Day 95: More Retroactive Cases and Vaccines

The news has picked up on the 42-year-old Algerian man in Paris who was in the ICU on December 27th for what turned out to be COVID-19, a month before France's first two official cases (ex Wuhan) on January 24th. The patient, a fishmonger with pre-existing conditions, had not travelled since an August trip to Algeria, but tested positive on retroactive testing of stored samples and so is considered an instance of early community spread. He also had a child who suffered from an influenza-like illness (ILI) before he himself fell ill. Some news outlets have since reported that the man's wife worked with Chinese people at a supermarket near the airport.

A pre-proof of the associated paper is available at ScienceDirect: SARS-COV-2 was already spreading in France in late December 2019, in the International Journal of Antimicrobial Agents. Perhaps the most interesting thing about the paper is that the authors were not hunting very hard for cases; they were merely associated with a hospital in the north of Paris which routinely preserves respiratory samples. They restricted their testing to their own ICU patients between December 2nd and January 16th, for whom the medical record included both ILI and ground glass opacity on a lung scan, and a negative result for other infectious disease (flu, other coronaviruses, etc.). The paper was not clear on what the hospital routinely tests for.

This exclusion process left them with only 14 samples, of which only one tested positive (twice). They conclude that their restricted sample (especially the exclusion of all other infection, as co-infection with the flu and COVID-19 has been documented in China), and the possibility of false negatives (due to the test itself or damage to the samples in cold storage) may explain finding only one case when that case was clearly of community spread.

On the vaccine front, another group has made the MMR connection PlagueBlogged back on Day 71. Though it's a rather sketchy "report" from "World Organization", the anecdotes (PlagueBlog hesitates to call anything within "statistics") are interesting. They note that the US Navy routinely administers MRCV (an unspecified measles and rubella-containing vaccine chosen out of the options of MR, MMR, and MMRV, which contains chickenpox vaccine) to new sailors, possibly explaining the low death rate aboard navy plague ships. Besides their anecdotal evidence for several countries, they do provide some references for the MRCV coverage rates noted in their anecdotes, as well as citing the paper from last month [PDF]. An enterprising person might actually analyze the data and write an actual paper about it.

Without any statistics it's hard to make any falsifiable claims, yet they do get some things wrong. One of them is the likelihood of people over 60 having been vaccinated, a topic on which they are technically correct because of undue focus on MRCV (which includes a measles vaccine), but quite wrong when arguing the efficacy of rubella vaccine as they seem to be doing. Non-immune women of childbearing age have gotten vaccinated since the introduction of rubella vaccine in 1969; in fact the risk of birth defects from rubella (as vividly demonstrated by rubella epidemics in the 60's) was the main impetus behind the creation of the vaccine. Needless to say, many of those women are well over 60 now.

They're also doing a titer study of COVID-19 survivors; you can sign up online. Considering their general methodology it may never get published, but you can apparently get your titers back from them.

The case count in Massachusetts is up 1.7% today. In Middlesex County it is up only 1.4%. PlagueBlog advises Somerville residents not to listen to lies from the city about the governor's face mask requirement; as reported in all honest sources, Governor Baker has only required face masks outdoors and in other unspecified public places in cases where you cannot maintain social distancing. The specific requirements are also unchanged and involve only stores and shared or public transit. PlagueBlog also notes that this is the last day of the grace period on the $300 fines, and recommends you breathe free one last time.