From an apartment with COVID-19 infected people, SARS-CoV-2 was found on surfaces in the unoccupied room upstairs. For example, these viruses were on 65% of surfaces near infected people ( Adenaiye et al.). SARS-CoV-2 could float through aerosols, land on fomite surfaces, and stay there ( Wang C, Prather K, et al.). In a large, multi-wing building, only people in rooms sharing the same ducts were infected, and were probably not infected by other sources ( Hwang et al.).
The large droplets probably did not travel that distance, proving that tiny aerosols probably transmitted the viruses ( Kozlov Kutter et al.).Īerosol transmission in air flowing around corners probably occurred in an apartment building through vertical air ducts connecting bathrooms. But, an experiment showed it could be transmitted through over a meter of air around corners, from infected ferrets to other ferrets. Liu, Ning, et al.).įinding SARS-CoV-2 RNA in the air still did not prove that it was actually transmitted through the air. Scientists also found the RNA in the air outside medical centers, where outpatients and others went, some of whom could be asymptomatic carriers ( Amato-Lourenço et al. Aerosols exhaled by patients float and spread all round a room ( Saw et al.). But the air in critical care unit (CCU), intensive care unit (ICU), ward room, and workstations had no or low concentrations of SARS-CoV-2 RNA, possibly because they exchanged air at high rates or were using negative pressure ventilation ( Liu, Ning et al. Perhaps the patients coughed the viruses into the air, and closed the bathroom door, leaving the tiny aerosol droplets to float for hours. Scientists found the RNA in the air of bathrooms, which patients used only a few minutes at a time. In Wuhan hospitals scientists found SARS-CoV-2 RNA in air samples in many rooms, with different kinds of patients, especially those having little ventilation ( Guo et al.). Even 12-47 days after symptom onset, air samples around patients had SARS-CoV-2 RNA ( Feng B, Xu K, et al.). They could not culture the viruses, perhaps because of low concentrations or long times since viruses were left ( Zhou J, Otter, et al.). In London hospitals, RT-qPCR found SARS-CoV-2 RNA in the air in patients’ room, staff rooms, and a public area. Most aerosols are 4 µm and 1–4 µm, even though none had aerosol-generating procedures or intranasal oxygen supplementation ( Chia et al.). Aerosols 5 seconds, farther than 2 meters distance, and enter a person’s respiratory tract ( Wang C, Prather K, et al.). The larger droplets (>100 μm, microns, micrometers in diameter) usually float less than 2 meters in distance (6 feet) and fall down onto a surface. Cases with higher viral loads were more likely to transmit to secondary cases, with shorter incubation periods in the secondary cases ( Marks et al.).Įxhaling, speaking, sneezing, or coughing spreads saliva droplets of different sizes into the air, that can go in the mouth, nose, or eyes of another person ( Anfinrud et al. But infected people did not infect another person more than 9 days after symptom onset ( Cevik, Tate, et al. SARS-CoV-2 viral load (the number of viruses) peaks at about the fifth day after start of symptoms, lasting on average 17 days.
Tests using viral cultures showed that some patients shed viable viruses for up to 60 days ( Arons et al. Zhang W, Du et al.), showing that saliva or mucous can probably transmit the novel coronavirus. PCR tests found SARS-CoV-2 RNA in saliva samples and oral swabs of patients ( Abasiyanik et al. Those viruses attach to those molecules to enter cells ( Huang N, Pérez, et al. SARS-CoV-2 replicates in the throat ( Wölfel et al.), mouth, tongue, and salivary glands because they have much angiotensin-converting enzyme 2 (ACE2), transmembrane protease serine 2 (TMPRSS2), and furin. Saliva and mucous, and the tissues producing them, are some of the main routes in which SARS-CoV-2 replicates and transmits ( Collins Huang N, Perez, et al.
0 kommentar(er)
