Adverse reactions to the ivermectin treatment of onchocerciasis patients: does infection with the human immunodeficiency virus play a role?

To assess and compare the adverse effects resulting from ivermectin treatment of onchocerciasis patients with and without infection with human immunodeficiency virus (HIV-1), 1256 Ugandan cases of onchocerciasis were investigated as they were treated for the first time with the drug. Treatment followed the protocol of the Mectizan Expert Committee (i.e. a single dose of 150 mug/kg body weight). Adverse reactions to the ivermectin were determined, within 48 h of treatment, through questioning and clinical examinations during house-to-house visits. The HIV-1 status of each patient aged >15 years was initially determined using indirect ELISA, and any ELISA-positives were then confirmed in a western-blot assay. Among the cases aged >15 years, the frequency of adverse reactions to ivermectin was higher among those seropositive for HIV-1 (53.4%) than among the seronegative (45.7%) but the difference was not statistically significant (P = 0.25). The severity of the adverse reactions observed was, however, significantly lower in the HIV-1-positive patients than in the seronegative patients, with median scores of 1.37 and 1.68, respectively (P = 0.044). The conclusion is that ivermectin can be safely used for mass treatment in areas where the prevalences of onchocerciasis and HIV-1 infection are both high.

A descriptive analysis of the institutional frameworks for disaster management in Uganda: structures, functions and gaps

BACKGROUND

There is insufficient documentation of the institutional frameworks for disaster management and resilience at different levels in sub-Saharan Africa. The objective of this study was to describe the institutional framework for disaster management in Uganda, and to identify actionable gaps at the different levels.

METHODS

This was part of a multi-country assessment in which 6 countries in Eastern Africa developed and applied a common tool. The assessment was qualitative in nature employing a mixed methods approach including review of documents, interviews with key informants from agencies involved in disaster management in Uganda, group discussions with stakeholder and synthesis meetings of the assessment team.

FINDINGS

The Office of the Prime Minister is the lead agency for disaster management, but management of disasters of a technical nature is devolved to line ministries (e.g. epidemics by the Health Ministry and Epizootics by the Agriculture Ministry). A new policy spells out disaster management structures at national, district, sub-county, and village levels. Key challenges included coordination, more focus on prevention than risk reduction, differences in capacity between sectors and inadequate inter-sectoral collaboration. The new policy and structures have not yet been rolled out to districts and sub-district levels, and districts lack a line item budget for disaster capacity building.

CONCLUSIONS

The institutional framework for disaster management in Uganda needs to be strengthened at all levels through initiation of the relevant structures, training, and resource allocation so that they develop disaster management plans.

A situational analysis of priority disaster hazards in Uganda: findings from a hazard and vulnerability analysis

BACKGROUND

Most countries in sub-Saharan Africa have not conducted a disaster risk analysis. Hazards and vulnerability analyses provide vital information that can be used for development of risk reduction and disaster response plans. The purpose of this study was to rank disaster hazards for Uganda, as a basis for identifying the priority hazards to guide disaster management planning.

METHODS

The study as conducted in Uganda, as part of a multi-country assessment. A hazard, vulnerability and capacity analysis was conducted in a focus group discussion of 7 experts representing key stakeholder agencies in disaster management in Uganda. A simple ranking method was used to rank the probability of occurance of 11 top hazards, their potential impact and the level vulnerability of people and infrastructure.

RESULTS

In-terms of likelihood of occurance and potential impact, the top ranked disaster hazards in Uganda are: 1) Epidemics of infectious diseases, 2) Drought/famine, 3) Conflict and environmental degradation in that order. In terms of vulnerability, the top priority hazards to which people and infrastructure were vulnerable were: 1) Conflicts, 2) Epidemics, 3) Drought/famine and, 4) Environmental degradation in that order. Poverty, gender, lack of information, and lack of resilience measures were some of the factors promoting vulnerability to disasters.

CONCLUSION

As Uganda develops a disaster risk reduction and response plan, it ought to prioritize epidemics of infectious diseases, drought/famine, conflics and environmental degradation as the priority disaster hazards.

