All You Need To Know About COVID-19 Airborne Disease

KEY OBSERVATIONS

• A study published in Nature had earlier found airborne coronavirus in a patient’s breath.
• A couple of more studies found airborne transmission of the virus during breathing and speaking.
• A new study posted on July 2 in preprint server MedRxiv has again found virus spread while breathing.
• The study adds to the existing body of evidence that suggests airborne transmission of the virus can play a role in virus spread.

WHO REMARKS

• On July 9, WHO acknowledged that coronavirus can be airborne in closed settings that lack good ventilation.
• It can spread from one person to another in such settings on prolonged exposure.

AIRBORNE TRANSMISSION

• EXHALING RATES : The study found that COVID-19 patients exhaled coronavirus into the air at an estimated rate of 1,000-1,00,000 RNA copies/minute.
• VIRUS LEVELS : The authors write that the virus levels in exhaled breath could reach 1,00,000 to 1,00,00,000 copies per metre cube at an average breathing rate of 12 litres per minute.

KEY INFLUENCES

• EMISSION RATES : The emission rate of the virus was found to be influenced by a few factors such as disease stage, patient activity and, possibly, age.
• HIGHEST VIRAL LOAD : They found that the SARS-CoV-2 breath emission rate into the air was the highest, up to 1,00,000 viruses per minute, during the earlier stages of COVID-19.

STUDYING THE VIRUS

• IN AIR : In these five patients, the emission rate in exhaled breath was 1,000-100,000 RNA copies/minute.
• HANDS : While the hands of all the five patients did not have any virus.
• PHONES : Two of 22 phone samples tested positive.
• TOILET PITS : The toilet pit surface tested positive for virus in the case of one patient.
• FLOOR : In all, 242 surface swab samples were collected and 13 tested positive for the virus.

THE VIRUS WAS FOUND ON FIVE CATEGORIES OF SURFACES —

1. Toilet pits (16.7%, n = 12),
2. Hospital floor (12.5%, n = 16),
3. Other surfaces (7.4%, n = 27),
4. Patient-touching surfaces (4.0%, n = 149), and
5. Medical-touching surfaces (2.6%, n = 38).

LOW PROBABILITY

• VIRUS ENTRY ROUTES : Large respiratory droplets and direct contact with contaminated surfaces are currently considered dominant routes of virus spread.
• LOW RISKS : But the present study has found that frequently touched surfaces like mobile phones have very low probability of virus presence.