Scientists who were investigating how coronavirus is transmitted to humans have previously suggested that the virus may have been transmitted to humans from pangolines. However, a new study in Canada suggests that the virus may have been transmitted from dogs to humans.
The coronavirus pandemic is among the deadliest outbreaks humanity has long experienced. While the dimensions of the outbreak continue to increase every day, scientists continue to study the source of the virus.
Previous studies on how coronavirus infects humans showed that the virus from bats was transmitted to another animal after bats, and from that animal to humans. The animal that transmitted the coronavirus to humans was thought to be pangolin. A new study suggests that dogs may be responsible for transmitting the virus to humans.
Is coronavirus transmitted from dogs?
Researchers from the University of Ottawa in Canada conducted a study to find out from which animal the coronavirus is transmitted to humans. Professor Xuhua Xia, the lead author of the article, which explains the results of the study, advocates a scenario where the virus is transmitted to humans from dogs eating bats with coronavirus.
Previous studies have shown that the coronavirus is caused by bats. Bats have been living with viruses like Ebola, rabies, and SARS for millions of years. However, the lack of interaction between humans and bats prevents these viruses from infecting humans. For this reason, living things that interact with bats are investigated as the coronavirus responsible.
According to the scenario of Xuhua Xia and colleagues, the bat coronavirus, which is the closest relative of SARS-CoV-2, was infected and infected the dogs’ intestines. The virus that evolved in the dog intestine was then transmitted to humans.
Researchers from the University of Ottawa have researched an antiviral protein called ZAP that prevents the virus from breaking down its genome. The target of the antiviral protein is a pair of RNA fragments called CpG dinucleotides. These antiviral proteins are used to search for and destroy the virus in a person’s immune system.
ZAP also patrols the human lungs and is abundant in the bone marrow and lymph nodes where the immune system performs its first attack. However, the studies revealed that coronavirus can avoid ZAP by reducing CpGs.
Xuhua Xia says that reducing CpG levels in viral pathogens is a health threat, and high amounts of CpG levels reduce the threat to viruses. The high CpG level allows the virus to be more easily detected and destroyed by the immune system.
CpG levels of coronavirus in dogs and humans are similar
In the study, it was seen that the CpG levels of the coronavirus in dogs have similar values to the CpG levels of the coronavirus in humans. The fact that the CpG levels are similar and the coronavirus is known to affect the human digestive system strengthens the possibility that the coronavirus may be transmitted by dogs. Professor Xia says that the transmission of coronavirus into the intestines with the protein ACE2 found in the intestines of people indicates that the virus comes from an ancestor with low CpG levels.
A large proportion of people suffering from coronavirus complain of digestive disorders. In fact, 48.5 percent of people who get the virus apply to hospitals with symptoms of digestive problems. A study conducted in the USA revealed that in the first 12 cases of coronavirus seen, diarrhea occurred before symptoms of fever and cough developed.
Dogs often lick their anal and genital areas after mating and excretion. Such behavior may have facilitated the transmission of the virus from the digestive system to the respiratory system. Professor Xia said, “These observations are consistent with the hypothesis that COVID-19 evolved in the mammalian intestine or intestinal tissues. That is why it is important to isolate the bat coronavirus (BaTCoV RaTG13) in feces. ”
The theory that the coronavirus is transmitted from bat-eating dogs to humans is not accepted by all scientists. Professor Mick Watson, Professor of Bioinformatics and Computational Biology at the Roslin Institute, says that the genome comparisons made are in bats but the gene sequence that most closely resembles SARS-CoV-2 is not in the bats.
Professor Watson said that the theory that SARS-CoV-2 originates from dogs is only due to speculation about CpG and high ZAP levels. Watson says this link is speculative and doesn’t offer strong evidence.