This story has been updated.
As health officials continue investigating a confirmed case of tuberculosis linked to two high schools in one San Antonio school district, it now appears that students and staff at a third campus may have been exposed.
The San Antonio Metropolitan Health District announced Friday that the person identified with TB may have had contact with others at O’Connor High School in the Northside Independent School District.
Earlier in the week, Metro Health confirmed the TB case and found that students and staff at two NISD schools, Clark and Brandeis high schools, could have been exposed.
Metro Health has conducted blood tests on 115 individuals at the three schools; the results of the tests will be available next week.
The case was reported to Metro Health by the local hospital where the patient sought treatment and tested positive for TB, said Anita Kurian, deputy director of Metro Health. She said the TB-positive individual is being tested periodically by Metro Health and is in isolation until they test negative.
The school district is following Metro Health’s guidance on how to navigate the reported case. The TB-confirmed individual is isolated until they are no longer infectious.
NISD informed staff and parents of students at O’Connor High of the possible exposure Thursday morning and invited them to a community meeting at 6 p.m. Monday at O’Connor High School Auditorium. The public is also welcome to attend the meeting.
This is not the first time the district has had a TB exposure, according to an NISD spokesman. Most recently, Metro Health confirmed a case of TB in May at Harlan High School.
Bexar County was among Texas counties with the most TB cases in 2020, the latest available data, according to the Texas Department of Health and Human Services. That year, 53 cases were reported.
University Hospital has not seen an increase in TB cases, said Bryan Alsip, chief medical officer at University Health, though he said it is not uncommon for the hospital to treat TB patients.
Alsip explained there are two categories of TB — active TB, which presents a persistent coughing with phlegm, and latent TB, which doesn’t present symptoms in positive patients and cannot spread to others.
He said transmission is more difficult than with COVID-19 or other respiratory viruses now making the rounds.
“You really have to have a certain amount of exposure for periods of time, significant duration, generally in a closed, indoor setting,” Alsip said. “I think that’s somewhat reassuring.”
Alsip said that if someone was close enough to an active TB case for a long enough period of time, vaccines aren’t commonly used for prevention in the U.S. because medication offers an effective treatment.
Kurian said both stages of TB are treatable, and confirmed that TB is not easy to catch.
“A close contact is someone who spends about six to eight hours a week in close proximity with this case,” Kurian said.