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Shield your face: Air particles could have droplets of the virus

Wednesday April 1 2020


A group of nurses wearing protective mask and gear pose for a group photo prior to their night shift on March 13, 2020 at the Cremona hospital, southeast of Milan, Italy. PHOTO | PAOLO MIRANDA | AFP 

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A World Health Organization (WHO) warning to health workers that proximity could lead to transmission through the air has led to curiosity among researchers that the virus could be airborne, making social distancing and wearing of masks a critical way to keep safe.

Whereas the health agency insisted the virus that causes the highly contagious Covid-19 disease is not airborne, it issued a warning to medical staff that the virus is likely to remain airborne in some places around health facilities.

Local respiratory infection experts declined to give a clear answer on whether or not the virus is spread through particles suspended in the air, but researchers in Japan through simulations have demonstrated that the virus could be suspended in the air for minutes causing risk of infection through breathing.


Dr Jeremiah Chakaya told the Nation: “Any time someone has a disease that affects the lungs, there is a possibility that when they speak, sneeze or cough, they will release large and small droplets in the air.”

His observation corroborates a simulation involving laser monitoring of air particles as minute as 0.1 micrometres from researchers from Toho University in Japan which showed that, while larger droplets from a person’s sneeze fall to the floor, lighter ones remain suspended for as long as 10 minutes.


The simulations showed that, in a room that is poorly ventilated and with more than three people, the spread could be much faster.

The researchers demonstrated that, apart from sneezing or coughing, even talking could discharge these micro particles.

Dr Chakaya explained: “The larger droplets drop to the ground or on surfaces while the smaller droplets can stay longer in the air.”

If the droplets containing the virus are released into the air, they are suspended to make a cloud that can infect anyone who inhales it.

Two weeks ago in live-streamed pressers, Dr Maria Van Kerkhove who is the head of WHO’s emerging diseases and zoonosis unit, said that Covid-19 spreads through human-to-human contact or through droplets carried through sneezing.

The WHO’s guidelines also say that the virus can be left on inanimate objects.


The Ministry of Health now recommends aggressive washing of hands, social distancing and wearing of face masks. People have also been advised against touching their faces.

However, some scientists have rejected this view. Speaking to American-based National Public Radio (NPR), Dr Donald Milton, an infectious disease aerobiologist expert at the University of Maryland's School of Public Health, said that very little is known of the virus and criticised the WHO for “being irresponsible in giving out that information”.

A Kenyan scientist who requested not to speak on record as they have not been cleared to speak to the press said that this is one of the reasons why the global health body may have shied away from declaring the disease as airborne.

This would mean that the provision of masks for everyone, and in the light of a shortage of supplies even for front-line health workers, the WHO did not want to put pressure on resource-starved countries like Kenya.

This raises questions on how much exposure healthcare workers in Mbagathi Hospital face, and the fact they are allowed to go back to their families as some use public service vehicles.

Another study from Nebraska Medicine in the United States found that there was high levels of the virus contamination by PCR on commonly used surfaces and in the air of rooms of Covid-19 patients.

In a presser on their website, the university wrote: “Covid-19 patients, even those who are only mildly ill, may create aerosols of virus and contaminate surfaces that may pose a risk for transmission.”
The negative pressure in the patient rooms creates air flow into the room in order to better isolate patients.

The study suggested that, apart from extra care taken for healthcare workers, isolation rooms should use “negative air pressure rooms for these patients whenever possible and being mindful about the method of entering and exiting these rooms”.

Prof Joshua Santarpia, an associate professor of pathology and microbiology at University of Nebraska Medical Center told Nation: “The negative pressure in the patient rooms creates air flow into the room in order to better isolate patients.”

The isolation centre at Mbagathi Hospital is not designed to have this pressure.

The study also noted that toilet facilities had evidence of the virus and that sharing such facilities could lead to infection.