Fourteen years of surveillance of HIV-1 prevalence among pregnant women attending antenatal care clinics in western Uganda

This study monitored long-term temporal trends in HIV-1 prevalence in antenatal clinic attendees living in western Uganda. Semi-annual data collection was done from 1991 to 2004. For each woman the following data were recorded: HIV-1 status, age, educational status, marital status, occupation and parity. The results show that the overall HIV-1 prevalence was 15.3% during the entire time period (urban 21.3%, semi-urban 12.7% and rural 7.1%). Between 1991 and 2004, we observed a gradual decline in the HIV-1 prevalence. The decline was most pronounced in urban women aged 15-19 years old and least pronounced in rural women aged 20-24 years. Women above 25 years of age did not show any decline in HIV-1 prevalence over time. The declining HIV-1 prevalence in the younger age groups (15-24 years) likely represents a declining risk for acquiring HIV infection as we have previously shown in the urban sub-sample of this data set.

Mortality from epilepsy in an onchocerciasis-endemic area in West Uganda

Mortality from epilepsy was investigated in a rural area of West Uganda where epilepsy is found to be closely linked to onchocerciasis. Thirty-three female and 28 male patients (age range 4-58 years, median 15 years) were identified in a population-wide prevalence survey and were followed from June 1994 to March 2001 (observation period 3,929 person-months). Patients had continuing access to antiepileptic drug (AED) treatment with phenobarbital. Eighteen patients died during the period of observation, corresponding to a standardised mortality ratio (SMR) of 7.2 (95% CI 4.4-11.6; P<0.0001). Adherence to treatment was considered good in 36 of 56 patients receiving regular AEDs, with a SMR of 7.4 in this group compared with a SMR of 8.0 for those 20 patients considered poorly adherent. These findings show high mortality in patients with onchocerciasis-associated epilepsy despite regular AED treatment. Epilepsy appears to have a dramatic impact on this community with high Onchocerca volvulus infestation. If the suspected causal relationship between epilepsy and infection with O. volvulus could be confirmed, this would further underline the importance of sustained control efforts against onchocerciasis.

Attitude of women in western Uganda towards pre-packed, unit-dosed malaria treatment for children

In the context of a larger study on malaria related knowledge, attitudes, practices and beliefs in western Uganda 813 women aged 15-49 years were shown a sample of a pre-packed, unit-dosed malaria treatment for children, its use was explained and attitudes of the women were investigated. Of all women, 90.5% (86% urban, 92% rural) said they would prefer the pre-packed over the conventional type of treatment and 93.9% of these were willing to pay between 0.17 (rural) and 0.29 (urban) US dollars more for this treatment. Two-thirds (67.8%) thought that they would not have to ask their spouses before making a decision on the kind of treatment and 59.5% said they would rather stock the treatment at home than buy it when a child gets sick. The most mentioned reason for preferring pre-packs was their safety and cleanliness, while ease of application, dosing and compliance were secondary. We conclude that pre-packed, unit-dosed malaria treatment is accepted by the caretakers of children in the area studied and that they readily understand and accept its concept. This indicates a high potential for this approach to improve the home management of malaria fevers and reduce malaria-related morbidity and mortality if adequate coverage can be achieved and if the intervention is embedded into an appropriate programme of behavioural change communication and provider training.

HIV counselling and testing in rural Uganda: communities' attitudes and perceptions towards an HIV counselling and testing programme

Study results on the assessment of a community-wide HIV counselling and testing programme are presented. The aim of this qualitative study was to elucidate whether HIV counselling and testing (HIV CT) was acceptable to a rural community and whether they expressed a need for it. From a total of 2,267 persons of Kigoyera Parish, western Uganda, who were HIV tested and counselled, 171 persons participated in 17 focus group discussions. Most participants expressed a strong need for HIV counselling and testing services. The counsellors were seen as competent and confidential. Community health workers were favoured as the preferred provider of HIV CT services. However, participants stressed that they should not come from the same community. Most participants felt that a HIV CT programme available only once is not enough and did not induce a change in sexual behaviour, e.g. increased condom use. They requested counselling services that are continuously offered. The study results also showed that there is a demand for HIV counselling services without being HIV tested.

