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.

Community-perceived benefits of ivermectin treatment in northeastern Nigeria

A 3-step approach involving focus group discussion, structured interviews and informal conversations with key individuals was used to investigate community usage and perceived benefits of ivermectin in nine Nigerian villages participating in a WHO-sponsored investigation of community-directed treatment with ivermectin (CDTI). Only 27% of 284 persons interviewed had received treatment. An under-estimation of the district's ivermectin needs led to inadequate supply of ivermectin to the communities, which was cited as the main reason (65%) for non-treatment. All those treated (N=76) were further interviewed using questionnaires. Worm expulsion (80%) and blindness prevention (68%) were the most frequently stated benefits. Other perceived benefits were an increase in vitality (68%), sexual drive and performance (29%). The sudden relief from a heavy burden of worms, which had built up over a long period, may have indirect effect on all aspects of an individual's health and account for the diverse experiences. The feeling of vitality, good appetite and general health following ivermectin treatment is an animating experience to many communities. Health planners face the challenge of preparing communities for fewer 'sensational' experiences and preventing a possible feeling of disappointment that may result from frequent usage.

Onchocerciasis in Taraba State, Nigeria: clinical-epidemiological study of at-risk males in Bakundi District

An epidemiological study of 1366 adult males from fourteen communities of Bakundi district of Taraba State, Nigeria was carried out to establish the prevalence and intensity of onchocerciasis. The findings of the study showed that 45.2% of subjects were infected. Ten communities had infection rates in excess of 30%. Lizard skin and leopard skin were seen in 3.5% and 2.0%, respectively, and increased with increasing age. Hanging groin (2.6%) and scrotal enlargement (8.6%) were also observed. There was a good correlation between the infection rate on one hand and the presence of nodules (r = 0.85, P < 0.05), hanging groin (r = 0.56, P < 0.05) and scrotal enlargement (r = 0.62, P < 0.05) on the other. There was also a significant correlation between the intensity of infection on the one hand and lizard skin (r = 0.67, P < 0.05), leopard skin (r = 0.88, P < 0.05) and hanging groin (r = 0.82, P < 0.05) on the other. Those who worked in the fields (such as hunters, farmers and fishermen) had higher infection than others because of frequent contact with the vector. Extensive surveys of all suspected river valleys must be carried out to identify all those communities which will benefit from ivermectin treatment.

Yaws and syphilis in the Garkida area of Nigeria

Sixty-four (4.2%) cases of yaws and forty-one (2.7%) cases of syphilis were encountered during an epidemiological survey for filariasis in the mid-Hawal river valley. This finding is despite the official position that yaws has been eradicated in Nigeria. The focus of the disease was localised in four of the six villages that were surveyed in the Garkida area of the valley. The disease was more common among farmers than among occupational groups. Aspart from yaws, syphilis (2.7%) which is another treponematoid infection was also encountered during the filariasis survey. The present findings imply that there still exists a benign transmission of the disease in the area and unless an immediate and effective control programme is initiated, yaws may still become a very important disease in Nigeria. The epidemiological aspects and public health implication of treponematosis especially of yaws, in this area are discussed.

Sociocultural factors of malnutrition among under-fives in Adamawa state, Nigeria

Sociocultural factors affecting malnutrition in over one thousand under fives living in villages and towns located in northeastern Nigeria were examined. Data was collected using a structured questionnaire and through examination of the children. The study showed that about a third of the children were malnourished. The observed malnutrition was higher among females. The age group most affected was 25-36 months. Poor weaning and food supplementation exerted the strongest influence on the nutritional status of the children whose diet consisted mainly of cereals. It is suggested that local but largely ignored protein sources should be given more attention. Adequate health education to mothers is essential especially in providing information on appropriate nutrition for the child that has just been weaned.

