Update on the current status of onchocerciasis in Côte d'Ivoire following 40 years of intervention: Progress and challenges

PLoS Negl Trop Dis. 2018 Oct 23;12(10):e0006897. doi: 10.1371/journal.pntd.0006897. eCollection 2018 Oct.

Abstract

Background: Onchocerciasis control in Côte d'Ivoire started with aerial insecticide spraying in 1974 and continued with community directed treatment with ivermectin (CDTi) from 1992 to the present. Onchocerciasis and lymphatic filariasis (LF) are co-endemic in 46 of the 81 health districts in the country. Fourteen and 12 districts are endemic for only LF or onchocerciasis, respectively. This paper aims to review the impact of past interventions on onchocerciasis in Côte d'Ivoire between 1975 and 2013, and review plans for disease elimination.

Methods: We reviewed microfilaria (MF, skin snip) prevalence and community microfilarial load (CMFL) data from published reports from 53 health districts during two major epidemiological assessment periods. Data from 1975 through 1991 provided information on the impact of vector control, and data from 1992 through 2016 provided information on the impact of CDTi.

Results: Weekly aerial insecticide spraying in 8 endemic districts between 1975 and 1991 reduced the overall MF prevalence by 68.1% from 43.5% to 13.9%. The CMFL also decreased in 7 out of 8 surveyed communities by 95.2% from 9.24 MF/snip to 0.44 MF/snip. Ivermectin distribution started in 1992. The coverage targets for control (65% of the total population) was reached in most endemic districts, and some areas achieved 80% coverage. Two sets of surveys were conducted to assess the impact of CDTi. Results from the first repeat surveys showed a significant decrease in overall MF prevalence (by 75.7%, from 41.6% to 10.1%). The second follow-up evaluation showed further improvement in most endemic districts and also documented major reductions in CMFL compared to baseline.

Conclusions: Extensive data collected over many years document the very significant impact of interventions conducted by the National Onchocerciasis and other Eyes Diseases Control Programme during challenging times with periods of civil unrest. The Health Ministry has now integrated efforts to control neglected tropical diseases and adopted the goal of onchocerciasis elimination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Child
  • Child, Preschool
  • Cote d'Ivoire / epidemiology
  • Disease Transmission, Infectious / prevention & control*
  • Elephantiasis, Filarial / epidemiology
  • Endemic Diseases*
  • Epidemiologic Studies
  • Female
  • Filaricides / therapeutic use
  • Humans
  • Insect Control / methods
  • Ivermectin / therapeutic use
  • Male
  • Middle Aged
  • Onchocerciasis / epidemiology*
  • Onchocerciasis / prevention & control*
  • Prevalence
  • Young Adult

Substances

  • Filaricides
  • Ivermectin

Grants and funding

Funds to support data collected in this manuscript came from OCP, APOC, Local Government and other international donor such as Sightsavers. During the writing of this manuscript, BGK was partly supported by DOLF project (GH5342) funded by Bill and Melinda Gates Foundation. The funders had no role in study design, data collection and analysis, the decision to publish, or preparation of the manuscript.