What we know about the resurgence of the whooping cough epidemic in France

Since the start of 2024, around twenty outbreaks of infection have been identified in eight regions of France, compared to two cases grouped in a single region in 2023, Public Health France alert.

A call for vigilance for all young parents and their infants. Public Health France (SPF) has recorded an increase in cases of whooping cough since the start of 2024. This highly contagious respiratory disease of bacterial origin can be serious in vulnerable people, particularly the elderly, pregnant women and babies under six months of age who are not yet protected by vaccination.

If France is not the only European country affected by this resurgence, the public health agency calls, in a bulletin published Thursday April 18, to “reinforced vigilance”. Here is what we know about this increase in cases in France and Europe.

A very contagious and dangerous disease for toddlers

Whooping cough is a respiratory infection causing coughing fits which, if left untreated, can continue for several weeks. It is particularly dangerous in the elderly, pregnant women and infants who have not yet been vaccinated (the first dose of vaccine is injected at two months of age, then a second dose is administered at four months).

In newborns, whooping cough can lead to hospitalization and even be fatal. “Hospital stay is systematic for babies under three months”, specifies Health Insurance. In France, “more than 90% of deaths from whooping cough occur during the first six months of life, and particularly during the first three months”also warns the High Authority for Health (HAS).

If Public Health France calls for vigilance, it is because this disease is very contagious. A sick person can infect on average 15 to 17 people and the incubation period, that is to say the time between the penetration of the bacteria into the body and the appearance of the first symptoms, is around ten days, recalls Health Insurance. This contamination occurs through the air, through contact with droplets coming from the patient’s nose or mouth and projected during coughing.

In France, where vaccination against this disease has been compulsory for infants since 2018, contamination occurs via adults, who contaminate babies too young to be vaccinated. This is why the HAS has recommended, since 2022, that pregnant women be vaccinated. More broadly, Health Insurance also encourages adults with a parental plan to be vaccinated against the disease.

Twenty sources of contamination identified in France since the start of the year

Since the beginning of January, around twenty sources of contamination have been identified by Public Health France, in eight regions of France. A figure ten times higher than for the whole of 2023. Last year, two clusters of cases were identified, in a single region: Ile-de-France. According to SPF, 18 babies suffering from whooping cough were then identified, including 13 in the family setting, four in the community and a final isolated case.

In total, Public Health France counted 70 cases of whooping cough in the first quarter of 2024, mainly in communities (nursery schools, primary schools, daycare centers and nursery homes) and in the family setting. In 2023, a total of 39 cases were recorded in France. “Given this clear increase in the number of cluster cases reported, Public Health France remains vigilant and recalls the importance of vaccination to protect people at risk of serious forms”notes the agency in its bulletin.

SPF fears an increase in cases “in the coming months”

This resurgence of the epidemic thus reveals “a resumption of community circulation of the bacteria which could intensify in the coming months”, warns Public Health France. Whooping cough has the particularity of evolving in cycles of recrudescence every three to five years. So much so that since 1997, six peaks have been listed by SPF. The last one dates from 2017-2018, with 162 cases recorded.

A new outbreak of cases should have been observed in 2021-2022, but the opposite happened, “probably” due to the health measures implemented to fight Covid-19, says SPF. The number of cases has continued to decrease since 2018, reaching 34 cases in 2022 and four cases in 2021 in infants under 12 months.

So, “vigilance remains essential, with the need to increase public awareness of this disease and its methods of prevention”, underlines Public Health France. And this even if, for the moment, “the French situation is not comparable with that of our European neighbors and across the Atlantic, who have reported several hundred cases per week since the last quarter of 2023”.

The epidemic is on the rise among our European neighbors

Outside French borders, Europe is indeed experiencing an increase in cases of whooping cough, raises a report from the European Center for Disease Prevention and Control (ECDC) published at the end of March. Significant epidemics have been observed in Croatia, with more than 1,000 cases recorded since the start of the year, compared to a few dozen usually. Significant increases have also been reported in Denmark, the United Kingdom and Belgium, where an infant died from the disease in December 2023, RTBF reports. Spain and Germany are also affected.

In the Czech Republic, which has nearly 11 million inhabitants, health authorities have recorded 7,888 cases of whooping cough since the start of the year, including three deaths (a 62-year-old man, an 84-year-old woman and a newborn), in a context of mistrust of vaccines since the health crisis. This is the largest spread of the disease since 1959, when vaccinations began, according to official Czech records. Four deaths have also been reported in the Netherlands, according to a report by the Dutch public health institute established in mid-March and relayed by the Belgian daily The evening.

In the United Kingdom, the government is concerned, in a press release, about the low vaccination of pregnant women and adults against whooping cough, while 52 infants under three months were infected with the disease in January and February 2024 , compared to two in 2022 and 48 in 2023. For the ECDC, “the current increase is potentially linked to lower circulation during the Covid-19 pandemic, combined with a suboptimal vaccination rate in certain groups during the pandemic”.