A whooping cough outbreak in Texas could be the worst the state has seen in 50 years — and nearly a fourth of the cases are in Tarrant County.
The Texas Department of State Health Services on Tuesday issued a health alert, advising doctors on 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.
The pertussis alert is the latest twist in what has turned out to be a strange year epidemiologically in Tarrant County. The Fort Worth area also has dealt with West Nile virus, measles and a stomach bug called cyclosporiasis.
Vaccine wears off
Whooping cough tends to be cyclical, state officials say.
In 2010, 27,550 cases of pertussis were reported in the United States, but many more go undiagnosed and unreported, according to the Centers for Disease Control and Prevention. That was the most cases reported in the country since 1959, when 40,000 were reported. In 2011, 18,719 cases were reported nationally.
Worldwide, there are an estimated 30 million to 50 million cases of pertussis and about 300,000 deaths per year, according to the CDC.
The number of cases in Texas peaked in the mid-1940s at over 20,000. The rate dramatically declined after 1949 when a vaccine was introduced. The highly contagious disease was almost nonexistent in the state from the early 1970s until 2000, when the number of cases started to climb, according to state health department records.
In the United States, the vaccine for infants and children is DTaP, a combination vaccine that protects against three diseases: diphtheria, tetanus and pertussis, according to the state health department.
But researchers are finding that immunity from the vaccine seems to wear off, particularly among youths ages 8-11, just before they’re scheduled to receive a booster shot prior to seventh grade.
Those youths may get through the disease relatively unscathed, but they can spread it to siblings —including infant brothers and sisters — who may not have the strength to fight it off.
“The pertussis vaccine isn’t doing what we had hoped it would do, but it’s still our best tool,” said Jones.
He said California research shows that those who aren’t vaccinated are eight times more likely to get the disease. Also, those who receive the vaccine but catch whooping cough anyway tend to have a less severe form of the illness, and it doesn’t last as long, Jones said.