MULTIMEDIA: Predicting the Next Pandemic

DISEASE X.

That is the name scientists use to refer to an epidemic-level illness caused by a previously unknown virus carried by wildlife for thousands of years which mutates and spills over to people.

The World Health Organisation (WHO) has listed Disease X, along with other diseases such as Covid-19, Ebola virus disease and Nipah and henipaviral diseases, as top priorities for research.

Ten years ago, an international project began to hunt and identify zoonotic viruses, including those that have the potential to cause Disease X.

PREDICT, as the project is known, is part of the United States Agency for International Development’s (USAID) Emerging Pandemic Threats programme.

So far, PREDICT has found 949 new viruses and 217 known viruses in samples taken from animals and people in 30 countries, including Malaysia.

“Based on current modelling, we believe there are about 1.5 million viruses still out there that have yet to be discovered, and around 700,000 could be dangerous to humans” says Tom Hughes, Director of Conservation Medicine and Project Coordinator for EcoHealth Alliance in Malaysia.

Director of Conservation Medicine and Project Coordinator for EcoHealth Alliance in Malaysia, Tom Hughes.
Director of Conservation Medicine and Project Coordinator for EcoHealth Alliance in Malaysia, Tom Hughes.

"....there are about 1.5 million viruses still out there that have yet to be discovered, and around 700,000 could be dangerous to humans."
Tom Hughes

EcoHealth Alliance is a global conservation and pandemic-prevention non governmental group, which manages the PREDICT project in Malaysia.

Hughes says that most of the new viruses that PREDICT has found would likely prove to be harmless to people.

“However, until we find, identify and characterise these new viruses, we will not know for sure what is lurking out there.”

In Malaysia, samples have been collected from more than 1,400 people including the Orang Asli, as well and over 5,000 animals in over 100 locations in the Peninsula and Sabah.

Identifying viruses in Malaysia’s wildlife

Hughes explains how sampling is typically done at one of the sites, located in Sabah’s Kinabatangan district.

Just slightly smaller than the whole state of Selangor, Kinabatangan boasts a rich biodiversity and is home to a huge variety of wildlife, including Borneo pygmy elephants, orangutan and proboscis monkeys.

At the Bod Tai Forest Reserve located in the small town of Sukau, a team made up of EcoHealth Alliance, Sabah Wildlife Department and the Danau Girang Research Centre would set up traps for rodents and bats.

EcoHealth Alliance Malaysia rangers setting up a mist net in an Orang Asli village to capture bats near human dwellings.
Photo by S Azian, EcoHealth Alliance / Conservation Medicine

The traps are placed at two sites - one for rodents and the other for bats and each measuring about a 100 sq metres in size.

Two types of traps are used for rodents, namely the Tomahawk and Sherman traps, which are designed to ensure that the animals can be captured safely.

The traps are placed either on the ground or tied to tree trunks.

Oil palm fruit is placed in each of the traps as bait to lure small mammals such as rats and foxes.

Gently does it

Bats, on the other hand, do not require bait as their traps are designed to safely net them in flight.

Three types of traps are used to collect bats.

The first, called a mist-net, is suspended from two poles. Measuring 9m by 3m, the net is made of fine strands of nylon or polyester, which distracted bats will not notice and fly into.

The animals either get trapped in the net or fall into a collection pocket at the bottom of the net.

Wildlife Health Unit Team Leader Andrew Ginsos removing a captured bat from a mist net at a Deep Forest Project sampling site.
Photo by J Lee, EcoHealth Alliance / Conservation Medicine

The second type is called a harp trap. Its “strings” are arranged in two layers, and bats that manage to fly through the first would get trapped by the second and fall into a collection pocket.

The third type known as the canopy trap is designed to capture bats flying at tree-top level.

These are set up at a height of between 30m to 50m above ground.

The traps are set up before sunset which is when bats become active as they hunt for food.

Drawing blood from a bat

The team can trap up to 60 bats each night.

The specimens include Creagh’s horseshoe bats which are insectivores that live in Gomantong Caves, an intricate cave system inside Bukit Gomantong, the largest limestone outcrop in the Lower Kinabatangan area.

To reduce stress on the bats, each animal is removed as soon as possible from the trap collection pocket and placed separately in cloth bags.

The bats are taken the same night to a makeshift laboratory housed in a nearby community hall.

At the lab, a fine 27-gauge needle syringe is used to draw a tiny amount of blood from the bat.

A throat swab is taken from the animal and urine and faecal specimens are also collected.

The bats claws are then marked with red nail polish so that the team will know that it has already been sampled in case it is trapped again in future.

The marking fades after a week.

With the sampling done, the bats are then suspended from a tree branch or string.

Several moments later, the bat begins to move its head as it sends out sound waves from its mouth or nose to determine its location.

It then flies away into the night.

