool children from the two communities, tested for microhaematuria using reagent strips and then processed and examined with a microscope for S. haematobium eggs. Focus group discussions on perceptions of the disease and water contact practices were held in the communities with their guardians, caregivers and preschool children, using an interview guide. The prevalence of S. haematobium in the two communities was 14 (16.9%), with no significant differences (P = 0.661) in infection rate between boys (18.4%) and girls (14.7%). Both prevalence and intensity of infection did not increase significantly with age in both Korede and Obada community. However, there were significant differences in prevalence of infection between the two communities (P = 0.035). There was no association (P = 0.750) between intensity in boys (0.176 eggs/10 ml urine) and girls (0.110 eggs/10 ml urine). Focal group discussions with guardians and caregivers revealed that preschool children acquired infection early in their lives through exposure to infected stream water by their mothers, while the older children visit the stream for playing, bathing and swimming. It has therefore become imperative for preschool children to be included in the planning of schistosomiasis intervention programmes as a means of reducing transmission.

Preliminary study on temporal variations in biting activity of Simulium damnosum s.l. in Abeokuta North LGA, Ogun State Nigeria.

BackgroundSimulum damnosum Theobald sensu lato (s.l.) is the vector of the parasitic filarial worm Onchocerca volvulus Leuckart which causes onchocerciasis. In order to understand the vector population dynamics, a preliminary 12 months entomological evaluation was carried out at Abeokuta, the Southwest Zone of Nigeria, an onchocerciasis endemic area, where vector control has not been previously initiated. S.damnosum s.l. flies were caught on human attractants between 700 to1800 hours each day, for 4 days each month, from August 2007 to July 2008. The flies caught were classified as either forest-dwelling or savanna-dwelling groups based on the colour of certain morphological characters. Climatic data such as rainfall, humidity and temperature were also collected monthly during the period of survey.ResultsA total of 1,139 flies were caught, 596 (52.33%) were forest-dwelling group while 543 (47.67%) were savanna-dwelling group of S. damnosum s.l. The highest percentage of forest-dwelling group was caught in the month of August 2007 (78.06%) and the least percentage of forest-dwelling groups was caught in November 2007 (8.14%). The highest percentage of savannah-dwelling group was caught in the month of November 2007 (91.86%) and the least percentage of savannah-dwelling group was caught in August 2007 (21.94%). There was no significant difference between the population of forest and savannah-dwelling groups of the fly when the means of the fly population were compared (P = 0.830). Spearman correlation analysis showed a significant relationship between monthly fly population with monthly average rainfall (r = 0.550, n = 12, P = 0.033), but no significant relationship with monthly average temperature (r = 0.291, n = 12, P = 0.179). There was also a significant relationship between monthly fly population and monthly average relative humidity (r = 0.783, n = 12 P = 0.001). There was no significant correlation between the population of forest-dwelling group of S. damnosum s.l. and monthly average rainfall (r = 0.466, n = 12, P = 0.064) and monthly average temperature (r = 0.375, n = 12, P = 0.115) but there was significant correlation with monthly average relative humidity (r = 0.69, n = 12, P = 0.006). There was significant correlation between savannah-dwelling group and monthly average rainfall (r = 0.547, n = 12, P = 0.033), and monthly average relative humidity (r = 0.504, n = 12, P = 0.047) but there was no significant correlation with monthly average temperature (r = 0.142, n = 12, P = 0.329)ConclusionThe results from this study showed that both the forest and the savannah dwelling groups of S. damnosum s.l. were caught biting in the study area. This could have implications on the transmission and epidemiology of human onchocerciasis if not monitored.

Assessment of the burden of soil-transmitted helminthiasis after five years of mass drug administration for Onchocerciasis and Lymphatic filariasis in Kebbi State, Nigeria

There is a hypothesis that Mass drug administration (MDA) of ivermectin and albendazole for the treatment of onchocerciasis and lymphatic filariasis could have an impact on the burden of soil-transmitted helminthiasis (STH) in MDA communities. We, therefore, assessed the burden of STH (Ascaris lumbricoides, Trichuris trichiura, and hookworm) infections in nine communities from 3 LGAs (two MDA local government areas (LGAs) and one control LGA) in Kebbi State, Nigeria after 5-years (2010–2015) of MDA for onchocerciasis and/or lymphatic filariasis. We also administered questionnaire to obtain demographic information and history of MDA in the past five years. The three LGAs are Bagudo (Ivermectin MDA); Zuru (Ivermectin/Albendazole MDA) and Dandi (No MDA). The study was a cross sectional survey. The total number of people that complied with provision of stool samples and questionnaire were 1357 persons; stool samples collected were examined for STH infections in the three LGAs. Zuru LGA had the highest prevalence of STH (41.89, 95% CI: 37.08–46.81) followed by Dandi LGA (24.66, 95% CI: 20.69–28.97) and Bagudo LGA (3.36, 95% CI: 1.97–5.32). Prevalence of STH infection was not significantly different among age group and sex. Geometric mean intensity per gram of infection for both A. lumbricoides and Hookworm were highest in Zuru LGA with (1.16 GMI, 95% CI: 0.97–1.36) and (1.49 GMI, 95% CI: 1.29–1.70) respectively. Treatment coverage was less than 65% from 2010 to 2013 in the intervention LGAs. The study shows that STH is still a public health problem in Zuru LGA (IVM + ALB) and requires MDA of albendazole for STH control to continue, while Dandi LGA (No MDA history) requires MDA with albendazole to scale up treatment for STH control.