Comparison of two sample survey methods for hyperendemic onchocerciasis and a new focus in Dakka, Nigeria

Most researchers rely only on large samples for the assessment of onchocerciasis prevalence in communities where it is endemic. However, because of the large population that must be included in the sample and the cost of surveys, several alternative methods are being explored. One is the selection of a small "at risk" sample of 30 persons from each community to determine the level of onchocercal endemicity. In this study both the Small Sample Survey (SSS) and the Complete Enumeration Survey (CES) techniques were used to determine the prevalence and intensity of onchocerciasis infection in sixteen communities in Dakka district, Nigeria, using conventional epidemiological procedures. The SSS showed that 82.3% of 390 at risk persons were microfilarial positive with a mean microfilaria density (MFD) of 90.9 microfilaria per skinsnip (MF/SS) and six communities were classified as hyperendemic (prevalence beyond 59.9%). The CES of 1529 persons produced a count of 78.2% positivity and a MFD of 88.44 MF/SS. For each of the physical symptoms of the disease and the MFD, computed T-test values showed that the SSS gives an estimate that is impressively close to the CES in the estimation of the prevalence of onchocerciasis in a community despite its low cost.

Rapid assessment of onchocerciasis prevalence and a model for selecting communities for ivermectin distribution in West Africa

Analysis of the prevalence of onchocerciasis in an area of north-east Nigeria indicates that clinical symptoms are generally good predictors of the rate of onchocerciasis infection and of the mean microfilarial density in infected individuals. However, differences between regions and anomalous communities within regions make reliance on a single indicator dubious. Use of multivariate equations was tested, but offered little improvement over bivariate ones and an algorithmic approach, making use of local knowledge of factors which might complicate interpretation, is proposed instead. The framework is suggested as a basis for screening, although a larger database is required to produce definitive equations.

Microfilaruria in an area of Nigeria with hyperendemic onchocerciasis

Urine samples collected from sixty-four Nigerians living in a community which is hyperendemic for onchocerciasis were examined for microfilaria. Each urine donor was examined for the physical symptoms of long-standing onchocerciasis. The microfilaruria rate was 23.4%. Males had a higher rate of microfilaruria (27.5%) than females (16.7%). The prevalence rates of leopard skin and nodules were 18.8% and 46.9%, respectively. Thirteen persons had microfilaruria and had nodules. Seventeen showed no microfilaruria but had nodules. Only two of those without nodules were without microfilaruria. A very strong association was found between nodule-possession, nodule-load and microfilaruria (coefficient of association 0.85). Nodule load seemed to be the major factor in having microfilaria in urine. Microfilaruria is not common in Nigeria and the present finding is the first report of microfilaruria in the Taraba river valley which is a continuous onchocerciasis zone with the Western Cameroun-Southern Chad focus of transmission where microfilaruria has been reported. This paper discusses the implications of the results of this investigation with respect to monitoring the impact of ivermectin distribution in the Taraba river valley of Nigeria.

Human behaviour, water usage and schistosomiasis transmission in a small settlement near Yola, Nigeria

A study of the social, environmental and parasitological factors involved in the transmission of schistosomiasis among 1834 residents of a small settlement within an agricultural establishment near Yola, Nigeria, was carried out between June 1991 and May 1992. Water-contact rates and the prevalences of urinary schistosomiasis and intestinal schistosomiasis (40.0% of all contacts, 98% and 79%, respectively) were highest among children of 5-12 years, who were also the major contributors to the contamination of the Lake Geriyo environment with faeces and urine. The frequency and duration of water contact followed a seasonal pattern and seemed to be influenced by physiological and social needs such as defecation, urination and avoidance of harsh weather conditions. The interplay between a need for water contact, sanitation, freshwater snails and a supportive environment ensures a recycling of parasites within the studied community. This, in turn, helps to maintain a parasite bank from which infection is probably spread to other areas of the state. The present study is part of a series, on the dynamics of schistosomiasis transmission, which began with a study of the ecology of the freshwater snails in the same area.

