Sammy Olufemi Sam-Wobo

Schistosomiasis and soil-transmitted helminthiasis (STH) are public health problems in communities which lack basic social amenities with poor hygienic conditions. Studies were carried out to determine the prevalence and effect of schistosomes and soil-transmitted helminths infection on labour input on rice production in 9 rice-growing communities of Ogun State. Parasitological examinations of urine and faecal samples, and structured questionnaires were conducted on 243 consented individuals from May 2009 to March 2010. The results showed an overall prevalence of 17% for Ascaris lumbricoides, 12% for hookworms, 2% for Trichuris trichiura, 1% for Schistosoma haematobium and 1% for Schistosoma mansoni. A. lumbricoides and hookworms were more prevalent in Agbajege (25%), and varied in the other 8 communities. T. trichiura was prevalent in three communities, Agbajege (5%), Akodu (4.2%), and Moloko-Asipa (4.8 %); S. haematobium was prevalent only in Ayedere (2.6%) and Lufoko (8%), while S. mansoni was prevalent only in Moloko-Asipa (9.5%). Infections among the gender were varied as 26.3 % of males and 33.8 % of females had an overall prevalence of: A. lumbricoides (16.8%), hookworms (11.8%), T. trichiura (1.6%), S. haematobium (1.1%) and S. mansoni (1.1%). On frequency of infection to incapacitation per year, 45% of respondents were incapacitated 1-2 times, 27% 3-4 times and 19% were incapacitated more than 4 times. Understanding the effect of these two diseases will not only improve the health status of residents but also increase their productivity and ensure food security.

A cytotaxonomic study was carried out to determine the species composition and dynamics of Simulium damnosum sensu lato in Oyan River, an onchocerciasis mesoendemic area in southwest Nigeria. Simulium larvae were collected fortnightly from different attachments between March and November 2012 fixed in Carnoy's solution for laboratory identification using cytotaxonomic keys. A total of 255 Simulium larvae were obtained and identified from their polytene chromosomes. Simulium soubrense Beffa (56.5 %) and Simulium damnosum sensu stricto (43.5 %) were the two cytospecies observed. No new inversions were found in the larvae. Statistical analysis revealed a significant difference (PS. damnosum s.s. and S. soubrense in relation to rainfall pattern. The sympatric breeding of both species in the area may suggest their involvement in the transmission of onchocerciasis in the area, as S. damnosum s.s. and S. soubrense Beffa are known vectors of Onchocerca volvulus in West Africa.

Epidemiological studies were carried out to assess the prevalence and community microfilarial load (CMFL) of onchocerciasis after repeated annual treatment with ivermectin along Ogun river System, southwest Nigeria. Skin snips were taken from consented participants in 11 selected communities along the River system. The microfilarial load of the community was estimated. The prevalence and CMFL varied significantly in the communities (p <0.05). The prevalence of onchocerciasis ranged from 19.1 to 45.6%, while the CMFL ranged from 0.11 to 1.03 microfilariae per skin snip. The CMFL recorded was <5 microfilariae per skin snip, i.e. recognized by WHO as threshold value in certifying the communities to be free of onchocerciasis as public health problem, thus, signifying the possibility of onchocerciasis elimination in the study area. Efforts should therefore be intensified to achieve improved ivermectin coverage and compliance in annual ivermectin treatment in order to completely eliminate onchocerciasis as a public health problem in the studied communities.

The root and leaf extracts of four plants, Occimum gratissimum, Azadirachta indica, Pterocarpus santalinoides, and Pistia hyptis, were studied for repellent activities against the adults of Simulium damnosum sensu lato. The leaves and roots were extracted with 95% ethanol and the stocks were diluted with paraffin. The repellent activities of the extracts were investigated using human baits along the banks of River Oyan and River Ogun in southwestern Nigeria. The results showed that the root extract of O. grattissium and leaf extract of P. hyptis had highest repellent potentials with 78% and 78.1% protection against S. damnosum sensu lato, respectively, whereas the root and leaf of P. santalinoides recorded the least. Although there were significant differences in the percentage of protection of the extracts of the plants (p < 0.05), the variations in the percentage of protection of the leaf and root extracts were not statistically significant (p > 0.05). The study concludes that there exist some repellent efficacies in the extracts of the plants, most importantly O. grattissimum and P. hyptis. The plant extracts can further be developed in the prevention of man–vector contact in onchocerciasis endemic communities.

The 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.

Knowledge and practices on malaria treatment measures among pregnant women in Aveokuta, Nigeria