Covid-19: How the coronavirus that causes it spreads


  • Wellness
  • Tuesday, 26 May 2020

A crowd is seen at a roadside stall near the Ayer Itam market in Penang on May 8 in this filepic. It is estimated that four out of five people who have Covid-19 may only have mild or no symptoms, which may result in them infecting other people unknowingly.

There is much that is known, but much more that is unknown about the SARS-CoV-2 virus, which causes Covid-19.

But we do know that this virus spreads easily.

From 44 cases reported in China on Jan 4 (2020), it spread globally to more than one million cases on April 4 (2020), two million on April 17 (2020), three million on April 29 (2020) and four million on May 11 (2020), according to the World Health Organization’s (WHO) Situation Reports.

Anyone can get infected.

About four out of five infected people have mild or no symptoms, and they can infect others without knowing it.

Staying on surfaces

The SARS-CoV-2 virus is spread primarily by close contact and respiratory droplets, with possible airborne transmission in instances where aerosols are formed.

There is as yet inconclusive linkage between fomites, i.e. objects or materials, to the spread of the virus.

However, the demonstration of SARS-CoV-2 contamination of surfaces in both healthcare and non-

healthcare settings have informed guidelines to mitigate potential fomite spread of the virus in these settings.

An article in the journal The Lancet reported that the virus was viable:

  • Up to one day on cloth and wood.
  • Up to two days on glass.
  • Four days on stainless steel and plastic.
  • Up to seven days on the surface of a medical face mask.

Meanwhile, a New England Journal of Medicine article reported that the virus was viable:

  • Up to four hours on copper.
  • 24 hours on cardboard.
  • Up to 72 hours on plastic and stainless steel.

An Emerging Infectious Disease journal article from China concluded that: “Contamination was greater in intensive care units than general wards.

“Virus was widely distributed on floors, computer mice, trash cans and sickbed handrails, and was detected in air about 4m from patients.”

Infected unconsciously

A shop assistant counts cash in the register at a supermarket in this filepic. We should wash our hands with soap and water after handling money as it may be contaminated with the SARS-CoV-2 virus.A shop assistant counts cash in the register at a supermarket in this filepic. We should wash our hands with soap and water after handling money as it may be contaminated with the SARS-CoV-2 virus.

There are various ways that one can contract the SARS-CoV-2 virus without realising it.

Some examples from daily life are described below, but they are not exhaustive.

The safest place is in the home, especially for senior citizens and those with health conditions like diabetes, high blood pressure (hypertension), heart disease and cancer.

Leaving home increases the chances of contracting the virus.

When an infected person coughs, sneezes or speaks loudly for some time, the virus is transferred into the air or onto a surface.

When one breathes in this air or touches the contaminated surface, one can get infected.

It is important to remember that on every occasion that one is in contact with another person, one is exposed to all the other contacts of that person.

There are various environmental surfaces in healthcare and non-healthcare settings that can be contaminated.

The chances of a surface being contaminated is higher in healthcare settings, especially when the surfaces are touched by many people.

These include furniture, counter tops, lift and ATM buttons, handrails, sinks, toilets, walls, surfaces of electronic devices, switches, wheelchairs, blood pressure cuffs and other non-critical medical equipment.

The virus can also be transferred to the surface of a fixed or mobile telephone, or work computer, particularly if shared.

Social distancing, which is staying 1-2m away from another person, is intended to reduce the chances of contracting the virus.

One of the more likely places to contract the virus is on public transportation, which is usually crowded, making it difficult to comply with social distancing.

Other places include markets, grocery shops and petrol kiosks.

One can contract the virus from touching contaminated surfaces, or even breathing the air shared by numerous people.

When ordering food to take away or deliveries to the home, the virus can be contracted through the surface of the packaging and/or interaction with those delivering it.

It is important to always remember that anything that one touches, which others also touch, is a means for viral spread.

Prevention is best

The movement control order (MCO) is a rudimentary instrument that cannot eliminate the SARS-CoV-2 virus by itself.

What the MCO does is to suppress the rate of increase of the number of cases so that the country can buy time to prepare and increase the health system’s capacity in order to deal with the threat posed by the virus.Research found that the SARS-CoV-2 virus can remain on clothes for as long as a day. — TNSResearch found that the SARS-CoV-2 virus can remain on clothes for as long as a day. — TNS

The virus will continue to afflict humans until such time a vaccination is available, which is estimated to take at least 18 to 24 months.

Until then, everyone has to always protect oneself and others from viral spread by:

  • Regular and frequent handwashing with soap and water for at least 20-30 seconds.

    The hands should be washed after blowing the nose, coughing or sneezing; after touching surfaces outside the home, including money; after visiting a public place; after using public transportation; before and after eating; after using the toilet; after handling garbage or touching pets and animals; after changing diapers or helping children use the toilet; when the hands are obviously dirty; and before, during and after caring for a sick person.

  • Alternatively, a hand sanitiser containing at least 60% alcohol can be used if the hands are not obviously dirty.
  • Avoid touching the eyes, nose or mouth, as contaminated hands can transfer the virus to these sites from which it enters the body.

    Touch the eyes, nose or mouth only after the hands have been washed with soap and water.

  • Adhere to good respiratory etiquette by covering the mouth and nose with a bent elbow or tissue when coughing or sneezing.

    The used tissue should be thrown away immediately and the hands washed.

  • Ensure that the people around you adhere to good respiratory etiquette.
  • Use a face mask when outside the home.
  • Don’t allow the use of disposable gloves to lull you into complacency.

    Gloves should be used for to touch one surface only and thrown away after a single use.

    Otherwise, they could be a transmitter of the virus.

    Never touch the eyes, nose or mouth with gloves that have been used.

  • Maintain at least 2m between yourself and others.
  • Avoid crowded and/or enclosed places, like lifts, queues etc.
  • Stay at home when you have minor symptoms like cough, mild fever or headache until you recover; and arrange for someone to bring you daily necessities.

    If you need to leave home, wear a face mask to avoid infecting others.

  • If there is fever, cough, difficulty breathing or minor symptoms still present after a few days, seek immediate medical attention.

    Call the healthcare facility you wish to go to in advance so that directions can be given to the right place rapidly.

    This will not only be protective, but also help prevent spread of any infection.

  • Keep updated on the latest information from trusted sources.

Take care and stay safe.

Dr Milton Lum is a past president of the Federation of Private Medical Practitioners Associations and the Malaysian Medical Association. For more information, email starhealth@thestar.com.my. The views expressed do not represent that of organisations that the writer is associated with. The information provided is for educational and communication purposes only and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.

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