Onchocerciasis in Taraba State, Nigeria: intensity, rate of infection and associated symptoms in 14 communities of Bali district

An epidemiological study of 14 communities situated along the major road passing through Bali district in Taraba State, Nigeria, was carried out in continuation of a statewide filariasis survey which began in 1989. Of the 4,024 people that were examined for Onchocerca volvulus microfilaria and for clinical symptoms of the disease, onchocerciasis, an unusually low 13.3% prevalence rate was recorded with a range between 1.1% and 45.5%. Only one community had prevalence rate beyond 30.0%, six had infection rates between 10 and 29% while the remaining seven had less then 10% prevalence of the disease. However, infection was recorded in every community. The prevalence of physical symptoms was equally low. Pruritus was 7.3% and leopard skin was 0.4%. The prevalence of onchocerciasis increased with age in both male and female thus supporting the age and sex specific pattern of infection that had been reported in other parts of the state. A case is made for the continued prospection for onchocerciasis in the other districts of the state in order to identify and treat all communities that must benefit from the ongoing ivermectin treatment.

Trichomoniasis amongst students of a higher institution in Nigeria

A total of 2048 urine specimens were examined to assess the infection prevalence and epidemiological factors of T. vaginalis amongst students in a Nigerian higher institution. Five hundred and five students were infected (24.7%). This included 131 (15.6%) males and 374 (31.0%) females. More male than female students were found to be asymptomatic. Infection was significantly higher in females than males and in the second and third than the fourth and fifth decades of life (P < 0.05). Infection increases progressively with increase in the number of sexual partners. The use and neglect of condoms were also assessed. The pH range of the vagina of most infected females was between 5.8-8.2. Clinical symptoms noted among females were local tenderness, vulval pruritus and intermittent burning sensations in addition to profuse vaginal discharges. The public health implication of the findings and some epidemiological factors enhancing the disease transmission are presented.

The effect of selected health education schemes on knowledge and attitude of the Kanuri towards certain parasitic diseases

The effect of 3 types of intervention schemes on the scientific knowledge and attitude of Kanuri towards malaria, diarrhoea and dysentery and intestinal worms was assessed using the Likert scale response type statements. 1383 respondents in our identical Kanuri villages were used in the study. The effect of still pictures and card games (Goramari), drama songs, storytelling and discussions (Yerimari) and a combination of both (Shetimari) on knowledge and attitude was tested. Gotimari was used as the control. Quarterly assessment of changes in knowledge and attitude showed that Goramari was the least effective while Yerimari and Shetimari were the most effective. Women were more influenced than men by health education schemes which involve drama songs and stories while card games and still pictures had very little effect on them (women). The implication of these findings on disease management through health education is discussed.

Observations on mansonellosis among the Ibos of Abia and Imo States, Nigeria

Between November, 1988 and April, 1991, parasitological and symptomatological methods of diagnosis were used to survey the prevalence of mansonellosis among the Ibo population in Abia and Imo States of Nigeria. 1,197 or 28.6% of the 4,183 persons examined were positive for microfilariae of Mansonella perstans. The prevalence of mansonellosis was significantly higher (P < 0.05) among rural dwellers (34.6%) than among urban dwellers (22.5%), in males (30.8%) than in females (26.3%), in farmers (59.8%) and palm wine tappers (46.1%) than in civil servants (7.6%), and in persons 21 years of age and above (36.2%) than in those in the first two decades of life (9.4%). Clinical signs observed in most infected persons include body itching, joint and back pains, occasional giddiness and elephantoid scrotum. Body itching was the most commonly observed clinical sign (14.7%), followed by joint pains (12.41%) with elephantoid scrotum (3.5%) as the least. The public health implication of the findings is discussed.

