The pandemic of COVID-19 continues to expand and impact over 213 countries and territories. The novel coronavirus disease has globally, as of 3:13 pm CEST, 22 September 2020, resulted in 31,174,627 confirmed cases, including 962,613 deaths, as reported to the World Health Organization. In terms of region, the Americas is leading the chart with 15,665,730 confirmed cases, followed by South-East Asia (6,250,751) and Europe (5,274,791) (as of 22 September 20203:13 pm CEST). The Centers of Disease Control and Prevention (CDC) had previously said that Covid-19 spread mainly between people in close contact -- about 6 feet when an infected person coughs, sneezes or talks, thereby passing respiratory droplets.
Now, CDC, in its latest statement on September 18, 2020, has acknowledged the spread of the virus through the air. The updated guidelines on CDC website highlight the spread of the novel coronavirus through respiratory droplets or small particles, such as those in aerosols, which are produced even when a person breathes. The particles are produced when an infected person coughs, sneezes, sings, talks or breathes and inhaling these particles into the nose, mouth, airways, and lungs can cause Covid-19. The guidelines highlighted that indoor environments without good ventilation can increase the spread of the virus.
Earlier, the CDC, in its investigation of around 1,600 cases of air travelers, reported identifying around 11,000 people who were potentially exposed to Covid-19 while flying. On March 31, 2020, the CDC under strict infection control procedures by the Korea Centers for Disease Control and Prevention, enrolled in its study 310 passengers who boarded an evacuation flight from Milan, Italy, to South Korea. The study reported asymptomatic transmission of the novel coronavirus on evacuation flight.
The CDC has also announced new guidelines regarding social distancing, stating to stay at least 6 feet away from others, whenever possible. The guideline differs from the previous version that required maintaining "good social distance" of about 6 feet. The CDC has also advised against commuting when sick and asked to wear a mask and routinely clean and disinfect. The CDC’s earlier version of defining asymptomatic transmission stated "some people without symptoms may be able to spread the virus". However, the updated version states "people who are infected but do not show symptoms can spread the virus to others."
Earlier, in July 2020, researchers from Queensland University of Technology, Australia, in its appeal, published in Clinical Infectious Diseases, to the medical community and to the relevant national and international bodies, reported that microdroplets of the novel coronavirus released during exhalation, talking, and coughing can remain aloft in air. The researchers asked international bodies to recognize the potential for airborne spread of Covid-19 at distances beyond 1–2 m from an infected individual. The appeal led the World Health Organization to release a new scientific report detailing the person to person transmission of the novel coronavirus, which included through the air during certain medical procedures. The change in the language from CDC has been praised by the scientific community.
