Sayeed Anuwar
(College of Veterinary Science,
AAU, Khanapara. sayeedanuwar09@gmail.com)
''When Beth Emhoff (Gwyneth Paltrow) returns to Minne sota from a Hong Kong business trip, she attributes the malaise she feels to jet lag. However, two days later, Beth is dead, and doctors tell her shocked husband (Matt Damon) that they have no idea what killed her. Soon, many others start to exhibit the same symptoms, and a global pandemic explodes." – This is the Google description for Contagion, a 2011 fictional movie that depicted the rapid spread of an infectious disease.
Eight years later, in December, 2019, a new, unknown virus, producing pneumonia-like symptoms in humans, emerged in Wuhan, China, before rapidly erupting into a global pandemic. But, this time, it was not any Hollywood movie.
All this started at the end of December, 2019, specifically on the 31st, where the Chinese Disease Control Centre reported 27 cases of patients with pneumonia of uncertain etiology and who had in common a Hunan seafood market that lacked sanitary measures, warning of a possible zoonosis. On January, 7 its causal agent was identified, which was a coronavirus and it was called with the name of the new coronavirus (2019-nCoV).
The world has received a crash course on pandemics, but they are not new to this century. In 2003, a mysterious disease with flu-like symptoms that came to be known as Severe Acute Respiratory Syndrome (SARS), ultimately spread to 26 countries, infecting more than 8,000 people and killing close to 800. While the source of what is considered to be an animal virus remains somewhat uncertain, it is believed SARS started in bats and then spread to other animals.
The Middle East Respiratory Syndrome (MERS), which first appeared in 2012, has since spread to 27 countries; it has been traced to originating in camels. But none of those numbers compare to the Spanish flu which, from around 1917 to 1918, infected an estimated 500 million people worldwide and killed an estimated 50 million people. The most important thing is that these diseases are zoonotic and airborne.
ZOONOTIC DISEASES:
A zoonosis is an infectious disease caused by a pathogen that has jumped from an animal to a human or vice versa. Typically, the first infected human transmits the infectious agent to at least one other human, who, in turn, infects others. The SARS virus is believed to have ultimately spread to and been carried by domestic cats and ferrets. COVID-19 is believed to have been carried by bats and, possibly, civet cats or pangolins. But could human give viruses to pets?
A Pomeranian dog in Hong Kong grabbed the international media's attention in February, 2020 after scientists found traces of coronavirus in the canine. Following confirmation that the dog's owner was positive for the virus causing COVID-19, the dog was taken from Hong Kong Island to a nearby animal quarantine facility. Subsequent tests performed on swabs collected from the dog's nose and throat unexpectedly revealed coronavirus.
A positive test for coronavirus in this dog simply means that a small piece of viral genome was detected in a sample. PCR (a test used to detect genetic material) is a highly sensitive method of testing. The widely held presumption was the "weak positive" test may have been the result of environmental contamination of the dog's mouth and nose. That is, a dog being a dog, the pet may have picked up (licked up) traces of the virus. Upon additional testing which resulted in "weak positive" results, some experts concluded that the dog had a "low level" infection caused by human-to-animal transmission, but the Centers for Disease Prevention and Control (CDC) has maintained: "To date, CDC has not received any reports of pets or other animals becoming sick with COVID-19. At this time, there is no evidence that companion animals including pets can spread COVID-19. However, since animals can spread other diseases to people, it's always a good idea to wash your hands after being around animals."
AIRBORNE INFECTIONS:
An airborne infection is an infection that is contracted by inhalation of microorganisms or spores suspended in air on water droplets or dust particles. Viruses and bacteria can be aerosolized through coughing, sneezing, laughing or through close personal contact. These pathogens ride on either dust particles or small respiratory droplets and can stay suspended in air and or are capable of travelling distances on air currents. In addition to being zoonotic, COVID-19, Spanish flu, SARS and MERS are also viruses that may be spread by the airborne route.
Many pathogens transmit by direct contact between dogs or between dogs and humans. Airborne respiratory infections are either inhaled or else cause infection via the nose, the mouth or the eyes. Particular attention should be paid when any flu epidemic sweeps through the human community or infects a staff member, as these diseases can be transmitted to and from animals. Outbreaks caused by airborne pathogens can be explosive.
Whether spread from animal to human, human to human, or animal to animal, the airborne route of transmission is a serious one. Surface cleaning is not enough to prevent transmission. And, when it comes to new and emerging diseases, there are no ready-to-go vaccines. Beyond those airborne diseases that impact humans, what about those that impact the animals in your care? For example, canine cough, dog flu and feline calicivirus may all be spread via the airborne route.
THE MAN-ANIMAL BOND:
As the human-animal bond continues to grow, and as the human population continues to expand geographically, as noted by the American Veterinary Medical Association, "The contact between human and wild animal habitats increases, introducing the risk of exposure to new viruses, bacteria and other disease-causing pathogens."
According to the CDC, six out of every 10 infectious diseases in people are zoonotic. In short, these diseases are an integral part of the human-animal bond. So, in protecting animal health and welfare, animal care providers contribute toward improving human health. The interdependence of human health and animal health has led to an initiative known as 'One Health', an approach that recognizes that the health of people is closely connected to the health of animals and our shared environment.
The One Health concept clearly focuses on consequences, responses, and actions at the animal-human-ecosystems interfaces, and especially emerging and endemic zoonosis. Animal-to-human transmission is a major threat in India, with several diseases such as avian flu and rabies. A major growing threat is from bovine tuberculosis which is on the increase. In addition, emerging zoonotic diseases are acquired through wild animals, and the One Health approach should look into the wild zoonotic diseases also. The successful implementation of the One Health model involves integration and collaboration between multiple sectors of agriculture, animal health, and human health.
The optimal health for both humans and animals require an approach beyond considering human-to-human or, separately, animal-to-animal transmission. In October 2019, the American Association of Feline Practitioners (AAFP) released their updated Feline Zoonoses Guidelines. In publishing the guidelines, the AAFP aims to provide accurate information about feline zoonotic diseases to owners, physicians and veterinarians to allow logical decisions to be made concerning cat ownership. Every country should take initiatives to maintain zero probability of getting zoonotic diseases that further leads to global pandemic, Pioneer a strong and sustainable global health security system. Build a deployable clinical capability for international infectious disease emergencies and invest more in a robust, highly capable national public health system that can manage the challenges of pandemic response.