Projecting the impact of an ebola virus outbreak on endangered mountain gorillas

Abstract

Ebola virus is highly lethal for great apes. Estimated mortality rates up to 98% have reduced the global gorilla population by approximately one-third. As mountain gorillas (Gorilla beringei beringei) are endangered, with just over 1000 individuals remaining in the world, an outbreak could decimate the population. Simulation modeling was used to evaluate the potential impact of an Ebola virus outbreak on the mountain gorilla population of the Virunga Massif. Findings indicate that estimated contact rates among gorilla groups are high enough to allow rapid spread of Ebola, with less than 20% of the population projected to survive at 100 days post-infection of just one gorilla. Despite increasing survival with vaccination, no modeled vaccination strategy prevented widespread infection. However, the model projected that survival rates greater than 50% could be achieved by vaccinating at least half the habituated gorillas within 3 weeks of the first infectious individual.

Warning sign of an accelerating decline in critically endangered killer whales (Orcinus orca)

“…Mountain gorillas (Gorilla beringei beringei) were thought to be extinct by the end of the 20 th century, but a large population now resides in protected forest in Uganda, Rwanda, and the Democratic Republic of the Congo 29 . Extreme vigilance in the form of veterinary monitoring and intervention is now needed to prevent backsliding and gorilla mortality 56 . Other populations brought back from the brink include black robin (Petroica traversi) 57 and the Eastern barred bandicoot (Perameles gunnii) 57 .…”

Anthropogenic Pressures on Gorillas: A Case of Grauer’s Gorillas in Maiko National Park, the Democratic Republic of Congo

“…The world is enduring a tragic example in the COVID-19 pandemic, which might have been caused by a virus believed to originate from wildlife hunted or consumed by people. Less appreciated is the fact that these same drivers lead to an increased risk of disease transmission from humans to wildlife [104,105]. This is particularly evident in great apes, human's closest relatives, which share susceptibility to most pathogens and diseases.…”

“…Therefore, transmissible human-gorilla diseases are easily shared through the air, water, green vegetation, fruits, direct contact with animal or bushmeat, and/or oral routes. For instance, the deadly Ebola virus model of transmission is through direct contact with body fluids [105]. Bushmeat consumption accelerates human-gorilla interaction, thus facilitating transmission as well as infestation of high-mortality zoonotic diseases such as Ebola and respiratory diseases [110].…”

“…This virus has an even higher mortality rate, from 95% to 99%, in gorillas [132,133]. Evidently, it was estimated that the Ebola virus had killed a third of the gorilla population in the DRC, while the species continue to remain at risk [105]. Overall, the Ebola virus disease is a concern in the DRC, Uganda, and spans the borders of Rwanda's forest landscape, which is the home to one of the two species of the endangered lowland eastern gorilla [95].…”

“…Overall, the Ebola virus disease is a concern in the DRC, Uganda, and spans the borders of Rwanda's forest landscape, which is the home to one of the two species of the endangered lowland eastern gorilla [95]. This region has experienced frequent Ebola virus disease outbreaks, with 14 outbreaks occurring in the DRC since the virus was first reported in the country [105].…”