In phase 2, airports are the hotspots

1. As on 19^th March, UAE has only 113 cases.
2. However, 15 people who entered Maharashtra from Dubai have been tested positive.
3. According to them, they were not infected in Dubai, aircraft, Indian Immigration.

Then where did they get the infection from? Is it Dubai airport?

Factors indicating Dubai airport as the culprit:

• One of the largest airports
• Centrally air conditioned
• Transit area for most airlines
• Transit time is usually in hours
• Humid atmosphere.

Cough

• A typical cough begins with a deep breath. It is followed by a compression of air in the lungs. Then, as that air is forced out in a fraction of a second, there is a crackling burst.
• The cough begins with an initial gasp that draws air deep into the lungs. Subsequently, the glottis snaps shut, covering the trachea, or windpipe. The next step is the forceful contraction of the muscles of the chest cage, abdomen, and diaphragm. In normal breathing, these muscles push air gently from the lungs up through the nose and mouth. But when the glottis is closed, the air cannot move out, so tremendous pressure builds up in the air passages. Finally, the glottis swings open and the air rushes out. And it is quite a rush; in a vigorous cough, the air travels out at approximately the speed of sound, creating the barking or whooping noise that we call a cough.
• A cough can be a conscious, voluntary act. On the contrary, it can be an uncontrollable, involuntary reflex. In the latter situation, the entire process is initiated by stimulation of nerves in the larynx ("voice box") and respiratory tract. These nerves can be irritated by various factors including cold air, infections, allergies, chemical agents such as smoke, mechanical factors like dust particles, tumors or normal body fluids such as nasal mucus or stomach acid.
• It is estimated that an average human cough would fill around three-quarters of a two-litter soda bottle with air — air that shoots out of the lungs in a jet several feet long. Coughs also force out thousands of tiny droplets of saliva. About 3,000 droplets are expelled in a single cough, and some of them fly out of the mouth at speeds of up to 50 miles/hour.
• Sneeze: It initiates at the back of the throat and produces even more droplets, as many as 40,000 to 1,00,000. Some of these droplets rocket out at speeds over 100-200 miles/hour. The vast majority of the droplets are < 100 microns across, the width of a human hair. Many of them cannot be seen with the naked eye as they are so tiny.
• If a person is sick, the droplets in a single cough may contain as many as 200 million individual virus particles. The number varies dramatically and changes over the course of an infection as the immune system clears out the virus. A sick person is most infectious as soon as the first symptoms appear and gradually becomes less infectious as his or her immune system clears the virus.

Airports and airplanes as major source of infection

• Airports and airplanes are notoriously germy given the high traffic and turnover. Various hotspots that tend to harbour bacteria are gate bench armrests, self-service check-in screens, water fountain buttons, door handles at airports, tray tables, seats, and handles of lavatories in aircraft. Therefore, it is extremely important to wash your hands after touching these areas.
• Using epidemiological modelling, researchers have shown how handwashing could affect the diffusion of infections across the world. The researchers reported that if 60% of travellers had clean hands, it may slow a global disease by 69%. But if just 30% of travellers kept their hands clean, it could reduce the impact of a disease by 24%.
• Researchers also identified the airports that theoretically could have the most impact in spreading a virus, as they provide direct connections to mega-hub airports, offer in- and out-bound international flights and are located at geographically conjunctive points.
• These include London’s Heathrow, Los Angeles International Airport, John F. Kennedy International Airport in New York, Sydney Airport and Paris-Charles De Gaulle Airport. Dubai airport may also fit into the same. 

In phase 3, hospitals will be the hotspots

• It is difficult to protect not only the patients but also the health care workers, including nurses, respiratory therapists, and those tasked to clean the rooms between patients against the novel coronavirus. Due to testing lags and the proportion of infected people who remain asymptomatic, it is too early to determine the rate of infection among caregivers. Moreover, these factors make infection control difficult. As reported by a doctor, “Although you wear protective gear and do the best you can, you cannot control it.”
• According to the director-general of the WHO, despite health workers’ being the glue that holds the health system and outbreak response together,41% of the Covid-19 cases in Wuhan occurred due to hospital-related transmission. It is noteworthy that health care providers are at a high risk of developing the condition and spreading it. Work stress is believed to weaken their immune systems. In addition, close, intimate care of patients can cause exposure to a higher viral load. Despite performing selfless work, health care workers have faced social stigma during this outbreak.
• The stability of SARS-CoV-2 has been found to be similar to that of SARS-CoV-1 under the experimental circumstances tested. This indicates that differences in the epidemiologic characteristics of these viruses is likely to be due to other factors, such as high viral loads in the upper respiratory tract and the potential for persons infected with SARS-CoV-2 to shed and transmit the virus while being asymptomatic. The investigators have shown that aerosol and fomite transmission of SARS-CoV-2 is plausible, since the virus can remain viable and infectious in aerosols for hours and on surfaces up to days. These results echo those with SARS-CoV-1, in which these modes of transmission were related to nosocomial spread and super-spreading events, and they provide information for pandemic mitigation efforts.

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA