Unraveling the drivers of MERS-CoV transmission

Simon Cauchemez1, Pierre Nouvellet2, Anne Cori2

  • 1Mathematical Modelling of Infectious Diseases Unit, Institut Pasteur, 75015 Paris, France; Centre National de la Recherche Scientifique, Unité de Recherche Associée 3012, 75015 Paris, France; Center of Bioinformatics, Biostatistics and Integrative Biology, Institut Pasteur, 75015 Paris, France;

Insights

Middle East respiratory syndrome coronavirus (MERS-CoV) outbreaks are driven by both animal-to-human transmission and human-to-human spread. Understanding these transmission patterns is crucial for public health, especially with ongoing reservoir exposure risks.

Area of Science:

  • Epidemiology
  • Infectious Disease Dynamics
  • Statistical Modeling

Background:

  • Middle East respiratory syndrome coronavirus (MERS-CoV) poses a significant public health threat with over 1,700 confirmed infections.
  • Limited data on transmission routes from animal reservoirs and between humans hinders understanding of MERS-CoV epidemic drivers.

Purpose of the Study:

  • To statistically analyze MERS-CoV transmission patterns in Saudi Arabia (2013-2014).
  • To quantify the contributions of animal reservoir, human mixing, and transmission heterogeneity to MERS-CoV epidemics.
  • To assess the dynamics of MERS-CoV transmission clusters.

Main Methods:

  • Development of a statistical framework for analyzing transmission patterns.
  • Comprehensive analysis of 681 MERS-CoV cases in Saudi Arabia.
  • Estimation of transmission sources (reservoir vs. human-to-human) and spatial spread.

Main Results:

  • Approximately 12% of cases originated from the animal reservoir; the remainder were human-to-human transmissions.
  • Human-to-human transmission occurred in clusters (60%), within regions (23%), and between regions (5%).
  • The average reproduction number at cluster onset was 0.45, decreasing significantly as clusters grew; 12% of clusters had a reproduction number >1.

Conclusions:

  • Ongoing human exposure to MERS-CoV from the animal reservoir is a major concern, posing risks for healthcare-associated outbreaks.
  • The statistical approach is valuable for studying infectious disease transmission with limited case-linking data.
  • Effective control strategies must address both zoonotic spillover and human-to-human transmission dynamics.

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