Sara Hersey

Exposure Patterns Driving Ebola Transmission in West Africa: A Retrospective Observational Study.

Background The ongoing West African Ebola epidemic began in December 2013 in Guinea, probably from a single zoonotic introduction. As a result of ineffective initial control efforts, an Ebola outbreak of unprecedented scale emerged. As of 4 May 2015, it had resulted in more than 19,000 probable and confirmed Ebola cases, mainly in Guinea (3,529), Liberia (5,343), and Sierra Leone (10,746). Here, we present analyses of data collected during the outbreak identifying drivers of transmission and highlighting areas where control could be improved. Methods and Findings Over 19,000 confirmed and probable Ebola cases were reported in West Africa by 4 May 2015. Individuals with confirmed or probable Ebola (“cases”) were asked if they had exposure to other potential Ebola cases (“potential source contacts”) in a funeral or non-funeral context prior to becoming ill. We performed retrospective analyses of a case line-list, collated from national databases of case investigation forms that have been reported to WHO. These analyses were initially performed to assist WHO’s response during the epidemic, and have been updated for publication. We analysed data from 3,529 cases in Guinea, 5,343 in Liberia, and 10,746 in Sierra Leone; exposures were reported by 33% of cases. The proportion of cases reporting a funeral exposure decreased over time. We found a positive correlation (r = 0.35, p < 0.001) between this proportion in a given district for a given month and the within-district transmission intensity, quantified by the estimated reproduction number (R). We also found a negative correlation (r = −0.37, p < 0.001) between R and the district proportion of hospitalised cases admitted within ≤4 days of symptom onset. These two proportions were not correlated, suggesting that reduced funeral attendance and faster hospitalisation independently influenced local transmission intensity. We were able to identify 14% of potential source contacts as cases in the case line-list. Linking cases to the contacts who potentially infected them provided information on the transmission network. This revealed a high degree of heterogeneity in inferred transmissions, with only 20% of cases accounting for at least 73% of new infections, a phenomenon often called super-spreading. Multivariable regression models allowed us to identify predictors of being named as a potential source contact. These were similar for funeral and non-funeral contacts: severe symptoms, death, non-hospitalisation, older age, and travelling prior to symptom onset. Non-funeral exposures were strongly peaked around the death of the contact. There was evidence that hospitalisation reduced but did not eliminate onward exposures. We found that Ebola treatment units were better than other health care facilities at preventing exposure from hospitalised and deceased individuals. The principal limitation of our analysis is limited data quality, with cases not being entered into the database, cases not reporting exposures, or data being entered incorrectly (especially dates, and possible misclassifications). Conclusions Achieving elimination of Ebola is challenging, partly because of super-spreading. Safe funeral practices and fast hospitalisation contributed to the containment of this Ebola epidemic. Continued real-time data capture, reporting, and analysis are vital to track transmission patterns, inform resource deployment, and thus hasten and maintain elimination of the virus from the human population.

Ebola Virus Disease--Sierra Leone and Guinea, August 2015.

The Ebola virus disease (Ebola) outbreak in West Africa began in late 2013 in Guinea (1) and spread unchecked during early 2014. By mid-2014, it had become the first Ebola epidemic ever documented. Transmission was occurring in multiple districts of Guinea, Liberia, and Sierra Leone, and for the first time, in capital cities (2). On August 8, 2014, the World Health Organization (WHO) declared the outbreak to be a Public Health Emergency of International Concern (3). Ministries of Health, with assistance from multinational collaborators, have reduced Ebola transmission, and the number of cases is now declining. While Liberia has not reported a case since July 12, 2015, transmission has continued in Guinea and Sierra Leone, although the numbers of cases reported are at the lowest point in a year. In August 2015, Guinea and Sierra Leone reported 10 and four confirmed cases, respectively, compared with a peak of 526 (Guinea) and 1,997 (Sierra Leone) in November 2014. This report details the current situation in Guinea and Sierra Leone, outlines strategies to interrupt transmission, and highlights the need to maintain public health response capacity and vigilance for new cases at this critical time to end the outbreak.

Assessments of Ebola knowledge, attitudes and practices in Forécariah, Guinea and Kambia, Sierra Leone, July–August 2015

The border region of Forécariah (Guinea) and Kambia (Sierra Leone) was of immense interest to the West Africa Ebola response. Cross-sectional household surveys with multi-stage cluster sampling procedure were used to collect random samples from Kambia (n = 635) in July 2015 and Forécariah (n = 502) in August 2015 to assess public knowledge, attitudes and practices related to Ebola. Knowledge of the disease was high in both places, and handwashing with soap and water was the most widespread prevention practice. Acceptance of safe alternatives to traditional burials was significantly lower in Forécariah compared with Kambia. In both locations, there was a minority who held discriminatory attitudes towards survivors. Radio was the predominant source of information in both locations, but those from Kambia were more likely to have received Ebola information from community sources (mosques/churches, community meetings or health workers) compared with those in Forécariah. These findings contextualize the utility of Ebola health messaging during the epidemic and suggest the importance of continued partnership with community leaders, including religious leaders, as a prominent part of future public health protection. This article is part of the themed issue ‘The 2013–2016 West African Ebola epidemic: data, decision-making and disease control’.

