(Updates with comments urging people who take part in large gatherings such as protests to take precautions against spreading the coronavirus.)

COVID-19 cases reported by the Alabama Department of Public Health have been incomplete this week, and more people have contracted the disease than the numbers being reported on the department’s website show.

The problem comes from an overwhelmed national surveillance system, which has caused delays in obtaining information, according to an email from Assistant State Health Officer Dr. Karen Landers in response to BirminghamWatch questions.

“Once the issue is resolved, more cases will be added to the data set which will show an increase in cases,” she said.

The issue does not affect individuals’ tests. Tests still are being given and processed, and the health department is continuing its work to investigate positive results. Rather the problem affects the process of aggregating the results, which helps track whether the disease is gaining or losing ground in the state.

The department was reporting 18,766 confirmed cases and 306 probable cases on its website Thursday. That’s an increase of just 831 combined cases for the week so far. The week before, cases rose by more than 500 on three separate days, going up by 664 cases on one day alone.

Landers stressed that the coronavirus is still circulating in Alabama, and face coverings, social distancing and hand washing remain important ways to reduce the spread of the disease.

She said she and others in her department are deeply concerned and saddened about the loss of the life of George Floyd, but Landers urged people who take part in protests to be cautious about spreading the coronavirus.

“But we do remain concerned when there’s a congregate group of any size for any reason, and social distancing measures are not taking place,” Landers said. “It concerns me as a physician to see people that are in large groups that aren’t taking any measures.

“They’re not distanced. They have no mask on and obviously they don’t have an opportunity to significantly sanitize their hands,” the doctor continued. “It’s a very concerning situation and we just want to remind that the COVID-19 is still circulating and that persons need to take these measures to protect themselves during such encounters.”

She also reminded people who are 65 or older or who have underlying health conditions — such as heart, lung, liver or kidney disease — to take extra precautions.

Of the 651 most recently reported deaths, only 33 were people with no underlying health condition.