The success of the Onchocerciasis Control Programme is undeniable and exemplary, say the authors, but it is too early to claim victory against river blindness.

Studies conducted during the past 10 years to investigate the possible relationship between onchocerciasis and epilepsy have led to contradictory results. In 1991-92 and 2001 we investigated 14 villages in central Cameroon to evaluate the relationship, at the community level, between the prevalence of epilepsy and the endemicity level of onchocerciasis. A case-control study compared the microfilarial loads of 72 epileptic and 72 non-epileptic individuals, matched according to sex, age, and village of residence. The prevalence of epilepsy and the community microfilarial load (CMFL) were closely related (P < 0.02), and the case-control study demonstrated that the microfilarial loads (microfilariae per snip) in the epileptic group (arithmetic mean = 288, median = 216) were significantly higher (P < 10(-4)) than in the control group (arithmetic mean = 141, median = 63). The results strongly support the existence of a link between onchocerciasis and epilepsy. The fact that such a relationship has not been found recently in some other West and Central African areas is probably due to the lowered endemicity of onchocerciasis following vector- and ivermectin-related control measures applied over the past 5-25 years. The socio-economic and demographic impact of onchocerciasis-related epilepsy should be evaluated, and taken into account as part of all onchocerciasis control programmes.

Summary:Purpose: To evaluate the demographic impact of epilepsy a rural area of Africa.Methods: A cohort study was conducted between 1991 and 2001 in the Mbam Valley (Cameroon) on two groups of subjects (one of persons with epilepsy, and the other of control individuals matched for sex, age, and village of residence). At the end of the follow-up, information on mortality, marital status, and numbers of offspring was obtained from 128 pairs of subjects.Results: Thirty-seven (28.9%) persons with epilepsy and six (4.7%) controls died between 1991 and 2001. The relative risk of dying during the follow-up among the group of people with epilepsy, compared with the controls, was 6.2 (95% CI, 2.7-14.1). The most frequent causes of death in the persons with epilepsy were status epilepticus, sudden unexpected death in epilepsy (SUDEP), and drowning. Of the 90 pairs, of which both members were still alive in 2001, 15 (16.7%) persons with epilepsy were married as compared with 53 (58.9%) controls. The mean number of children was 0.9 in the subjects with epilepsy, and 1.7 in the controls (p < 0.0001).Conclusions: Health personnel should be trained and sensitized about the devastating effect of this neglected disease in developing countries. In those areas where onchocerciasis control programs are organized by using the community-directed-treatment approach, the possibility that the ivermectin distributors could also be responsible for distributing antiepileptic drugs should be considered.

Ivermectin treatment may induce marked adverse effects in those harbouring > 8000 Loa microfilariae (mff)/ml of blood, individuals with > 30 000 Loa mff/ml being at risk of developing serious neurological reactions. It is thus necessary to delineate the geographical areas where such responses may occur. To determine if the simple measure of prevalence of Loa microfilaraemia would be appropriate to identify the communities at risk, the relationships between prevalence and intensity of Loa microfilaraemia were investigated in 67 villages in Cameroon. The prevalence recorded in the adult population was found to be closely related to each of the indicators of infection intensity investigated. For example, when the prevalences of Loa microfilaraemia in adults were 20%, 30% and 40%, approximately 5%, 9% and 16% of the adults had microfilarial loads exceeding 8000 mff/ml, respectively; the corresponding percentages of adults with > 30 000 mff/ml were about 1%, 3% and 5%-6%. Thus it seems that, in areas where loiasis is co-endemic, the monitoring procedure during large-scale ivermectin treatments for the control of onchocerciasis only needs to be strengthened in those communities where the prevalence of Loa microfilaraemia in adults exceeds 20%.

No abstract