Zoonotic Diseases And Why COVID-19 Is A Matter Of Concern

As humanity gets ready for the unfolding of 2020, a team of researchers has uncovered the discovery of a novel (new and unidentified) coronavirus emerging in Wuhan, China near the end of December 2019.

Tracing the origins of the virus led researchers to conclude that patient-zero might have contracted the virus from Hua Nan seafood and wet animal wholesale market.

It is then given the provisional name (a name to identify new coronaviruses before a permanent name is given) 2019-nCoV which stands for 2019-novel CoronaVirus. 

From there, the virus has spread like wildfire in other Chinese provinces, as well as in other parts of the globe, infecting thousands where it has become present. Shortly, on January 30, 2020, the World Health Organization declared a Public Health Emergency of International concern with regards to this potential pandemic.

After more research has been conducted, the virus was then named Severe Acute Respiratory Syndrome – CoronaVirus 2. It was immediately identified as a beta coronavirus which is related to the SARS-CoV –which blew up in 2003, and other bat-borne coronaviruses.

Just a few weeks after WHO’s announcement, the outbreak seems to easily go out of hand, effectively killing thousands in its path and infecting tens of thousands more across the globe. By March 11, the World Health Organization declared COVID-19 as a global pandemic.

What is a Zoonotic Disease and Why Are They Considered More Dangerous For Humans

In history, humanity has survived multiple accounts of pandemics that had plagued the Earth. It is worth noting that the majority of the gravest pandemic humanity has ever survived, could be classified as a zoonotic disease.

Zoonotic disease or zoonoses is known to be caused by harmful microorganisms and pathogens like viruses, bacterias, fungi, and parasites that have jumped from one animal species to another. Multiple zoonotic diseases seem to be harmless to its animal host yet it could be dangerous if humans contract it. 

Other types of zoonotic diseases can have varying health effects on both its human and animal host. Zoonotic diseases are a result of germs that perform “host-jumps” from one specie of an animal-host to that of another species, in some cases, from animals to humans or even vice versa.

The majority of disease experts concluded that 60% of the infectious diseases in humans can be attributed as a result of cross-species transmission. And about 4 out of 5 new human diseases can be traced back to be of zoonotic origin, meaning they are from other animals.

Put simply, zoonotic diseases are pretty common in our environment, and as humans exploit other animals’ natural habitats, we are brought closer to contracting or developing diseases from other creatures.

Humans have lived with animals for the longest time, and we have learned to domesticate some of them. Our close connection with other animals helps promote each others’ species survival, as well as promulgate new obstacles that challenge the existence of both.

It is exactly for this reason why humans are highly susceptible to contracting diseases from animals.

Take dogs for example. The man’s best friend has been domesticated over the years, and both species learned to survive side by side. However, this close connection also made us more susceptible to getting rabies.

Rabies is an example of a zoonotic disease that is contracted through direct contact. This method of transmission is possible when a human comes into close contact with the infected animals’ blood, saliva, urine, mucous, feces, and other bodily fluids.

One good way of contracting diseases through direct contact is by petting animals, as well as getting bitten or scratched by the infected host.

Aside from direct contact from infected animals, other methods of infection can also be caused by the following:

Indirect Contact – This occurs when a possible host comes in contact with areas where infected animals roam, and live. This includes surfaces that may have been contaminated with microorganisms like aquariums/aquarium water, chicken coops, barns, plants, soil, as well as food and water dishes for pets.

Water-borne – consumption or direct contact with water that could have been infected with the fecal matter of an infected animal host.

Foodborne – some zoonotic diseases can contaminate the food that humans eat. Foodborne diseases can be contracted by eating or drinking unsafe food products such as unpasteurized (untreated or raw) milk, undercooked meat, raw or undercooked eggs, even fruits and vegetables that have been contaminated with feces of infected hosts. A common example of this is salmonella which humans can get from undercooked chicken meat or eggs.

Vector-borne – Vector-borne diseases are caused by germs, viruses, bacterias, and parasites that are transmitted by vectors. Vectors are living organisms that can transmit pathogens from one human to another, or from an animal source to a human host. Examples of vectors include ticks, mosquitoes, and fleas. Once infected, a vector organism can transmit the pathogen for the rest of its life, effectively infecting any human that is unfortunate enough to get bitten by it.

Common examples of vector-borne diseases are malaria, dengue, schistosomiasis, human African trypanosomiasis, leishmaniasis, Chagas disease, yellow fever, Japanese encephalitis, and onchocerciasis.

Coronaviruses like the one that caused COVID-19, are a large family of viruses that infects birds and other mammals including bats. These types of viruses are responsible for several infectious outbreaks around the world.

However, the bat coronavirus that is closely related to that of the SARS-CoV-2 is believed to be incapable of infecting humans directly, which means that an intermediate host is responsible for allowing this virus to latch on to a human host. That intermediate host is still being identified but there are a few speculations that suspect pangolins, snakes, and even dogs (for human consumption) to be the catalyst of this viral spillover.