Community-based Guinea worm surveillance in Chad: Evaluating a system at the intersection of human and animal disease

PLoS Negl Trop Dis. 2021 Mar 18;15(3):e0009285. doi: 10.1371/journal.pntd.0009285. eCollection 2021 Mar.

Abstract

Background: Guinea worm is a debilitating parasitic infection targeted for eradication. Annual human cases have dropped from approximately 3,500,000 in 1986 to 54 in 2019. Recent identification of canine cases in Chad threatens progress, and therefore detection, prevention, and containment of canine cases is a priority. We investigated associations between disease knowledge, community engagement, and canine cases in Chad to identify opportunities to improve active surveillance.

Methods: We surveyed 627 respondents (villagers, local leaders, community volunteers, and supervisors) across 45 villages under active surveillance. Descriptive statistics were analyzed by respondent category. Logistic regression models were fitted to assess the effects of volunteer visit frequency on villager knowledge.

Results: Knowledge increased with respondents' associations with the Guinea worm program. Household visit frequency by community volunteers was uneven: 53.0% of villagers reported visits at least twice weekly and 21.4% of villagers reported never being visited. Villagers visited by a volunteer at least twice weekly had better knowledge of Guinea worm symptoms (OR: 1.71; 95% CI: 1.04-2.79) and could name more prevention strategies (OR: 2.04; 95% CI: 1.32-3.15) than villagers visited less frequently. The primary motivation to report was to facilitate care-seeking for people with Guinea worm. Knowledge of animal "containment" to prevent contamination of water, knowledge of rewards for reporting animal cases, and ability to name any reasons to report Guinea worm were each positively correlated with village canine case counts.

Conclusions: Community volunteers play crucial roles in educating their neighbors about Guinea worm and facilitating surveillance. Additional training and more attentive management of volunteers and supervisors could increase visit frequency and further amplify their impact. Emphasizing links between animal and human cases, the importance of animal containment, and animal rewards might improve surveillance and canine case detection. The surveillance system should be evaluated routinely to expand generalizability of data and monitor changes over time.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Chad / epidemiology
  • Dog Diseases / epidemiology*
  • Dog Diseases / parasitology
  • Dogs
  • Dracunculiasis / epidemiology*
  • Dracunculiasis / veterinary*
  • Dracunculus Nematode / isolation & purification
  • Female
  • Health Knowledge, Attitudes, Practice*
  • Humans
  • Male
  • Middle Aged
  • Patient Education as Topic
  • Primary Prevention / education
  • Primary Prevention / methods*
  • Surveys and Questionnaires

Grants and funding

This work was supported by The Carter Center, whose work to eradicate Guinea worm disease has been made possible by financial and in-kind contributions from many donors. A full listing of supporters can be found at The Carter Center website (http://www.cartercenter.org/donate/corporate-government-foundation-partners/index.html). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.