Genetic diversity of Plasmodium falciparum and its relationship to parasite density in an area with different malaria endemicities in West Uganda

Field populations of Plasmodium falciparum can be effectively genotyped by PCR-amplification of selected fragments of the Merozoite Surface Proteins 1 and 2 (MSP1 and MSP2). Genetic diversity of P. falciparum populations in areas with different transmission levels (holo- vs. mesoendemic) was investigated in Kabarole District, West Uganda. 225 samples positive for P. falciparum were analysed by amplification of polymorphic regions and classified according to prevalence of allelic families. A large number of alleles was detected for each locus: 22 for MSP1 block 2 and 24 for MSP2 and, 175 (78%) of MSP1 alleles and 143 (64%) of MSP2 showed multiple infections within a range of 2-8 clones. Significant differences between holoendemic and mesoendemic areas in regards of population structure and number of multiclonal infections of P. falciparum were not apparent. However, a significant correlation between parasite density, selected MSP2 loci and differences between parasite density in monoclonal vs. multiclonal infections occurred. Multiplicity of infection was age-dependent.

Low impact of a community-wide HIV testing and counseling program on sexual behavior in rural Uganda

Study results on the assessment of a community-wide HIV counseling and testing program are presented. The aim of this study was to elucidate whether HIV counseling and testing was effective in reducing high risk sexual behavior of a rural population in Uganda. From a total of 2,267 persons of Kigoyera Parish, western Uganda, who were HIV tested and counseled, 495 persons were selected and interviewed about their sexual behavior. Persons who were HIV tested showed no difference in sexual behavior compared to those who were not tested (condom use 4.3% vs. 5.5%, mean number of sexual partner in the past three months 1.8 vs. 2.0). The conclusion is that only knowing the HIV serostatus is not enough to reduce high risk behavior. The study results also showed that there is a demand for HIV counseling services without being HIV tested.

Clinical and electro-clinical classification of epileptic seizure in west Uganda

When compared to that of industralised countries, the prevalence of epilepsy in developing countries has generally been found to be higher and in some areas extremely high rates of up to 57 cases per 1000 inhabitants have been reported. The reasons for this difference are still widely unknown and detailed epidemiological as well as clinical data are scarce, especially from rural Africa. The present study was conducted in western Uganda, in an area of high epilepsy prevalence, known to be endemic for onchocerciasis. The seizures of all 91 epilepsy patients diagnosed in this area over the period of two years were classified according to the criteria of the International League against Epilepsy. Based on seizure description alone, the predominant seizure was classified as generalised in 57 patients (63%), as partial in 22 (24%) and unclassified in 12 (13%). An EEG record was analysed in 55 out of 91 patients, showing focal epileptiform activity (EA) in 12, multifocal EA in 9 and primarily generalised EA in 6 patients. When in addition to clinical information, the EEG results in the 27 patients with EA were taken in consideration for seizure classification, the proportion of partial seizures increased to 78% (n = 21); inversely the proportion of generalised seizures fell to 22% (n = 6). The predominance of partial seizures would be compatible with a localised brain lesion as a frequent cause for epileptic seizures in the study area. The findings further corroborate recent observations from several African countries of an association between epilepsy and onchocerciasis.

Correlation of in vivo-resistance to chloroquine and allelic polymorphisms in Plasmodium falciparum isolates from Uganda

The efficacy of chloroquine in the treatment of uncomplicated falciparum malaria in Africa is heavily compromised by high levels of drug resistance. The occurrence of active site mutations in the Plasmodium falciparum multi drug resistance-gene 1 (pfmdr1) has been associated with development of resistance to chloroquine. This study investigates the occurrence of several mutations at codons 86, 1042 and 1246 of the pfmdr1-gene in infected blood samples taken from Ugandan children before treatment with chloroquine and their relationship to clinical and parasitological resistance. Even though a clear association of CQR to one certain pfmdr1 single point mutation could not be substantiated, the frequency of resistance was consistently higher for samples revealing any of the mutations than among wild type samples, and 90% of the clinically resistant samples did present a mutation. Thus detection of these allelic pfmdr1 polymorphisms is not a decisive factor for prediction of clinical chloroquine resistance, but an interplay of the different mutations with unknown cofactors is to be assumed and the possible role of other genetic alterations remains to be investigated.

