Epidemiology and antibiotic use of pertussis and pertussis-like cough in Italian children: a population-based study from 2010 to 2024
Emelyne Gres, Giulia Sturniolo, Sofia Masenello, Carlo Giaquinto, Giulia Brigadoi, Vincenzo Baldo, Benedetta Bellini, Daniele Petrone, Patrizio Pezzotti, Andrea Lo Vecchio, Daniele Dona, Elisa BarbieriAbstract
Background and aims
Although widespread vaccination has greatly reduced pertussis incidence and mortality, pertussis has resurged globally following the COVID-19 pandemic, with several European countries reporting substantial increases in incidence. This study aimed to describe temporal trends in recorded pertussis and pertussis-like cough episodes and associated antibiotic prescribing among children aged <14 years between 2010 and 2024 in Italy.
Methods
We selected children aged <14 years from 2010 to 2024 using Pedianet, a representative paediatric primary care database. Pertussis and pertussis-like cough episodes, with or without microbiological confirmation, were identified using ICD-9-CM codes and free text. Incidence rates per 100,000 person-years (PY) and incidence rate ratios (IRR) were calculated and stratified by age group and component. Antibiotics associated with episodes were evaluated using ATC-coded prescriptions. Additionally, to contextualise our pertussis data, regional trends in pertussis vaccination coverage were also described using the Italian National Institute of Health.
Results
Between 2010 and 2024, 5,130 episodes of pertussis and pertussis-like cough were identified among 456,912 children. In 2024, the incidence reached 1,316.9 per 100,000 person-years (PY; 95% CI, 1,261.5–1,374.2), compared with 156.06 (95% CI, 150.07–162.06) during 2010–2019, representing an 8.44-fold increase (IRR=8.44; 95% CI, 7.96–8.93). The increase was particularly marked among children aged 10–13 years, whose incidence rose from 83 per 100,000 PY in 2023 to 1,777.8 in 2024. This age group also had a higher incidence in 2024 than children aged under 10 years (1,777.8 vs 1,143.3 per 100,000 PY; IRR, 1.55; 95% CI, 1.42–1.69). Overall, 64.9% of episodes were treated with antibiotics (3,331/5,130), and macrolides accounted for 90.1% of antibiotic prescriptions (3,788/4,196). Among children aged 1–13 years, azithromycin use increased sharply, whereas clarithromycin use declined after 2014. Pertussis vaccination coverage remained approximately 95% from 2022 onward, although it had not fully returned to pre-2010 levels.
Conclusions
Using a population-based national database, we generated estimates of the countrywide burden and temporal trends of pertussis and pertussis-like cough and antibiotic use in Italy. The marked increase in episodes observed in 2024 was particularly pronounced among children aged 10–13 years. Together, these findings provide epidemiological evidence to inform and target future pertussis prevention and control strategies, especially for teenagers or incompletely vaccinated infants.