Paediatric invasive pneumococcal disease on the island of Gran Canaria: 16-year prospective study (2001-2016).

Objectives: To calculate the incidence of invasive pneumococcal disease (IPD) in the paediatric population of Gran Canaria (Spain), its clinical and epidemiological characteristics, serotype distribution, antibiotic resistance, and variations in these variables before and after the introduction of the PCV13 vaccine.

Methods: Prospective hospital-based study including all patients (190) aged 0-14 years admitted with confirmed IPD between January 2001-May 2010 (152 cases) and June 2010-December 2016 (38 cases). Patients were divided into 3 age groups (<2 years; 2-5 years; and >5 years). Clinical symptoms were mutually-exclusively classified as meningitis, bacteraemic pneumonia, pleural effusion (PE), empyema or bacteraemia without a focus.

Results: Most cases occurred in boys (59.47%), during autumn-winter (65.79%), in children aged <2 years (55.79%) and with mean age increasing from the pre-PCV13 to the post-PCV13 period (2.5 vs 3.1 years). Incidence between periods reduced by 66.4% (p<0.001): from 13.1/100,000 to 4.4/100,000. PEs (3.9% vs 18.4%, p<0.005) and empyemas (1.5% vs 16.7%, p=NS) increased in the post-PCV13 period whereas all other symptoms decreased, although this was not statistically significant. Vaccine serotypes (77% vs 40.6%, p=0.000), particularly serotypes 19A (23.9% vs 12.5%) and 14 (14.2% vs 9.4%), as well as erythromycin resistance (57.2% vs 7.9%, p=0.000) decreased in the post-PCV13 period.

Conclusion: IPD incidence, vaccine serotypes and erythromycin resistance decreased in the post-PCV13 period whereas PEs increased.