Why are the COVID-19 numbers from Dallas County going down for the rest of the state?

Dallas County health officials have reported a declining trend of COVID-19 cases and deaths this month to a high of at least 1,000 cases each day for more than two weeks in mid-July.

But the Dallas County improvement is not being replicated across the state. As a whole, Texas has yet to experience a consistent decline in cases, and deaths are still very much on the rise.

The seemingly conflicting numbers raise questions about whether both trends are possible, as the number of Texans seeking COVID-19 tests drops and health experts stress people should continue to wear masks and wear social distance.

Here’s what you need to know.

Why do Dallas’ trends not match those of the rest of the state?

Health experts say it is possible for some areas to improve during the COVID-19 pandemic, even if the general state is not.

This is especially true in a state as massive as Texas, said Dr. Mark Casanova, president of the Dallas County Medical Society.

“Large urban areas are initially independent, and then you are dispersed into foreign communities,” he said. “You’re sure you see that in North Texas … everyone in the state is sitting on a different clock.”

Health experts credit the local trend of lesser cases of compliance with social distance and mask mandates, which went into effect in Dallas County in June, for the statewide order. Although the province saw a slight uptick in new cases this week after a few weeks of lower numbers.

“We think our community has responded well to the universal masking, closing the bars,” said Dr. Philip Huang, Dallas County Director of Health.

Is Dallas really better?

Health experts say the decline in Dallas County cases appears to show what is really happening here with COVID-19 cases. If the number of cases was actually on the rise, the province would likely see a rise in hospital settings. But at the moment that is not happening.

“Working with the models, looking at hospital data, looking at all these indicators, they are consistent,” Huang said. “We are certainly seeing positive signs of that.”

As of Friday, Dallas County had an average of at least 497 daily cases this week. The province’s daily average of new cases fell last week to 463, from 654 cases the previous week and 827 the week before.

Health experts acknowledge that state-of-the-art testing technology, different testing methods and rapidly evolving knowledge about the virus create limitations for COVID-19 data.

In Dallas County, COVID-19 deaths and cases can vary significantly from day to day, in large part due to reporting delays, raising questions about the reliability of current trends.

But health experts say looking at data over the long term gives a clearer picture of how the province is performing. Even with the ups and downs, the province is generally trending in the right direction: downwards.

Since the virus can spread relatively quickly when someone becomes ill, averages of seven days are used to evaluate daily business trends, Casanova said. But hospitalizations and deaths need to be evaluated with 14- or even 21-day averages, because serious cases of the disease can last weeks.

The province’s seven-day business average has been declining since mid-July, while the 14-day average for deaths has declined somewhat since earlier this month.

Therefore, it is said that the general trends are the right direction, although there have been several days in recent weeks where the province reports deaths in double digits, even as it reports fewer cases.

“A 50-year-old in a hospital undergoing intensive care is not unlikely to have been in the hospital for five, six weeks, sometimes even longer,” Casanova said.

Casanova said that when Dallas County had two weeks of at least 1,000 cases a day, people asked why there were not so many deaths.

“Our comment was sad, ‘Just wait,'” he said.

Slow transfer in Dallas County

Hospital officials have also expressed cautious optimism about the local reproductive number, as well as the number of transmissions that result from each infection. A number below 1 means that cases go down. A number above 1 means that cases are increasing.

At a news conference Thursday, County Judge Clay Jenkins said the current reproductive number is 0.87. Huang said that, based on data from Parkland Hospital, the reproductive number in the community has been below one since July 4th.

That is slightly lower than some current estimates for the statewide reproductive number, which this week is estimated at 1.2 by Statista and as high as 1.3 by the site Rt.live, which estimates reproductive numbers per state based on data from the COVID Tracking Project.

But Jenkins warned Thursday that the province’s reproductive number could change easily, and was even lower, at 0.68, 10 days earlier.

“All of these numbers – hospitalizations, infections – are slowly moving up and down,” Jenkins said. ‘But like the stock market, you can’t look at an end, two or three days, one way or the other, and read a lot about it. You should review it on a weekly and biweekly basis. ”

Positive test rate

In the same way, the province is generally better than the state when it comes to the positivity levels of COVID-19 tests. While a rate for all of the county’s county sites is unavailable due to test restrictions, Jenkins said the rate was just under 16% for all of the province’s hospitals.

Statewide, changes to computer systems had recently caused the number of total tests and the number of positive results to come in at different times, which counted the proportion of tests inflated as positive, said state health department spokeswoman Lara Anton.

For example, the rough average of the state on Thursday stood at a record high of 24.5%. But the next day it dropped again, to 16.1%. The state is busy reconciling the data and hopes to raise the issue by next week.

But even a 16% rate is still much higher than the 5% positivity rate that the Federal Centers for Disease Control and Prevention has said is indicated on adequate testing, Jenkins said.

“When the positivity rate is high, it’s about you that the people you test are just the sickest people, and that you miss a lot of people,” Jenkins said.

Why are fewer people being tested?

Huang has expressed reservations about the reliability of the positivity rate, as complete data for the number of tests performed each day can be challenging to compile, both at the provincial and state level.

But he said the improving situation in the province is also supported by the lower demand for tests. The province said this week that there was a 40% request in tests for urban and provincial towns, which have not reached test capacity in several days.

“I don’t think it’s just that people are tired of testing,” Huang said. “I think the masking reduces the transmission and fewer people are symptomatic.”

Health Experts: Continue to take precautionary measures

Other health experts are worried that the declining demand for testing – a trend seen on community test sites across the state recently – is due in part to a false sense of security that improving numbers might lead to to make.

Statewide, the seven-day average for COVID-19 cases fell from July 20 to August 1 before jumping again, and then declining a few days later. State-wide deaths have not experienced any decline. Texas, as a whole, has seen the consistent downward trend that Dallas County is not experiencing.

Health experts said they feared that because the drop-off in testing coincided with an ebb and flow of cases, people would become less eager about masking and follow disease prevention guidelines.

In Dallas County, health experts warn that the downward trend does not mean the county is in the clear. Even with the declining number of cases, the overall numbers are still much higher than they were before the stay-at-home orders were lifted, Jenkins said.

Casanova said while it is important to drive the positive trend, the data is strong evidence that residents need to continue with prevention efforts such as masks and social distance.

“My ICU colleagues, my friends from Infectious Disease, we have no control over the public and individual decisions that are made over full control [the outbreak], “Said Casanova.” We are here together, but the public can make this happen. We will do our damn thing to save as many lives as possible, and do everything we can with as much as we can for as long as we can once they “Our hospitals are coming. But so much of this is in the hands of the public.”

Staff Writer Sue Ambrose contributed to this report.