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Infectious Diseases

01 October 2020

Coronavirus morning recap: Phantom smells, faulty genes and update on travel

Research on smell distortions, possible reasons behind severe Covid-19 in younger people and South Africa’s full red list of countries.

LATEST SCIENCE AND RESEARCH

READ | Covid-19 can cause a number of smell distortions

The loss of smell is such a widespread symptom of Covid-19 that it has become one of the main ways to diagnose the disease.

But survivors who lost this sense are also reporting other olfactory conditions: parosmia and phantosmia. The former distorts existing smells into an unpleasant, abrasive experience, while the latter conjures up smells that don't exist.

These conditions are closely linked to anosmia and tend to be the result of damage to olfactory nerve fibres, in this case, caused by a viral infection. It can also be caused by smoking, cancer, brain trauma and other neurological conditions.

While they don't have an impact on your health, the above conditions can impede quality of life when your favourite foods start smelling like garbage and affect your appetite. The largest study on parosmia found that the biggest triggers were tobacco, coffee, perfumes, chocolate and gasoline.

According to a study on Covid-19's impact on the senses, other chemosensory distortions are understudied in reports on loss of taste and smell. Fortunately, cases of parosmia and phantosmia still appear to be rare: about 7.5% of the study's respondents reported parosmia, with around 8.3% reporting phantosmia.

These disorders also present much later after recovery – sometimes months later. The study focused on people recently recovered, which means there has not been enough time to investigate the true prevalence of these smell distortions.

READ | Severe Covid-19 in younger people could be due to faulty genes and an autoimmune condition

We now understand that there are risk factors that make some people more susceptible to severe Covid-19 than others. These include being elderly, obese and suffering from diabetes.

But what baffles many people, including experts, is the fact that a number of young and healthy people also suffer severe outcomes or die from Covid-19.

Now, new research from the Rockefeller University has shown that more than 10% of young and healthy people who develop severe Covid-19 have “misguided” antibodies that, instead of attacking only the virus, end up targeting the immune system – leading to severe symptoms.

Another 3.5% of young people with severe Covid-19 carry a specific genetic mutation that may explain their severe reaction.

The new research, published in the journal Science, explains that in both groups of younger patients with severe Covid-19, there is a lack of type I interferon – a set of 17 proteins responsible for protecting the body against viruses.

There are two ways the lack of interferon may occur in these cases. In some cases, the proteins are neutralised by auto-antibodies, while in others, patients lack sufficient levels of interferons because of a faulty gene.

CORONAVIRUS CASES LATEST

SA cases update: 

The latest number of confirmed cases is 674 339.

According to the latest update, 16 734 deaths have been recorded in the country.

There have been 608 112 recoveries.

So far, more than 4.18 million tests have been conducted, with 23 426 new tests reported.

Global cases update:

For the latest global data, follow this interactive map from Johns Hopkins University & Medicine.

Late on Wednesday night, positive cases worldwide were over 33.79 million, while deaths were more than 1 million.

The United States had the most cases in the world - more than 7.2 million, as well as the most deaths - more than 206 000.

WHAT'S HAPPENING IN SA

Latest news:

READ | No UK or US tourists: Here is South Africa’s full red list of countries

South Africa will use its own level of coronavirus risk to determine what countries are considered high, medium, or low risk, international relations minister Naledi Pandor announced on Wednesday at a press conference on new travel measures.

Those with significantly higher levels of infection spread and deaths than South Africa will be rated as high risk – and leisure travellers from those countries will not be permitted entry into South Africa.

The only exceptions will be those with high-skills visas, diplomats, sports people, and investors.

“We’ve agreed that we will gradually open our borders and ports of entry of international travellers, primarily in the first instance for business and some leisure travellers," Pandor said – strongly stressing that it will be "some" leisure travellers – "and other aspects of travel such as investors coming into South Africa [and] sea crews that need to spend a short time, having docked in our ports. So we still are in a restricted domain, but we are gradually opening up."

All countries on the African continent automatically fall outside the high-risk category, ministers said, so tourists will be allowed to travel to and from those countries regardless of their SARS-CoV-2 statistics.

"If the passport of the traveller from a high risk country indicates that he/she has spent 10 days or more in a low risk country before departure, he/she will be considered to be arriving from a low risk country," one government statement said.

WHAT'S HAPPENING IN THE REST OF THE WORLD 

Latest news:

READ | A Covid-19 test that gives results in 15 minutes without a lab has been cleared for use in Europe

A Becton Dickinson lab-free Covid-19 test that returns results in 15 minutes has been cleared for use in Europe. 

The US medical device maker said on Wednesday that its testing kit for coronavirus, which has been available in the US since July, met the requirements to be sold in Europe.

It will be available in countries that recognise the CE mark, which shows that a manufacturer has ensured a product meets European Union safety requirements.

Becton Dickinson said it expects its test to be commercially available in European markets by the end of October. It will most likely be used by emergency departments, pediatricians, and general practitioners, it said.

The portable BD Veritor Plus System can quickly identify antigens on the surface of the coronavirus without requiring a lab. Antigen tests are designed to produce results rapidly, but are generally less reliable than the gold-standard PCR assay.

Troy Kirkpatrick, a spokesperson for Becton Dickinson, said that a new clinical study shows the test correctly identifies infections 93.5% of the time, whilst the rate of correct negative results stands at 99.3%, per Bloomberg.

READ | Trump-touted hydroxychloroquine shows no benefit in Covid-19 prevention - study

A malaria drug taken by US President Donald Trump to prevent Covid-19 did not show any benefit versus placebo in reducing coronavirus infection among healthcare workers, according to clinical trial results published on Wednesday.

The study largely confirms results from a clinical trial in June that showed hydroxychloroquine was ineffective in preventing infection among people exposed to the new coronavirus.

Trump began backing hydroxychloroquine early in the pandemic and told reporters in May he started taking the drug after two White House staffers tested positive for Covid-19. Studies have found the drug to offer little benefit as a treatment.

In the study of 125 participants, four who had taken hydroxychloroquine as a preventative treatment for eight weeks contracted Covid-19, and four on placebo tested positive for the virus.

All eight were either asymptomatic or had mild symptoms that did not require hospitalisation, according to the results published in the JAMA Internal Medicine journal.

The research shows that routine use of the drug cannot be recommended among healthcare workers to prevent Covid-19, researchers from the University of Pennsylvania said.

HEALTH TIPS (as recommended by the NICD and WHO)

• Maintain physical distancing – stay at least one metre away from somebody who is coughing or sneezing

• Practise frequent hand-washing, especially after direct contact with ill people or their environment

• Avoid touching your eyes, nose and mouth, as your hands touch many surfaces and could potentially transfer the virus

• Practise respiratory hygiene – cover your mouth with your bent elbow or tissue when you cough or sneeze. Remember to dispose the tissue immediately after use.

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