In the jungle, the mighty jungle, the virus hunters will not sleep tonight.” They may not be the original lyrics from the song, but I couldn’t help but sing them to myself as we set up our small mammal and bat traps in the Kuamas Forest Reserve – an area of jungle near the small town of ??? in the Telupid District, in the middle of Sabah.

When you are working to find zoonotic viruses, sleepless nights in the jungle are necessary. Myself and our sampling team of “virus hunters” always set the traps before dusk to enable us to spend the night catching and sampling the animals we were studying for the Deep Forest Project – part of the USAID funded PREDICT program.

Deep Forest was started in 2012 to explore the impact of increasing land use change on patterns of animal biodiversity, the viruses they carry, and also patterns of human occupancy, abundance and behaviour that may influence contact rates with wildlife in these dynamic landscapes. Understanding all these factors is key when preventing zoonotic spillover.

Preventing zoonotic spillover events - setting up bat trap in the forest

A bat trap is erected in the Kuamas Forest Reserve before the long night begins.

The aim of the Deep Forest Project

The ultimate aim of the Deep Forest Project was to gain an understanding of the local hotspots for zoonotic diseases and create an early warning system of the potential for virus transmission. We were working at preventing zoonotic spillover events such as the SARS outbreak in 2004, which originated in a wildlife market in Guangzhou, China, and was transmitted from a species of horseshoe bat to a civet, which then amplified the virus before passing it onto the human population.

If we could identify the zoonotic viruses carried by the wildlife in Sabah we could then make the case for the conservation of their environment, and also against the sale of these animals into the wildlife trade. Loss of habitat brings these animals in closer contact with the human population, increasing the chances of zoonotic spillover. Placing them in unhygienic conditions in wildlife markets brings them closer to other species which they would not normally encounter, increasing the risk of disease transmission between animals and then into the human population.

If these animals are found to be reservoirs for viruses that could be potentially lethal to humans, then it should be a priority to protect these animals from coming into contact with us as much as possible.

"Loss of habitat brings these animals in closer contact with the human population, increasing the chances of zoonotic spillover."

Catching animals in sampling sites

Nine sampling sites with different human disturbance grades were selected, each site being plotted with a bat and a rodent square. Within the rodent square, 100 small mammal traps were deployed, while the bat square was set up with 8 mist nets and 2 harp traps.

The sampling team stayed in the jungle from dusk to dawn to capture and collect biological samples from the animals. After the traps were baited for the night, the team would return to check them in the morning.

“Hey Jimmy, we’ve got one”… another virus hunter would shout from afar. If we were lucky, we captured a Malayan civet – a magnificent creature with black spots on its body, black and grey stripe on its tailed and stunning black lines on its neck (which sometimes I think it looks like those fancy necklaces).

We would carefully transfer the civet into a cloth bag to minimize its stress – who wouldn’t be afraid when surrounded by a bunch of people wearing weird layers of blue plastic on their hands, white rounded stuff covering their nose and mouth and shiny pieces of glass on their eyes? – before transferring it to our temporary lab in the forest.

Preventing zoonotic spillover from bats to humans

A bat is caught in the Kuamas Forest Reserve during Conservation Medicine’s Deep Forest Project. The animals were sampled for potential viruses before being released back into the forest.

Deep Forest Project sampling

After the animals arrived at the temporary lab, the field veterinarian would start to anaesthetize them. As soon as the animals started to fall asleep, the sample collection process was started.

Samples including swabs samples, tiny amount of blood and ectoparasite were collected. During the sampling process the animals welfare was maintained by a veterinarian or trained field biologist. Once the sampling process was complete, they were returned to their original location.

The samples were then transported back to the Wildlife Health, Genetic and Forensic Lab – the first biosafety level 2 wildlife lab in Borneo – for zoonotic virus surveillance. The testing results are vital to inform the potential zoonotic viruses carried by the wildlife in Sabah and its risk of transmission.

Preventing zoonotic spillover - sampling civets in Sabah

Samples are taken from a civet on a typically long night during the Deep Forest Project.