PLoS Neglected Tropical Diseases (Apr 2015)

A household serosurvey to estimate the magnitude of a dengue outbreak in Mombasa, Kenya, 2013.

  • Esther M Ellis,
  • John C Neatherlin,
  • Mark Delorey,
  • Melvin Ochieng,
  • Abdinoor Haji Mohamed,
  • Daniel Ondari Mogeni,
  • Elizabeth Hunsperger,
  • Shem Patta,
  • Stella Gikunju,
  • Lilian Waiboic,
  • Barry Fields,
  • Victor Ofula,
  • Samson Limbaso Konongoi,
  • Brenda Torres-Velasquez,
  • Nina Marano,
  • Rosemary Sang,
  • Harold S Margolis,
  • Joel M Montgomery,
  • Kay M Tomashek

DOI
https://doi.org/10.1371/journal.pntd.0003733
Journal volume & issue
Vol. 9, no. 4
p. e0003733

Abstract

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Dengue appears to be endemic in Africa with a number of reported outbreaks. In February 2013, several individuals with dengue-like illnesses and negative malaria blood smears were identified in Mombasa, Kenya. Dengue was laboratory confirmed and an investigation was conducted to estimate the magnitude of local transmission including a serologic survey to determine incident dengue virus (DENV) infections. Consenting household members provided serum and were questioned regarding exposures and medical history. RT-PCR was used to identify current DENV infections and IgM anti-DENV ELISA to identify recent infections. Of 1,500 participants from 701 households, 210 (13%) had evidence of current or recent DENV infection. Among those infected, 93 (44%) reported fever in the past month. Most (68, 73%) febrile infected participants were seen by a clinician and all but one of 32 participants who reportedly received a diagnosis were clinically diagnosed as having malaria. Having open windows at night (OR = 2.3; CI: 1.1-4.8), not using daily mosquito repellent (OR = 1.6; CI: 1.0-2.8), and recent travel outside of Kenya (OR = 2.5; CI: 1.1-5.4) were associated with increased risk of DENV infection. This survey provided a robust measure of incident DENV infections in a setting where cases were often unrecognized and misdiagnosed.