Case-control studies on the onchocerciasis-epilepsy relationship: study areas characteristics and odds ratios (OR).

aThe first four studies are those achieving control for intensity and time of exposure and gender. In these studies people with epilepsy were matched for gender, age and place of residence to one or two people without epilepsy; in the study by Kaiser et al. (2011), 5 of 38 pairs were not matched for sex.
bPmf = prevalence of skin microfilariae (mf) in subjects aged ≥5 years; PNod = prevalence of nodules in males aged ≥20 years; Hypo = hypoendemic (Pmf<35% or PNod<20%); Meso = mesoendemic (35%≤Pmf<60% or 20%≤PNod <40%); Hyper = hyperendemic (Pmf≥60% or PNod≥40%).
cCDTI = Community-Directed Treatment with Ivermectin; VC = Vector control.
dOR mf = Odds ratio for epilepsy in patients with skin mf; OR Nod = Odds ratio for epilepsy in patients with nodules; 95%CI = 95% Confidence interval; NA = not assessable.
ePassive ivermectin treatment had been organized in these areas before the implementation of the CDTIs organized by the African Program for Onchocerciasis Control (APOC).
fOR calculated on the number of persons examined (6 of the 36 controls were “missing” for nodule palpation). If all the missing controls had nodules, the OR would be 1.00 (0.31–3.19) and if none of them had nodules, the OR would be 1.96 (0.62–6.22).