Human quarantine: Toward reducing infectious pressure on chimpanzees at the Taï Chimpanzee Project, Côte d'Ivoire

Abstract

Due to their genetic relatedness, great apes are highly susceptible to common human respiratory pathogens. Although most respiratory pathogens, such as human respiratory syncytial virus (HRSV) and human metapneumovirus (HMPV), rarely cause severe disease in healthy human adults, they are associated with considerable morbidity and mortality in wild great apes habituated to humans for research or tourism. To prevent pathogen transmission, most great ape projects have established a set of hygiene measures ranging from keeping a specific distance, to the use of surgical masks and establishment of quarantines. This study investigates the incidence of respiratory symptoms and human respiratory viruses in humans at a human-great ape interface, the Taï Chimpanzee Project (TCP) in Côte d'Ivoire, and consequently, the effectiveness of a 5-day quarantine designed to reduce the risk of potential exposure to human respiratory pathogens. To assess the impact of quarantine as a preventative measure, we monitored the quarantine process and tested 262 throat swabs for respiratory viruses, collected during quarantine over a period of 1 year. Although only 1 subject tested positive for a respiratory virus (HRSV), 17 subjects developed symptoms of infection while in quarantine and were subsequently kept from approaching the chimpanzees, preventing potential exposure in 18 cases. Our results suggest that quarantine-in combination with monitoring for symptoms-is effective in reducing the risk of potential pathogen exposure. This research contributes to our understanding of how endangered great apes can be protected from human-borne infectious disease.

Leprosy in wild chimpanzees

“…To maximise the chances of recording specific behaviours and identify leprosy-like symptoms in individuals, targeted camera traps were set up in locations that chimpanzees were known to use most often, sometimes in clusters, Abnormalities in behaviour or clinical signs of disease are immediately reported and followed by detailed observation by the on-site veterinarian. In order to reduce the risk of transmission of human diseases to the chimpanzees, stringent hygiene measures have been put in place, including an initial five days quarantine for observers, keeping a distance of at least 7 meters, obligatory wearing of masks, with only healthy observers allowed to work in the forest 50,51 .…”

Plan d’action régional pour la conservation des chimpanzés d’Afrique de l’Ouest (Pan troglodytes verus) 2020–2030

“…Par ailleurs, les touristes internationaux sont plus sensibles de transporter de nouvelles maladies auxquelles les chimpanzés n'ont jamais été exposés. Ainsi, il est fortement recommandé aux chercheurs et aux autres visiteurs de longue durée (équipes de tournage par exemple) d'appliquer des mesures de quarantaine et des règles strictes d'hygiène (Gilardi et al 2016;Grützmacher et al 2018).…”

<FROM THE FIELD SITE>40 years of research at the Taï Chimpanzee Project

“…The chimpanzee population had to cope with extensive individual losses due to zoonotic diseases transmission from human respiratory viruses (Köndgen et al 2008). Only after rigorous quarantine and hygiene rules with strict reinforcement in the years 2010-2012, respiratory disease transmission was stopped (Grützmacher et al 2017) and the population started slowly to recover. A veterinary program led by Fabian Leendertz of the Robert Koch Institute in Berlin (Germany) guarantees the constant presence of a qualified veterinarian in the field.…”