Spatial and Temporal Dynamics of a Mortality Event among Central African Great Apes

PLoS One. 2016 May 18;11(5):e0154505. doi: 10.1371/journal.pone.0154505. eCollection 2016.

Abstract

In 2006-2007 we observed an unusual mortality event among apes in northern Republic of Congo that, although not diagnostically confirmed, we believe to have been a disease outbreak. In 2007-2011 we conducted ape nest surveys in the region, recording 11,835 G. g. gorilla nests (2,262 groups) and 5,548 P. t. troglodytes nests (2,139 groups). We developed a statistical model to determine likely points of origin of the outbreak to help identify variables associated with disease emergence and spread. We modeled disease spread across the study area, using suitable habitat conditions for apes as proxy for local ape densities. Infectious status outputs from that spread model were then used alongside vegetation, temperature, precipitation and human impact factors as explanatory variables in a Generalized Linear Model framework to explain observed 2007-2011 ape nest trends in the region. The best models predicted emergence in the western region of Odzala-Kokoua National Park and north of the last confirmed Ebola virus disease epizootics. Roads were consistently associated with attenuation of modeled virus spread. As disease is amongst the leading threats to great apes, gaining a better understanding of disease transmission dynamics in these species is imperative. Identifying ecological drivers underpinning a disease emergence event and transmission dynamics in apes is critical to creating better predictive models to guide wildlife management, develop potential protective measures for wildlife and to reduce potential zoonotic transmission to humans. The results of our model represent an important step in understanding variables related to great ape disease ecology in Central Africa.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Africa, Central
  • Animals
  • Animals, Wild
  • Ape Diseases / etiology
  • Ape Diseases / mortality*
  • Ape Diseases / transmission
  • Computer Simulation
  • Congo / epidemiology
  • Disease Outbreaks
  • Geography
  • Hominidae*
  • Models, Statistical
  • Mortality
  • Population Dynamics
  • Population Surveillance
  • Spatio-Temporal Analysis*

Grants and funding

This work was supported by the United States Fish and Wildlife Service (http://www.fws.gov/international/wildlife-without-borders/great-ape-conservation-fund.html) Grant Nos. 98210-6-G107, 98210-7-G292, 98210-8-G643, and 98210-0-G280; KNC, PR, DBM, AIO, WBK; and United States Agency for International Development (http://predict.global) Grant No. USAID-M-OAA-GH-HSR-09-877; KNC, PR, DBM, AIO, SHO, WBK. Funding was also provided by the Paul G. Allen Family Foundation, the Association of Zoos and Aquariums (Ape TAG), Columbus Zoo and Aquarium, the Max Planck Society and Robert Bosch Stiftung. This study was made possible by the generous support of the American people through the United States Agency for International Development (USAID) Emerging Pandemic Threats PREDICT. The contents are the responsibility of the authors and do not necessarily reflect the views of USAID or the United States Government. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.