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Infectious Diseases

Updated 31 July 2020

4 unusual things we’ve learned about the new coronavirus

We’re more than six months into the outbreak of SARS-CoV-2, and in the meantime, some interesting discoveries have been made.

  • The world as we know it has changed drastically since the Covid-19 pandemic started.
  • Scientists have been working around the clock to understand this fairly new, deadly viral disease.
  • We take a look at some interesting and unusual discoveries made so far.

The spread of the new coronavirus (which causes Covid-19) has caused immense disruptions within a very short space of time, with governments around the world responding in various ways to the crisis. Understandably, a lot of attention has been paid to this virus, and a considerable number of emerging studies have already shed some light on it. Here are some key discoveries:

One blood type appears to be more resistant against the virus

Although more research needs to be done on the potential link between blood groups and SARS-CoV-2, recent data from 750 000 participants show that type O blood appears to be more resilient against contracting the virus, as well as severe symptoms, compared to other blood types. Health24 reported on the story.

The preliminary data came from US-based private genetic testing company 23andME. According to the results, people with type O blood appear to be 9% to 18% less likely to test positive for Covid-19. In another sample set limited to those with high exposure to the virus, such as essential workers, they found those with type O blood to be 13% to 26% less likely to contract the virus.

In another study of 2 173 participants, results indicated that blood group A was associated with a higher risk of contracting Covid-19, compared to non-A blood groups. The study was published in preprint server medRxiv.

Covid-19 can cause loss of smell and taste

One aspect that has puzzled scientists and clinicians is the loss of smell and taste (known as "anosmia"), something that could actually be pivotal in the early detection of the virus. Scientists have been noticing the effect of the virus on the olfactory pathways for quite some time. Health24 notes that respiratory viruses, both cold and flu viruses, are known to sometimes trigger anosmia.

In a recent study, reported by Health24, about 55.4% of participants reported a reduced sense of taste, while 41.7% had a reduced sense of smell. Although the study has its limitations, additional studies with similar findings have advised general practitioners to look out for these symptoms when screening patients.  

Domestic animals can be infected but can’t pass on the virus

Some people have been concerned over whether they can pass the virus to their pets. One study found that humans with Covid-19 can pose a risk to certain animals, such as cats or ferrets, but not dogs.

However, another study found that dogs may also catch the virus from their owners. The good news, however, is that this risk is really small. "There have really only been a handful of known domestic animal infections in the entire world," said Dr John Howe, president of the American Veterinary Medical Association.

Although more research is needed to determine the extent of owners infecting their pets, there is credible evidence to suggest that while human-to-animal transmission can occur in some situations, animals do not play a significant role in spreading the virus. 

The Centers for Disease Control and Prevention (CDC) states: "At this time, there is no evidence that animals play a significant role in spreading the virus that causes Covid-19. Based on the limited information available to date, the risk of animals spreading Covid-19 to people is considered low. More studies are needed to understand how different animals could be affected by Covid-19."

Your antibodies against the disease may only last a few months

Another area under substantial observation is that patients who recover from Covid-19 may only retain their antibodies against the disease for between two and three months. Health24 reported on this recently discovered finding from a Chinese study published in the journal Nature.

The article explains that antibodies against other types of coronaviruses usually last around a year, but that this study that examined patients recovering from Covid-19 (including asymptomatic individuals) found that they retained their antibodies for a much shorter period. 

According to the researchers, the use of "immunity certificates" is, therefore, not a useful tool to help communities manage the outbreak, and that isolation regulations from governments should continue to stay in place.

Immunity certificates, also known as "immunity passports" or "risk-free certificates" enable individuals to travel or to return to work assuming that they are protected against re-infection.