Incidence and severity of pertussis hospitalisations in infants aged less than 1 year in 37 hospitals of six EU/EEA countries, results of PERTINENT sentinel pilot surveillance system, December 2015 to December 2018

Lore Merdrignac (1) , Fatima Aït El Belghiti (2) , Elisabetta Pandolfi (3) , Mireia Jané (4) , Jane Murphy (5) , Kateřina Fabiánová (6) , Manuel García Cenoz (7) , Elmira Flem (8) , Sophie Guillot (9) , Alberto E Tozzi (3) , Gloria Carmona (4) , Adele Habington (10) , Jana Zavadilová (6) , Ana Navasués (11) , Håkon Bøås (8) , Daniel Lévy-Brühl (2) , Beatrice Ferretti (3) , Miguel Lanaspa (12) , Niam O'Sullivan (10) , Pavla Křížová (6) , Leticia Fernandino (7) , Terese Bekkevold (8) , Thomas Hanslik (13) , Carmen Muñoz-Almagro (12, 14, 15) , Sabrina Bacci (16) , Gianfranco Spiteri (16) , Marta Valenciano (1) , Alain Moren (1)

1 EpiConcept [Paris]
2 Direction des maladies infectieuses - Infectious Diseases Division [Saint-Maurice]
3 IRCCS Ospedale Pediatrico Bambino Gesù = Bambino Gesù Children’s Hospital
4 PHAC - Public Health Agency of Catalonia [Barcelona, Spain]
5 Temple Street Children's University Hospital [Dublin]
6 National Institute of Public Health [Prague]
7 IdiSNA - Instituto de Investigación Sanitaria de Navarra [Pamplona, Spain]
8 NIPH - Norwegian Institute of Public Health [Oslo]
9 Biodiversité et Epidémiologie des Bactéries pathogènes - Biodiversity and Epidemiology of Bacterial Pathogens
10 OLCHC - Our Lady's Children's Hospital Crumlin
11 Complejo Hospitalario de Navarra
12 Institut de Recerca Pediàtrica Hospital Sant Joan de Déu [Barcelona, Spain]
13 iPLESP - Institut Pierre Louis d'Epidémiologie et de Santé Publique
14 UIC - Universitat Internacional de Catalunya [Barcelona]
15 CIBERESP - Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública = Consortium for Biomedical Research of Epidemiology and Public Health
16 ECDC - European Centre for Disease Prevention and Control [Stockholm, Sweden]

Introduction PERTINENT is a pilot active surveillance system of infants hospitalised with pertussis in six European Union/European Economic Area countries (37 hospitals, seven sites). Aim This observational study aimed to estimate annual pertussis incidence per site from 2016 to 2018 and respective trends between 2017 and 2018. Pertussis cases were described, including their severity. Methods We developed a generic protocol and laboratory guidelines to harmonise practices across sites. Cases were hospitalised infants testing positive for Bordetella pertussis by PCR or culture. Sites collected demographic, clinical, laboratory data, vaccination status, and risk/protective factors. We estimated sites' annual incidences by dividing case numbers by the catchment populations. Results From December 2015 to December 2018, we identified 469 cases (247 males; 53%). The median age, birthweight and gestational age were 2.5 months (range: 0-11.6; interquartile range (IQR): 2.5), 3,280 g (range: 700-4,925; IQR: 720) and 39 weeks (range: 25-42; IQR: 2), respectively. Thirty cases (6%) had atypical presentation either with cough or cyanosis only or with absence of pertussis-like symptoms. Of 330 cases with information, 83 (25%) were admitted to intensive care units including five deceased infants too young to be vaccinated. Incidence rate ratios between 2018 and 2017 were 1.43 in Czech Republic (p = 0.468), 0.25 in Catalonia (p = 0.002), 0.71 in France (p = 0.034), 0.14 in Ireland (p = 0.002), 0.63 in Italy (p = 0.053), 0.21 in Navarra (p = 0.148) and zero in Norway. Conclusions Incidence appeared to decrease between 2017 and 2018 in all but one site. Enhanced surveillance of hospitalised pertussis in Europe is essential to monitor pertussis epidemiology and disease burden.

Mots clés: active surveillance; hospital surveillance; pertussis; pertussis incidence

Domaines: Santé publique et épidémiologie

Lore Merdrignac, Fatima Aït El Belghiti, Elisabetta Pandolfi, Mireia Jané, Jane Murphy, et al.. Incidence and severity of pertussis hospitalisations in infants aged less than 1 year in 37 hospitals of six EU/EEA countries, results of PERTINENT sentinel pilot surveillance system, December 2015 to December 2018. Eurosurveillance, 2021, 26 (4), pp.1900762. ⟨10.2807/1560-7917.ES.2021.26.4.1900762⟩. ⟨pasteur-03197871⟩