Reliability of malaria microscopy in epidemiological studies: results of quality control

To assess the interrater reproducibility of malaria microscopy in epidemiological studies, 711 thick blood films from population-based surveys were randomly selected and reread by 4 experienced microscopists. Sample estimates of the prevalence of P. falciparum infection, geometric mean parasite density and the proportion of samples above various parasite density cut-off levels were almost identical in the routine and quality control readings. Differences were, however, encountered in the sample estimates for gametocyte ratio, proportion of mixed infection and average density index. In all three cases the quality control result was significantly higher than the routine evaluation. On the level of the individual slide there was good interrater agreement for the presence of P. falciparum infections (Kappa index kappa = 0.79) which was even better when parasite densities between 4 and 100/microl were excluded (kappa = 0.94). With respect to the assessment of parasite density, a high level of disagreement was found. While the mean difference between the two readings was not different from 0, the second reading was between 0.12 and 10 times that of the first. However, the level of disagreement significantly fell with increasing parasite densities. Thus malaria microscopy is very reliable for the estimation of parasite ratios and geometric mean parasite densities within and between studies as long as the same methodology is used, but tends to underestimate the gametocyte ratio and proportion of mixed infections. Care must be taken, however, when individual parasite density is related to other explanatory variables, due to the high degree of variability in the parasite enumeration.

Plasmodium falciparum resistance to sulfadoxine/pyrimethamine in Uganda: correlation with polymorphisms in the dihydrofolate reductase and dihydropteroate synthetase genes

The efficacy of sulfadoxine/pyrimethamine (S/P) in treatment of uncomplicated falciparum malaria in Africa is increasingly compromised by development of resistance. The occurrence of active site mutations in the Plasmodium falciparum gene sequences coding for dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS) is known to confer resistance to pyrimethamine and sulfadoxine. This study investigated the occurrence of these mutations in infected blood samples taken from Ugandan children before treatment with S/P and their relationship to parasite breakthrough by day 7. The results confirm the occurrence of mutations in DHFR and DHPS that were significantly selected under S/P pressure at day 7: a combination of alleles 51-isoleucine and 108-asparagine in DHFR, and 436-serine, 437-alanine, 540-lysine and 581-alanine in DHPS, appears to play a major role in the development of in vivo resistance in P. falciparum strains against S/P. Therefore, earlier results derived from isolates from hyperendemic areas in Tanzania were confirmed by this investigation.

Plasmodium falciparum: selection of serine 108 of dihydrofolate reductase during treatment of uncomplicated malaria with co-trimoxazole in Ugandan children

In vivo testing for resistance of Plasmodium falciparum to co-trimoxazole (trimethoprim/sulfamethoxazole) was performed in Uganda in 41 children with uncomplicated malaria, and blood samples were screened before and after treatment for polymorphisms in the antifolate target genes for dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS). Selection towards a specific genotype at some codons of the DHFR and DHPS genes was observed in samples collected after exposure to co-trimoxazole drug pressure. The alleles 51-isoleucine, 59-arginine, and 108-serine of DHFR were significantly associated with clinical resistance, as was allele 581-alanine of DHPS. Resistance against antifolate combinations probably requires resistance-related polymorphisms in both the DHFR and the DHPS genes. In addition, it appears that the trimethoprim-resistant DHFR genotype differs from that for pyrimethamine at residue 108.

Population structure of recrudescent Plasmodium falciparum isolates from western Uganda

It has been proposed that polymorphisms of the Merozoite Surface Protein 1 and 2 (MSP1 and MSP2) and the Glutamate Rich Protein (GLURP) genes can be considered as genetic markers for the genotyping of field populations of Plasmodium falciparum. During a field study on in vivo drug resistance against chloroquine, sulphadoxine/pyrimethamine (S/P) and cotrimoxazole in West Uganda, sensitive and resistant isolates were collected from patients by fingerprick for genotyping. 59 (72.8%) of the 81 P. falciparum samples isolated at day 0 showed multiclonal infection with 2-7 clones. Among the isolates we investigated, presence of the allelic family MAD20 of MSP1 at day 0 was significantly (P = 0.0041) associated with decreased resistance to antimalarials. Use of this method in a field study on in vivo drug resistance demonstrates another potential application of genotyping as a tool for epidemiological investigations.

