The Midweek Sun

Flattening the Covid-19 Viral Load Curve

- BY HOWARD ARMISTEAD

Everyone knows about flattening the curve. That is flattening the curve of Covid-19 viral transmissi­on so hospitals, ICUs and medical staff do not become so overwhelme­d they have to turn sick patients away when they most need lifesaving care. At the beginning of the pandemic in South Africa flattening the curve entailed a total lockdown because medical personnel did not possess adequate personal protective equipment – PPE – to protect themselves. The nation needed to reduce transmissi­on rates to provide time to prepare medical infrastruc­ture, mobilize, and pray science and trial and error would gradually provide better treatments for this disease; and a vaccine could be rushed through to developmen­t, production, and distributi­on.

Due to remarkable scientific advances, vaccines are on their way, but will still take months to arrive. While modern medicine made progress, the virus did not stand still. Like influenza, the virus that causes Covid-19 is an RNA virus named SARS-CoV-2, or just

SARS-2. SARS-2 is a member of a large family of viruses called coronaviru­ses, only seven of which currently infect humans. Four human corona viruses cause only mild symptoms, like the common cold. If a person has ever been infected with one of those four, that might provide some cross-immunity that could help reduce the impact of Covid-19. Scientists are not sure of that yet, but the possibilit­y exists. Besides SARS-2, the other two corona viruses that cause severe illness are SARS- CoV- 1, or just SARS-1. SARS-1 infected several thousand people in 2003 and killed 10% of those. MERS – Middle East respirator­y syndrome appeared in 2013, has infected about six hundred people, and killed 40% of those.

Luckily, SARS-2 kills only about 2.5% of those it infects, although in some countries with much more elderly population­s it has killed as many as 7% of those infected. With three deadly novel corona viruses emerging in the last seventeen years – two of which spread internatio­nally - what are the chances of another one emerging from the bat population in the next decade or two? Highly likely to extremely likely. Over one hundred other corona virus species exist in bats.

Are hospitals, government­s, or the World Health Organizati­on ( WHO) as prepared as they should be? No. A better understand­ing of and applicatio­n of known viral science would help. What about this new, mutant-variant Covid-19 virus? How does that change the pandemic equation? Luckily, the new variant virus appears to be no more deadly than the original. But scientists calculate the mutant variant is 1.7 times more contagious. That means that an infected person is 70% more likely to infect another. That also means this pandemic is about to get much worse, fast. With an increase of 70%, the number that get infected over time will not increase mathematic­ally but exponentia­lly. The curve will not flatten.

Instead, it will rise rapidly, as with the third wave in the US. Already bursting at the seams, hospitals will have no room to admit anyone else, no matter how ill. They will have to turn many sick people away. What should a person do? How should one prepare?

There is a significan­t interest and growth of sport psychology in Botswana. The University of Botswana just introduced a Sport Science degree in sport and exercise psyFirst learn how to flatten the Covid-19 chology. it from The day government two. currently viral load curve. What is that? Viral load A third factor affecting viral load

sponsors students for a sport psyis how much virus a person has in their and disease progressio­n is how strong

chology master’s programme. I want body as measured from their blood. The the immune system is when first inmore virus or viral load one has, to the encourage fected. Is teams, a person corporatio­ns 100% healthy? Or sicker they will get, and the more severe does someone have cancer, active TB, the outcome of their infection will be. chronic disease, diabetes, poor nutriFlatt­ening the viral load curve from the tion, smoke, or do drugs? If so, the start might keep a person out of the immune system already will have been hospital or save their life. Four major weakened to some extent. Obviously, it factors affect viral load. First, how much is beneficial to have a strong immune virus one is initially exposed to. system prior to infection.

Did a person enjoy a long conversaTh­e final factor affecting viral load is tion at close range with a person with what a person does personally to slow Covid when not wearing a mask and viral replicatio­n. The more replicatio­n get a full dose? Or did they come into can be slowed, the lower the viral load contact with just a few viral particles will be and the greater chance the imfloating in the air in a busy taxi rank or mune system will have time to gain the shopping mall? The amount of initial upper hand to suppress infection and exposure to the virus makes a big differprev­ent hospitaliz­ation. ence. It establishe­s a “set point”. Continues next week………………

A second factor affecting viral load is how long a person has been infected.

It takes time for a virus to replicate and gather strength by multiplyin­g.

Viral load increases dramatical­ly over time. It takes three or four days before one starts to feel symptoms of Covid, though once infected one can transmit

Howard Armistead is an AIDS researcher and director of the Selenium Education and Research Centre (SERC) in Johannesbu­rg, South Africa. Visit winagainst­hiv.com for more informatio­n.

practice doctors waiting to answer has a line-up of specialist and general

Sun Your exciting and revealing paper health bugs and let this week’s free! So come on, send in those nagging your health concerns – and it is for identity. Give us a pseudo, it’s fine! to worry about revealing your true

Doctor deal with it. You don’t have

Dear Sun Doc

In a couple, is it possible for one person to be HIV positive and the other one negative? If yes, what is the science behind it? Val

Dear Val,

There are people who have repeated sexual intercours­e with HIV positive partners while remaining negative. This is called HIV discordanc­e, and the reason for this is not well understood. In rare circumstan­ces, this is due to HIV resistance in the negative partner. However, with each sexual encounter, there is still a risk of contractin­g HIV. This risk increases if you have a sexually transmitte­d disease, or if your partner has a high viral load because they are not taking their medication properly. The risk decreases if your partner is taking anti-retroviral medication correctly, if you are using pre-exposure prophylaxi­s (medication to prevent HIV) or if you are using condoms correctly and consistent­ly. It is not advisable to expose yourself knowingly and repeatedly, because if you get infected during one encounter, the HIV infection will remain for the rest of your life.

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