Persistence of onchocerciasis in villages in Enugu and Ogun states in Nigeria following many rounds of mass distribution of ivermectin
Abstract Background Onchocerciasis is endemic in most local government areas (LGAs) in Enugu and Ogun states. Most meso- and hyper-endemic LGAs have received many rounds of ivermectin mass drug administration (MDA). This study aimed to determine the current prevalence of onchocerciasis in villages i...
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| Format: | Article |
| Language: | English |
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BMC
2022-11-01
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| Series: | BMC Infectious Diseases |
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| Online Access: | https://doi.org/10.1186/s12879-022-07811-7 |
| _version_ | 1828098562094792704 |
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| author | Uwem F. Ekpo Obiora A. Eneanya Edith N. Nwankwo Islamiat Y. Soneye Gary J. Weil Peter U. Fischer Obioma C. Nwaorgu |
| author_facet | Uwem F. Ekpo Obiora A. Eneanya Edith N. Nwankwo Islamiat Y. Soneye Gary J. Weil Peter U. Fischer Obioma C. Nwaorgu |
| author_sort | Uwem F. Ekpo |
| collection | DOAJ |
| description | Abstract Background Onchocerciasis is endemic in most local government areas (LGAs) in Enugu and Ogun states. Most meso- and hyper-endemic LGAs have received many rounds of ivermectin mass drug administration (MDA). This study aimed to determine the current prevalence of onchocerciasis in villages in Enugu and Ogun states that were formerly highly endemic and to assess progress toward elimination of the infection in areas believed to be at high risk for persistence. Methods Cross-sectional community surveys were conducted 8 to 12 months after the last round of MDA in 16 villages (6 in Enugu state and 10 in Ogun state) in individuals aged ≥ 18 years. Study participants were examined for the presence of palpable subcutaneous nodules. Skin snips from the posterior iliac crests were used to assess microfiladermia (Mf) prevalence and density. Results 643 subjects were palpated for nodules and 627 individuals (225 in Enugu state; 402 in Ogun state) provided skin snips. Nodule prevalence in the study villages ranged from 42 to 66.7% in Enugu state and from 0 to 25.0% in Ogun state. Mf prevalence in the Enugu and Ogun study villages ranged from 32 to 51.1% and 0 to 28.6%, respectively. Geometric mean skin Mf density in surveyed Enugu state villages ranged between 1 and 3.1 Mf/mg; these values were < 1 Mf/mg in all but one community in Ogun state villages. Conclusion Results from this study show that onchocerciasis persists in adults in many villages in Enugu and Ogun states despite many prior rounds of ivermectin MDA. Prevalence was higher in villages surveyed in Enugu than in Ogun. Low Mf densities suggest the MDA program is working well to reduce disease, but more time will be required to reach the elimination goal. |
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| format | Article |
| id | doaj.art-f1c096a0e0d44745b9a3d9c1aa32e245 |
| institution | Directory Open Access Journal |
| issn | 1471-2334 |
| language | English |
| last_indexed | 2024-04-11T08:04:17Z |
| publishDate | 2022-11-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Infectious Diseases |
| spelling | doaj.art-f1c096a0e0d44745b9a3d9c1aa32e2452022-12-22T04:35:38ZengBMCBMC Infectious Diseases1471-23342022-11-012211610.1186/s12879-022-07811-7Persistence of onchocerciasis in villages in Enugu and Ogun states in Nigeria following many rounds of mass distribution of ivermectinUwem F. Ekpo0Obiora A. Eneanya1Edith N. Nwankwo2Islamiat Y. Soneye3Gary J. Weil4Peter U. Fischer5Obioma C. Nwaorgu6Department of Pure and Applied Zoology, Federal University of AgricultureInfectious Diseases Division, Washington University School of MedicineDepartment of Parasitology and Entomology, Faculty of Biosciences, Nnamdi Azikiwe UniversityNeglected Tropical Disease Control Unit, Ogun State Ministry of HealthInfectious Diseases Division, Washington University School of MedicineInfectious Diseases Division, Washington University School of MedicineDepartment of Parasitology and Entomology, Faculty of Biosciences, Nnamdi Azikiwe UniversityAbstract Background Onchocerciasis is endemic in most local government areas (LGAs) in Enugu and Ogun states. Most meso- and hyper-endemic LGAs have received many rounds of ivermectin mass drug administration (MDA). This study aimed to determine the current prevalence of onchocerciasis in villages in Enugu and Ogun states that were formerly highly endemic and to assess progress toward elimination of the infection in areas believed to be at high risk for persistence. Methods Cross-sectional community surveys were conducted 8 to 12 months after the last round of MDA in 16 villages (6 in Enugu state and 10 in Ogun state) in individuals aged ≥ 18 years. Study participants were examined for the presence of palpable subcutaneous nodules. Skin snips from the posterior iliac crests were used to assess microfiladermia (Mf) prevalence and density. Results 643 subjects were palpated for nodules and 627 individuals (225 in Enugu state; 402 in Ogun state) provided skin snips. Nodule prevalence in the study villages ranged from 42 to 66.7% in Enugu state and from 0 to 25.0% in Ogun state. Mf prevalence in the Enugu and Ogun study villages ranged from 32 to 51.1% and 0 to 28.6%, respectively. Geometric mean skin Mf density in surveyed Enugu state villages ranged between 1 and 3.1 Mf/mg; these values were < 1 Mf/mg in all but one community in Ogun state villages. Conclusion Results from this study show that onchocerciasis persists in adults in many villages in Enugu and Ogun states despite many prior rounds of ivermectin MDA. Prevalence was higher in villages surveyed in Enugu than in Ogun. Low Mf densities suggest the MDA program is working well to reduce disease, but more time will be required to reach the elimination goal.https://doi.org/10.1186/s12879-022-07811-7OnchocerciasisIvermectinMass drug administrationNigeria |
| spellingShingle | Uwem F. Ekpo Obiora A. Eneanya Edith N. Nwankwo Islamiat Y. Soneye Gary J. Weil Peter U. Fischer Obioma C. Nwaorgu Persistence of onchocerciasis in villages in Enugu and Ogun states in Nigeria following many rounds of mass distribution of ivermectin BMC Infectious Diseases Onchocerciasis Ivermectin Mass drug administration Nigeria |
| title | Persistence of onchocerciasis in villages in Enugu and Ogun states in Nigeria following many rounds of mass distribution of ivermectin |
| title_full | Persistence of onchocerciasis in villages in Enugu and Ogun states in Nigeria following many rounds of mass distribution of ivermectin |
| title_fullStr | Persistence of onchocerciasis in villages in Enugu and Ogun states in Nigeria following many rounds of mass distribution of ivermectin |
| title_full_unstemmed | Persistence of onchocerciasis in villages in Enugu and Ogun states in Nigeria following many rounds of mass distribution of ivermectin |
| title_short | Persistence of onchocerciasis in villages in Enugu and Ogun states in Nigeria following many rounds of mass distribution of ivermectin |
| title_sort | persistence of onchocerciasis in villages in enugu and ogun states in nigeria following many rounds of mass distribution of ivermectin |
| topic | Onchocerciasis Ivermectin Mass drug administration Nigeria |
| url | https://doi.org/10.1186/s12879-022-07811-7 |
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