Deaths, late deaths, and role of infecting dose in Ebola virus disease in Sierra Leone: retrospective cohort study.

OBJECTIVES:  To assess the frequency of fatal recrudescence from Ebola virus disease after discharge from treatment centres, and explore the influence of infecting dose on case fatality rates. DESIGN:  Retrospective cohort study. SETTING:  Western Area, Sierra Leone. PARTICIPANTS:  151 survivors treated for Ebola virus disease at the Kerry Town treatment centre and discharged. Survivors were followed up for a vital status check at four to nine months after discharge, and again at six to 13 months after discharge. Verbal autopsies were conducted for four survivors who had died since discharge (that is, late deaths). Survivors still living in Western Area were interviewed together with their household members. Exposure level to Ebola virus disease was ascertained as a proxy of infecting dose, including for those who died. MAIN OUTCOME MEASURES:  Risks and causes of late death; case fatality rates; odds ratios of death from Ebola virus disease by age, sex, exposure level, date, occupation, and household risk factors. RESULTS:  Follow-up information was obtained on all 151 survivors of Ebola virus disease, a mean of 10 months after discharge. Four deaths occurred after discharge, all within six weeks: two probably due to late complications, one to prior tuberculosis, and only one after apparent full recovery, giving a maximum estimate of recrudescence leading to death of 0.7%. In these households, 395 people were reported to have had Ebola virus disease, of whom 227 died. A further 53 people fulfilled the case definition for probable disease, of whom 11 died. Therefore, the case fatality rate was 57.5% (227/395) for reported Ebola virus disease, or 53.1% (238/448) including probable disease. Case fatality rates were higher in children aged under 2 years and adults older than 30 years, in larger households, and in infections occurring earlier in the epidemic in Sierra Leone. There was no consistent trend of case fatality rate with exposure level, although increasing exposure increased the risk of Ebola virus disease. CONCLUSIONS:  In this study of survivors in Western Area, Sierra Leone, late recrudescence of severe Ebola virus disease appears to be rare. There was no evidence for an effect of infecting dose (as measured by exposure level) on the severity of disease

Effects of Mother's Illness and Breastfeeding on Risk of Ebola Virus Disease in a Cohort of Very Young Children.

BACKGROUND: Young children who contract Ebola Virus Disease (EVD) have a high case fatality rate, but their sources of infection and the role of breastfeeding are unclear. METHODS/PRINCIPAL FINDINGS: Household members of EVD survivors from the Kerry Town Ebola Treatment Centre in Sierra Leone were interviewed four to 10 months after discharge to establish exposure levels for all members of the household, whether or not they became ill, and including those who died. We analysed a cohort of children under three years to examine associations between maternal illness, survival and breastfeeding, and the child's outcome. Of 77 children aged zero to two years in the households we surveyed, 43% contracted EVD. 64 children and mothers could be linked: 25/40 (63%) of those whose mother had EVD developed EVD, compared to 2/24 (8%) whose mother did not have EVD, relative risk adjusted for age, sex and other exposures (aRR) 7·6, 95%CI 2·0-29·1. Among those with mothers with EVD, the risk of EVD in the child was higher if the mother died (aRR 1·5, 0·99-2·4), but there was no increased risk associated with breast-feeding (aRR 0·75, 0·46-1·2). Excluding those breastfed by infected mothers, half (11/22) of the children with direct contact with EVD cases with wet symptoms (diarrhoea, vomiting or haemorrhage) remained well. CONCLUSION/SIGNIFICANCE: This is the largest study of mother-child pairs with EVD to date, and the first attempt at assessing excess risk from breastfeeding. For young children the key exposure associated with contracting EVD was mother's illness with EVD, with a higher risk if the mother died. Breast feeding did not confer any additional risk in this study but high risk from proximity to a sick mother supports WHO recommendations for separation. This study also found that many children did not become ill despite high exposures

Variability in Intrahousehold Transmission of Ebola Virus, and Estimation of the Household Secondary Attack Rate.

