Viruses (Oct 2021)

A Multidisciplinary Investigation of the First Chikungunya Virus Outbreak in Matadi in the Democratic Republic of the Congo

  • Anja De Weggheleire,
  • Antoine Nkuba-Ndaye,
  • Placide Mbala-Kingebeni,
  • Joachim Mariën,
  • Esaie Kindombe-Luzolo,
  • Gillon Ilombe,
  • Donatien Mangala-Sonzi,
  • Guillaume Binene-Mbuka,
  • Birgit De Smet,
  • Florian Vogt,
  • Philippe Selhorst,
  • Mathy Matungala-Pafubel,
  • Frida Nkawa,
  • Fabien Vulu,
  • Mathias Mossoko,
  • Elisabeth Pukuta-Simbu,
  • Eddy Kinganda-Lusamaki,
  • Wim Van Bortel,
  • Francis Wat’senga-Tezzo,
  • Sheila Makiala-Mandanda,
  • Steve Ahuka-Mundeke

DOI
https://doi.org/10.3390/v13101988
Journal volume & issue
Vol. 13, no. 10
p. 1988

Abstract

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Early March 2019, health authorities of Matadi in the Democratic Republic of the Congo alerted a sudden increase in acute fever/arthralgia cases, prompting an outbreak investigation. We collected surveillance data, clinical data, and laboratory specimens from clinical suspects (for CHIKV-PCR/ELISA, malaria RDT), semi-structured interviews with patients/caregivers about perceptions and health seeking behavior, and mosquito sampling (adult/larvae) for CHIKV-PCR and estimation of infestation levels. The investigations confirmed a large CHIKV outbreak that lasted February–June 2019. The total caseload remained unknown due to a lack of systematic surveillance, but one of the two health zones of Matadi notified 2686 suspects. Of the clinical suspects we investigated (n = 220), 83.2% were CHIKV-PCR or IgM positive (acute infection). One patient had an isolated IgG-positive result (while PCR/IgM negative), suggestive of past infection. In total, 15% had acute CHIKV and malaria. Most adult mosquitoes and larvae (>95%) were Aedes albopictus. High infestation levels were noted. CHIKV was detected in 6/11 adult mosquito pools, and in 2/15 of the larvae pools. This latter and the fact that 2/6 of the CHIKV-positive adult pools contained only males suggests transovarial transmission. Interviews revealed that healthcare seeking shifted quickly toward the informal sector and self-medication. Caregivers reported difficulties to differentiate CHIKV, malaria, and other infectious diseases resulting in polypharmacy and high out-of-pocket expenditure. We confirmed a first major CHIKV outbreak in Matadi, with main vector Aedes albopictus. The health sector was ill-prepared for the information, surveillance, and treatment needs for such an explosive outbreak in a CHIKV-naïve population. Better surveillance systems (national level/sentinel sites) and point-of-care diagnostics for arboviruses are needed.

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