Oladele O. Kale

Rapid assessment method for prevalence and intensity of Loa loa infection

OBJECTIVE To assess the validity of observations on eye worm and Calabar swellings for the rapid assessment of the prevalence and intensity of loiasis at the community level. METHOD A total of 12895 individuals over the age of 15 years living in 102 communities in Cameroon and Nigeria took part in the study. A standardized questionnaire was administered to participants from whom finger-prick blood samples were collected and examined for Loa loa microfilariae. Rapid assessments of the prevalence and intensity of loiasis were made on the basis of a history of eye worm or Calabar swellings. FINDINGS There was a strong correlation between the indices of the rapid assessment procedures and the parasitological indices of L. loa endemicity. The rapid assessment indices were effective in diagnosing high-risk communities (sensitivity 94-100%; specificity 66-92%). The highest sensitivity (100%) and specificity (92%) were obtained with a rapid assessment procedure based on a history of eye worm lasting 1-7 days together with confirmation by the guided recognition of a photograph of adult L. loa in the eye. CONCLUSION Rapid assessment of the prevalence and intensity of loiasis at the community level can be achieved using a procedure based on the history of eye worm lasting 1-7 days together with confirmation by the guided recognition of a photograph of an adult L. loa in the eye.

The effects of ivermectin on onchocercal skin disease and severe itching: results of a multicentre trial.

objective To determine the effects of ivermectin in annual, 3‐monthly and 6‐monthly doses on onchocercal skin disease (OSD) and severe itching.

Onchocerciasis: the burden of disease.

The greatest burdens related to human onchocerciasis are the result of the eye and skin lesions and severe itching produced by the microfilariae. Although the major manifestations of the disease do show geographical variation (e.g. onchocercal blindness is not a common complication in all endemic countries), they are often sufficiently severe to prevent human use of the often very fertile land close to the rivers in which the vectors breed. Though for many years thought to be of relatively minor importance compared with onchocercal eye disease, the skin lesions of onchocerciasis have recently been shown to be a major socio-economic burden, in terms of disability-adjusted life-years. The demonstration of an excellent correlation between the prevalence of palpable nodules in a community and the community microfilarial load has led to the development of rapid, safe and non-invasive methods to assess and map the levels of endemicity across whole countries. This has enabled mass treatment with Mectizan (ivermectin, MSD) to be targeted first at hyperendemic communities. Estimates of the burden of onchocerciasis will continue to change as better means of measurement become available. It seems possible, however, that use of Mectizan will eliminate the disease before its true burden can be estimated accurately.

Farm land size and onchocerciasis status of peasant farmers in south-western Nigeria

Summary Concern is being raised about the economic impact of the non‐blinding strain of onchocerciasis, since half of those affected with onchocerciasis in Africa live in the forest zones where the non‐blinding form is prevalent. WHOs TDR programme has embarked on multi‐country studies on the social and economic effects of onchocercal skin disease (OSD). Baseline data from one site, the Ibarapa Local Government Area of Oyo State, Nigeria, is presented here. Farmers were screened for signs and symptoms of onchocerciasis including palpable nodules, reactive skin lesions and self‐reported severe itching. Those having two or more of these conditions were classified as having severe OSD. A matching group of farmers without any of the signs or symptoms formed a control group. Women in the area either did not farm or held only one small plot. Land size comparisons were undertaken with 51 pairs of male farmers matched for age and location within 23 small hamlets bordering the Ogun River. Farmers with OSD had significantly less farmland under cultivation (9117 m2) than those with no OSD (13850 m2). The farmers with OSD did not appear to have alternative income strategies to compensate and, consequently, they had a lower value of personal wealth indicators (e.g. iron sheet roofing, motorcycle) than those without OSD. One can conclude that although the effect of forest strain onchocerciasis is less dramatic than of the blinding from, the disease poses an important economic threat in the region.

Community-directed treatment of onchocerciasis with ivermectin in Takum, Nigeria.

A study to identify factors within the community that can ensure sustainable community‐directed treatment (ComDT) with ivermectin compared the effectiveness of programme‐designed (PD) and community‐designed (CD) strategies in 37 villages in the Takum area of Nigeria. In a subset of PD villages, designated PD1, communities were asked to use the village heads as community‐directed distributors (CDD), and the other communities (PD2) were asked to select female distributors, and both were instructed to use the house‐to‐house method of distribution. Community‐designed communities, on the other hand, were asked to design their own approach. All study communities received health education, treatment guidelines, and training enabling them to determine appropriate dosage. A total of 1744 people were interviewed about their experiences after two treatment cycles. Communities preferred honest, reliable community members as CDDs, but few women were selected. The results show striking similarity between PD and CD villages in many respects. In the PD1 villages, where the programme designated the village head as CDD, the mode of distribution was changed from house‐to‐house to central point, and distribution took place in the compound of the village head. In the PD2 villages, where the programme specified distributors should be women, the women who were selected were replaced by their male children. These changes to the original design were consistent with the local cultural norms and made the arrangement for distribution more acceptable to the people. Programme‐designed villages that used the village head as distributors performed better than those that used women, and the coverage in the former group compares well with that of CD villages. Only five villages achieved coverage > 60%, but dosage was correct in most cases (87.4%). Drug shortage was the most frequent reason for non‐treatment. Communities devised means for ensuring equity and fairness in sharing their limited supply and freely altered the original designs to fit local norms and values. These changes to the original design were consistent with local norms and were acceptable to the people. The success of this strategy should be tested in other parts of Nigeria. Long‐term success of ComDT, however, requires a reliable drug supply and inputs from professionals in the health system for minimal supervision. The core issues that determine sustainability of ComDT appear to be not so much in the structure, but in the process by which they are introduced. Communities will only sustain a programme where the process of implementation fits well with local norms and where communities are free to alter PD procedures that are inconsistent with local customs.