Transmission between family members accounts for most Ebola virus transmission, but little is known about determinants of intrahousehold spread. From detailed exposure histories, intrahousehold transmission chains were created for 94 households of Ebola survivors in Sierra Leone: 109 (co-)primary cases gave rise to 317 subsequent cases (0-100% of those exposed). Larger households were more likely to have subsequent cases, and the proportion of household members affected depended on individual and household-level factors. More transmissions occurred from older than from younger cases, and from those with more severe disease. The estimated household secondary attack rate was 18%

Asymptomatic infection and family contact patterns in households of Ebola Virus Disease survivors, Sierra Leone 2015

The data set contains information on 937 people (living and dead) who were resident in the households of people who survived Ebola Virus Disease (EVD) in the Kerry Town Ebola Treatment Centre in Western Area Province, Sierra Leone, during the 2014-2016 epidemic. It includes individual and household characteristics, information on exposure levels, symptoms experienced by individuals during the period when the household was affected by EVD, outcomes, possible routes of transmission, and ELISA results from antibody testing for Ebola IgG in oral fluid. Survivor households were chosen because they were more easily contactable through the Save the Children survivors outreach programme: 123 of 152 survivors and their households were interviewed

Asymptomatic infection and unrecognised Ebola virus disease in Ebola-affected households in Sierra Leone: a cross-sectional study using a new non-invasive assay for antibodies to Ebola virus.

BACKGROUND: The frequency of asymptomatic infection with Ebola virus is unclear: previous estimates vary and there is no standard test. Asymptomatic infection with Ebola virus could contribute to population immunity, reducing spread. If people with asymptomatic infection are infectious it could explain re-emergences of Ebola virus disease (EVD) without known contact. METHODS: We validated a new oral fluid anti-glycoprotein IgG capture assay among survivors from Kerry Town Ebola Treatment Centre and controls from communities unaffected by EVD in Sierra Leone. We then assessed the seroprevalence of antibodies to Ebola virus in a cross-sectional study of household contacts of the survivors. All household members were interviewed. Two reactive tests were required for a positive result, with a third test to resolve any discrepancies. FINDINGS: The assay had a specificity of 100% (95% CI 98·9-100; 339 of 339 controls tested negative) and sensitivity of 95·9% (89·8-98·9; 93 of 97 PCR-confirmed survivors tested positive). Of household contacts not diagnosed with EVD, 47·6% (229 of 481) had high level exposure (direct contact with a corpse, body fluids, or a case with diarrhoea, vomiting, or bleeding). Among the contacts, 12·0% (95% CI 6·1-20·4; 11 of 92) with symptoms at the time other household members had EVD, and 2·6% (1·2-4·7; 10 of 388) with no symptoms tested positive. Among asymptomatic contacts, seropositivity was weakly correlated with exposure level. INTERPRETATION: This new highly specific and sensitive assay showed asymptomatic infection with Ebola virus was uncommon despite high exposure. The low prevalence suggests asymptomatic infection contributes little to herd immunity in Ebola, and even if infectious, would account for few transmissions. FUNDING: Wellcome Trust ERAES Programme, Save the Children

Eine Untersuchung kommerzieller Terminverwaltungs-Software im Hinblick auf die Kopplung mit natuerlichsprachlichen Systemen

The project COSMA (Cooperative Schedule Management Agent) is developing a machine secretarial assistent, that can autonomously schedule appointments with several participants via electronic mail in natural language. COSMA provides natural language service for autonomous appointment scheduling machine agents. Adaptation of different commercial software products for appointment management could support the claim of generality of the approaches pursued within COSMA. The study described in this document includes products available on the German market between March and May 1995. Some allow access to their appointment data via an application program interface, but no one provides any agent functionality; i.e. all planning and decision making is left to the user. For some systems, adaptation to COSMA is possible technically, but seems meaningful only after developing and adapting suitable agent systems. (orig.)SIGLEAvailable from TIB Hannover: RR 1813(95-11) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Details of exposure and outcomes in mother-child pairs in which the mother had Ebola.

<p>Details of exposure and outcomes in mother-child pairs in which the mother had Ebola.</p

Associations with Ebola in children under three years.

<p>Associations with Ebola in children under three years.</p