Updated at. 10:25 Revised to include a sixth case confirmed by state health officials.
Six cases of measles have been confirmed in Texas in recent days, health officials say.
The Texas Department of State Health Services confirmed a case in Bell County on Tuesday, one day after five cases were announced – three in Harris County, one in Galveston County and one in Montgomery County. Four of these involve children under 2 years of age.
The three Harris County patients are two boys younger than 2 and a woman between 25 and 35 years old. The cases are the first in Harris County this year. The last one was in Houston in 2018, according to the county health department.
"We know there is a connection between two of the Houston cases and public health is investigating to determine whether the others are connected or whether they are independent," said spokesman Chris Van Deusen of the Texas Department of State Health Services.
In Galveston County, the confirmed case is a boy between 1 and 2 years of age tested on January 28. Health officials say the case is part of the cluster in the region.
Officials have not released the identities of any of the people.
All four of the children had received the first of the two vaccines Houston Chronicle reported. County officials worked to confirm that the woman had been vaccinated.
Two of the children were recently immunized and "likely to be exposed to measles before receiving the vaccine or before the body could mount a full immune response," Van Deusen said.
The disease control and prevention centers recommend children to receive two doses of measles, kisses and rubella vaccines – one between 12 and 15 months and the other between 4 and 6 years – to be fully protected against measles.
"Although this is a relatively small number of cases, it is a good time to ensure that you and your children have received the recommended two doses of measles vaccine," said Van Deusen.