EcoHealth Alliance Malaysia Country Coordinator Tom Hughes and EcoHealth Alliance Veterinarian Dr. Melinda Rostal sampling a bat captured at a Deep Forest Project site. Photo by J Lee. EcoHealth Alliance/Conservation Medicine.

A squirrel trapped in a small tomahawk trap secured to a tree trunk to target arboreal rodents.
Photo by J Lee, EcoHealth Alliance / Conservation Medicine

EcoHealth Alliance Malaysia ranger Adilah Aziz transferring a captured rodent from the trap into a cloth bag to decrease its stress level and minimise risk of contact with any body fluids during transport to the sampling site.

Photo by Zahidah Zeid, EcoHealth Alliance / Conservation Medicine

Sabah Wildlife Health Unit Team Leader Andrew Ginsos teaching Arnold Supil a new WHU ranger the technique for collecting blood samples from rodents according to the PREDICT protocols. Photo by Adilah Aziz, EcoHealth Alliance.

EcoHealth Alliance Malaysia field veterinarian Dr Zahidah Zeid and ranger Adilah Aziz conducting health check on a Bornean sun bear at the Bornean Sun Bear Conservation Centre. Photo by Y Wazlan, EcoHealth Alliance / Conservation Medicine

What PREDICT found

From the samples collected in Malaysia, Predict has found 12 new coronaviruses and 64 other novel viruses.

“We don’t know yet which of those 12 novel coronaviruses – if any – we need to be worried about.

“The next thing we need to do is to further characterise those viruses,” says Hughes.

A novel virus is one that has not previously been recorded.

Coronaviruses are a large family of viruses, some of which can cause illnesses including Middle East Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS) and the latest, which is still surging around the world, Covid-19.

A visualisation of the novel coronavirus SARS-CoV-2 that is behind the Covid-19 pandemic currently ravaging the world. Currently, there are some 20mil cases of infections and over 750,000 deaths. - AFP
A visualisation of the novel coronavirus SARS-CoV-2 that is behind the Covid-19 pandemic currently ravaging the world. Currently, there are some 20mil cases of infections and over 750,000 deaths. - AFP

Covid-19: Current situation in Malaysia (updated daily)

Virus in Malayan pangolin similar

More than 100,000 tests have been done so far on the samples collected throughout Malaysia.

Hughes says experiments are currently ongoing with some of the 76 novel viruses to see which among them could attach to, infect and replicate in human cells.

“Any novel virus that can do that is a potential threat to human health and our economies.”

The samples taken in Malaysia will also be tested for Covid-19 in the coming months.

However, Hughes says that he does not not expect any of the samples to test positive for Covid-19.

But he adds that it possible that the coronavirus would be found in samples taken in Malaysia and other countries, especially from bats of the Rhinolophus genus, which comprises more than 100 species.

“The Rhinolophus bats were the reservoir for SARS and based on what we know so far, we expect them to also be the reservoir species for SARS-CoV-2 (the coronavirus that causes Covid-19).”

Protecting our wildlife and forest habitats

Some wild animals such as bats are natural reservoirs for zoonotic viruses but they are not to blame when their viruses spill over to people.

Bats, for instance, are not only under threat from habitat loss, they are also perceived as a pest and are hunted to protect crops and in some instances, for food.

But bats play many important roles, from controlling insect populations to pollinating durian.

Development and agricultural activities such as durian farming or oil palm planting are also not the underlying reasons why diseases spillover.

“It’s caused by a lack of respect for the natural environment.

“It is human beings changing the environment, changing our interactions with wildlife, changing our contact with these wild animals that creates these disease emergence events,” says Hughes.

EcoHealth Alliance Malaysia laboratory technician Suraya Hamid conducting viral testing at the Molecular Diagnostic Laboratory established in collaboration with PERHILITAN and certified to international standards at the National Wildlife Forensic Laboratory.Photo by E Osman, Management and Science University
EcoHealth Alliance Malaysia laboratory technician Suraya Hamid conducting viral testing at the Molecular Diagnostic Laboratory established in collaboration with PERHILITAN and certified to international standards at the National Wildlife Forensic Laboratory.Photo by E Osman, Management and Science University

EcoHealth Alliance, he says, aims to work more closely with industry and others involved in land use and development planning to help them develop the tools needed to make informed decisions about where and how to carry out land use change.

Malaysia, he says, needs to avoid touching the pristine forest we have left.

Rainforests play a vital role in preventing disease because it provides a habitat for wildlife - safe and away from human beings and livestock.

Hughes says Covid-19 has shown that the world is very much connected.

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“What happens in a wet market in Wuhan China, affects every single one of us.

Members of the public wearing face masks and walking on a pedestrian crossing in Kuala Lumpur, Malaysia. Wearing face masks in crowded public areas has been mandatory since Aug 1. Taken by YAP CHEE HONG on Aug 8, 2020.
Members of the public wearing face masks and walking on a pedestrian crossing in Kuala Lumpur, Malaysia. Wearing face masks in crowded public areas has been mandatory since Aug 1. Taken by YAP CHEE HONG on Aug 8, 2020.