Eye lesions, blindness and visual impairment in the Taraba river valley, Nigeria and their relation to onchocercal microfilariae in skin

2876 persons in fourteen communities in the Taraba River Valley, Nigeria were examined for eye lesions and tested for visual acuity using the 'tumbling E'. The individuals were also examined for microfilaria of Onchocerca volvulus. More than one-tenth of the population were blind, while another 16.1% had visual impairment. The prevalence of blindness was in excess of 20% in six communities, with one community recording 71.9% blindness rate. All forms of visual involvement increased with age but were similar between sexes. Eye lesions were related to the level of vision. Both eye lesions and vision deteriorate with increase in age. Vision seems to worsen with increase in prevalence and intensity of O. volvulus. Large microfilarial loads were associated with severe eye damage and blindness. These findings indicate that the Taraba river valley could be one of West Africa's worst foci of onchocercal blindness.

Filariasis in Gongola State Nigeria. I: Clinical and parasitological studies in Mutum-Biyu District

A total of 2,552 persons living in 9 villages along the Benue river valley, Mutum Biyu district of Gongola State, Nigeria were examined between October and December 1989 for filariasis. It is the first time a filariasis survey will be carried out in this state. 276 (10.8%) had Wuchereria bancrofti, 50 (2.0%) had Loa loa, 281 (11.0%) were positive for Mansonella perstans while 12 (0.5%) were positive for Onchocerca volvulus. Villages located near the Benue river had higher prevalence rates than those further away. Dermatitis and hydrocoele were common and clinical manifestations were associated with parasite types. Clinical symptoms without microfilaremia and microfilaremia without clinical symptoms were also observed.

Hyperendemic onchocerciasis in the Taraba river valley of Gongola state (Old Adamawa province), Nigeria

A survey of the prevalence of onchocerciasis was carried out in the Taraba river valley, Nigeria where Simulium damnosum s. l. is known to breed but about which no epidemiological data exists. Skin biopsies taken from 2,876 persons in 14 communities were examined for the microfilariae of Onchocerca volvulus. 100% infection rate was recorded in one of the communities, five other communities had prevalence rates between 81.0% and 94.7%. Three communities had infection rates between 44.8% and 69.1%. The mean microfilarial density in all the communities was 64.7 with a range between 3.2 and 167.6. The present findings indicate that the Taraba river valley may be one of the worst onchocerciasis zones in Nigeria.

Water demand and schistosomiasis among the Gumau people of Bauchi State, Nigeria

A helminthological study of stool and urine samples from 1037 people from 4 rural communities in Gumau District of Bauchi State, Nigeria, was carried out using formol-ether concentration and direct centrifugation methods respectively. 39.0% of persons examined were infected. Ova of Ascaris lumbricoides, Schistosoma haematobium and S. mansoni were the most common. Trichuris trichiura, hookworm, tapeworm and Strongyloides stercoralis were also encountered. 17.9% and 10.8% of examined persons had S. haematobium and S. mansoni infections respectively. A significant relationship was found between water demand index (number of persons per well) and infection with S. haematobium (r = 0.95) and S. mansoni (r = 0.88) (P less than 0.01). Such a relationship was not found with other helminth infections. A significant association was also found between distance from a river and prevalence of S. haematobium (r = 0.94) and S. mansoni (r = 0.95) (P less than 0.01), but not with the other helminth infections. These findings suggest that the water demand index may be an important factor in the epidemiology of schistosome infections in rural communities.

Some social aspects of helminthiasis among the people of Gumau District, Bauchi State, Nigeria

A helminthological study of faecal materials collected from 1037 people from four rural communities in Gumau District of Bauchi State, Nigeria was carried out using a standard diagnostic procedure. The study is the first parasitological survey to be carried out in this rural district. Thirty-nine percent of examined persons were infected with helminths. Ascaris lumbricoides, Schistosoma mansoni, Trichuris trichiura, Hymenolepis nana, Strongyloides stercoralis, Taenia sp. and hookworm were encountered. Mixed infections were very common. There did not seem to be any difference between these and results obtained half a century ago in similar areas of northern Nigeria. The findings are discussed from the point of view of the social aspects of the people which encourage host-parasite contact and their implications for public health. Suggestions are made for the control of helminth parasites in the district.