Lymphatic filariasis among the Ezza people of Ebonyi State, eastern Nigeria.

A total of 1,243 Ezza people living in 10 communities of Ebonyi State, eastern Nigeria were examined between July 2002-January 2003 for lymphatic filariasis. This is the first time a filariasis survey due to Wuchereria bancrofti has been carried out in this state. Of the 1,243 persons examined, 210 (16.9 %) had W. bancrofti microfilariae. Infection varied significantly among communities and ages (p < 0.05) but not sex-related (p > 0.05). The Ezza people are predominantly farmers and professional hired labourers. There was a close association between microfilaria rate and microfilaria -density in various age groups (r = 0.812; p < 0.01). Microfilaria density is an important measure in the epidemiology, treatment and control of human filarisis in this endemic foci. Clinical signs and symptoms of the disease include elephantiasis, hydrocoele, dermatitis and periodic fever. Clinical symptoms without microfilaraemia and microfilaraemia without clinical symptoms were also observed. Of 1,603 mosquitoes dissected, Anopheles gambiae, An. funestus and Culex quinquefasciatus showed infectivity rates of 6.3 %, 5.1 % and 6.0 % respectively. The affected persons and other key informants are unaware of the cause of the disease and attributed it to witchcraft, violation of taboo, bad water and food. Intervention strategies to be integrated into the on-going Community-Directed Treatment with Ivermectin (CDTI) project are discussed.

Control of endemic dracunculiasis in Ebonyi state, south-eastern Nigeria.

A field study was carried out in Ozibo and the Ebonyi local government area of Ebonyi state, south-eastern Nigeria to determine the effectiveness of several intervention strategies in the control of endemic dracunculiasis in that area. During the initial study prior to the application of such measures, 14,421 subjects were examined. A total of 8,688 (60.2%) persons had either Dracunculus ulcers or emergent worms. Sex-related prevalence rates were 56.1% and 63.9% for males and females respectively. Age specific prevalence rates increased with age in males, whereas highest infection rates were found in females younger than 20 years. Twenty-eight months after the introduction of intervention strategies the prevalence rate fell by 85.1% to 9% (males: by 88.2% to 6.6%, females: by 83.0% to 10.8%). Reduction rates of more than 90% were observed in males aged 10 to 19 and in females aged 0 to 9 years. Intervention measures included systematic pond treatment, distribution or replacement of filters, intensive health education, provision of hand-dug wells, regular bore-hole installation/rehabilitation as well as active case detection, containment, management, and prompt reporting. Active involvement of the endemic communities, governments and the Global 2000 staff regarding the control efforts is a necessity towards the final eradication of the disease in the near future. The relationship between some of these intervention strategies and community development are highlighted.

Endemicity of vesical schistosomiasis in the Ebonyi Benue river valley, south eastern Nigeria.

The investigation on the prevalence of patent and clinically severe infections with Schistosoma haematobium was carried out amongst inhabitants of Ebonyi Benue river valley, South Eastern Nigeria between August 2000 and June 2001. The inhabitants are predominantly farmers. Of the 3296 subjects examined from 15 randomly selected villages in the valley, 776 (23.5%) were excreting the eggs of S. haematobium in their urine. Infection rates varied between 18.9% and 30.6%. The severity of infection calculated by arithmetic mean egg counts (AMEC) and geometric mean egg counts (GMEC) varied significantly between the age groups and the villages (P < 0.05). The prevalence and severity of infection increased with age from 0 to 25 years and decreased thereafter. Symptoms associated with the disease include visible hematuria (63.1%), suprapubic pain (10.3%) and stranguary (9.9%). While 65 positive persons had more than one symptom, 64 of the positive persons had no noticeable symptoms. Visible hematuria showed moderate sensitivity and high specificity for the disease. Female genital schistosomiasis (FGS) of the lower reproductive tract was recorded in 19 females of child bearing age that complained of severe suprapubic pain. Eight snail species were recorded in the stagnant ponds and both Bulinus globosus and B. truncatus were infected with schistosome cercariae. The factors contributing to these observations and feasible control measures are discussed.