Drowning in Coronavirus Research, Part 87

For those of us who suspect that CV-19 was around earlier than is believed, this study from a prominent Los Angeles medical center provides some support for that view.  (JMIR Article)   The authors used the center’s large patient base and electronic medical record system to search for patients who presented with cough as a symptom, and compare late 2019/early 2020 with averages from earlier years.  About 200 visits with cough above average were recorded from December 22, 2019 through the end of February 2020.  The authors believe these could have been CV-19 cases.

Nasal viral load can predict outcomes of a CV-19 case, according to this research.  (VL Paper)   Data from 170 Israeli patients who were admitted to a hospital was used.  The viral load, measured by cycle number, was correlated with a number of variables.  Older patients had higher viral loads, as did those who needed ICU and ultimately died.  Blood oxygen level was also associated with viral load.

This paper was a review of the research on outdoor transmission.  (Medrxiv Paper)   The conclusion from the review was that outdoor transmission was rare, but there was more likelihood of transmission in larger groups of people.  Higher temperatures, that might encourage more outdoor activity, were associated with lower transmission in the outdoors.

A lot of discussion lately about vitamin D levels and infection or illness risk, and some research suggesting that higher levels were protective.  This study comes to a different conclusion.  (Medrxiv Paper)   The authors note that there are many confounding variables in regard to any association of vitamin D and CV-19.  They looked at genetic variations that can affect those levels and concluded that when those are taken into account, any beneficial effect of higher levels disappears.  The apparent benefits shown in some studies may be due to association of lower levels of vitamin D with older, frailer people, who are most susceptible to CV-19.  The research around vitamin D is a cautionary tale regarding the importance of repeatable findings, and sophisticated understanding of what factors may cause an apparent relationship to either actually exist or not.

A study from Canada revealed that not only do children generally have milder cases of CV-19 disease, but about half of those who are hospitalized with CV-19 were hospitalized for another reason.  The hospitalization rate for children is about a tenth of the rate for other ages.  (Can. Story) 

In this article, researchers compared New York City and Los Angeles to understand factors which may account for epidemic course.   (City Article)   The unit of analysis was zip codes and smaller suburban entities.  Population density emerged as a particular strong association with more cases and deaths.  This is very logical, given that more density probably means more contacts.  Lower household income and more persons per household had the strongest relationships.  Those two variables are likely inter-related, and given the amount of transmission that occurs at home, also make sense.

And not surprisingly, many of those with severe illness or who die are quite frail.  (Lancet Study)   The study comes from Italy, and found that half the hospitalized patients were classified as frail.