Shelby County sixth-graders will have to add another item to their back-to-school lists this year in an effort to cut down on the number of cases of a once-uncommon disease.

A recent spike in the number of whooping cough cases throughout Shelby County and Alabama has prompted the Alabama Department of Public Health to require all students 11 or older entering sixth grade to receive the tetanus-diphtheria-acellular pertussis (tdap) vaccine before returning to school this year.

In past years, sixth-graders were only required to receive the tetanus-diphtheria (td) vaccine. Because of the change, all sixth-grade students 11 or older must have an updated certificate of vaccination before reporting to school.

The Department of Public Health will raise the tdap requirement by one grade level each year, with seventh-graders added to the requirement list in the 2011-2012 school year, eighth grade in the 2012-2013 school year and so forth.

Twelfth-graders will be required to have the tdap vaccination on their immunization forms for the 2016-2017 school year. The U.S. Center for Disease Control recommends receiving the tdap vaccination every 10 years.

The Health Department is placing a greater focus on pertussis, commonly known as whooping cough, vaccinations for school-aged children because of an exponential growth in the number of cases reported throughout the state during the past few years.

In 2008, the Health Department reported 68 pertussis cases statewide for all age groups. Last year, the number jumped to 315 cases, and had already reached 93 cases in June 2010.

In Shelby County, the number of cases jumped from three in 2008 to 16 in 2009. The disease may be on the rise because many adolescents who were vaccinated against pertussis when they were infants have now lost immunity to the disease.

Because the disease is highly contagious and can sometimes be fatal, state Health Department officials said they are attempting to take a proactive approach toward preventing the disease.

“Adolescents have one of the highest rates of pertussis cases,” said Winkler Sims, director of the Health Department’s Immunization Division.

“The new sixth-grade requirement for students age 11 or older will protect students from pertussis at the adolescent age in school, and will protect them through the remainder of their school experience,” he added.

Those who are diagnosed with whooping cough, which stems from a bacterial infection of the lungs, typically experience sessions of violent coughing, vomiting and dehydration. The disease can also lead to fatal complications, like pneumonia and seizures, according to the CDC.

Once a person is infected with the disease, symptoms can last six weeks or longer.

The disease is transmitted through the air by moisture droplets, which likely originate from coughs and sneezes, according to the state Health Department.

Shelby County students and residents who are looking to receive the tdap vaccination can do so at the Shelby County Health Department on County Services Drive in Pelham.

Personal physicians and several drug stores, including the Rite Aid pharmacies in Alabaster, Pelham and on Valleydale Road, are also offering the tdap immunization. For more information about the disease and the vaccinations, visit Adph.org and click on the “Pertussis” link in the “ADPH Notices” section of the site.