Onchocerciasis in Anambra State, Southeast Nigeria

endemicity and clinical manifestations

Evaristus Chibunna Mbanefo, Christine Ifeoma Eneanya, Obioma C Nwaorgu, Moses Obiefuna Otiji, Victor Mmaduabuchi Oguoma, Bernice Amala Ogolo

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

BACKGROUND: A cross-sectional study was performed to determine the current endemicity of onchocerciasis in Ayamelum Local Council, Anambra State, Southeast Nigeria, where community-directed treatment with ivermectin has been implemented for over a decade.

METHODS: An estimate of the endemicity of onchocerciasis was obtained using the rapid assessment method in 894 subjects from 13 communities selected by multistage sampling. Dermatological and ocular manifestations were analysed and classified using standard criteria.

RESULTS: Onchocerca volvulus nodules were recorded in 86 (9.6 ± 1.9%) of the subjects, and 186 (20.8 ± 3.7%) had one or more of the various classes of onchocercal skin diseases (OSD). Prevalence was dependent on age (p = 0.001), but not on sex (p = 0.31). There was a total absence of symptoms in the youngest age group and a low prevalence among subjects in their second decade of life. Pearson's correlation showed a strong positive correlation between nodular rate and prevalence of chronic papular onchodermatitis (r = 0.943) and a poor correlation with acute papular onchodermatitis (r = 0.259). Age-dependent analysis of various classes of OSDs showed that the rate of acute papular onchodermatitis increased with age up to the third decade of life and decreased steadily thereafter, while the chronic forms of OSD increased with age for both sexes. Infection was dependent on occupation and proximity of the village to the vector breeding sites.

CONCLUSIONS: Generally low prevalence in the population and absence of symptoms among the youngest age group emphasise the success of the intervention, but the persistent occurrence of acute disease may suggest a shortfall due to low coverage or non-compliance with the mass chemotherapeutic regimen.

Original languageEnglish
Pages (from-to)578-583
Number of pages7
JournalPostgraduate Medical Journal
Volume86
Issue number1020
DOIs
Publication statusPublished - Oct 2010
Externally publishedYes

Fingerprint

Onchocerciasis
Nigeria
Skin Diseases
Eye Manifestations
Age Groups
Onchocerca volvulus
Ivermectin
Acute Disease
Occupations
Breeding
Cross-Sectional Studies
Infection
Population

Cite this

Mbanefo, Evaristus Chibunna ; Eneanya, Christine Ifeoma ; Nwaorgu, Obioma C ; Otiji, Moses Obiefuna ; Oguoma, Victor Mmaduabuchi ; Ogolo, Bernice Amala. / Onchocerciasis in Anambra State, Southeast Nigeria : endemicity and clinical manifestations. In: Postgraduate Medical Journal. 2010 ; Vol. 86, No. 1020. pp. 578-583.
@article{d447864eccf84026bd72fd63900b8a8a,
title = "Onchocerciasis in Anambra State, Southeast Nigeria: endemicity and clinical manifestations",
abstract = "BACKGROUND: A cross-sectional study was performed to determine the current endemicity of onchocerciasis in Ayamelum Local Council, Anambra State, Southeast Nigeria, where community-directed treatment with ivermectin has been implemented for over a decade.METHODS: An estimate of the endemicity of onchocerciasis was obtained using the rapid assessment method in 894 subjects from 13 communities selected by multistage sampling. Dermatological and ocular manifestations were analysed and classified using standard criteria.RESULTS: Onchocerca volvulus nodules were recorded in 86 (9.6 ± 1.9{\%}) of the subjects, and 186 (20.8 ± 3.7{\%}) had one or more of the various classes of onchocercal skin diseases (OSD). Prevalence was dependent on age (p = 0.001), but not on sex (p = 0.31). There was a total absence of symptoms in the youngest age group and a low prevalence among subjects in their second decade of life. Pearson's correlation showed a strong positive correlation between nodular rate and prevalence of chronic papular onchodermatitis (r = 0.943) and a poor correlation with acute papular onchodermatitis (r = 0.259). Age-dependent analysis of various classes of OSDs showed that the rate of acute papular onchodermatitis increased with age up to the third decade of life and decreased steadily thereafter, while the chronic forms of OSD increased with age for both sexes. Infection was dependent on occupation and proximity of the village to the vector breeding sites.CONCLUSIONS: Generally low prevalence in the population and absence of symptoms among the youngest age group emphasise the success of the intervention, but the persistent occurrence of acute disease may suggest a shortfall due to low coverage or non-compliance with the mass chemotherapeutic regimen.",
keywords = "Adolescent, Adult, Age Distribution, Aged, Child, Child, Preschool, Cross-Sectional Studies, Female, Humans, Male, Middle Aged, Nigeria/epidemiology, Onchocerciasis/epidemiology, Prevalence, Young Adult",
author = "Mbanefo, {Evaristus Chibunna} and Eneanya, {Christine Ifeoma} and Nwaorgu, {Obioma C} and Otiji, {Moses Obiefuna} and Oguoma, {Victor Mmaduabuchi} and Ogolo, {Bernice Amala}",
year = "2010",
month = "10",
doi = "10.1136/pgmj.2009.094946",
language = "English",
volume = "86",
pages = "578--583",
journal = "Postgraduate Medical Journal",
issn = "0032-5473",
publisher = "BMJ Publishing Group",
number = "1020",

}

Onchocerciasis in Anambra State, Southeast Nigeria : endemicity and clinical manifestations. / Mbanefo, Evaristus Chibunna; Eneanya, Christine Ifeoma; Nwaorgu, Obioma C; Otiji, Moses Obiefuna; Oguoma, Victor Mmaduabuchi; Ogolo, Bernice Amala.

