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

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.

Surveillance of Human Guinea Worm in Chad, 2010–2018

“…A 2019 CGWEP surveillance system evaluation found that the frequency of volunteer visits to households was varied despite program guidance that requires that volunteer visits are to be conducted on a daily basis. 42 Improved supervision and volunteer training and consistent application of program standards throughout different times of year have been identified as future priorities for the CGWEP. 42 Until full control of the zoonotic reservoir(s) is achieved in Chad, renewed transmission to humans will likely remain a risk.…”

“…42 Improved supervision and volunteer training and consistent application of program standards throughout different times of year have been identified as future priorities for the CGWEP. 42 Until full control of the zoonotic reservoir(s) is achieved in Chad, renewed transmission to humans will likely remain a risk. This is further complicated by the additional difficulty of detecting and containing infections in mobile groups of people, and by extension their dogs, underscoring the need for a multipronged approach to surveillance and control of Guinea worm.…”

“… 34 Improved supervision and volunteer training and consistent application of program standards throughout different times of year have been identified as future priorities for the CGWEP. 34 …”

Assessment of the Chad guinea worm surveillance information system: A pivotal foundation for eradication

“…This investigation resulted in identification of system level problems and potential solutions. Although informatics assessments have been conducted on macrolevels for infectious disease [39] and surveillance evaluations performed for Guinea worm disease [4,20,40], our approach is novel in that we assessed the information system from the surveillance need, data management, and data use perspectives for Guinea worm disease. The framework we used here could be adapted by other programs looking to assess their information systems to support surveillance and programmatic needs.…”

“…To address the data and information system-related challenges, the Chad Ministry of Public Health and National Solidarity (MoPH) and The Carter Center requested informatics assistance from the Centers for Disease Control and Prevention (CDC) in the form of an "Info-Aid," a mechanism that allows Public Health Informatics Fellows (CDC's "data detectives") to provide short-term technical assistance in the event of an urgent public health need for applied information science and technology [19]. Although a previous, rigorous surveillance evaluation had been conducted [20], it was determined that an additional assessment would be needed specifically to address informatics needs.…”