Just pure research summaries today.
I am going to start as I usually do with a story explaining the outrage I feel over the abuse and killing of children caused by the pandemic response. Now that we have an administration more to its liking, even the New York Times has discovered that we are literally ruining the lives of and killing children by keeping schools closed and limiting their social and athletic opportunities. (NYT Story) The story deals specifically with suicides in Las Vegas among students and the role these tragedies have played in finally getting officials to reopen schools. 18 children committed suicide, one only 9 years old. That is far, far more than would ever die from CV-19 in Las Vegas. These are young people that we supposedly care so much about. I will say again, I would trade every old person who dies from CV-19 for that 9 year old’s life. The story is the same everywhere. I literally want leaders of teachers unions and school boards and any other political leader who has supported closed schools to be tried, fined and imprisoned. This conduct was inexcusable and unjustified by any rational consideration of the risks.
An interesting paper on the physical dynamics of potential spread via aerosols. (Royal Soc. Paper) The researchers were exploring the nature and composition of exhaled droplets and aerosols and the likely viral load associated with those exhalations. An exhalation typically consists of a variety of droplet sizes. The larger ones tend to drop rapidly, the smaller ones can “float” for some time. Obviously larger droplets are likely to carry larger virus loads. Understanding the fate and trajectory of exhalations is very complex, depending on the composition of the exhalation, the environmental conditions where the exhalation occurs, such as airflow, humidity and temperature, and on other factors. This research suggested that many components of an exhalation can travel an extended distance and are of a size sufficient to carry many virus particles. A very detailed and complex paper, but gives a lot of the factors which need to be considered in understanding potential spread of the virus.
Research on the effect of various climatic and geographic factors on virus spread continues. (Nature Article) There is a clear geographical/seasonal pattern; the question is why. According to this paper it is almost exclusively latitudinal, which would suggest variations in the intensity and amount of sunlight, which in turn likely impacts temperature and potentially humidity, and also may effect various human factors, such as vitamin D levels and behaviors in terms of indoor/outdoor time, as well as effecting the virus itself, which does not appear to do well in ultraviolet light. The authors looked at the experience this fall of 18 European countries at varying latitudes. In addition to latitude, they examined correlations with temperature and humidity on cases two weeks later. According to the researchers, when the daily ultraviolet light amount drops below 34% of the amount experienced at the equator, cases tend to begin rising. They found almost no correlation between temperature and humidity, but a very strong effect of latitude. Case charts in the US suggest some similar effect. They attribute the effect to both rising declining vitamin D levels and inactivation of the virus by UV light. I would lean much more to the latter explanation. The authors believe it is largely vitamin D.
And as a sort of follow up to the above paper, this one looked at the effect of temperature on the stability of specific proteins in the CV-19 genome. (Medrxiv Paper) The authors looked at molecules in the receptor binding and strutural protein segments and modeled the effects of changing temperature on the durability of the molecules. They found that these were quite temperature stable, which they said indicated that the virus likely could survive in a wide variety of temperatures. So effects of temperature and humidity on the virus itself may not be a significant factor in explaining seasonal variation.
I have wondered about the ability of the virus to survive in the general environment in ways we don’t understand. This study looks at the role of particulate matter in the air. (Medrxiv Paper) The study comes from Turkey and air was sampled a number of times around the country and particles examined for the presence of CV-19. Positive results were found on about 10% of the samples. It was unclear, however, whether this represented actual viable, i.e., capable of replication, virus. Not sure why they didn’t culture the samples.
This study covered factors related to household transmission. (Lancet Article) The study comes from China and involved over 27,000 households. Secondary transmission occurred in only about 16% of the households. The elderly were more at risk, and children less at risk of secondary transmission. Asymptomatic cases were much less likely to transmit than symptomatic ones, at only one-fifth the rate, although the symptomatic ones appeared to transmit more often in the period before symptoms developed. The article found less transmission among those over 60, probably due to lower contact rates even within a household, and higher among some children, although this may be confounded by more contacts.
I have expressed before my interest on the effect of advance directives, including do not resuscitate orders, on the supposed death toll from CV-19. Here is a paper with some peripheral bearing on the topic. (Medrxiv Paper) It comes from the UK and covers about 14,000 hospitalized patients. About 30% had some form of do not resuscitate order before admission. The remainder either had no such order or one put in effect after admission. As you might expect, those who already had DNR orders tended to be in much worse health and to experience much higher mortality in the hospital. Notwithstanding the DNR orders, however, they still frequently received intensive care.
Just a quick note on another study of the impact on routine health care. (Medrxiv Paper) People with appendicitis delayed going to the emergency room and ended up more complicated and dangerous cases.