<p>A recent case of a Covid-positive 25-year-old ENT postgraduate student has illustrated that close and sustained indoor proximity to Covid-19 patients will lead to infection despite masking.</p>.<p>Frontline medical personnel have also reiterated the point.</p>.<p><strong>Also Read: <a href="https://www.deccanherald.com/national/contacts-of-covid-patients-dont-need-to-get-tested-unless-they-are-in-at-risk-category-icmr-1070024.html" target="_blank">Contacts of Covid patients don't need to get tested unless they are in 'at risk' category: ICMR</a></strong></p>.<p>The student, found positive at the Bangalore Medical College and Research Institute (BMCRI) last Tuesday, may have contracted the disease after visiting a pub on January 1 and is said to have infected a 30-year-old nurse after a 30- to 40-minute interaction in an office on-campus on Monday, sources said.</p>.<p>The infection happened despite the individuals involved were wearing masks. While the student wore an N-95 mask, the nurse protected herself with a triple-layered surgical mask.</p>.<p>“The postgraduate student did not remove her mask, but the nurse may have done so for a few minutes. This was a closed room. The two people were sitting about six feet apart,” a source said.</p>.<p>The student was found to be positive a day later. She is said to not have had symptoms. The nurse went on to develop a severe sore throat, along with mild fever.</p>.<p>Medical personnel said the nurse had developed symptoms even though she was vaccinated twice with Covishield and had also received a booster dose in the form of Covaxin.</p>.<p><strong>Also Read: <a href="https://www.deccanherald.com/science-and-environment/uk-scientist-says-omicron-maybe-1st-ray-of-light-against-covid-1069548.html" target="_blank">UK scientist says Omicron maybe '1st ray of light' against Covid</a></strong></p>.<p>Dr Saptarshi Basu, Professor of Mechanical Engineering at the Indian Institute of Science (IISc), who has conducted fluid mechanics studies and efficacy of facemasks, noted that a masked person who spends time with a Covid-19 positive patient indoors faces a risk of infection, especially if confronted with Omicron.</p>.<p>“During the second wave, people would get sick if they ingested roughly about 100 virions of the Delta variant. With Omicron, infections can happen with the ingestion of just 20-30 virions. Masks when used in a sustained fashion indoors do not offer fool-proof protection,” Dr Basu said.</p>.<p>He pointed to several factors where a mask may not work — gaps around the nose left by masks in addition to improperly worn masks that expose people to gradually rising concentration of virions in aerosols circulating in indoor air.</p>.<p>“Closed places of any sort are a problem. Air conditioning poses particular hazards as 90% of the airflow is recycled air,” he said.</p>.<p>It is not yet known which variant of the virus the two positive cases were infected by.</p>.<p><strong>Watch the latest DH Videos here:</strong></p>
<p>A recent case of a Covid-positive 25-year-old ENT postgraduate student has illustrated that close and sustained indoor proximity to Covid-19 patients will lead to infection despite masking.</p>.<p>Frontline medical personnel have also reiterated the point.</p>.<p><strong>Also Read: <a href="https://www.deccanherald.com/national/contacts-of-covid-patients-dont-need-to-get-tested-unless-they-are-in-at-risk-category-icmr-1070024.html" target="_blank">Contacts of Covid patients don't need to get tested unless they are in 'at risk' category: ICMR</a></strong></p>.<p>The student, found positive at the Bangalore Medical College and Research Institute (BMCRI) last Tuesday, may have contracted the disease after visiting a pub on January 1 and is said to have infected a 30-year-old nurse after a 30- to 40-minute interaction in an office on-campus on Monday, sources said.</p>.<p>The infection happened despite the individuals involved were wearing masks. While the student wore an N-95 mask, the nurse protected herself with a triple-layered surgical mask.</p>.<p>“The postgraduate student did not remove her mask, but the nurse may have done so for a few minutes. This was a closed room. The two people were sitting about six feet apart,” a source said.</p>.<p>The student was found to be positive a day later. She is said to not have had symptoms. The nurse went on to develop a severe sore throat, along with mild fever.</p>.<p>Medical personnel said the nurse had developed symptoms even though she was vaccinated twice with Covishield and had also received a booster dose in the form of Covaxin.</p>.<p><strong>Also Read: <a href="https://www.deccanherald.com/science-and-environment/uk-scientist-says-omicron-maybe-1st-ray-of-light-against-covid-1069548.html" target="_blank">UK scientist says Omicron maybe '1st ray of light' against Covid</a></strong></p>.<p>Dr Saptarshi Basu, Professor of Mechanical Engineering at the Indian Institute of Science (IISc), who has conducted fluid mechanics studies and efficacy of facemasks, noted that a masked person who spends time with a Covid-19 positive patient indoors faces a risk of infection, especially if confronted with Omicron.</p>.<p>“During the second wave, people would get sick if they ingested roughly about 100 virions of the Delta variant. With Omicron, infections can happen with the ingestion of just 20-30 virions. Masks when used in a sustained fashion indoors do not offer fool-proof protection,” Dr Basu said.</p>.<p>He pointed to several factors where a mask may not work — gaps around the nose left by masks in addition to improperly worn masks that expose people to gradually rising concentration of virions in aerosols circulating in indoor air.</p>.<p>“Closed places of any sort are a problem. Air conditioning poses particular hazards as 90% of the airflow is recycled air,” he said.</p>.<p>It is not yet known which variant of the virus the two positive cases were infected by.</p>.<p><strong>Watch the latest DH Videos here:</strong></p>