ABSTRACT
Purpose: Despite its critical role in containing outbreaks, the efficacy of contact tracing (CT), measured as the sensitivity of case detection, remains an elusive metric. We estimated the sensitivity of CT by applying unilist capture-recapture methods on data from the 2018-2020 outbreak of Ebola virus disease in the Democratic Republic of Congo. Methods & Materials: We applied different distributional assumptions to the zero-truncated count data to estimate the number of unobserved cases with a) any contacts and b) infected contacts, to compute CT sensitivity. Geometric distributions were the best fitting models. Results: Our results indicate that CT efforts identified almost all (n=792, 99%) of the cases with any contacts, but only half (n=207, 48%) of the cases with infected contacts, suggesting that CT efforts performed well at identifying contacts during the listing stage, but performed poorly during the contact follow-up stage. Conclusion: This novel approach can be applied to assess the effectiveness of CT. Importantly, the approach described is disease-agnostic, and can be extended to assess the sensitivity of CT for any disease, including COVID-19, for which CT has been identified as a crucial component of the response activities.
ABSTRACT
The world has seen outbreaks of emergency and re-emergency of infectious diseases very often in the past years, many of them with devastating consequences for low-income countries with fragile or nonexistent health system, covid-19 being by now the last of a long series of global challenges. Although it is a huge challenge for the whole world, one country is facing it together with a current Ebola outbreak plus violence and some other diseases. The Democratic Republic of Congo is facing the immediate effects of both epidemics as illness and death, however its consequences at the political and economic level are usually more complex and may be protracted. Following the debate on why poor countries remain poor, it is maybe useful to rethink poverty and inequality keeping in mind Amartya Sen's seminal concepts: development must comprise freedom and respect for human rights and institutions at the price of fostering a vicious circle of (re)emerging diseases and structural violence. Ebola epidemics, that usually face some challenges when they happen alone, now together with malaria, measles, plague and covid, on top of violence in some areas, the disease sees its protocols harmed: for covid the orientation is to stay isolated, for Ebola the response includes tracking contacts. What means coming with a team to field to do the mapping in the middle of a confinement. The surveillance for such many epidemics on top of violence and humanitarian crisis makes the Democratic Republic of Congo one of the most worrying countries in terms of consequences of the Covid outbreak. Key messages Study of the association between the Covid, Ebola virus disease outbreak and the at-risk population living in the conflict zone in Eastern Democratic Republic of Congo. The study presents the difficulties that the population encountered in the face of restrictions imposed by armed groups to reach health services during an Ebola outbreak, in a conflict zone.