RESUMO
Background: Transmission by unreported cases has been proposed as a reason for the 2013-2016 Ebola virus (EBOV) epidemic decline in West Africa, but studies that test this hypothesis are lacking. We examined a transmission chain within social networks in Sukudu village to assess spread and transmission burnout. Methods: Network data were collected in 2 phases: (1) serological and contact information from Ebola cases (n = 48, including unreported); and (2) interviews (n = 148), including Ebola survivors (n = 13), to identify key social interactions. Social links to the transmission chain were used to calculate cumulative incidence proportion as the number of EBOV-infected people in the network divided by total network size. Results: The sample included 148 participants and 1522 contacts, comprising 10 social networks: 3 had strong links (>50% of cases) to the transmission chain: household sharing (largely kinship), leisure time, and talking about important things (both largely non-kin). Overall cumulative incidence for these networks was 37 of 311 (12%). Unreported cases did not have higher network centrality than reported cases. Conclusions: Although this study did not find evidence that explained epidemic decline in Sukudu, it excluded potential reasons (eg, unreported cases, herd immunity) and identified 3 social interactions in EBOV transmission.
RESUMO
Background: Based on findings from other contexts, informed by intergroup contact theory, that more contact is associated with less stigma, we hypothesized that community members with greater exposure to cases of Ebola virus disease (EVD) were less likely to report EVD-related stigma towards EVD survivors. We assessed personal stigmatizing attitudes towards Ebola survivors, which reflects personal fear and judgement, as well as perceived stigma towards EVD survivors, which reflects an individual's perception of the attitudes of the community towards a stigmatized group. Methods: From September 2016 to July 2017, we conducted a cross-sectional, community-based study of EVD-related stigma among individuals who did not contract Ebola in four EVD-affected rural communities of Kono District, Sierra Leone. We identified individuals from all quarantined households and obtained a random sample of those who were unexposed. Exposed individuals either lived in a quarantined household or were reported to have been in contact with an EVD case. Our explanatory variable was proximity to an EVD case during the outbreak. Our primary outcome was stigma towards EVD survivors, measured by a 6-item adapted HIV-related stigma index validated in Zambia and South Africa, with 1 item reflecting personal stigmatizing attitudes and 5 items reflecting perceived community stigma. The 6-item EVD stigma index had good internal consistency (Cronbach's alpha=0.82). We used modified Poisson and negative binomial regression models, adjusting for potential confounders, to estimate the association between exposure proximity and EVD stigma. Results: We interviewed 538 participants aged 12 to 85 years. Most (57%) had been quarantined. Over one-third (39%) reported personal stigmatizing attitudes or perceived community stigma; the most frequently endorsed item was fear and judgment towards EVD survivors. Having contact with someone with EVD was significantly associated with a lower likelihood of perceived community stigma (prevalence ratio [PR], 0.26; 95% CI, 0.13-0.54) and personal stigmatizing attitudes (PR, 0.44; 95% CI, 0.29-0.65). In contrast, being quarantined was significantly associated with a higher likelihood of perceived community stigma (PR, 3.9; 95% CI, 1.5-10.1). Conclusions: In this cross-sectional study, we found evidence of an inverse relationship between EVD-related stigma and contact with an EVD case. This finding substantiates intergroup contact theory and may form the basis for anti-stigma interventions.