Ebola Response Impact on Public Health Programs, West Africa, 2014–2017

Events such as the 2014–2015 West Africa epidemic of Ebola virus disease highlight the importance of the capacity to detect and respond to public health threats. We describe capacity-building efforts during and after the Ebola epidemic in Liberia, Sierra Leone, and Guinea and public health progress that was made as a result of the Ebola response in 4 key areas: emergency response, laboratory capacity, surveillance, and workforce development. We further highlight ways in which capacity-building efforts such as those used in West Africa can be accelerated after a public health crisis to improve preparedness for future events.

The 117 call alert system in Sierra Leone: from rapid Ebola notification to routine death reporting

A toll-free, nationwide phone alert system was established for rapid notification and response during the 2014–2015 Ebola epidemic in Sierra Leone. The system remained in place after the end of the epidemic under a policy of mandatory reporting and Ebola testing for all deaths, and, from June 2016, testing only in case of suspected Ebola. We describe the design, implementation and changes in the system; analyse calling trends during and after the Ebola epidemic; and discuss strengths and limitations of the system and its potential role in efforts to improve death reporting in Sierra Leone. Numbers of calls to report deaths of any cause (death alerts) and persons suspected of having Ebola (live alerts) were analysed by province and district and compared with numbers of Ebola cases reported by the WHO. Nearly 350 000 complete, non-prank calls were made to 117 between September 2014 and December 2016. The maximum number of daily death and live alerts was 9344 (October 2014) and 3031 (December 2014), respectively. Call volumes decreased as Ebola incidence declined and continued to decrease in the post-Ebola period. A national social mobilisation strategy was especially targeted to influential religious leaders, traditional healers and women’s groups. The existing infrastructure and experience with the system offer an opportunity to consider long-term use as a death reporting tool for civil registration and mortality surveillance, including rapid detection and control of public health threats. A routine social mobilisation component should be considered to increase usage.

Community-based HIV prevalence in KwaZulu-Natal, South Africa: results of a cross-sectional household survey

BACKGROUND In high HIV burden settings, maximising the coverage of prevention strategies is crucial to achieving epidemic control. However, little is known about the reach and effect of these strategies in some communities. METHODS We did a cross-sectional community survey in the adjacent Greater Edendale and Vulindlela areas in the uMgungundlovu district, KwaZulu-Natal, South Africa. Using a multistage cluster sampling method, we randomly selected enumeration areas, households, and individuals. One household member (aged 15-49 years) selected at random was invited for survey participation. After obtaining consent, questionnaires were administered to obtain sociodemographic, psychosocial, and behavioural information, and exposure to HIV prevention and treatment programmes. Clinical samples were collected for laboratory measurements. Statistical analyses were done accounting for multilevel sampling and weighted to represent the population. A multivariable logistic regression model assessed factors associated with HIV infection. FINDINGS Between June 11, 2014, and June 22, 2015, we enrolled 9812 individuals. The population-weighted HIV prevalence was 36·3% (95% CI 34·8-37·8, 3969 of 9812); 44·1% (42·3-45·9, 2955 of 6265) in women and 28·0% (25·9-30·1, 1014 of 3547) in men (p<0·0001). HIV prevalence in women aged 15-24 years was 22·3% (20·2-24·4, 567 of 2224) compared with 7·6% (6·0-9·3, 124 of 1472; p<0·0001) in men of the same age. Prevalence peaked at 66·4% (61·7-71·2, 517 of 760) in women aged 35-39 years and 59·6% (53·0-66·3, 183 of 320) in men aged 40-44 years. Consistent condom use in the last 12 months was 26·5% (24·1-28·8, 593 of 2356) in men and 22·7% (20·9-24·4, 994 of 4350) in women (p=0·0033); 35·7% (33·4-37·9, 1695 of 5447) of womens male partners and 31·9% (29·5-34·3, 1102 of 3547) of men were medically circumcised (p<0·0001), and 45·6% (42·9-48·2, 1251 of 2955) of women and 36·7% (32·3-41·2, 341 of 1014) of men reported antiretroviral therapy (ART) use (p=0·0003). HIV viral suppression was achieved in 54·8% (52·0-57·5, 1574 of 2955) of women and 41·9% (37·1-46·7, 401 of 1014) of men (p<0·0001), and 87·2% (84·6-89·8, 1086 of 1251) of women and 83·9% (78·5-89·3, 284 of 341; p=0·3670) of men on ART. Age, incomplete secondary schooling, being single, having more than one lifetime sex partner (women), sexually transmitted infections, and not being medically circumcised were associated with HIV-positive status. INTERPRETATION The HIV burden in specific age groups, the suboptimal differential coverage, and uptake of HIV prevention strategies justifies a location-based approach to surveillance with finer disaggregation by age and sex. Intensified and customised approaches to seek, identify, and link individuals to HIV services are crucial to achieving epidemic control in this community. FUNDING The Presidents Emergency Plan for AIDS Relief through the Centers for Disease Control and Prevention.

