Thread by @AllisonRBond

Need-to-know updates re: COVID from the experts, courtesy of infectious disease grand rounds @UCSF_ID yesterday:

(Caveat: Much is changing minute-to-minute, and this was as of 3/9/20 at 9 am PST)

1/x

As a little background: Like SARS and MERS, this new virus is a coronavirus. Coronaviruses also cause the common cold – there are lots of them.

SARS-CoV2 is the pathogen that is causing today’s outbreak. The disease SARS-CoV2 causes is called COVID-19.

2/x

SARS-CoV infects epithelial cells in the lung then causes lung injury. Viral titers appear to decrease when a person is sickest, which may point to the body’s inflammatory response (rather than the virus itself) as the root of lung damage.

3/x

As of 3/8 at 9 am PST, there were 107,754 cases (likely an underestimate for many reasons), 464 of which were in the United States. At that time, there had been 3,656 deaths worldwide (19 of which were in the United States).

4/x

Here in California, there are 83 known cases and there has been one death; nine of those cases were in San Francisco.

Again, likely an underestimate.

5/x

What does COVID-19 (the disease caused by SARS-CoV2) look like? Its symptoms can range from mild to life-threatening.

6/x

The most common symptoms are fever (found in >75% of hospitalized patients) and cough (dry or productive; 60-80% of patients).

Also relatively common are shortness of breath (20-40%) and muscle aches (10-50%).

7/x

A study of 99 patients found the triad of fever, cough, and shortness of breath was present in only 15% of those with COVID-19. And it’s important to remember that more than half of patients hospitalized with the disease had no fever on admission (but developed one later).

8/x

Headache, sore throat, runny nose, diarrhea, and vomiting are sometimes part of the syndrome, but these are less common (< 10-15%).

9/x

What sort of lab abnormalities are commonly found among patients with COVID-19? The median WBC was 4.7 (low-normal), with leukopenia in 30-45% and lymphopenia in 33-85%. C-reactive protein and lactate dehydrogenase are commonly, but not always, elevated.

10/x

Would caution to not put too much stock in cell counts, though – bacterial suprerinfection could majorly throw these off, although a recent study of 99 patients with COVID-19 found that only one also had a bacterial superinfection.

11/x

What is seen radiographically in COVID-19?

Not all have abnormal X-ray or CT, although most do if disease is severe. Like other viral lung infexns, most common CT findings = ground glass opacities and/or patchy consolidation. These may be in a peripheral distribution.

12/x

How deadly is COVID-19? It varies a lot by age.

Among those under age 50, the fatality rate ranges from 0 to 0.4%. For people over age 80, that number is much higher -- around 15%.

13/x

I’m won't delve much into diagnostics, but will say oropharyngeal swab = less sensitive than nasopharyngeal. Most sensitive to do both types of swabs, which brings the diagnostic sensitivity to ~84% (CI 0.73-0.90). Lower tract testing on intubated pts may increase yield.

14/x

How do you treat COVID-19? So far, that's not clear.

Drugs being tried include lopinavir/ritonavir (the HIV med), ribavirin, chloroquine, and remdesivir.

15/x

Data are sparse; there *may* be a signal towards benefit with chloroquine. Some centers are giving this empirically to patients with COVID-19; it is not clear how helpful this will be.

Hopefully more data will be available soon.

16/16

Thanks @BSchwartzinSF @SDoernberg @jen_babik @VivekJainMD & many others for your incredible work & wisdom in this arena!

(Would add here I should have been clearer in the original tweet -- these numbers are based off of data for other respiratory viruses). References used here were Lieberman et al. J. Clin Micro. 2009 and Dawood et al. JID. 2015.)