A recent finding on the circulation of a type of animal virus, made by a researcher from the National University of Colombia (UNAL), raises concerns about the fact that, although it is not dangerous in principle, it could affect the functioning of the immune system of the species that carry it and make them more vulnerable to other diseases.
In fact, the researcher, Laura Valentina Sanchez Quintana, who holds a master’s degree in Animal Health and Production from the National University of Colombia (UNAL), warns that detecting a virus does not necessarily mean that the animal is sick, but it must be given attention. In any case, it is not considered a known threat to human health.
In this case, it is circovirus, one of the smallest viruses known (they measure about 17 nanometers in diameter, making them impossible to observe with conventional microscopes). The virus usually associated with domestic dogs and pigeons was found in Andean bears, jaguars, ocelots, mountain coatis, parrots, and macaws.
The importance of studying circovirus
The finding, made at the Wakata Biopark in Jaime Duque Park, north of Bogota, is the first report of these viruses in the country’s wildlife and raises the need to monitor their circulation among species, especially in animals rescued from illegal trafficking, a Unimedios statement specifies.
The circovirus studied most extensively so far is porcine circovirus, whose impact on the pig farming industry, with health and economic consequences for producers, led the scientific community to investigate it in depth. However, before this study, canine circovirus and pigeon circovirus had not been reported in the wild species analyzed in Colombia.
Of the 19 mammals analyzed by researcher Sanchez Quintana, six (31.6%) tested positive for canine circovirus. The animals in which the virus was detected included native species, some of them threatened, such as the Andean bear (Tremarctos ornatus), the jaguar (Panthera onca), the ocelot (Leopardus pardalis), and the mountain coati (Nasuella olivacea).
Among the birds, 12 of the 40 specimens studied (30%) tested positive for pigeon circovirus. They included the chestnut-fronted macaw (Ara severus) and the mealy amazon parrot (Amazona farinosa), species belonging to the parrot and macaw family (Psittacidae), which are among the birds affected by illegal wildlife trafficking, the statement adds.
“Although the animals tested positive, none of them showed clinical symptoms, but the findings demonstrate the importance of studying this virus, its history, and what it may cause in the individual,” the researcher explained, as quoted in the statement.
The research results constitute the first reported record in Colombia of canine circovirus in Andean bears, mountain coatis, ocelots, and jaguars, and of pigeon circovirus in the wild birds studied. However, they still do not make it possible to determine when the infection occurred, how it happened, or whether the viruses will cause diseases in these animals.
The damage caused by illegal animal trafficking
For Sanchez Quintana, one of the main challenges is determining when and where the animals became infected. However, the results provide information about the possible circulation of these viruses in animals living in reserves or bioparks and raise new questions about their transmission between different species.
One of her hypotheses is that some animals may already have been infected before entering the biopark. Many of them come from illegal wildlife trafficking, an activity that exposes them to contact with domestic species and other animals with which they would be unlikely to interact in their natural environments.
“In the case of birds, since the samples were taken from individuals that were in quarantine, it is possible that they arrived infected from their place of origin,” Sanchez Quintana points out. However, another hypothesis is that the virus may have arrived through indirect contact with feral pigeons that move freely around the facilities.
She also explains that animals involved in illegal wildlife trafficking are often taken to bioparks such as Wakata, but that, due to various medical conditions, behavioral changes, and the damage resulting from their removal from their natural habitats, many cannot be returned to the wild.
These difficulties are compounded by a less visible risk: because wild animals are removed from their ecosystems, transported, and kept near other species, they may come into contact with microorganisms to which they would not normally be exposed. This increases the possibilities of infectious agents being transmitted and poses new challenges for their recovery and conservation.
On the other hand, there is a risk of cross-contamination because wildlife trafficking breaks down the natural barriers that separate certain species and exposes them to conditions that may favor the circulation of viruses and bacteria. This does not mean that all exposed animals will develop diseases, but it does mean that health controls and monitoring of their health status need to be strengthened.