Impact of Ebola experiences and risk perceptions on mental health in Sierra Leone, July 2015

Background The mental health impact of the 2014–2016 Ebola epidemic has been described among survivors, family members and healthcare workers, but little is known about its impact on the general population of affected countries. We assessed symptoms of anxiety, depression and post-traumatic stress disorder (PTSD) in the general population in Sierra Leone after over a year of outbreak response. Methods We administered a cross-sectional survey in July 2015 to a national sample of 3564 consenting participants selected through multistaged cluster sampling. Symptoms of anxiety and depression were measured by Patient Health Questionnaire-4. PTSD symptoms were measured by six items from the Impact of Events Scale-revised. Relationships among Ebola experience, perceived Ebola threat and mental health symptoms were examined through binary logistic regression. Results Prevalence of any anxiety-depression symptom was 48% (95% CI 46.8% to 50.0%), and of any PTSD symptom 76% (95% CI 75.0% to 77.8%). In addition, 6% (95% CI 5.4% to 7.0%) met the clinical cut-off for anxiety-depression, 27% (95% CI 25.8% to 28.8%) met levels of clinical concern for PTSD and 16% (95% CI 14.7% to 17.1%) met levels of probable PTSD diagnosis. Factors associated with higher reporting of any symptoms in bivariate analysis included region of residence, experiences with Ebola and perceived Ebola threat. Knowing someone quarantined for Ebola was independently associated with anxiety-depression (adjusted OR (AOR) 2.3, 95% CI 1.7 to 2.9) and PTSD (AOR 2.095% CI 1.5 to 2.8) symptoms. Perceiving Ebola as a threat was independently associated with anxiety-depression (AOR 1.69 95% CI 1.44 to 1.98) and PTSD (AOR 1.86 95% CI 1.56 to 2.21) symptoms. Conclusion Symptoms of PTSD and anxiety-depression were common after one year of Ebola response; psychosocial support may be needed for people with Ebola-related experiences. Preventing, detecting, and responding to mental health conditions should be an important component of global health security efforts.

Implementing a Multisite Clinical Trial in the Midst of an Ebola Outbreak: Lessons Learned From the Sierra Leone Trial to Introduce a Vaccine Against Ebola

The Sierra Leone Trial to Introduce a Vaccine against Ebola (STRIVE), a phase 2/3 trial of investigational rVSV∆G-ZEBOV-GP vaccine, was conducted during an unprecedented Ebola epidemic. More than 8600 eligible healthcare and frontline response workers were individually randomized to immediate (within 7 days) or deferred (within 18-24 weeks) vaccination and followed for 6 months after vaccination for serious adverse events and Ebola virus infection. Key challenges included limited infrastructure to support trial activities, unreliable electricity, and staff with limited clinical trial experience. Study staff made substantial infrastructure investments, including renovation of enrollment sites, laboratories, and government cold chain facilities, and imported equipment to store and transport vaccine at ≤-60oC. STRIVE built capacity by providing didactic and practical research training to >350 staff, which was reinforced with daily review and feedback meetings. The operational challenges of safety follow-up were addressed by issuing mobile telephones to participants, making home visits, and establishing a nurse triage hotline. Before the Ebola outbreak, Sierra Leone had limited infrastructure and staff to conduct clinical trials. Without interfering with the outbreak response, STRIVE responded to an urgent need and helped build this capacity. CLINICAL TRIALS REGISTRATION ClinicalTrials.gov [NCT02378753] and Pan African Clinical Trials Registry [PACTR201502001037220].

The WHO global reference list of 100 core health indicators: the example of Sierra Leone

The global reference list of 100 core health indicators is a standard set of indicators published by the World Health Organization in 2015. We reviewed core health indicators in the public domain and in-country for Sierra Leone, the African continent and globally. Review objectives included assessing available sources, accessibility and feasibility of obtaining data and informing efforts to monitor program progress. Our search strategy was guided by feasibility considerations targeting mainly national household surveys in Sierra Leone and topic-specific and health statistics reports published annually by WHO. We also included national, regional and worldwide health indicator estimates published with open access in the literature and compared them with cumulative annual indicators from the weekly national epidemiological bulletin distributed by the Sierra Leone Ministry of Health and Sanitation. We obtained 70 indicators for Sierra Leone from Internet sources and 2 (maternal mortality and malaria incidence) from the national bulletin. Of the 70 indicators, 14 (20%) were modified versions of WHO indicators and provided uncertainty intervals. Maternal mortality showed considerable differences between 2 international sources for 2015 and the most recent national bulletin. We were able to obtain the majority of core indicators for Sierra Leone. Some indicators were similar but not identical, uncertainty intervals were limited and estimates differed for the same year between sources. Current efforts to improve health and mortality surveillance in Sierra Leone will improve availability and quality of reporting in the future. A centralized core indicator reporting website should be considered.