_{*Editor’s note: This story was updated March 4 with the latest statistics from the Texas Department of State Health Services.}

Nearly 200 people have contracted mumps at detention facilities across Texas since October, according to a state health agency.

The Texas Department of State Health Services says 186 people, including immigrants and detention facility employees, had confirmed cases of mumps.

Lara Anton, a spokeswoman for the Department of State Health Services, said in an email that patients range in age from 13-66 and that “there has been no reported transmission to the community.”

She added that the state doesn’t know the vaccination status of detained migrant adults or the children who entered the U.S. with them but that “all unaccompanied minors are vaccinated when they are detained.”

There were 191 cases of mumps reported in Texas in 2016, the most cases in 22 years. But due to high vaccination rates in the state, the incidence of mumps is generally low here, according to the Department of State Health Services’ website. Among Texas children, 90.3 percent were vaccinated for mumps in 2017, according to the National Immunization Survey.

The Centers for Disease Control and Prevention recommends children get two doses of the mumps vaccine before they’re 6 years old. The agency also encourages teens and adults to be up to date on their mumps vaccinations. The vaccine has an 88 percent effective rate when people have the recommended two doses.

Symptoms of mumps include fever, headache, muscle aches, fatigue and loss of appetite, followed by swollen salivary glands, according to the Centers for Disease Control and Prevention. The agency website notes that outbreaks commonly occur among people in “prolonged, close contact.”

Detention centers are required to report illnesses that occur among immigrants and employees, including mumps, measles, chicken pox, HIV, tetanus, hepatitis and tuberculosis.

Detained migrants receive medical, dental and mental health intake screenings within 12 hours of their arrival to centers, in keeping with U.S. Immigration and Customs Enforcement standards. If they have urgent medical or mental health needs, they receive priority screening.

But in the case of mumps, someone who has been exposed might not show symptoms right away, said Dr. Hector Gonzalez, director of health at the City of Laredo Health Department. Symptoms can occur within 25 days of being exposed to someone who has mumps.

Gonzalez’s agency recently investigated five cases of mumps at the local immigration detention center. His department waited to see if more people in the facility would develop mumps but hasn’t seen new cases.

“We go in and take the measures that we need to protect against further spread,” Gonzalez said, including isolating patients, providing vaccinations, and urging detainees to remember to wash their hands and cover their mouths when coughing.

While most U.S. kids are immunized for mumps, different countries have varying immunization standards and exposure to diseases, said Dr. Andrea Caracostis, CEO of Hope Clinic, a health center in southwest Houston that often cares for immigrants. She said putting detainees together for long periods of time — and not fully knowing what they’ve been exposed to — is how communicable diseases spread.

“You don’t need to be in the facility to know the conditions in there are not quite sanitary and are not equipped to deal with disease,” Caracostis said. “These are contagious diseases; they thrive in places where there’s no proper sanitary management.”

Urging detention centers to separate immigrants during a disease outbreak of any kind is challenging. A person with mumps needs to be isolated until recovery — and all who had contact with that person need to be quarantined separately until it’s clear they aren’t developing symptoms.

Dr. David Persse, public health authority for the Houston Health Department, said he’s frustrated that he’s still seeing mumps cases out of the ICE facility in his city. The department initially confirmed seven cases on Feb. 9. Now that number is up to 11.

“It tells me the isolation and quarantine efforts are not being done as diligently as it could be done,” Persse said.

Persse said he’s frustrated more cases have developed in recent weeks but noted that the warden at the Houston facility has been working closely with the local health department to separate detainees with mumps.

“Let’s say [the warden] does everything exactly right. He’s still at risk,” Persse said, because migrants are transferred in from other facilities and may not have symptoms or know they’ve been exposed.

 Learn about The Texas Tribune’s policies, including our partnership with The Trust Project to increase transparency in news.