A lady dwelling in a high-rise condo in the Lal Bahadur Shastri Nagar space of Bengaluru developed fever, headache and physique ache final week. She has been homebound for many of the second wave of Covid-19 pandemic. She had not stepped out for the final 10-12 days. The fever got here quickly after Cyclone Tauktae battered coastal areas of Karnataka and swung climate in Bengaluru.
Among many questions to verify the possible causes of her sickness, she needed to know whether or not vertical transmission — spread of an infection from one floor to other — of Covid-19 was doable. A household above her floor had Covid-19 optimistic affected person(s).
This query has been a topic of curiosity for researchers for the reason that days of the SARS outbreak in 2002. This study found that SARS transmission between flats on completely different flooring was “a fact”.
The research stated, “One of the concerns is that there may be multiple transmission routes across households in high-rise residential buildings, one of which is the natural ventilative airflow through open windows between flats, caused by buoyancy effects.”
“Our early on-site measurement using tracer gases confirmed qualitatively and quantitatively that the re-entry of the exhaust-polluted air from the window of the lower floor into the adjacent upper floor is a fact.”
A study published in December 2020 in the context of SARS-CoV-2 — the virus behind the Covid-19 pandemic — discovered outcomes “consistent with the vertical spread of virus-laden aerosols” between “aligned flats connected by drainage pipes in the master bathrooms”.
This research was performed to verify Covid-19 sources in three households dwelling in China. They contracted Covid-19 between January 26 and February 13 final 12 months.
One of the households had returned from Wuhan, the epicentre of coronavirus outbreak from the place it spread to remainder of the world. The researchers established that there was no contact between the three households that would have led to transmission of SARS-CoV-2.
The researchers examined the elevator route of transmission and stated, “No evidence was found for transmission via the elevator or elsewhere.”
“The families lived in 3 vertically aligned flats connected by drainage pipes in the master bathrooms. Both the observed infections and the locations of positive environmental samples are consistent with the vertical spread of virus-laden aerosols via these stacks and vents,” they stated.
This paper examining scientific literature on the possibility of Covid-19 outbreak in high-rise buildings authenticates the likelihood of the vertical transmission of SARS-CoV-2.
It lists out defective air flow techniques, air leakage or unintentional air flows and defective plumbing stacks because the doable technique of the spread of Covid-19 in multi-unit residential buildings. This paper lays nice emphasis on air flow techniques.
However, some other studies include those conducted in the famous example of a Chinese restaurant the place 9 individuals received contaminated with SARS-CoV-2 in January 2020. The air conditioner was blamed for the infectious spread. But in the identical instance 79 other diners didn’t catch the an infection.
This signifies that whereas defective plumbing, staircases and elevators generally is a transmission route of SARS-CoV-2, the HVAC (heating, air flow, and air-con) techniques haven’t been discovered to be a Covid-19 spreader between flats in high-buildings.
To reply the unique query on the idea of research performed for the reason that coronavirus outbreak, sure, vertical transmission of Covid-19 from one flat to one other in a high-rise constructing is feasible.
Though precise the explanations for such SARS-CoV-2 an infection sample usually are not clearly established the Brihanmumbai Municipal Corporation (BMC) in March stated 90 per cent of all Covid-19 circumstances in the earlier two months got here from high-rise buildings in Mumbai.