By Joseph S. Masangkay, DVM, PHD

The appearance of viral diseases like COVID-19, SARS, and MERS has been linked to wildlife, particularly bats. In any crisis situation, the negative aspect is always given emphasis and highlighted, and the positive is almost always ignored. It is indeed a fact that bats have a role in the transmission of zoonotic diseases. However, the role of bats is maintaining the balance of our ecosystem must not be ignored.

How bats help the planet

1. Bats are pollinators

Fruit bats play a big role in the pollination of many fruit trees, such as mangoes. Maintaining the continuous growth of trees in a forest is done by bats by spreading and dispersing seeds through their feces far away from the mother tree.

2. Bats maintain ecological balance

The harvest of corn in the US, Canada, and Australia would not be possible without insectivore bats who eat the moths that destroy crop. This biological insect control also saves the planet from harmful pesticides, which become pollutants in the environment and cause harm to humane. Farmers also save a lot of money by not using chemical pesticides.

3. Bats help us monitor environment status

Bats have been proven to serve as a biological monitor for environmental pollution.

4. Bat poop is a great fertilizer

Lastly, the accumulated feces of bats (guano) is a very good organic fertilizer.

Zoonoses from bats

Here are some of the diseases transmitted by bats – and how we should deal with them.

1. Rabies

Relax – just keep cool, because the bat species that transmits rabies to humans and other animals is not present in the Philippines.

The vampire bat (Desmodus rotundus) is present only in the southern part of the US (Texas, California) and the whole of Central and South America up to Argentina.

2. Hendra Virus Disease

Another zoonotic disease transmitted by bats is Hendra virus (HiV) disease affecting horses, humans, and carnivorous animals, such as dogs and cats who eat the flesh of horses who died of the disease.

Hendra disease was first reported in Australia in 1994, causing deaths in horses and humans.

3. Nipa Virus Disease

Related to Hendra virus is Nipah virus disease (NiV) affecting pigs and humans. Nipah was first reported in Malaysia in 1998, causing death in pigs and humans.

4. Other diseases

These include Ebola, Hantavirus, Herpes virus, Cryptosporidium, and Toxoplasma.

Locan conditions

Are the above diseases present in the Philippines? To answer this question, we formed a Bat Research Team composed of scientists from the University of the Philippines Los Banos (UPLB) College of Veterinary Medicine; zoologists from UPLB Museum of Natural History; and scientists from different universities in Japan, such as the University of Tokyo, Okayama University of Science, and Tokyo University of Agriculture and Technology.

We made several scientific expeditions to different parts of the Philippines to examine bats for possible zoonotic pathogens. In Luzon, bats from the UPLB campus, Polillo Island, Atimonan and Pinagbilao in Quezon, UP Diliman, Sto. Tomas, Batangas, Tanay, Rizal, Mabini in Pangasinan, Mt. Isarog in Bicol, and Biak na Bato in San Miguel, Bulacan were included. In Visayas, we included bats from Aklan, while in Mindanao, those from Davao, Samal Island, Talikud Island, and Siargao. All scientific expeditions were given proper permits from the Department of Environment and Natural Resources (DENR).

Our preliminary results showed antibodies for Dengue fever, Gammaherpesvirus, and Salmonella. The tests revealed weak positive results for Ebola reston, positive results for virus genomes of Coronavirus (not COVID-19), Yokose virus, and ectoparasites.

Is it the bats’ fault?

The most alarming report related to zoonoses transmitted by bats was the presence of suspected Henda virus in horses in Sultan Kudarat, Mindanao. This research was a joint program of the Department of Health, RITM, and US and Japanese scientists in 2014.

Deaths were observed in horses and in humans, cats and dog which ate the meat from the infected horse. Our team will later on examine bats in the vicinity for the possible presence of Hendra virus and other zoonotic pathogens.

We theorized that the Hendra virus was carried by the pteropine bats (flying fox) from Malaysia due to the forest haze that occurred in 2014. The flying fox is a big bat with a very long wingspan and can fly for a long distance. The burning of the forest to clear it for palm oil plantation disturbed the bats who escaped from Malaysia to Mindanao.

What can we do?

How doe we prevent humans from getting zoonotic pathogens from bats? Let us refrain from eating bats and other wildlife, maintain balance in the ecosystem, and report any deaths in wild animals to proper authorities.

We can also launch an Information Education Campaign program for indigenous tribes so that they can be properly informed of the danger of eating wild animals.

(Animals are here with us, not for us, and it pays to acknowledge their presence in this world as our neighbors. With this in mind, we are unlikely to consume animals who naturally carry viruses that cause pandemics. – Ed.)

Joseph S. Masangkay, DVM, PhD is a Professor Emeritus at the University of the Philippines Los Banos College of Veterinary Medicine.

This appeared in Animal Scene magazine’s January-February 2021 issue.

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