Contact Tracing Activities during the Ebola Virus Disease Epidemic in Kindia and Faranah, Guinea, 2014

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Meredith G. Dixon, Melanie M. Taylor, Avi Hakim, Paul Cantey, Jacob Dee, Travis Lim, Hawa Bah, Sékou Mohamed Camara, Clement B. Ndongmo, Mory Togba, Leonie Yvonne Touré, Pepe Bilivogui, Mohammed Sylla, Michael Kinzer, Fátima Coronado, Jon Eric Tongren, Mahesh Swaminathan, Lise Mandigny, Boubacar Diallo, Thomas Seyler, Marc Rondy, Guénaël Rodier, William A. Perea, and Benjamin Dahl

Author affiliations: US Centers for Disease Control and Prevention, Atlanta, Georgia, USA (M.G. Dixon, M.M. Taylor, A. Hakim, P. Cantey, J. Dee, T. Lim, M. Kinzer, F. Coronado, M. Swaminathan, B. Dahl); World Health Organization, Brazzaville, Congo (H. Bah, S.M. Camara); US Centers for Disease Control and Prevention, Lusaka, Zambia (C.B. Ndongmo); Ministry of Health, Guinea (M. Togba, L.Y. Touré, P. Bilivogui, M. Sylla); US Centers for Disease Control and Prevention, Kigali, Rwanda (J.E. Tongren); World Health Organization, Geneva, Switzerland (L. Mandigny, B. Diallo, G. Rodier, W.A. Perea); EpiConcept, Paris, France; World Health Organization Ebola Response Team, Conakry, Guinea (T. Seyler, M. Rondy)

Abstract

The largest recorded Ebola virus disease epidemic began in March 2014; as of July 2015, it continued in 3 principally affected countries: Guinea, Liberia, and Sierra Leone. Control efforts include contact tracing to expedite identification of the virus in suspect case-patients. We examined contact tracing activities during September 20–December 31, 2014, in 2 prefectures of Guinea using national and local data about case-patients and their contacts. Results show less than one third of case-patients (28.3% and 31.1%) were registered as contacts before case identification; approximately two thirds (61.1% and 67.7%) had no registered contacts. Time to isolation of suspected case-patients was not immediate (median 5 and 3 days for Kindia and Faranah, respectively), and secondary attack rates varied by relationships of persons who had contact with the source case-patient and the type of case-patient to which a contact was exposed. More complete contact tracing efforts are needed to augment control of this epidemic.

During March 23, 2014–July 8, 2015, Guinea reported 3,748 Ebola virus disease (EVD) cases and 2,499 EVD-related deaths (1), as part of what is the largest reported EVD epidemic to date (2). Thorough case identification and contact tracing are necessary to end this epidemic (3). Contact tracing involves locating all persons who have been exposed to someone infected with Ebola virus (case-patients) or their body fluids and monitoring them daily for EVD symptoms during the 3 weeks after the last exposure (4). This tracing permits immediate identification and isolation of symptomatic contacts (suspected case-patients). Incomplete contact tracing and delayed time to isolation of suspected case-patients may result in transmission of EVD to others in the community, perpetuating the epidemic.

Thumbnail of Ebola virus disease incidence (confirmed cases per 100,000 population), by prefecture, Guinea, 2014. Distances and driving times for the transport of suspect case-patients from Kindia or Faranah to the nearest Ebola treatment unit are shown (red lines). Data sources: Guinea Ministry of Health; Guinea Ministry of Planning; Database of Global Administrative Areas (GADM); Europa.

Figure 1. Ebola virus disease incidence (confirmed cases per 100,000 population), by prefecture, Guinea, 2014. Distances and driving times for the transport of suspect case-patients from Kindia or Faranah to the nearest Ebola...

Excluding Conakry, the capital, Guinea is divided into 33 prefectures, which are subdivided into >300 subprefectures; these divisions are large and smaller administrative governmental units, respectively. Of all Ebola cases nationwide, 3.0% and 1.9% have been identified in Kindia and Faranah (Organisation mondiale de la Sante, unpub. data), respectively, where respective populations are 4.1% and 2.6% of the national population (Institut National de la Statistique, Guinée, unpub. data). At the time of data collection, neither prefecture had its own Ebola treatment unit (ETU) or laboratory with Ebola virus testing capabilities; suspected case-patients were transported by ambulance to the nearest ETU, which was at minimum a 3-hour drive from either prefecture (Figure 1). We conducted a retrospective review of case and contact tracing data collected from a convenience sample from 2 Guinea prefectures, Kindia and Faranah, during the EVD epidemic response from September 20 through December 31, 2014. We provide descriptive analyses of case and contact tracing for these 2 prefectures to identify gaps in reporting and the yield of contact tracing; we also propose actions for improvement of the contact tracing process.

Dr. Dixon joined the Centers for Disease Control and Prevention in 2013 as an Epidemic Intelligence Service officer in the Division of Global HIV/ AIDS. Her research interests are Ebola virus disease infections of health care workers, plasmodium-Ebola coinfection, and surveillance methods.

Acknowledgments

We thank Michael Wellman and Robert Neurath for creating the maps used to display data.

Surveillance and contact tracing activities were done by the Surveillance and Contact Tracing Teams in Kindia, Faranah, and Conakry, during September 20–December 31, 2014.

This project was supported by the US Centers for Disease Control and Prevention, World Health Organization, and Guinea Ministry of Health.

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Suggested citation for this article: Dixon MG, Taylor MM, Hakim A, Cantey P, Dee J, Lim T, et al. Contact tracing activities during the Ebola virus disease epidemic in Kindia and Faranah, Guinea, 2014. Emerg Infect Dis. 2015 Nov [date cited]. http://dx.doi.org/10.3201/eid2111.150684

DOI: 10.3201/eid2111.150684