geoffrey modest medical blogs

A recent modeling study suggested that the current Covid-19 pandemic will be minimally affected by changes in seasons, or climate drivers (see    https://science.sciencemag.org/content/early/2020/05/15/science.abc2535/tab-pdf  ,  covid climate role science2020  in dropbox, or 10.1126/science.abc2535 )   Details: -- increased specific humidity (the mass of water vapor in a unit mass of moist air) does decrease the transmissibility of influenza and respiratory syncytial virus (RSV), affecting their seasonality and the increased transmission/epidemics in the cool dry winters in northern latitudes -- this is not true for all viruses: for example, enteroviruses often peak in summer months -- emerging pathogens, on the other hand, have dynamics more driven by high population susceptibility and their intrinsic transmissibility (R 0  value) -- we do not know the climate susceptibility of the SARS-CoV-2 virus, so the researchers looked at 2 common Coronaviruses...

The CDC just published their recommendations for the 2019-20 flu vaccine (see   https://www.cdc.gov/mmwr/volumes/68/rr/rr6803a1.htm?s_cid=rr6803a1_w%20CDC%20Offers%20Vaccine%20Recommendations%20for%202019%E2%80%9320%20Flu%20Season  ) Details: -- flu vaccine is recommended for all persons >6 mo old --trivalent influenza vaccines:  hemagglutinin s (HA) derived from an A/Brisbane/02/2018 (H1N1)pdm09–like virus, an A/Kansas/14/2017 (H3N2)–like virus, and a B/Colorado/06/2017–like virus (Victoria lineage) --quadrivalent influenza vaccines: as with trivalent but additional hemagglutinin derived from influenza B vaccine virus, a B/Phuket/3073/2013–like virus (Yamagata lineage) --flu vaccines do work, though somewhat variably from season to season (some vaccines have better actual virus matches than others). But overall, the CDC estimates that from 2010-11 through 2015-6, the vaccine prevented per season:     --1.6-6.8 million illnesses   ...

The recent CDC estimate is that 80,000 Americans died from the flu last year. This is way above the usual 12,000 to 56,000, and is the single highest toll in the past 4 decades, per the CDC (see  https://apnews.com/818b5360eb7d472480ebde13da5c72b5 ); [they do not have exact counts on the numbers of deaths, just statistical models]. a few points: --CDC reports of the last year flu epidemic (see  https://www.cdc.gov/flu/about/season/flu-season-2017-2018.htm ):     --the increase in morbidity and mortality was general: more kids died (180, the highest number ever), 80% in kids who were not immunized; and hospitalizations were the highest ever (58% of them in those >65yo)     --last year, the vaccine did not work so well (estimated overall effectiveness of 40%, though the flu vaccine was a good match for the majority of flu viruses that season )     --and, in terms of viral suscept...

Given the upcoming flu season and the current availability of flu vaccines, i have decided to re-send this blog from 8/17/17, suggesting that we wait to immunize. The issue in Boston is that if the patient is seen regularly and could reliably get the vaccine later in the season, there really is no great rush: the flu season does typically give us ample warning: begins overseas, then comes to southern US and makes its way north (and the vaccine does work within 2 weeks). though the onus is on us to make sure that the vaccine is given....  geoff From:  Geoff A. Modest, M.D. Sent:  Thursday, August 17, 2017 7:35 AM To:  Geoff A. Modest, M.D. Subject:  should we delay giving flu vaccine?? There are several studies finding that influenza vaccine effectiveness may wane over time, suggesting that it might be better to delay vaccination to closer to the onset of the influenza outbreak. A new study looked at the effectiveness of vaccines from the 20...

​(second of 2 blogs) a recent study found that influenza virus could spread just by exhaled breath (see  doi: 10.1073/pnas.1716561115  )​. Details: --355 symptomatic volunteers  with  acute respiratory illness in a college community, with 142 of 178 confirmed influenza infections in patients --in those with complete data: 50% male, 22% flu vaccination in current year, 15% vaccinated in current plus past year, asthma in 21%, 15% smokers, mean age 20, BMI 22.7, median coughs/30 min= 18, no sneezes, 8% systemic symptoms, 3% lower  resp  tract and 7% upper  resp  tract  sx --218 paired nasopharyngeal (NP) samples as well as 30-minute breath samples on days 1-3 after symptom onset, with the breath samples divided into coarse (>5  m m) vs fine (<=5  m m) particles Results: --infectious influenza virus was recoverable from:     --89% of the NP swabs, with 8.2x10 8 ...

​​ There have been several interesting studies recently on influenza, so will divide them into 2 days' worth of blogs. This flu season has been a pretty bad one, peaking earlier than usual, with widespread flu activity pretty much throughout the US, some novel strains of influenza A discovered, 37 pediatric deaths so far, and the proportion of deaths attributed to pneumonia and influenza increasing sharply to 9.1% in the week ending 1/6/18 (see  https://www.cdc.gov/flu/weekly/summary.htm ​ ) A recent Spanish case-control study found that older adults getting repeated flu vaccine had half as much severe influenza as compared to  nonsevere  infections (see  Casado  I. CMAJ 2018 January 8;190:E3-12)   Details: --130 with severe and 598 with  nonsevere  flu  admitted to 20 Spanish hospitals during the 2013/14 and 2014/15 influenza seasons  were matched with 333 and 1493 controls, re...