Transmission models indicate Ebola virus persistence in non-human primate populations is unlikely

Abstract

Infectious diseases that kill their hosts may persist locally only if transmission is appropriately balanced by susceptible recruitment. Great apes die of Ebola virus disease (EVD) and have transmitted ebolaviruses to people. However, understanding the role that apes and other non-human primates play in maintaining ebolaviruses in Nature is hampered by a lack of data. Recent serological findings suggest that few non-human primates have antibodies to EVD-causing viruses throughout tropical Africa, suggesting low transmission rates and/or high EVD mortality (Ayouba A et al. 2019 J. Infect. Dis. 220 , 1599–1608 ( doi:10.1093/infdis/jiz006 ); Mombo IM et al. 2020 Viruses 12 , 1347 ( doi:10.3390/v12121347 )). Here, stochastic transmission models of EVD in non-human primates assuming high case-fatality probabilities and experimentally observed or field-observed parameters did not allow viral persistence, suggesting that non-human primate populations are highly unlikely to sustain EVD-causing infection for prolonged periods. Repeated introductions led to declining population sizes, similar to field observations of apes, but not viral persistence.

Impact of Infectious Diseases on Wild Bovidae Populations in Thailand: Insights from Population Modelling and Disease Dynamics

“…DD transmission is assumed when the contact rate is proportionate to the population density, while FD transmission is assumed when the contact rate is independent of the population density [24, 23]. We assumed the transmission modes for each pathogen and then compared them by introducing both transmission modes because, for some infections, there is no clear evidence of which type suits the pathogen’s transmissions and these represent both extremes [10]. Transmission is often likely a mix of both DD and FD in many cases such as FMD and bTB [25, 26].…”

“…Because the Gaur and other endangered bovid populations are small and we are interested in how infections might lead to their decline and because we also wanted to allow infection to go extinct in populations if they could not be maintained, we used stochastic models. First, we built the population dynamics model without infectious disease classes and parameters as a baseline model [10]. Then, we introduced an infectious adult ( I a = 1) to the susceptible ( S ) population.…”

Robust evidence for bats as reservoir hosts is lacking in most African virus studies: a review and call to optimize sampling and conserve bats

“…By contrast, there is convincing evidence for EBOV spillover from symptomatic great apes and potentially duikers to humans [190][191][192][193][194] (figure 2a; electronic supplementary material, text S6). Importantly, spillovers have exclusively been documented within the distribution ranges of chimpanzees and bonobos (electronic supplementary material, text S6, figure S6), which may have had contact with the natural reservoir(s) of EBOV [195,196] when feeding at the same fruit trees, through consuming infected animals [197] or even through contact with aquatic or semi-aquatic reservoir hosts [198]. Molecular evidence from recent EBOV outbreaks suggests a human survivor origin rather than zoonotic transmission [199,200], raising the possibility that some previous outbreaks (including the 2013 West African outbreak) are not from spillover [201].…”

Modelling the impact of stigmatisation of Ebola survivors on the disease transmission dynamics

“…The sturm sequences evaluated at c 1 and c 2 are given on ( 24) and ( 25) respectively. Theorem 3 Consider the Sturm sequences evaluated at c 1 and c 2 as shown in (24) and (25). we have the following four possibilities.…”