Journal Article > Meta-AnalysisFull Text
Epidemics. 2019 March 2; Volume 27; DOI:10.1016/j.epidem.2019.03.001
Robert A, Camacho A, Edmunds WJ, Baguelin M, Muyembe JJT, et al.
Epidemics. 2019 March 2; Volume 27; DOI:10.1016/j.epidem.2019.03.001
Health care workers (HCW) are at risk of infection during Ebola virus disease outbreaks and therefore may be targeted for vaccination before or during outbreaks. The effect of these strategies depends on the role of HCW in transmission which is understudied. To evaluate the effect of HCW-targeted or community vaccination strategies, we used a transmission model to explore the relative contribution of HCW and the community to transmission. We calibrated the model to data from multiple Ebola outbreaks. We quantified the impact of ahead-of-time HCW-targeted strategies, and reactive HCW and community vaccination. We found that for some outbreaks (we call "type 1″) HCW amplified transmission both to other HCW and the community, and in these outbreaks prophylactic vaccination of HCW decreased outbreak size. Reactive vaccination strategies had little effect because type 1 outbreaks ended quickly. However, in outbreaks with longer time courses ("type 2 outbreaks"), reactive community vaccination decreased the number of cases, with or without prophylactic HCW-targeted vaccination. For both outbreak types, we found that ahead-of-time HCW-targeted strategies had an impact at coverage of 30%. The vaccine strategies tested had a different impact depending on the transmission dynamics and previous control measures. Although we will not know the characteristics of a new outbreak, ahead-of-time HCW-targeted vaccination can decrease the total outbreak size, even at low vaccine coverage.
Journal Article > ResearchFull Text
Emerg Infect Dis. 2015 March 1; Volume 21 (Issue 3); 393-399.; DOI:10.3201/eid2103.141892
Kucharski AJ, Camacho A, Checchi F, Waldman RJ, Grais RF, et al.
Emerg Infect Dis. 2015 March 1; Volume 21 (Issue 3); 393-399.; DOI:10.3201/eid2103.141892
In some parts of western Africa, Ebola treatment centers (ETCs) have reached capacity. Unless capacity is rapidly scaled up, the chance to avoid a generalized Ebola epidemic will soon diminish. The World Health Organization and partners are considering additional Ebola patient care options, including community care centers (CCCs), small, lightly staffed units that could be used to isolate patients outside the home and get them into care sooner than otherwise possible. Using a transmission model, we evaluated the benefits and risks of introducing CCCs into Sierra Leone's Western Area, where most ETCs are at capacity. We found that use of CCCs could lead to a decline in cases, even if virus transmission occurs between CCC patients and the community. However, to prevent CCC amplification of the epidemic, the risk of Ebola virus-negative persons being exposed to virus within CCCs would have to be offset by a reduction in community transmission resulting from CCC use.
Journal Article > ResearchFull Text
PLoS Curr. 2015 February 10; DOI:10.1371/currents.outbreaks
Camacho A, Kucharski AJ, Aki-Sawyerr Y, White M, Flasche S, et al.
PLoS Curr. 2015 February 10; DOI:10.1371/currents.outbreaks
Between August and November 2014, the incidence of Ebola virus disease (EVD) rose dramatically in several districts of Sierra Leone. As a result, the number of cases exceeded the capacity of Ebola holding and treatment centres. During December, additional beds were introduced, and incidence declined in many areas. We aimed to measure patterns of transmission in different regions, and evaluate whether bed capacity is now sufficient to meet future demand.
Journal Article > LetterFull Text
Nat Med. 2020 August 7; Volume 26 (Issue 9); 1411–1416.; DOI:10.1038/s41591-020-1025-y
Sherrard Smith E, Hogan AB, Hamlet A, Watson OJ, Whittaker C, et al.
Nat Med. 2020 August 7; Volume 26 (Issue 9); 1411–1416.; DOI:10.1038/s41591-020-1025-y
The burden of malaria is heavily concentrated in sub-Saharan Africa (SSA) where cases and deaths associated with COVID-19 are rising. In response, countries are implementing societal measures aimed at curtailing transmission of SARS-CoV-2. Despite these measures, the COVID-19 epidemic could still result in millions of deaths as local health facilities become overwhelmed. Advances in malaria control this century have been largely due to distribution of long-lasting insecticidal nets (LLINs), with many SSA countries having planned campaigns for 2020. In the present study, we use COVID-19 and malaria transmission models to estimate the impact of disruption of malaria prevention activities and other core health services under four different COVID-19 epidemic scenarios. If activities are halted, the malaria burden in 2020 could be more than double that of 2019. In Nigeria alone, reducing case management for 6 months and delaying LLIN campaigns could result in 81,000 (44,000-119,000) additional deaths. Mitigating these negative impacts is achievable, and LLIN distributions in particular should be prioritized alongside access to antimalarial treatments to prevent substantial malaria epidemics.