“Similarly, if we wish to have healthy human beings, we need to have a healthy environment, wildlife, and livestock.

“If any of these are not looked after properly, then everything else will be impacted.”

Information on the novel viruses is available online at PREDICT’s health map website.

Malaysia’s winged night-time gardeners need protection

WHEN it comes to preventing wildlife viruses from spreading to people, bats are not our enemy.

Similar to some other types of wildlife, bats are natural reservoirs, meaning that they may host certain viruses within their bodies.

But far from being a threat, bats play a vital role in Malaysia’s ecosystem, economy and human health.

Tom Hughes, Director of Conservation Medicine and Project Coordinator for EcoHealth Alliance in Malaysia, says that indiscriminate land use change and wildlife trading are the actual culprits when wildlife viruses spill over to people.

“For example, if we clear our pristine rainforests, we bring people into contact with wild animals that they have not encountered before.

“It is these kinds of activities which actually increase the chances for disease spillover events to happen,” says Hughes.

Bats, which are active at night, play many important roles.

Fruit bats, for example, can be considered as the country “winged, night-time gardeners” because they pollinate certain types of trees and also disperse seeds, says flying fox conservation ecology specialist Dr Sheema Abdul Aziz.

She explains that fruit bats - from the Pteropodidae family - are the principal pollinators for durian.

Durian seller Muhammad Rusdi Abdul Rashid, 40, commutes daily from Sungkai, Perak to Paya Jaras, Selangor to sell durian. Malaysians' love for the King of Fruits have remain unabated even in the midst of a pandemic. Taken by MUHAMAD SHAHRIL ROSLI on June 17, 2020.
Durian seller Muhammad Rusdi Abdul Rashid, 40, commutes daily from Sungkai, Perak to Paya Jaras, Selangor to sell durian. Malaysians' love for the King of Fruits have remain unabated even in the midst of a pandemic. Taken by MUHAMAD SHAHRIL ROSLI on June 17, 2020.

Fruit bats could also be the pollinators for other fruits, such as mango and certain timber species, although she says further research is still needed in order to verify this.

Research in Sarawak and Terengganu has shown that fruit bats help pollinate mangrove trees such as the Sonneratia, commonly known in Malay as the Berembang and Perepat.

“Fruit bats are critically important for maintaining wetland ecosystems, such as mangroves, which are, in turn, important for other conservation initiatives such as fireflies, coral reefs, marine ecosystems, and local livelihoods that depend on fisheries and eco-tourism,” says Dr Sheema.

Bats are also important as seed dispersers.

When fruit bats feed on fruits, they are providing a 'gardening service' in rainforests, orchards and gardens by either carrying off large seeds and dropping these elsewhere, or swallowing small seeds and defecating these, sometimes even in midflight.

Dr Sheema says this role is vital for reforesting cleared or degraded areas, and to maintain the health of multiple ecosystems.

Bats also provide important pest control services by feeding on the insects that damage farmers' crops, such as rice, and help reduce the population of disease vectors like mosquitoes.

Despite their importance, however, bats are, unfortunately, not only the victims of negative perception as health threats and pests.

They are also coming under threat.

Malaysia’s two flying fox species – Pteropus vampyrus and Pteropus hypomelanus – are both listed as endangered by the Department of Wildlife and National Parks (Perhilitan) due to, among others, intensive hunting and habitat loss.

"Essentially, any bat species that rely on rainforest, mangrove and swamp habitats are at risk from logging and clearance.

“And any bat species that rely on cave or limestone habitats are at risk from quarrying," says Dr Sheema, who is also the co-founder and president of Rimba, a non-profit conservation research group.

Rimba co-founder and president Dr Sheema Abdul Aziz.
Rimba co-founder and president Dr Sheema Abdul Aziz.

"...any bat species that rely on rainforest, mangrove and swamp habitats are at risk from logging and clearance and any bat species that rely on cave or limestone habitats are at risk from quarrying."
Dr Sheema Abdul Aziz

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In Peninsula Malaysia, Perhilitan is taking steps to fully protect our flying foxes under the Wildlife Conservation Act 2010 while in Sarawak, all the state’s bat species are legally protected under the state’s Wildlife Protection Ordinance 1998.

In 2012, Rimba started Project Pteropus to help conserve Malaysia’s endangered flying foxes.

Under the project, a Peninsula-wide survey of flying fox populations was conducted to get a better idea of their population and distribution, and to identify important sites for habitat protection.

“We also hope to start working with other partners to expand further on public outreach and to really get this message out to a wider audience so that more Malaysians learn to start loving our native bats,” she adds.

To find out more about Project Pteropus, go to its website.