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Poking the beehive

Vet Advice with Dr. Ron Clarke

Poking the beehive

COVID-19 may never go away — with or without a vaccine. Dr. Vineet Menachery, a coronavirus researcher at the University of Texas medical branch, is guarded in his forecast of how we will adapt to COVID-19. The future has a lot to do with immunity.

Menachery points out that we haven’t been successful at eradicating many viruses at all — an exception being smallpox. “Many of these viruses exist in both human and animal populations. So coronaviruses, like SARS in 2002, may be removed from human populations, but we know similar viruses still exist in nature. And at any time, they may gain the ability to re-emerge in humans.”

The trajectory of the current pandemic is having a significant effect on modern livestock production. The actions taken in many countries, such as lockdown, travel restrictions and border controls, have resulted in unintended or negative consequences for animal agriculture, including: difficulty moving live animals and animal products like milk, meat and eggs to markets; restricted capacity to purchase production inputs; restricted access to labour and professional services.

These difficulties decreased processing capacity and loss of sales. Overall, market activity lagged. During the COVID-19 pandemic, the capacities of countries to prevent and control animal diseases seriously diminished. Of particular concern are current outbreaks of transboundary animal diseases such as African swine fever, foot-and-mouth disease, avian influenza and other infectious animal diseases whose prevention and control were severely compromised.

As of mid-October, about 39 million people had tested positive for the coronavirus globally, and at least 1.1 million died, according to CNN. In the U.S., nearly eight million people tested positive, more than 200,000 died. While scientists race to find a cure, there’s a chance COVID-19 will never fully go away. But that doesn’t mean everyone will have to self-isolate forever.

Many health experts state they would be surprised if we’re still wearing masks and maintaining six feet of separation in two or three years. The most likely outcome is that human populations will eventually develop herd immunity through vaccination and natural exposure.

Menachery’s view is that the virus will become the next common cold coronavirus. The question is whether common cold coronaviruses have gone through a similar transition period.

For example, OC43 is a common cold coronavirus that emerged from cattle and initially caused severe disease, says Menachery.

“After a few years, the virus became just the common cold. And so in three to five years, it may be that you’re still getting COVID-19 in certain populations of people every few years. But the expectation is hopefully that it’ll just be a common cold and it’s something that we can each deal with. It won’t lead to hospitalization and the shutting down of society.

“COVID-19 is unique in a couple of different ways: One, like the common cold coronaviruses, it spreads easily. But unlike the common coronaviruses, it causes severe disease. What we know about common cold coronaviruses is that immunity is not long-lasting, that it wanes in time and after two to three years, exposure can result in reinfection. On the other end, coronaviruses like SARS and MERS, the immune response lasts a long time. What we don’t know with COVID-19 is where it sits between the two poles.”

SARS-CoV-2 (COVID-19) is closely related to a group of coronaviruses in bat populations. Severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus, which appeared in 2002 and 2012, respectively, are part of this group.

Another overlooked aspect of the COVID-19 pandemic is the threat of antimicrobial resistance, which seems to be worsening.

“Since the emergence of COVID-19, collected data have shown an increase in antibiotic use,” says Dawn Sievert, senior science advisor for antibiotic resistance at the U.S. Centers for Disease Control and Prevention (CDC). “The resulting increased exposure to health care settings and invasive procedures, along with expanded antibiotic use, amplifies the opportunity for resistant pathogens to emerge and spread.”

A review of data from COVID-19 cases, mostly in Asia, found that more than 70 per cent of patients received antimicrobial treatment — often broad-spectrum antimicrobials — despite less than 10 per cent of patients exhibiting signs associated with bacterial or fungal co-infections.

Complacency about “superspreading” events represents a major part of COVID-19 transmission.

“Viral load actually increases a couple of days before symptoms show up,” says Smita Gopinath, an immunologist at the Harvard School of Public Health.

Many superspreading events during this pandemic have taken place in bars, nightclubs, restaurants and places such as meat plants. The virus is spreading even though the person who’s spreading it feels fine. In addition, some individuals naturally spread virus more effectively. So when a person with a high viral load walks into a crowded bar — one with poor ventilation and where nobody is wearing masks or social distancing — they represent a superspreading cocktail.

In animals, we’ve known for years that between 10 to 20 per cent of infected individuals are responsible for about 80 per cent of transmission events.

Scientists have long warned that reshaping Earth’s landscapes will have broad ramifications for the climate and biodiversity. A growing body of evidence shows that forest loss and fragmentation increases the risk of animal-borne infectious disease, similar to the one that’s currently upending the world.

Research has shown there are ways to limit the chances of pandemics happening. Perhaps it starts with being better stewards of climate change and wildlife management. Perhaps we can do a better job of maintaining protected areas of habitat to limit interactions between people and wildlife. Perhaps we need to better support people in high-risk areas to lessen their dependence on natural resources, which becomes an equity issue. We must invest in more robust surveillance systems to identify infectious disease outbreaks before they become pandemics.

The financial and political strain on governments is intense, but somehow humans must find ways to stop poking the beehive.

About the author

Columnist

Dr. Ron Clarke

Dr. Ron Clarke prepares this column on behalf of the Western Canadian Association of Bovine Practitioners. Suggestions for future articles can be sent to Canadian Cattlemen ([email protected]) or WCABP ([email protected]).

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