Trend in Coronavirus cases in Maryland, USA

Disclaimer: Although I work in infectious diseases, I’m not a specialist in Coronavirus. For the most up-to-date information on Coronavirus in the US, please visit the CDC website. For the most up-to-date information on Coronavirus in Maryland, please visit the Maryland Department of Health. That being said, now you can proceed at your own risk 😉

This post was updated by one post on March 28 and another one here on April 27. Read the latest one here.

Living in Maryland during the Coronavirus pandemic, I am interested to follow the number of cases that my state has so far. The Maryland Department of Health (MDH) has now a dashboard representing the count of positive cases and the breakdown by different counties. It’s nice but it only includes the latest update and the past trend is forgotten. So I decided to plot the number of cases with whatever numbers is given on the dashboard.

Here are the plots that I will try to update daily (last update: March 25, 2020; after that, I continued to update trends on this post):

Trend in total Coronavirus cases in Maryland, USA, 2020 - up to March 25, 2020
Trend in Coronavirus cases in Maryland counties, USA, 2020 - up to March 25, 2020
Trend in Coronavirus cases by age groups in Maryland, USA, 2020 - up to March 25, 2020

Now, a bit of background … I started this as a simple exercise with no other intention than plotting the trend of cases tested positive since Maryland started reporting cases (March 9, 2020). After a few days, it stopped reporting the total of negative testing done daily. The reason was: “Now that COVID-19 testing has expanded and is available through commercial laboratories, MDH is no longer reporting negative and pending numbers of tests in Maryland. All positive results obtained by commercial laboratories are reported to MDH and included in the confirmed cases count“. Although the reason is certainly understandable, this doesn’t allow us to follow the evolution of testing in general in the state. Testing and the availability of tests is a sensitive topic in the US …

On March 15, the MDH started to report the number of positive tests in each county. Initially, only 8 (of 24) states had cases. On March 16, the total count for Anne Arundel county dropped from 2 to 1. I don’t know the reason.

On March 17, MDH reported an increase in positive cases detected higher than previously. This can be due to a lot of things (increase in testing, increase in cases per se, …). Frederick County reported its first case.

On March 19, MDH unfortunately reported the first death due to Coronavirus. The total number of positive tests reported is now above 100. Allegany County and Calvert County reported their first positive tests. Today, I also started to split my graph in 3: one for the total number of cases, one for the cases by counties and the last one by age group. This reporting by age group was started on March 17 by MDH. We see the burden is mainly in adults younger than 65 – but this may be simply due to higher level of testing in this population (again, without the number of tests done, you can’t really conclude anything).

On March 20, first cases appeared in Wicomico County and Worcester County. It seems that the number of positive tests is increasing faster (again, without the total number of tests done, you can’t really conclude anything).

On March 23, we see that all counties, except Allegany, Kent and Dorchester, have cases now. I changed the y-axis of the total number of cases to a log scale (therefore it gives a “flatter” look to the curve). But we are still in a rapidly increasing phase of the disease …

On March 24, we now have more than 300 positive tests, among which 107 in Montgomery County alone.

I continued to update the different trends in another post here. Read the latest post here.

All the data and scripts are on a Github repository if you want to play.

2 thoughts on “Trend in Coronavirus cases in Maryland, USA

Comments are closed.