Cases of whooping cough are notably increasing, particularly in Europe, prompting health authorities and scientists to call for vigilance and vaccination after this disease, caused by a bacterium that leads to severe respiratory infections, had been largely forgotten.
**What is Whooping Cough?**
Whooping cough (or "shahoq") is caused by a type of bacterium called Bordetella pertussis, which causes a highly infectious and prolonged respiratory inflammation. The primary symptom of the disease is recurrent and severe coughing fits. The infection spreads easily through the air, transmitted from person to person by inhaling droplets emitted from an infected person, happening within households or crowded places. Each infected person typically spreads the infection to about 15 others. The incubation period averages between 9 to 10 days, after which the clinical symptoms of the disease begin with a cold-like phase followed by paroxysmal cough and concluding with a characteristic "whoop" sound. Whooping cough can pose a risk to infants, especially the acute type, which may be associated with breathing difficulties and the deterioration of one or more organs. Vulnerable individuals (those with chronic respiratory diseases, people with weakened immune systems, and pregnant women) are at higher risk than others. While whooping cough seldom leads to fatalities, deaths can occur particularly among unvaccinated infants.
**How Much Have Infections Increased?**
Before the COVID-19 pandemic, the bacterium caused epidemic peaks approximately every three to five years. Whooping cough began re-emerging since late 2023 in several countries in Europe and across the Atlantic. Epidemic peaks can last for several months. More than 32,000 cases of whooping cough were recorded in 30 European countries in the first three months of 2024, significantly surpassing the figure reported for all of 2023 (over 25,000 cases), according to the European Centre for Disease Prevention and Control. Major epidemic peaks have been reported in Croatia, Denmark, and the UK, with significant increases in cases in Belgium, Spain, and Germany. In France, the number of cases rose from 495 in all of 2023 to over 5,800 cases in the first five months of 2024, according to the National Reference Center for Whooping Cough at the Pasteur Institute. Sylvain Brisse, the director of the National Research Center, remarked in an interview with AFP that this represented a "strong resurgence" of cases, noting that "France has not seen a volume of cases like this in at least 20 years." He observed that "this stage of the epidemic is still increasing," predicting a significant rise in cases during the Olympic Games in Paris.
**What Are the Reasons?**
Scientists believe that this increase in infections is a result, similar to other pathogens, of the cessation of preventive measures from the COVID-19 pandemic. A specialist from the Pasteur Institute mentioned, "We expected a sharp rise in whooping cough, as it is a cyclical disease, noting that the last peak in France occurred in 2018. The COVID phase delayed the return of whooping cough, and now it is coming back strongly." Although a resurgence was anticipated in 2021-2022, health measures associated with the COVID-19 pandemic likely contributed to limiting the transmission of the disease. This expert also suggested that the current increase could be linked to a decrease in herd immunity since the last outbreaks of the infection. Other scientists believe that one reason could also be the lower vaccination rates against whooping cough among certain population groups during the COVID-19 pandemic.
**What About Vaccination?**
Vaccination is the best form of protection. The most vulnerable groups include infants under two months who cannot yet be vaccinated due to their young age, and adolescents and adults who have lost the vaccine-induced protection, often due to lack of booster doses or illness. While the incidence of whooping cough has significantly decreased since the introduction of the vaccine, vaccination, like the disease, does not provide lifelong protection against infection. Experts emphasize that vaccinating pregnant women is crucial to protect their future children. Since the vaccine does not completely prevent transmission of the infection, it is possible for someone to carry the bacterium without showing symptoms and subsequently spread the disease, highlighting the necessity for vigilance when around young children.