Gender and ethnic differences in onchocercal skin disease in Oyo State, Nigeria

During preparation for a study on the effects of ivermectin treatment on onchocercal skin disease in the Ifeloju Local Government Area of Oyo State, Nigeria, 1032 adults aged20 years and older were examined for skin lesions and palpable nodules. It was found thatfor 4 types of skin lesions, acute papular onchodermatitis (APOD), chronic papular onchodermatitis (CPOD), lichenified onchodermatitis (LOD) and depigmentation (leopard skin), as well as for subcutaneous nodules, females had a significantly higher prevalence than males. Although the area is inhabited primarily by the Yoruba people, the study also included some of the cattle‐herding Fulani ethnic group. The reactive skin lesions, APOD, CPOD and LOD, were found to be more common among the Fulani, although there were no significant differences in leopard skin and nodules between both groups. While there is need for further research on both immunological and behavioural factors that may lead to these differences in disease. The need to achieve equity in health programming by ensuring that women and ethnic minorities receive full disease control services is of more immediate concern.

Illness Behavior in Guineaworm Disease

Guineaworm, a waterborne helminthic disease, affects a large portion of the population in Idere, Nigeria. Although preventive health education interventions are experiencing success, it is slow due to the low economic status of the community. In the meantime people suffer and seek treatment. The decision-making process during illness with guineaworm does not fit neatly into individual psychosocial theoretical models. Concepts of the disease and potential remedies are strongly influenced by the local culture. In the process of studying these cultural influences, suggestions for new models have arisen. These suggest a mediating role for health education between traditional and Western scientific viewpoints in promoting efficacious illness behavior in endemic tropical diseases.

Age and sex differences in new and recurrent cases of guinea worm disease in Nigeria

In this population-based cross-sectional survey of the prevalence and incidence of guinea worm disease in Idere, a rural agricultural community of Oyo state in Nigeria, epidemiological data were collected by household interview of all 501 households (6527 persons, 3594 females and 2933 males). 86% of the households had at least one case. The prevalence was 32.4% in the overall population, but varied markedly by age and sex. About 10% of prevalent cases were first-time infections or new cases. Males over 19 years of age had a higher prevalence rate than adult females; however, females had a higher prevalence rate at younger ages. The prevalence in females peaked (47%) at 35 to 44 years; for males the proportion was highest (57%) at ages 45 to 54 years.

The development of a treatment guideline for childhood malaria in rural Southwest Nigeria using participatory approach

OBJECTIVE To describe the development of a treatment guideline for the effective case management of malaria in children at the home level. METHODS Thirty-three mothers selected from 11 communities in a rural health district, community members and the research team developed a guideline for treatment of malaria at home by caregivers using a participatory approach. This was done in phases using modified focus group discussion sessions. Suggested ideas were depicted in illustrations by a graphic artist. RESULTS A guideline which illustrated the presentation of clinical types of malaria, the appropriate steps to take for each type and the correct dosage schedule of chloroquine (based on the age of the child) for treatment of uncomplicated malaria was developed. The guideline was in cartoon format and the script in the local language. CONCLUSION Use of a participatory approach was found acceptable and effective in the development of the guideline. This approach is therefore recommended irrespective of the target population or the intervention to be developed. Practice implications Preparation of educational materials with contributions from end users does not only build capacity at the local level but also increases the acceptability and ownership of such materials.

Improving recognition of onchocerciasis in primary care--1: Nonclassical symptoms.

The symptomatology of onchocerciasis appears to show some variations in different parts of the world, This may be related to race (Guderian et al. 1984; Molea et al. 1984), to the strain of parasite which is associated with the geography and vegetation type forest or savannah (Anderson et al. 1974), and to endemicity (Buck 1974), Despite these local variations, all published descriptions list three cardinal features: nodules, pruritus (with skin signs), and ocular manifestations. That many patients have microfilaria-positive skin snips without nodules, skin or eye changes is also documented (Duke & Anderson 1972), but there is a dearth of studies that look for other premonitory symptoms or signs which might be useful diagnostic indicators in early stages of the disease. This paper focuses on the diagnostic potential of other symptoms, particularly musculo-skeletal pain (MSP).