title: Network visualization for outbreak response: Mapping the Ebola Virus Disease (EVD) chains of transmission in N'Zérékoré, Guinea.
abstract: During the 2014-2015 Ebola Virus Disease (EVD) outbreak in N'Zérékoré, Forested Guinea, modes of transmission remained unexamined for a number of new cases. We used network visualization to investigate EVD transmission chains (TC) in seven sub-prefectures of N'Zérékoré in order to adapt outbreak response.
  
  
  
  Between August 2014 and February 2015, the EVD outbreak response team including the World Health Organization (WHO) and local health authorities routinely collected information among new cases regarding hospital visits, cases within a household, participation in burials, as well as dates of symptom onset, serial intervals (SI) and exposure to EVD. SI's were defined as the interval between symptom onset in an index case and symptom onset in a secondary case infected by that index case. Cases who reported hospital visits, contact with a case in the household or participating in burials were attributed to these exposures.
  
  
  
  We identified seven TC (two urban and five rural) gathering characteristics of 109 probable/confirmed cases. Overall, 61% (66 cases, SI range: 7-20 days) were household related, 32% (35 cases, SI range 8-30 days) were household or burial related and 7% (8 cases, SI range: 4-20 days) were hospital-related. In the urban chains (18 cases, SI range: 7-20 days), 12 cases were household related and 6 cases were hospital related, none where household or burial related. In the rural chains (84 cases, SI range: 7-30 days), 60% (50 cases) were household related, 1% (1 case) was hospital related and 39% (34 cases) were household or burial related. No cases reported multiple exposures.
  
  
  
  Network visualization during field response is crucial in enhancing local control strategies, refining outbreak response and aiding rapid response teams in insuring psychosocial and socio-economic recovery. Urban settings need to focus on reducing hospital EVD transmission whereas rural settings should focus on raising awareness of transmission within a household and safeguarding EVD burials.
authors.affiliation: European Programme for Interventional Epidemiology Training (EPIET), ECDC, Stockholm, Sweden; Scientific Institute of Public Health, Brussels, Belgium. Electronic address: cvalencia1987@gmail.com.
authors.forename: C
authors.initials: C
authors.lastname: Valencia
authors.affiliation: World Health Organization, Conakry, Guinea. Electronic address: habilbah1711@yahoo.fr.
authors.forename: H
authors.initials: H
authors.lastname: Bah
authors.affiliation: World Health Organization, Conakry, Guinea. Electronic address: barris88@hotmail.fr.
authors.forename: B
authors.initials: B
authors.lastname: Fatoumata
authors.affiliation: World Health Organization, Conakry, Guinea. Electronic address: rodierg@who.int.
authors.forename: G
authors.initials: G
authors.lastname: Rodier
authors.affiliation: World Health Organization, Conakry, Guinea. Electronic address: dbiallo@who.int.
authors.forename: B
authors.initials: B
authors.lastname: Diallo
authors.affiliation: World Health Organization, Conakry, Guinea. Electronic address: mkone@who.int.
authors.forename: M
authors.initials: M
authors.lastname: Koné
authors.affiliation: European Programme for Interventional Epidemiology Training (EPIET), ECDC, Stockholm, Sweden; Health Protection Surveillance Centre, Dublin, Ireland. Electronic address: coraliegiese@hotmail.com.
authors.forename: C
authors.initials: C
authors.lastname: Giese
authors.affiliation: Department of Health, N'zérékoré Prefecture, Guinea. Electronic address: lilaluciec@yahoo.fr.
authors.forename: L
authors.initials: L
authors.lastname: Conde
authors.affiliation: Ministry of Health, Guinea. Electronic address: malanoroland@gmail.com.
authors.forename: E
authors.initials: E
authors.lastname: Malano
authors.affiliation: European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden. Electronic address: thomas.mollet@ecdc.europa.eu.
authors.forename: T
authors.initials: T
authors.lastname: Mollet
authors.affiliation: European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden. Electronic address: Josep.jansa@ecdc.europa.eu.
authors.forename: J
authors.initials: J
authors.lastname: Jansa
authors.affiliation: European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden. Electronic address: denis.coulombier@ecdc.europa.eu.
authors.forename: D
authors.initials: D
authors.lastname: Coulombier
authors.affiliation: European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden. Electronic address: bertrand.sudre@ecdc.europa.eu.
authors.forename: B
authors.initials: B
authors.lastname: Sudre
mesh_terms: D004196:Disease Outbreaks / Q000517:prevention & control; D029043:Ebolavirus / Q000235:genetics / Q000302:isolation & purification; D062665:Epidemiological Monitoring; D016679:Genome, Viral; D016701:Guinea / Q000453:epidemiology; D019142:Hemorrhagic Fever, Ebola / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission* / Q000821:virology; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D012424:Rural Population; D014944:World Health Organization
keywords: Ebola virus disease (EVD); Guinea; Mapping; Network visualization; Outbreak; Transmission