First up, a study on masks, from Nature Medicine. (NM Study) This is the kind of real-life research that creates useful information. The researchers tried to ascertain the extent of seasonal coronaviruses, influenza viruses and rhinoviruses in exhaled breath and coughs in people wearing surgical masks as opposed to those not wearing a mask. 246 people were tested. 122 were randomized to wearing a surgical face mask and 124 to not wearing one. 49 of the people volunteered to breathe with the alternate situation from that they started with, and thus were tested with and without a mask. The researchers looked at both droplets and aerosols, since both may play a role in transmission. They were examining seasonal coronavirus, influenza virus and rhinovirus. 123 of the subjects were infected with some virus, 17 with coronavirus, 43 with influenza virus, and 54 with rhinovirus. One of the subset with coronavirus, influenza or rhinovirus was co-infected, so there were 111 people in the group with these three viruses, and these subjects breathed for 30 minutes and their coughs were measured during that period as well. Coronavirus-infected people coughed the most, an average of 17 times during the 30 minutes. Viral shedding was tested in nasal swabs, throat swabs and in droplets and aerosols. Viral shedding was higher in nasal swabs. Viral RNA was collected from 30% of droplets and 40% of aerosols captured from that subset of persons with seasonal coronavirus infection when not wearing a mask. It was also present in droplets and aerosols from person with influenza and rhinovirus infections, in somewhat varying percentages. Among infected persons, coronavirus was present in 3 of 10 droplet samples and 4 of 10 aerosol samples from people not wearing a face mask but not in any samples from those who wore a face mask. The masks were less efficacious at preventing the presence of droplets and aerosols with influenza or rhinovirus particles. Assuming coronavirus is larger than the particle size which can be detected by the equipment used, the study indicates that masks are effective at preventing expulsion of virus through breathing or coughing. It is interesting, however, that the majority of infected persons, 13 out of 20, had no virus detected even without a face mask. And the viral load for those who were shedding coronavirus was low. The authors noted that this suggested that “prolonged close contact would be required for transmission to occur, even if transmission was primarily via aerosols”. And they said the results suggested substantial variability among individuals in regard to their contagiousness.
Netherlands, which has had a lot of cases, has sent children back to school and is keeping them there and this statement explains why. (NL Statement) Children up to age 17 are 20.7% of the population and represent only .9% of cases, .6% of hospitalizations and no deaths. Workers in the schools and day care centers are testing positive at a lower rate than the general population. There has been no increase in cases among children since the schools reopened. In a study of 693 paired infections, most occurred between people of the same age and very few occurred among children. Among ten children who were infected, there were 43 close contacts and none became infected. Looking at 54 families, in not one was a child under the age of 12 the source of infection. And so on. I don’t how much more information people need to see before coming to the conclusion that children should resume all normal activities.
Almost half the people in an Austrian ski village were found to have antibodies (Austrian Article). 79% of the population was tested and 42% had antibodies. The rate for people under 18 was only 27%, indicating again that children are just not as likely to get infected.
Here is a somewhat interesting paper on co-infection by other viruses. (Medrxiv Paper) Among 3348 residents of nursing homes and assisted living facilities in 22 states, with an average age of 77, 42% tested positive for the coronavirus. Of this group, 77% were co-infected with a bacteria and 48% with another virus. Residents with this coronavirus were somewhat more likely to have some co-infection. Among the Covid-19 cases, 56% had staph bacteria, 40% had pneumonia, and 27% had herpes 6 virus. The high rate of co-infection both indicates how susceptible these people are and helps explain why they tend to have serious illnesses.