BackgroundHigh epilepsy prevalence and incidence have been reported in areas with high onchocerciasis transmission. Recent findings suggest that proper community-directed treatment with ivermectin (CDTI) is potentially able to prevent onchocerciasis-associated epilepsy (OAE). We assessed the epilepsy prevalence and onchocerciasis transmission in two Nigerian villages following more than 20 years of CDTI.MethodsA cross-sectional door-to-door survey was performed in two villages in the Imo River Basin reported to be mesoendomic for onchocerciasis (Umuoparaodu and Umuezeala). Individuals were screened for epilepsy using a validated 5-item questionnaire. Persons suspected to have epilepsy were examined by a neurologist or a physician with training in epilepsy for confirmation. Onchocerciasis was investigated via skin snip microscopy and rapid diagnostic tests for Ov16 antibodies. Results were compared with previous findings from the Imo river basin.ResultsA total of 843 individuals from 257 households in the two villages were encountered. We detected four persons with epilepsy (PWE) giving a crude epilepsy prevalence of 0.5%. This finding differs from observations reported 14 years ago which showed an epilepsy prevalence of 2.8% in the neighbouring village of Umulolo (P = 0.0001), and 1.2% from 13 villages in the Imo river basin (P = 0.07). The seroprevalence of Ov16 antibodies was found to be 0%. Only 4.6% of skin snips were positive compared to 26.8% in previous surveys (P < 0.0001). Ivermectin mass distribution coverage in the study sites in 2017 was 79.7%.ConclusionsA low epilepsy and onchocerciasis prevalence was observed following more than 20 years of CDTI in the Imo River Basin. Absence of Ov16 antibodies indicates minimal transmission of onchocerciasis. These results contrast with observations from areas of high onchocerciasis transmission, where epilepsy prevalence and incidence remain high. Findings from this study suggest that sustained efforts could eventually achieve elimination of onchocerciasis in these villages.Electronic supplementary materialThe online version of this article (10.1186/s40249-019-0517-9) contains supplementary material, which is available to authorized users.

In Nigeria infection with onchocerciasis has been under control with the introduction of ivermectin in most affected communities for a decade. To assist ‘stop mass drug administration (MDA)’ decision, a cross-sectional survey evaluated the impact of ivermectin on onchocercal Skin Diseases (manifestations) from 540 participants in 5 endemic communities. The rapid epidemiological assessment (REA) method with palpable nodules and skin depigmentation (leopard skin, LS) as diagnostic indices were used. The prevalence profiles of palpable nodules and leopard skin was 5.9% and 12.2% respectively. Prevalence of clinical features varied among the farming community (P<0.05). Similarly, age group 21-30 years had significant prevalence of clinical features than other age groups (P<0.05).  Males had significantly higher prevalence of these indices (palpable nodules 6.8(%; LS 13.3%) than females (palpable nodules 4.6%; LS 11.1%). Although, Onchocercal Skin Diseases (clinical manifestations) were observed in all age groups, it occurred most in older groups. These groups with nodules could portend as reservoir for transmission. The implications of the results were discussed in the context of the on-going prediction of possible elimination of onchocerciasis in Africa and ‘stop MDA’ decision.

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Heavy metals (HM) have been a global concern for its toxic and detrimental effect on the environment especially when it exceeds the permissible limit through anthropogenic activities like kaolin mining. Kaolin mining has improved the economic wellbeing of the local people through employment and otherwise; and at the same time attached with environmental consequences that threatens the livelihood of the community members. This study was carried out to ascertain the concentrations of selected heavy metals in kaolin mined soils and water body and its pollution density using single pollution indices such as contamination factor (CF), geo-accumulation (Igeo) and ecological risk factor (Er ). Soil sample were collected from three different kaolin mined sites labelled (A,B and C) also surface water samples were collected from upper and down streams of Iyi-ugbohoroAmaudara, both samples were digested and elemental analysis was carried out using Atomic Absorption Spectrophotometer (AAS UNICAM 919 model). The concentration of the metals in three different kaolin mined soil samples ranges from Pb(40.00, 52.00 and 55.09 mg/kg) Cr(45.01, 70.00 and 71.00 mg/kg) Ni( 32.10, 50.50 and 51.00 mg/kg) Cd( 2.16, 6.25 and 6.15 mg/kg) Co( 19.68, 57.06 and 56.00 mg/kg) Se(1.06, 0.50, and 1.00 mg/kg) Mn(0.001, 0.01 and 0.01 mg/kg) Hg( 2.01, 2.00 and 2.50 mg/kg) As( 1.07, 1.10 and 1.05 mg/kg) and Cu(33.01, 60.00 and 57.5 mg/kg). Results from single pollution indices used for the selected heavy metals from kaolin mined soil, samples (A,B and C) showed that Mn, As, Cr, Ni and Cu indicated low to moderate contamination factor while Cd, Se, Co and Hg indicated high to very high contamination factor in all the samples. The distribution trend of heavy metals concentrations in the upper and down streams of the river body during wet season, showed that there were significant difference between upper and down streams while dry season showed variations in significant differences between the upper and down streams of some of the heavy metals. The study therefore concludes that kaolin soils are contaminated with heavy metals as a result of kaolin deposit and its mining activities. The single pollution indices used for the study pointed out that Cd, Se, Co and Hg are very high in the kaolin soils. The surface waters of Iyi-ugbohoroAmaudara River at the study area are polluted with heavy metals as a result of kaolin mining activities in the area; more especially during wet season of the study. Consequently, these outcomes would pose a toxic effect to both fauna and flora and possibly threatens the aquatic lives and the local populace.