Persistence of onchocerciasis and associated dermatologic and ophthalmic pathologies after 27 years of ivermectin mass drug administration in the middle belt of Ghana

Kenneth Bentum Otabil, María-Gloria Basáñez, Blessing Ankrah, Stephen Agyemang Opoku, Dennis Ofori Kyei, Rhoda Hagan, Richmond Ababio, Emmanuel John Bart-Plange, Theophilus Nti Babae, Prince-Charles Kudzordzi, Vera Achiaa Darko, Joseph G. Bamfo, Joseph Ameyaw, Abdul Sakibu Raji, Amber Hadermann, Henk D. F. H. Schallig, Robert Colebunders

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Abstract

Objectives: There is a pressing need to regularly evaluate the progress of onchocerciasis elimination programmes to timely identify and mitigate potential risks hindering the reaching of the 2030 targets proposed by the World Health Organization (WHO) in its roadmap on neglected tropical diseases (NTDs). We determined the prevalence of onchocerciasis and associated dermatological and ophthalmological manifestations in six endemic communities in the Bono Region of Ghana after 27 years of ivermectin mass treatment. Methods: In a cross-sectional study, 564 participants aged ≥5 years were enrolled (49.1% females), with a median age of 26 (range: 5–89) years. In 54% and 47%, skin-snip microscopy and Ov16 rapid diagnostic tests were performed, respectively. Skin disease was determined using the WHO Skin NTD App. Visual function assessments included tests of visual acuity. Results: The overall microfilarial prevalence was 12.5% (38/305) and Ov16 seroprevalence was 24.2% (64/265). Severe itching was recorded in 24.3%, acute papular onchodermatitis in 52.8%, chronic papular onchodermatitis in 12.5%, lichenified onchodermatitis in 0.7%, skin atrophy in 11.3%, depigmentation in 1.7% and palpable nodules in 5.3%. Of the 301 persons in which visual acuity was examined, 17% were visually impaired and 5.3% were blind and 47.3% presented with cataract. Chronic papular onchodermatitis, lichenified onchodermatitis, depigmentation and visual impairment were significantly associated with the presence of skin microfilariae and Ov16 seropositivity. Conclusions: The persistence of Onchocerca volvulus infection and onchocerciasis-associated dermatological and ophthalmological pathologies after prolonged treatment is of concern. There is a need to include morbidity management in onchocerciasis elimination programmes and understand better patterns of treatment coverage, adherence and actual intake of ivermectin.
Original languageEnglish
Pages (from-to)844-854
Number of pages11
JournalTropical Medicine and International Health
Volume28
Issue number11
Early online date2023
DOIs
Publication statusPublished - Nov 2023

Keywords

  • Ov16 seroprevalence
  • microfilariae
  • onchocercal skin disease
  • onchocerciasis
  • prevalence
  • visual acuity

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