Application of the ParaSight-F dipstick test for malaria diagnosis in a district control program

A rapid test for the diagnosis of Plasmodium falciparum infections based on the detection of histidine-rich-protein II, the ParaSight-F test, was evaluated after introduction in a district malaria control program in Uganda. Suspected treatment failures, pregnant women and infants with clinical malaria and general fever cases were tested at health facilities in malaria hypo-, meso- and holoendemic areas. A total of 1326 tests were carried out by health unit staff, cross read by experienced laboratory staff and results compared with thick film microscopy as the standard. Rater agreement in reading the dipstick result between health unit staff and laboratory staff was high, kappa index 0.94 (0.88-0.99). Sensitivity was 99.6% (99.0-100) for parasite densities above 500/microl, 98.6% (97.7-99.6) for densities above 50/microl and 22.2% (8.6-42.3) for densities below 10/microl. With the applied testing strategies no differences were found between endemicity levels or patient categories. Specificity was 86.2% (83.3-88.8) overall, but significantly higher in general fever cases (92.7%) compared to the other patient groups (84.3%, P=0.009). At the given prevalences positive predictive values (ppv) were above 80% and negative predictive values (npv) above 90% in all cases except in pregnant women (ppv: 77.8%). We conclude that in certain situations this test is an alternative to microscopy to improve diagnostic facilities for case management in malaria control programs in endemic African countries.

Reductions in risk behaviour provide the most consistent explanation for declining HIV-1 prevalence in Uganda

OBJECTIVE

To monitor the HIV-1 epidemic in Western Uganda and the possible impact of interventions.

DESIGN

Results from sentinel surveillance of HIV-1 seroprevalence were compared with cross-sectional serosurvey data and model simulations.

METHODS

Age-specific trends in HIV-1 prevalence between 1991 and 1997 amongst antenatal clinic (ANC) attenders in the town of Fort Portal, where a comprehensive AIDS control programme has been implemented since 1991, were analysed. Results were compared with outputs from a mathematical model simulating the HIV-1 epidemic in Uganda. Two scenarios were modelled: one without and one with behaviour change. Sentinel surveillance data were compared with data from a population-based HIV-1 serosurvey at the study site, which was carried out in early 1995.

RESULTS

Data from 3271 ANC attenders identified greater education and being single as risk factors for HIV-1 infection. A significant decrease of risk for women with secondary school education over time was observed, whereas the risk for illiterate women remained high. Among women aged 15-19 years (n = 1045) education and marital status-adjusted HIV-1 prevalence declined steadily from 32.2% in 1991 to 10.3% in 1997. For 20-24-year-old women (n = 1010) HIV-1 prevalence increased until 1993 from 19.9% to 31.7% and decreased thereafter (21.7% in 1997). These trends closely follow the prediction of the model simulation assuming behaviour change, and for 1995-1997, confidence intervals of the HIV-1 prevalence estimate exclude the model output for an uninfluenced epidemic. No clear trends of HIV-1 prevalence were found in older women (n = 1216) and comparisons with the model were ambiguous. Sentinel surveillance data at the time of the population survey closely reflected results for the female general population sample for the two younger age-groups (15-19 and 20-24 years). In contrast, pregnant women aged 25-29 years showed significantly lower rates than the population sample (20.8% versus 45.1%).

CONCLUSION

HIV-1 prevalence amongst ANC attenders aged 15-24 years can be used to monitor the HIV-1 epidemic in the given setting. Declining trends of HIV-1 prevalence in women aged 15-19 and 20-24 years most likely correspond to a reduced HIV-1 incidence attributable to changes in behaviour. Our data also show that sentinel surveillance data need to be age-stratified to give useful information.

High incidence of epilepsy related to onchocerciasis in West Uganda

The incidence of epilepsy was assessed in an onchocerciasis endemic area in West Uganda over a period of 4 years. A high overall crude incidence rate of 215 per 100000 person-years was found (age-adjusted: 156 per 100000 person-years) and the incidence in zones of high onchocerciasis endemicity was significantly higher than in low endemic zones (age adjusted rates: 232 per 100000 person-years versus 77 per 100000 person-years; Yates corrected chi2: P < 0.01). The data constitute a baseline for an ongoing intervention study on the effects of onchocerciasis control on epilepsy incidence in the study area. If a causal relationship between onchocerciasis and epilepsy can be confirmed, this would have significant implications for the concept of morbidity due to onchocerciasis and for the prevention of epilepsy in the endemic areas.

