ST. LOUIS — In the four months since Missourians learned that COVID-19 had arrived in the state, it has become easier for residents to find out whether their community’s cases are rising, flat or declining. But many still are noticing inconsistencies in the numbers, as health departments struggle to gather and report information in real time.
Counties sometimes report different numbers of infections than the state reports for them. And state numbers are sometimes revised to show more or fewer new infections on a given day.
Public health officials say that tracking the virus is an unprecedented challenge.
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“Every one of these cases is hours of work for somebody in public health,†said , program coordinator and epidemiologist at Missouri’s .
His office tracks over 150 diseases, and in the past three months alone, he said, the bureau has received as many COVID-19 reports as it would normally receive for all reportable conditions over an entire year.
Cases moving ‘constantly’
The state’s COVID-19 dashboard displays a graphic showing the number of new cases on each day of the pandemic. Those numbers, Koffarnus said, “are constantly in a state of potential revision.â€
Illinois residents sometimes come to Missouri for medical care, which can lead to a mistaken tally in the Missouri cases. Or, a Missouri resident may have been staying in a different state for several months, including during the time that they were symptomatic.
“We’re constantly passing cases back and forth between us and other states,†Koffarnus said.
Medical providers normally report necessary information to the state, like the date symptoms started, and the location of a case. But generally, the state hears from the labs first, which aren’t required to report all of those details, according to Lisa Cox, a spokeswoman for the state Department of Health and Senior Services.
If the state does not receive the location data from the lab or provider that handled the case right away, state employees use LexisNexis, a searchable database, to try to locate a patient’s last known address. Koffarnus said this is only necessary in a small number of cases. Otherwise, the location defaults back to that of the health care provider: If a patient went to a doctor in St. Louis, the case is assigned to that city until the state receives more information.
Because of that, Koffarnus said, sometimes more cases are assigned to the bigger cities at first, where more doctors are located. Within a day or so, they are redistributed to the county where the patient lives.
This issue is not new, Koffarnus said, but it is more noticeable in the COVID-19 data because the numbers are higher than other conditions.
“Nobody really notices ... if a jurisdiction has 22 salmonella cases this week, and next week they have 21,†Koffarnus said. “Everybody is paying close attention to COVID.â€
Sometimes there are also delays because of the testing turnaround. It generally takes 72 hours for the state to receive most of the results for a given day. And other needed information is sometimes slow to follow.
Koffarnus said the state prefers to record COVID-19 cases under the day an individual first began experiencing symptoms, but usually it does not have that date right away. Until it does, the case is often counted under the date of the test.
Numbers differ
As people try to find out about the state of the pandemic in their community, many turn to COVID-19 data trackers.
The and trackers show similar numbers to the , but since they also take some county and city health department numbers into account, there are some differences. For example, the university’s tracker shows that there were 17,371 total cases of the virus in ÁñÁ«ÊÓƵ on June 18, and The New York Times data shows that there were 17,488. Missouri, according to the most recent calculations, shows 18,121 cases on that date.
, an associate professor at St. Louis University’s , said he would urge residents to pay the closest attention to local, city or county data on COVID-19. In a smaller region, there will be less variation in how the data is collected, he said.
Wiemken said that as long as the data is gathered in a consistent way, it will be possible to identify when something is wrong, or when there is an outbreak.
But that is not always easy, or possible. For example, he said, as medical professionals learn more about the virus, the population receiving tests has changed.
In the early stages of the pandemic, tests were only available for a narrow population that fit specific criteria for symptoms and exposure. Since then, testing has become far more widely available. And the medical community has identified more symptoms that can be potential indications of the virus.
Different states differ in how they report COVID-19 data to the public, and in Missouri, local health departments each decide how they report virus numbers. Wiemken and other public health experts have advocated for more universal reporting requirements.
“Unquestionably there should be a national standardization,†Wiemken said. “There’s absolutely no reason to not have that.â€
