Texas is experiencing the worse whooping cough outbreak in 50 years, according to the Department of State Health Services after issuing an alert. Doctors have been advised of the outbreak and how to diagnose and treat pertussis.

Health officials urged residents to make sure their own vaccinations and those of their children are up to date.

Officials also are urging residents statewide to especially avoid exposing newborn babies to the highly-contagious disease. The illness features a persistent cough that gives the disease – known clinically as pertussis – its nickname.

Statewide, 1,935 people had been diagnosed with the disease as of Aug. 27, the most recent figure available, officials at the Texas Department of State Health Services said.

A large number of the cases are concentrated in the Fort Worth-Arlington area. There were 433 cases in Tarrant County as of Tuesday, said Al Roy, Tarrant County Public Health Department spokesman.

“If you have a cough, stay away from the babies,” said Russell Jones, Tarrant County chief epidemiologist.

No deaths have been reported in Tarrant County, but 38 cases required hospitalization – and, in 33 of those, the patients were infants.

“If you’re exposed to pertussis and you know it, go to a physician,” Jones said.

By the end of this year, the total cases of whooping cough in Texas likely will be higher than the recent high of 3,358 cases in 2009, state officials said.

“This is extremely concerning. If cases continue to be diagnosed at the current rate, we will see the most Texas cases since the 1950s,” Dr. Lisa Cornelius, Texas Department of State Health Services infectious diseases medical officer, said in a statement. “Pertussis is highly infectious and can cause serious complications, especially in babies, so people should take it seriously.”

This year, the statewide cases include two deaths – both involving infants who were younger than two months, too young to be vaccinated.

To help protect newborns, pregnant women are recommended to receive a pertussis vaccine between 27 and 36 weeks of gestation.

Whooping cough, a bacterial infection, often initially resembles a cold with a mild cough. But the cough persists for several weeks and gets worse.

Some patients vomit during coughing fits. Jones said he knows of a case in which a patient coughed hard enough to separate a rib.

Pertussis spreads easily through the air, often when an infected person coughs or sneezes.

Whooping cough tends to be cyclical, state officials say.