COVID presenting as mild flu

A recent study from Los Angeles found that 5% of people presenting with mild influenza-like illnesses actually had Covid-19 (see covid presenting as mild flu jama2020 in dropbox, or doi:10.1001/jama.2020.4958

Details:

-- 131 patients with mild influenza-like illness presenting to the Los Angeles County  + University of Southern California Medical Center between March 12-16 had nasopharyngeal swabs for influenza and RSV infection

-- these swabs were automatically tested for SARS-CoV-2

-- patients were excluded if they had travel exposure or contact with a traveler, or if they were severely ill patients admitted for respiratory tract infections

Results:

-- 7 of the swabs were positive for SARS-CoV-2 (5.3%)

-- median age of the patients who were positive was 38 years, 3 were male, median duration of symptoms was 4 days

-- 6 of 7 patients had fever, 5 myalgias, and only one had a cough.

-- All patients had mild illnesses, and all tested negative for influenza and RSV

Commentary:

-- one interesting side note: they did look at reported influenza-like illnesses in LA County and found a late 3^rd spike during the weeks before this study, which is quite unusual (none seen in the last 4 years). Of note the percentage of positive influenza tests declined during this 3rd spike, supporting the finding above of a different viral infection, perhaps by SARS-CoV-2 (not clear if they tested for other potential viruses than flu and RSV)

-- it has been well-known from early studies that there are huge viral loads of SARS-CoV-2 virus (1000 times higher than with SARS), and that large viral loads are present on the 1^st days of mild nonspecific symptoms. That is likely the reason that this new virus is so much worse than SARS, even though SARS actually had a higher mortality rate (10%, vs about 2% for SARS-CoV-2); SARS viral infection was associated with more severe cases which were more easily identified and isolated (for the SARS-CoV-2 virology data, see the really interesting small study presented in http://gmodestmedblogs.blogspot.com/2020/03/covid-19-update-31120.html) and just formally published in Nature yesterday (see covid early virologic assessment Nature2020 in dropbox, or doi.org/10.1038/s41586-020-2196-x)

-- the issue here is that any strategy of viral containment requires knowing which patients have the infection in order to contain/isolate them

    -- but, given our (embarrassing) lack of adequate testing, and focusing the testing on those are sicker will therefore miss a large number of patients with the virus, especialy since the symptoms may be so minimal or even nonexistent. So, out approach morphs into the much more difficult strategy of  general mitigation of viral spread through nonmedical means such as social distancing. this mitigation strategy is much harder to achieve at a societal level, and sustain for a long time (we may even need more toilet paper in the next few months)

        --it will be really hard getting pretty much everyone to do social distancing, minimizing contacts at work if they are not laid off, not socializing with friends/family (in China, 90% of cases were from family clusters), using masks and frequent hand-washing consistently, and doing all of this for at least several months. and, if we can't, we will have great difficulty eradicating the virus and all of its medical and social effects (eg, destroying the economy, dramatically increasing unemployment, increasing lack of health insurance as employer-based plans vanish for the unemployed, and generally increasing social anomy/decreasing social adhesion/increasing income inequality as these effects will disproportionately affect low-income and minority communities.

 

The bottom line is: the lack of available tests has led to lack of testing of early symptomatic people (or, for that matter, totally asymptomatic people who also are able to transmit the virus); we are testing only those who meet specific symptomatic criteria.  

    --this is not only an approach that is unable to identify and focus on those huge numbers of people with COVID who are infectious,

    --BUT also, our current approach of testing only those with significant symptoms reinforces the misbelief among non-medical and (it seems) many medical folks that communicability is tied to these more advanced symptoms (and even clinicians may dismiss mild early URI symptoms, as in the above study, as insignificant). And, this might lead to highly contageous individuals with minimal symptoms just ignoring them and spreading the virus

-- this study is also reminiscent of many years ago, prior to widespread HIV testing, where a few studies found that HIV was present in blood samples of patients tested for mononucleosis (the initial symptoms are indistinguishable). as a result of these studies, many clinicians learned to reflexively check for HIV whenever one thought of mononucleosis as a diagnosis. In this case with Covid-19, this should be a considered diagnosis in anyone presenting with URI symptoms, even without a cough or fever (only about 1/2 of patients with COVID-19 cases present with cough or fever). in the case of HIV, the issue largely subsided as we developed strategies for wide-spread testing.

-- Limitations of the study include:

    -- the fact that it was only one medical center, for a one week period, and they only included patients presenting to a health care facility (ED or urgent care) during the daytime

    -- what about patients with even less severe symptoms who don't seek medical care for their little cough or fatigue?? how often are they SARS-CoV-2 positive and spreading the infection?? we have no (as in, zero) idea

sorry if i come out so strongly about our state of affairs. i just see way too many diversions from the real issue. people focusing on hoarding toilet paper and a medical system that reinforces not testing for possibly SARS-CoV-2 infected people. i just really hope there is not complacency by these diversions. there are so many really serious issues here: overwhelming our health care system (likely leading to infected health care personnel/many bad outcomes, making it hard for people to get optimal care who have acute serious non-Covid problems) and fundamentally affecting the basic lives of most people (increasing social inequities, loss of jobs, loss of income, loss of health care coverage, loss of social connectedness, lack of general access to primary care and routine medical care as many clinicians work from home and try to focus on the increasing all-consuming pandemic (eg, how many people will not get routine beneficial screening and have bad outcomes??) ...

so, 

--it really is essential that we be testing many more people, especially those with minimal symptoms (and would also be a good idea to do reasonably large studies of asymptomatic people to see what the rate of SARS-CoV-2 is in the community: numbers thrown out are pretty much all over the place, from 1-25%, and the reality is that we do not have systematic data in different communities).  Knowing these numbers as well as focusing on patients with minimal or prodromal symptoms are essential to inform the best strategy to contain this current pandemic. this is what they did, for example, in China and South Korea: identifying patients early and doing rigorous case management to enforce quarantine

--and, though our current testing criteria exclude those with mild disease, we need to reinforce that even mild symptoms may be from SARS-CoV-2 (a message undercut by our testing criteria), and that people with these mild symptoms should really self-isolate, pending our ability to have plentiful accurate rapid-turnover tests (which we keep being told is right around the corner.  still looking for which corner that is).

geoff​

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