Antiepileptic drug treatment in rural Africa: involving the community

The vast majority of patients with epilepsy in developing countries do not receive adequate medical treatment and an estimated percentage of 80-90% are without any treatment. Poor infrastructure, insufficient availability of drugs and scarcity of trained medical personnel are relevant factors for this situation. Traditional concepts about epilepsy may also affect acceptance and compliance to modern treatment. We report our experience with anti-epileptic drug (AED) treatment in a rural African community with a high prevalence of epilepsy. After identification of the patients during a prevalence survey on epilepsy, the input of the medical service of the district to the treatment scheme was reduced to a 6-monthly medical visit to the area and long-term provision of AED to the patients. Members of the community were integrated as assistants in the distribution of the drugs and community participation was gradually enhanced over the first year of the programme. A cost-sharing system for the financing of the community assistants was introduced and a self-help committee of epilepsy patients and their families was founded. Within the first 20 months the patients showed good compliance as indicated by a growing number of patients presenting for treatment and a low rate of discontinuation of the treatment. A marked improvement could be observed for most of the patients treated with phenobarbitone in terms of reduction of seizure frequency although complete seizure control was achieved in only a few.

Resistance in vivo of Plasmodium falciparum to co-trimoxazole in western Uganda

In the context of the 'integrated management of childhood illnesses' (IMCI) programme the World Health Organization recommends treating children in malarious areas presenting with fever and respiratory symptoms with co-trimoxazole. In order to verify its effectiveness in uncomplicated Plasmodium falciparum malaria we carried out a study in vivo in western Uganda: 180 children under 5 years old were enrolled and treated with 40/8 mg/kg/d co-trimoxazole over 5 d, and 159 could be followed on days 3, 7 and 14. Effectiveness of treatment was found to be significantly different in various parts of the study area. In Bundibugyo District, bordering République Democratique du Congo (Zaire), 59.1% (39/66) of children were clinically cured after 14 d and 56.1% were parasitologically cured. In the east of Kabarole District (43 children), the figures were 76.7% and 65.1%, respectively. In western Kabarole (50 children) the rates were 96.0% and 90.0%, respectively. We conclude that, in view of the high level of clinical failures in parts of the study area, co-trimoxazole should not be used in the IMCI programme for combined treatment of malaria and pneumonia in the region. Assessment of therapeutic effectiveness of antimalarial drugs needs to consider the microepidemiology of resistance.

Geographic differences in the sensitivity of a polymerase chain reaction for the detection of Plasmodium falciparum infection

The amplification of target DNA by highly specific probes using the polymerase chain reaction (PCR) provides a highly sensitive and specific method for the detection of malaria infection. The use the of PCR in settings with varying endemicity within one survey area has not been investigated intensively. Therefore, a cross-sectional study was conducted in the districts of Kabarole and Bundibugyo in western Uganda using material from three villages with different epidemiologic situations regarding malaria and DNA primers for a PCR that had shown satisfactory sensitivity and specificity in previous trials. The sensitivity of the PCR varied significantly (P < 0.001) in the three survey villages (between 63.2% and 83.9% for the primer pair K1-14-1 and between 37.9% and 69.9% for the primer pair MSP-1) and was highly linked to geographic differences and social exchanges of the inhabitants with other areas of the district. According to the results of this investigation, it is advisable not to use a single primer pair in epidemiologic field studies for the detection of falciparum malaria. The use of combined primer pairs and the frequent confirmation of the results by microscopy are recommended.

The prevalence of epilepsy follows the distribution of onchocerciasis in a west Ugandan focus

Epidemiological surveys indicate that the prevalence of epilepsy is higher in developing countries than in industrialized countries. Except for neurocystocercosis due to Taenia solium, little is known about possible underlying causes. This article reports the relationship between epilepsy and onchocerciasis in an Onchocerca volvulus endemic area in West Uganda. Individuals complaining of seizures were identified by means of a population census in 12 villages. Active epilepsy was confirmed in 61 of 4743 inhabitants (crude prevalence rate = 1.3%; age-standardized rate = 1.1%). Distribution of epilepsy in the study area was clustered, ranging from a prevalence of 0.2% to 3.4% in different villages. Age-specific prevalence was highest between 10 and 19 years, with a rate of 3.6% for the study are as a whole, and up to 10.0% in villages of high epilepsy prevalence. The prevalence of onchocerciasis in the 10-19-year-old age group was assessed by skin-snip biopsy and ranged from 15% to 85% in different villages. Epilepsy was significantly more frequent in the three villages with the highest levels of O. volvulus endemicity than in other villages (P < 0.0001). Serological testing for T. solium infection was positive in one and borderline in three of 53 epilepsy patients tested. The significant correlation between epilepsy and onchocerciasis did not change when these four patients were excluded from the analysis. These findings suggest a strong association between epilepsy and onchocerciasis in this area. This could have significant implications for the concept of morbidity due to O. volvulus.