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

<p>Abstract</p> <p>Background</p> <p><it>Simulum damnosum </it>Theobald <it>sensu lato </it>(<it>s.l</it>.) is the vector of the parasitic filarial worm <it>Onchocerca volvulus </it>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. <it>S.damnosum s.l</it>. 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.</p> <p>Results</p> <p>A total of 1,139 flies were caught, 596 (52.33%) were forest-dwelling group while 543 (47.67%) were savanna-dwelling group of <it>S. damnosum s.l</it>. 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 (<it>P </it>= 0.830). Spearman correlation analysis showed a significant relationship between monthly fly population with monthly average rainfall (<it>r </it>= 0.550, n = 12, <it>P </it>= 0.033), but no significant relationship with monthly average temperature (<it>r </it>= 0.291, <it>n </it>= 12, <it>P </it>= 0.179). There was also a significant relationship between monthly fly population and monthly average relative humidity (<it>r </it>= 0.783, <it>n </it>= 12 <it>P </it>= 0.001). There was no significant correlation between the population of forest-dwelling group of <it>S. damnosum s.l</it>. and monthly average rainfall (<it>r </it>= 0.466, <it>n </it>= 12, <it>P </it>= 0.064) and monthly average temperature (<it>r </it>= 0.375, n = 12, <it>P </it>= 0.115) but there was significant correlation with monthly average relative humidity (<it>r </it>= 0.69, <it>n </it>= 12, <it>P </it>= 0.006). There was significant correlation between savannah-dwelling group and monthly average rainfall (<it>r </it>= 0.547, <it>n </it>= 12, <it>P </it>= 0.033), and monthly average relative humidity (<it>r </it>= 0.504, <it>n </it>= 12, <it>P </it>= 0.047) but there was no significant correlation with monthly average temperature (<it>r </it>= 0.142, <it>n </it>= 12, <it>P </it>= 0.329)</p> <p>Conclusion</p> <p>The results from this study showed that both the forest and the savannah dwelling groups of <it>S. damnosum s.l</it>. were caught biting in the study area. This could have implications on the transmission and epidemiology of human onchocerciasis if not monitored.</p

The Use of Waste Management Techniques to Enhance Household Income and Reduce Urban Water Pollution

Appropriate waste management options are major concerns in the developing world. Current methods include incineration in the open and accumulation of wastes in designated places where they constitute nuisance to the environment. Apart from air pollution from the incinerators, leachates from decomposed wastes are either washed off where they serve as source of pollutants to the adjourning streams and rivers or contaminate groundwater through deep percolation. We present viable options for managing agricultural wastes in this chapter. The options presented are so simple and sustainable such that it can be managed by individuals. Hence, they are independent of the government bureaucratic bottlenecks that have been the bane of the previous government interventions. If embraced, it will also serve as sources of income for the concerned household, hence enhance their livelihood

Helicobacter pylori patient isolates from South Africa and Nigeria differ in virulence factor pathogenicity profile and associated gastric disease outcome

Helicobacter pylori is a gram-negative, spiral-shaped bacterial pathogen and the causative agent for gastritis, peptic ulcer disease and classified as a WHO class I carcinogen. While the prevalence of H. pylori infections in Africa is among the highest in the world, the incidence of gastric cancer is comparably low. Little is known about other symptoms related to the H. pylori infection in Africa and the association with certain phenotypes of bacterial virulence. We established a network of study sites in Nigeria (NG) and South Africa (ZA) to gain an overview on the epidemiological situation. In total 220 isolates from 114 patients were analyzed and 118 different patient isolates examined for the presence of the virulence factors cagA, vacA, dupA, their phylogenetic origin and their resistance against the commonly used antibiotics amoxicillin, clarithromycin, metronidazole and tetracycline. We report that H. pylori isolates from Nigeria and South Africa differ significantly in their phylogenetic profiles and in their expression of virulence factors. VacA mosaicism is intensive, resulting in m1-m2 vacA chimeras and frequent s1m1 and s1m2 vacA subtypes in hpAfrica2 strains. Gastric lesions were diagnosed more frequent in Nigerian versus South African patients and H. pylori isolates that are resistant against one or multiple antibiotics occur frequently in both countries

Baseline and recurrent exposure to the standard dose of artemisinin-based combination therapies (ACTs) induces oxidative stress and liver damage in mice (BALB/c)

Abstract Background In malaria-endemic countries, repeated intake of artemisinin-based combination therapies (ACTs) is rampant and driven by drug resistance, improper usage, and easy accessibility. Stress effects and potential liver toxicity due to the frequent therapeutic use of ACTs have not been extensively studied. Here, we investigated the effects of repeated treatment with standard doses of the commonly used ACTs artemether/lumefantrine (A/L) and artesunate-amodiaquine (A/A) on oxidative stress and liver function markers in male mice (BALB/c). Methods Forty Five mice were divided into three groups: control, A/L, and A/A. The drugs were administered three days in a row per week, and the regimen was repeated every two weeks for a total of six cycles. The levels of oxidative stress and liver function markers were measured in both plasma and liver tissue after initial (baseline) and repeated exposures for the second, third, and sixth cycles. Results Exposure to A/L or A/A caused a significant (p < 0.001) increase in plasma malondialdehyde (MDA) levels after the first and repeated exposure periods. However, Hepatic MDA levels increased significantly (p < 0.01) only after the sixth exposure to A/A. Following either single or repeated exposure to A/L or A/A, plasma and liver glutathione peroxidase (GPx) and catalase (CAT) activities, plasma aspartate and alanine transaminase, alkaline phosphatase activity, and bilirubin levels increased, whereas total plasma protein levels decreased significantly (p < 0.001). Varying degrees of hepatocyte degeneration and blood vessel congestion were observed in liver tissues after a single or repeated treatment period. Conclusion Irrespective of single or repeated exposure to therapeutic doses of A/L or A/A, plasma oxidative stress and liver damage were observed. However, long-term repeated A/A exposure can led to hepatic stress. Compensatory processes involving GPx and CAT activities may help reduce the observed stress