STUDY: Houston could have had 4 times more COVID-19 cases than reported in September

Mayor Sylvester Turner at press conference
By mid-September, an estimated 13.5% of Houston's population, or 250,000 people, had contracted the coronavirus, according to results from a study of antibody samples. (Courtesy HTV)

By mid-September, an estimated 13.5% of Houston's population, or 250,000 people, had contracted the coronavirus, according to results from a study of antibody samples. (Courtesy HTV)

A new study released Dec. 14 found that potentially four times as many people had contracted COVID-19 in Houston than was previously known.

Houston Public Health officials in collaboration with the Baylor College of Medicine and Rice University conducted voluntary antibody tests on 678 individuals in mid-September to better understand the prevalence of the virus in the city.

“The participation was really amazing,” said Dr. Loren Hopkins, chief environmental science officer with the Houston Health Department.

Given the results of the antibody survey, health officials estimate that up to 13.5% of the city’s population, or over 250,000 people, had contracted the coronavirus by September. At the time, about 57,000 cases had been reported, according to the health department.

To reach “herd immunity,” Houston Emergency Medical Director Dr. David Persse said the city will likely need to see 70% of residents immune to the virus at the same time.


The antibody test differs from diagnostic tests taken with mouth and nasal swabs because it detects a previous immune response to the virus rather than an active infection. This means it could find people who previously contracted the virus and were unaware or did not receive a diagnostic test. The study estimates as many as 40% of people infected with the virus show no symptoms but will develop antibodies.

Vaccine distribution will speed up the process of reaching herd immunity however if too many residents are hesitant to to receive the vaccine, it will impede the process, Persse said. Researchers do not yet know how long antibodies last in the immune system.

“If people become immune but only for a short period of time, the herd immunity is going to fluctuate. ... That is why it is so important to get this vaccine,” Persse said.

The study found that the prevalence of antibodies was higher in underserved communities, among women, residents under the age of 40 and Black and Hispanic residents.

The health department will conduct a second phase of the study in January to retest the first individuals who received the antibody tests along with testing another batch of 420 households.

By retesting the original residents, health officials will be able to measure the level of antibodies that remain present in those individuals and determine if the levels dropped at all over time.

The findings may help researchers far beyond Houston, Persse said.

“It is incredibly important,” Persse said. “This study is looking at the real world population in the 4th largest city in the US and is going to provide us with real world answers.”

The new tests will continue to help determine the prevalence of the virus’s spread in the city. Results are expected about three months after the study is conducted, officials said.
The city also reported 745 new cases and six newly reported deaths Dec. 14. The 14-day average positivity rate increased from 8.8% to 10.5%.
By Emma Whalen
Emma is Community Impact Newspaper's Houston City Hall reporter. Previously, she covered public health, education and features for several Austin-area publications. A Boston native, she is a former student athlete and alumna of The University of Texas at Austin.


MOST RECENT

The “Click It or Ticket” enforcement period across Texas roads will start on May 24. (Courtesy Adobe Stock)
TxDOT will launch annual ‘Click It or Ticket’ campaign Monday, May 24

The campaign comes after a 2020 that saw a 16% increase in deaths of unbuckled motorists.

Public schools cannot require students, teachers, parents and other staff members or visitors to wear masks after June 4, Gov. Greg Abbott declared in an executive order issued May 18. (Courtesy Adobe Stock)
Public schools can't require students, staff to wear masks after June 4, Gov. Abbott says

"Texans, not government, should decide their best health practices, which is why masks will not be mandated by public school districts or government entities," Gov. Greg Abbott said.

George Strait will perform at the Houston Livestock Show and Rodeo's 90th anniversary celebration next year. (Courtesy Pexels)
George Strait to close 2022 Houston Livestock Show and Rodeo with concert March 20

Tickets for George Strait's rodeo performance will go on sale June 24.

Effective June 26, unemployed Texans will no longer be eligible to receive the $300 weekly unemployment supplement from the Federal Pandemic Unemployment Compensation program. (Courtesy Adobe Stock)
Gov. Greg Abbott announces end-date for Texans to receive federal pandemic-related unemployment benefits

Effective June 26, unemployed Texans will no longer be eligible to receive the $300 weekly unemployment supplement from the Federal Pandemic Unemployment Compensation program.

Photo of an H-E-B store
H-E-B makes curbside services free

Previously, curbside shoppers were charged a $4.95 fee on all orders, but moving forward that fee will be waived on purchases of $35 or more. Orders worth less than $35 will have a $2.95 "small basket surcharge" attached.

Each of the new locations will be available to the public to distribute and receive voter registration forms and applications to vote my mail as well as assisting with other election-related services. (Courtesy Unsplash)
Harris County elections administrator announces 8 new branch office locations

Registering to vote will soon be more convenient for Harris County residents with the opening of eight new branch office locations announced by the Harris County Elections Administrator's Office in a news release May 17.

Imperio Wine & Spirits sells a variety of liquor, beer, wine and spirits. (Courtesy Adobe Stock)
Imperio Wine & Spirits opens in Katy; Montgomery Chick-fil-A to open dining room and more Houston-area news

Read the latest business and community news from the Greater Houston area.

After the U.S. Centers for Disease Control and Prevention issued new guidance May 13 that ended all mask requirements for fully vaccinated people, HISD released a statement saying mask mandates would remain in place for the time being for facilities and campuses. (Community Impact staff)
Houston ISD to leave mask policy in place for now

The district is also soliciting feedback on how to spend $800M in pandemic relief funding.