Coughing fits caused by a pertussis infection, also known as whooping cough, can last over 10 weeks, earning it the nickname the “100 day cough.” A study led by Kay Wang at the University of Oxford has revealed that 20 percent of children in the United Kingdom who visit their family doctor with a persistent cough are actually suffering from whooping cough.

"Pertussis can still be found in a fifth of school age children who present in primary care with persistent cough and can cause clinically significant cough in fully vaccinated children," the authors said in a statement. "These findings will help to inform consideration of the need for an adolescent pertussis booster vaccination in the UK."

Oxford researchers analyzed the patient records of 279 children from the age of 5 to 15, who visited their family doctor between November 2010 and December 2012. Patients had visited their doctor as the result of a persistent cough that lasted from two to eight weeks. Pertussis infections were confirmed through laboratory testing of oral fluid and six of the patients had their cough frequency monitored for 24 hours via wearable automated devices.

Out of the 279 children, 56 displayed evidence of a recent pertussis infection, including 39 who had not received their full whooping cough vaccination. Four out of the six children given wearable automated devices coughed over 400 times in 24 hours. Children who received their preschool pertussis booster vaccine over seven years prior to visiting their doctor with a persistent cough were three times more likely to be diagnosed with a pertussis infection.

Before the UK introduced the preschool pertussis booster vaccination in 2001, signs of a pertussis infection could be found in 40 percent of school-age children who visited a primary care physician to be treated for a persistent cough. Researchers hope the findings from their study will help inform future decisions regarding the need for adolescent booster vaccinations in the UK.

According to the Centers for Disease Control and Prevention, whooping cough is a serious illness that affects infants, children, and adults that can turn life-threatening, especially in infants. A total of 48,277 cases of pertussis were reported in the United States in 2012. An estimated 16 million pertussis cases are reported around the world each year, resulting in 195,000 deaths.

Source: Fry N, Campbell H, Wang K, et al. Whooping cough in school age children presenting with persistent cough in UK primary care after introduction of preschool pertussis booster vaccination: prospective cohort study. BMJ. 2014.