COLLIN COUNTY, Texas — Collin County Health Care Services (CCHCS) has identified a second case of measles, the health organization said Monday.

The infected person was at a Kroger on North Preston Road in Prosper on March 15th between 9 a.m.-10 a.m. while contagious, officials said. The person did not go to any pother public locations, officials said, 

This is the third case of measles reported in North Texas this year. The first North Texas case was reported in Denton County in February. This is the 12th confirmed case statewide, according to the Texas Department of State Health Services. 

The most common way to prevent measles is vaccination. 

Dr. Kathleen Stokes is a pediatrician at Frisco Pediatrics. She's been in practice for over 30 years and has one very important rule: "My rule is if you don't vaccinate, you don't come to this practice," Stokes said.

There is literature throughout her office talking about the importance of vaccinations. She is concerned about the growing number of parents who do not believe in vaccinations or believe it should be a choice.

"It's not really a controversial issue. Vaccines work and they save lives," she said.

Stokes says her rule of treating only vaccinated patients is to protect the babies and immune-compromised children she sees. This comes on the the heels of news that Collin County has its second confirmed case of measles.

"I don't think it's going to be its last. I'm not surprised," she said.

DCPH said children should receive measles vaccination via one dose of MMR (measles, mumps, rubella) between 12 to 15 months old, and another dose prior to entering school, between 4-6 years old.

If you were born in 1957 or later, you should verify your vaccination history; those born before 1957 are thought to be immune to measles, according to DCPH.

 Measles is a highly contagious virus that spreads through the air via coughing and sneezing, according to the Centers for Disease Control and Prevention. Symptoms start with a fever, runny nose, cough, red eyes and sore throat, followed by a rash that spreads over the body.

The disease is so contagious that if just one person has it, up to 90 percent of people who aren't immune and are close to the infected person could become infected. It can stay airborne for up to two hours and can be transmitted from four days before or after the rash starts to appear, DCPH said.