In: Postgraduate Medical Journal, Vol. 86, No. 1020, 10.2010, p. 578-583.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Onchocerciasis in Anambra State, Southeast Nigeria

T2 - endemicity and clinical manifestations

AU - Mbanefo, Evaristus Chibunna

AU - Eneanya, Christine Ifeoma

AU - Nwaorgu, Obioma C

AU - Otiji, Moses Obiefuna

AU - Oguoma, Victor Mmaduabuchi

AU - Ogolo, Bernice Amala

PY - 2010/10

Y1 - 2010/10

N2 - BACKGROUND: A cross-sectional study was performed to determine the current endemicity of onchocerciasis in Ayamelum Local Council, Anambra State, Southeast Nigeria, where community-directed treatment with ivermectin has been implemented for over a decade.METHODS: An estimate of the endemicity of onchocerciasis was obtained using the rapid assessment method in 894 subjects from 13 communities selected by multistage sampling. Dermatological and ocular manifestations were analysed and classified using standard criteria.RESULTS: Onchocerca volvulus nodules were recorded in 86 (9.6 ± 1.9%) of the subjects, and 186 (20.8 ± 3.7%) had one or more of the various classes of onchocercal skin diseases (OSD). Prevalence was dependent on age (p = 0.001), but not on sex (p = 0.31). There was a total absence of symptoms in the youngest age group and a low prevalence among subjects in their second decade of life. Pearson's correlation showed a strong positive correlation between nodular rate and prevalence of chronic papular onchodermatitis (r = 0.943) and a poor correlation with acute papular onchodermatitis (r = 0.259). Age-dependent analysis of various classes of OSDs showed that the rate of acute papular onchodermatitis increased with age up to the third decade of life and decreased steadily thereafter, while the chronic forms of OSD increased with age for both sexes. Infection was dependent on occupation and proximity of the village to the vector breeding sites.CONCLUSIONS: Generally low prevalence in the population and absence of symptoms among the youngest age group emphasise the success of the intervention, but the persistent occurrence of acute disease may suggest a shortfall due to low coverage or non-compliance with the mass chemotherapeutic regimen.

AB - BACKGROUND: A cross-sectional study was performed to determine the current endemicity of onchocerciasis in Ayamelum Local Council, Anambra State, Southeast Nigeria, where community-directed treatment with ivermectin has been implemented for over a decade.METHODS: An estimate of the endemicity of onchocerciasis was obtained using the rapid assessment method in 894 subjects from 13 communities selected by multistage sampling. Dermatological and ocular manifestations were analysed and classified using standard criteria.RESULTS: Onchocerca volvulus nodules were recorded in 86 (9.6 ± 1.9%) of the subjects, and 186 (20.8 ± 3.7%) had one or more of the various classes of onchocercal skin diseases (OSD). Prevalence was dependent on age (p = 0.001), but not on sex (p = 0.31). There was a total absence of symptoms in the youngest age group and a low prevalence among subjects in their second decade of life. Pearson's correlation showed a strong positive correlation between nodular rate and prevalence of chronic papular onchodermatitis (r = 0.943) and a poor correlation with acute papular onchodermatitis (r = 0.259). Age-dependent analysis of various classes of OSDs showed that the rate of acute papular onchodermatitis increased with age up to the third decade of life and decreased steadily thereafter, while the chronic forms of OSD increased with age for both sexes. Infection was dependent on occupation and proximity of the village to the vector breeding sites.CONCLUSIONS: Generally low prevalence in the population and absence of symptoms among the youngest age group emphasise the success of the intervention, but the persistent occurrence of acute disease may suggest a shortfall due to low coverage or non-compliance with the mass chemotherapeutic regimen.

KW - Adolescent

KW - Adult

KW - Age Distribution

KW - Aged

KW - Child

KW - Child, Preschool

KW - Cross-Sectional Studies

KW - Female

KW - Humans

KW - Male

KW - Middle Aged

KW - Nigeria/epidemiology

KW - Onchocerciasis/epidemiology

KW - Prevalence

KW - Young Adult

U2 - 10.1136/pgmj.2009.094946

DO - 10.1136/pgmj.2009.094946

M3 - Article

VL - 86

SP - 578

EP - 583

JO - Postgraduate Medical Journal

JF - Postgraduate Medical Journal

SN - 0032-5473

IS - 1020

ER -