To determine the repellent activity of Ocimum gratissimum volatile oil against Simulium damnosum (blackflies), a 12 month (January-December 2003) field study was conducted in three onchocerciasis endemic communities (Idomido, Obio camp, and Ikot Adaha) in Ini Local Government Area of Akwa Ibom State, Nigeria. The result revealed that topical application of 20% (v/v) concentration of the oil with liquid paraffin as a base, reduced the biting rate of S. damnosum by 90.2, 81.6, and 79.7%, in Idomido, Obiocamp, and Ikot Insect-transmitted diseases remains a major source of morbidity and mortality globally. In Nigeria, Onchocerca volvulus the causative agent of onchocerciasis (river blindness), is transmitted primarily by the blackflies (Simulium damnosum) complex (WHO 1995, Aisen et al. 2004, Opara et al. 2005. Onchocerciasis is both a public health hazard and socio-economic problem of considerable magnitude in Nigeria (Opara et al. 2005). They cause itching and disfiguring skin disease, serious eye lesions, and blindness (WHO 1995). The habit of S. damnosum, crawling on the skin of the individual constitute an intolerable nuisance, their painful bite lead to blood loss and serve as portal for viruses, bacteria, protozoa, and nematodes which the flies may carry on their bodies.The strategy for control of onchocerciasis is based on destruction of the vector's larvae, prevention of vector migration, and contact with human host, killing the adult filarial and microfilarial worms in the human host. Several attempts have been made to use DDT, larvicide, and chlorinated hydrocarbon insectide in the control of blackflies. Despite a remarkable reduction in the blackfly population the epidemiological results are not impressive (Walsh 1970, WHO 1995. The strategy being used to control onchocerciasis in Nigeria is mass drug administration (MDA) through community directed treatment with ivermectin. Ivermectin has a positive effect in reducing microfilariae load in the infected individuals, it reduces transmission of infection, prevents onchocercal blindness, and skin disease (Boaten et al. 1998, Ndyomugyenyi et al. 2004.Control of the parasites vector though desirable, is not feasible in view of the expansive areas infested and the long flight range of the fly, which facilitates the reinvasion of treated communities by flies from untreated contagious communities (Aisen et al. 2004). The worldwide threat of arthropod-transmitted disease, with their associated morbidity and mortality underscores the need for effective insect repellent. The quest to make human less attractive to blackflies has stimulated research on blackfly behaviour and control. A reduction in human vector contact through repellent action would significantly reduce the transmission of infective larvae to human hosts.Extracts from plant sources have been shown to possess insecticidal (Iwuala & Osisiogu 1981, Pathake & Dixit 1988, Anyanwu & Uloko 1997, Oda et al. 1997, Ayanwu & Amefule 2001 and repellent (Bernard 1999, Tawatsin et al. 2001, Aisen et al. 20...

Background and objectives There is a dearth of information on the geographical distribution of bancroftian filariasis in Africa on which to establish elimination programmes. The aim of this study is to assess the prevalence and density of microfilaraemia and the prevalence of clinical manifestations of bancroftian filariasis in six rural communities of Lower Cross River Basin, Nigeria. Methods A total of 829 finger prick blood smear samples were collected from volunteers between 22.00 and 02.00 h and were examined for presence of helminth parasite Wuchereria bancrofti using standard parasitological method of diagnosis. All the volunteers were also screened for clinical manifestations of lymphatic filariasis. Results Forty-six (5.6%) of the 829 samples collected were found to be microscopically positive for W. bancrofti. The prevalence of microfilaraemia was significantly (P<0.05) higher in females (8.4%) than males (3.6%). There is a significant variation (P<0.05) in the age-specific prevalence, with the age group 41-60 years being the most affected (10.2%). The overall geometric mean microfilarial density of the infected persons was 9 mf/50 μl. It was higher in males (11 mf/50 μl) than females (7 mf/50 μl) (P>0.05). The prevalence of infection and geometric mean density showed large variations; there was a trend towards increasing prevalence and density with increase in age in both sexes. The overall disease prevalence was 9.2%; the most important clinical manifestation was hydrocele (10.5%) and lymphoedema (2.9%). These chronic disease manifestations increased with age (P<0.05). Conclusion These baseline data would be useful in planning for the elimination of lymphatic filariasis in Africa as per the WHO goal to eliminate lymphatic filariasis by the year 2020.

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A parasitological mapping of urinary schistosomiasis using filtration method was conducted in Biase and Yakurr LGAs of Cross River State, Nigeria by the Neglected Tropical Diseases Control unit in collaboration with the schistosomiasis/soil transmitted helminths unit of the Federal Ministry of Health, Nigeria in November 2012. The results of the study revealed a mean urinary schistosomiasis prevalence of 49% for the six schools under study in Biase and 30% for the six schools under study in Yakurr LGA. The mean ova load was 0.9 for males and 0.8 for females in the two LGAs. Integrated control measures put in place, included chemotherapy of infected individuals with praziquantel and health education on the predisposing factors responsible for the transmission of urinary schistosomiasis. An evaluation of the interventions was carried out in November 2014, after two rounds of treatment with Praziquantel and intensive education were given. Urine samples were collected from 600 school children, 300 from each of the two LGAs. The evaluation study using the urine filtration technique revealed a mean schistosomiasis prevalence of 0% for the six schools under study in Biase and 0.02% for the six schools under study in Yakurr LGA with mean ova load reduced to 0.3 for males and 0 for females in the two LGAs. Data analysis with SPSS package revealed a 100% participation of all selected school children in 12 schools (6 in each LGA). Statistical analysis showed that there was no significant difference in the prevalence between male and female (p>0.005). A student t-test showed a significant difference between prevalence rates in 2012 and the results in 2014 (p>0.005). The spatial distribution showed that endemic schools were distributed within marshy areas where rice was cultivated in the two LGAs. These results showed that with wide scale integrated control measures, urinary schistosomiasis can be eliminated or reduced to a disease of no public health importance.