The project, led by Dra. Carmen Ardanuy and Dr. Jordi Càmara, describes the impact of the introduction of conjugated pneumococcal vaccines on antibiotic multidrug resistance. In Streptococcus pneumoniae during the last 25 years
The work, which has been published in the Journal of Antimicrobial Chemotherapy, describes the changes that have taken place in the population of S. pneumoniae strains causing invasive disease. The project has been possible thanks to the historical pneumococcal collection of the Microbiology Service of the Bellvitge University Hospital, which was initiated by Dra. Josefina Liñares in 1980.
Pneumococcus is the main cause of serious infections such as pneumonia and meningitis, as well as less severe ones such as otitis media. In recent years, the introduction of conjugated pneumococcal vaccines in children has allowed for a decrease in pneumococcal diseases. This decrease has been observed in both children, the vaccine target population, and adults due to group protection. However, the appearance and expansion of S. pneumoniae clones carrying capsules not included in the vaccine may limit their efficacy.
The period analyzed in the work includes two key moments for the study of the evolution of invasive pneumococcal disease such as the introduction in the pediatric population of conjugate vaccines of 7 and 13 serotypes (PCV7 and PCV13) in the years 2001 and 2010, respectively. The study describes changes in the incidence of invasive pneumococcal disease, the evolution of clones responsible for multidrug resistance, and the clinical characteristics of patients with invasive pneumococcal disease.
The results show that the introduction of conjugated pneumococcal vaccines has had a beneficial effect especially in decreasing the incidence of resistant strains while the incidence of sensitive strains has remained stable. This has led to a general decline in resistance rates to most antimicrobials. The work also evaluates the coverage rates of two vaccines currently under development (PCV15 and PCV20) and concludes that almost half of current multidrug strains express serotypes not included in these vaccines so that their efficacy with respect to antibiotic resistance could be limited.
Finally, the work also analyzes the clinical characteristics of patients with invasive disease due to resistant strains concluding that, although not an independent factor associated with mortality, these strains appear mainly in patients with worse prognosis (advanced age, more comorbidities, nosocomial acquisition and previous antibiotic therapy), leading to increased mortality. The work, published in the Journal of Antimicrobial Chemotherapy, has been made possible thanks to the collaboration with researchers from the Infectious Diseases Service of the HUB, and the National Center for Microbiology (CNM-Madrid). It has been funded by the FIS (PI18 / 00339) and CIBERES (CB06 / 06/0037).
- See the article “A historical perspective of MDR invasive pneumococcal disease in Spanish adults”