title: The impact of active surveillance and health education on an Ebola virus disease cluster - Kono District, Sierra Leone, 2014-2015.
abstract: BACKGROUND
  During December 2014-February 2015, an Ebola outbreak in a village in Kono district, Sierra Leone, began following unsafe funeral practices after the death of a person later confirmed to be infected with Ebola virus. In response, disease surveillance officers and community health workers, in collaboration with local leadership and international partners, conducted 1 day of active surveillance and health education for all households in the village followed by ongoing outreach. This study investigated the impact of these interventions on the outbreak.
  
  
  METHODS
  Fifty confirmed Ebola cases were identified in the village between December 1, 2014 and February 28, 2015. Data from case investigations, treatment facility and laboratory records were analyzed to characterize the outbreak. The reproduction number (R) was estimated by fitting to the observed distribution of secondary cases. The impact of the active surveillance and health education was evaluated by comparing two outcomes before and after the day of the interventions: 1) the number of days from symptom onset to case-patient isolation or death and 2) a reported epidemiologic link to a prior Ebola case.
  
  
  RESULTS
  The case fatality ratio among the 50 confirmed Ebola cases was 64.0 %. Twenty-three cases occurred among females (46.0 %); the mean age was 39 years (median: 37 years; range: 5 months to 75 years). Forty-three (87.8 %) cases were linked to the index case; 30 (61.2 %) were either at the funeral of Patient 1 or had contact with him while he was ill. R was 0.93 (95 % CI: 0.15-2.3); excluding the funeral, R was 0.29 (95 % CI: 0.11-0.53). The mean number of days in the community after onset of Ebola symptoms decreased from 4.0 days (median: 3 days; 95 % CI: 3.2-4.7) before the interventions to 2.9 days (median: 2 days; 95 % CI: 1.6-4.3) afterward. An epidemiologic link was reported in 47.6 % of case investigations prior to and 100 % after the interventions.
  
  
  CONCLUSIONS
  Initial case investigation and contact tracing were hindered by delayed reporting and under-reporting of symptomatic individuals from the community. Active surveillance and health education contributed to quicker identification of suspected cases, interrupting further transmission.
authors: Centers for Disease Control and Prevention, Atlanta, GA, USA. ydi9@cdc.gov.
authors: Tasha
authors: http://orcid.org/0000-0001-8117-7243
authors: T
authors: Stehling-Ariza
authors: School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia.
authors: Alexander
authors: A
authors: Rosewell
authors: District Health Management Team, Ministry of Health and Sanitation, Koidu, Sierra Leone.
authors: Sahr A
authors: SA
authors: Moiba
authors: District Health Management Team, Ministry of Health and Sanitation, Koidu, Sierra Leone.
authors: Brima Berthalomew
authors: BB
authors: Yorpie
authors: District Health Management Team, Ministry of Health and Sanitation, Koidu, Sierra Leone.
authors: Kai David
authors: KD
authors: Ndomaina
authors: District Health Management Team, Ministry of Health and Sanitation, Koidu, Sierra Leone.
authors: Kai Samuel
authors: KS
authors: Jimissa
authors: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors: Eva
authors: E
authors: Leidman
authors: International Federation of Red Cross and Red Crescent Societies, Geneva, Switzerland.
authors: Dingeman J
authors: DJ
authors: Rijken
authors: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors: Colin
authors: C
authors: Basler
authors: School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia.
authors: James
authors: J
authors: Wood
authors: District Health Management Team, Ministry of Health and Sanitation, Koidu, Sierra Leone.
authors: Dumbuya
authors: D
authors: Manso
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003150:Community Health Workers; D003299:Cooperative Behavior; D004196:Disease Outbreaks; D029043:Ebolavirus / Q000302:isolation & purification; D004777:Environment; D005191:Family Characteristics; D005260:Female; D006266:Health Education; D006268:Health Facilities; D019142:Hemorrhagic Fever, Ebola / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010356:Patient Isolation; D012307:Risk Factors; D012424:Rural Population; D012807:Sierra Leone / Q000453:epidemiology; D055815:Young Adult
keywords: Ebola virus disease; Health education; Sierra Leone; Surveillance