Michigan reported a big spike in coronavirus (COVID-19) cases on Thursday (March 19) afternoon, pushing the state reported total to 334.

UPDATE: Michigan coronavirus (COVID-19) cases continue to rise, state total now 549

The state originally reported the total was 336, but that number was changed. A Genesee County case was removed and an Isabella County case was removed.

Cases reported by the state increased by 254 cases since Wednesday’s data release. (See latest county breakdowns below)

The state updates its totals at 2 p.m. daily. The numbers often do not reflect an individual county’s case count because the counties may report confirmed cases a day earlier than the state. Washtenaw County reported a doubling of their COVID-19 cases on Thursday, and Oakland County reported 104 total cases.

Wayne County is expected to report cases on Thursday, as well. Detroit reported 63 cases on Thursday, but the state is reporting 75 cases in the city.

Overall, the numbers continue to rise from the state and county level as testing ramps up in Michigan, which was expected.

“We are pleased to announce that we are now able to provide testing results from hospitals and other entities outside of our state laboratory,” said Dr. Joneigh Khaldun, chief medical executive and chief deputy for health. “We knew there were additional people in Michigan with COVID-19 that had not yet been tested. This emphasizes the need to continue to practice social distancing and other community mitigation practices to help slow the spread of this disease.”

MDHHS is currently receiving reports from commercial labs LabCorp and Quest Diagnostics and several clinical labs including Sparrow Hospital in Lansing, the Beaumont Hospital Network, Henry Ford Health System and the MDHHS Bureau of Laboratories (BOL).

The state reports 2,449 total tests between the three testing sources. Only two of the positive COVID-19 tests came from commercial labs.

Related: 3 confirmed coronavirus deaths in Michigan: What we know about the patients

The cases reported by the state on Thursday include:

The Michigan Department of Health and Human Services announced a change in the way it reports coronavirus cases earlier this week.

This data is becoming problematic as doctors make it clear that the vast majority of COVID-19 cases may go unreported. Health officials are advising people with mild symptoms to stay home, do not go to a hospital and do not consider getting tested. That means only the most serious cases will be tested.

Related: March 19 updates: Tracking newest confirmed COVID-19 cases in Metro Detroit

Nine days ago, on March 10, Michigan confirmed its first two COVID-19 cases. Numbers are expected to rise as testing ramps up. Health care providers, local health departments or others may publicly announce cases or deaths before they are included in the statewide count.

For most people, the coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia. The vast majority of people recover.

The worldwide death toll crept toward 10,000 as the total number of infections topped 220,000, including nearly 85,000 people who have recovered.

Here is a charted timeline of confirmed coronavirus (COVID-19) cases in Michigan:

Here’s the Michigan county case count mapped and the total number of cases in each US state:

Here are Michiagn’s COVID-19 deaths mapped per county:

Here are Michigan COVID-19 cases broken down by age range:

Here are Michigan COVID-19 cases showing how many are hospitalized:

Here are Michigan COVID-19 cases broken down by gender:

The following map is showing data per state -- click on a particular state to filter the data in the table for a breakdown:

How COVID-19 Spreads

Person-to-person spread

The virus is thought to spread mainly from person-to-person.

Between people who are in close contact with one another (within about 6 feet).

Through respiratory droplets produced when an infected person coughs or sneezes.

These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.

Can someone spread the virus without being sick?

People are thought to be most contagious when they are most symptomatic (the sickest).

Some spread might be possible before people show symptoms; there have been reports of this occurring with this new coronavirus, but this is not thought to be the main way the virus spreads.

Spread from contact with contaminated surfaces or objects

It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.

How easily the virus spreads

How easily a virus spreads from person-to-person can vary. Some viruses are highly contagious (spread easily), like measles, while other viruses do not spread as easily. Another factor is whether the spread is sustained, spreading continually without stopping.

Prevention & Treatment

There is currently no vaccine to prevent coronavirus disease 2019 (COVID-19). The best way to prevent illness is to avoid being exposed to this virus. However, as a reminder, CDC always recommends everyday preventive actions to help prevent the spread of respiratory diseases, including:

Avoid close contact with people who are sick.

Avoid touching your eyes, nose, and mouth.

Stay home when you are sick.

Cover your cough or sneeze with a tissue, then throw the tissue in the trash.

Clean and disinfect frequently touched objects and surfaces using a regular household cleaning spray or wipe.

Wash your hands often with soap and water for at least 20 seconds, especially after going to the bathroom; before eating; and after blowing your nose, coughing, or sneezing.

MORE: Beaumont Health launches coronavirus hotline for patients with symptoms

People who think they may have been exposed to COVID-19 should contact their healthcare provider immediately.

Question about coronavirus? Ask Dr. McGeorge here.

Read more about coronavirus here.