Continuous Pneumococcal Invasive Disease Reduction, High Impact on Pneumococcal Empyemas and Meningitis, and Serotype 19A Disappearance Following PCV-13 Vaccination in Children: Eleven and a Half Years of Active Surveillance in a Mexican Hospital on the U.S. Border

BACKGROUND: The Tijuana, Mexico and San Diego, California, is the world’s most transited frontier. We have previously published pneumococcal serotype replacement following PCV-7 introduction, especially by serotypes 19-A, 3 and 6A/C. Since May/2012 universal vaccination with PCV-13 was introduced for all children. This study analyzes the effectiveness of PCV-13 after its implementation in the region. METHODS: Since October/2005 until March/2017 (11.5 years) we underwent an active surveillance for all Invasive Pneumococcal Diseases (IPD) in children < 16 years admitted at the Tijuana General Hospital. Only culture-confirmed cases were included. Following identification, serotyping was performed using the Quellung Reaction (Statens Serum Institute(®) Copenhagen, Denmark). Descriptive analysis was performed using Excel(®). RESULTS: Fifty-seven cases of confirmed IPD were found. Clinical diagnosis were pleural empyemas (PPE) (45.6%), meningitis (PM) (28%), otomastoiditis (15.7%), only sepsis (7%), and bacteremic pneumonia (3.5%). Median age was of 3.9 years (2 days – 15.9 years), median hospitalization days was of 14 (1–90). Overall mortality was of 6 (10.5%). Following PCV13 introduction there was a decreased on overall IPD mortality by 73.29%, overall IPD by 68%, PPE by 68.1%, and PM by 55.4%. However, during 2015–16, we had three PM cases, two of which were immunocompromised patients, and none vaccinated with PCV13. From an average of 1.75 yearly cases due to pneumococcal serotype 19-A before PCV13 implementation, there had been no patients with IPD’s caused by this serotype. (See Figure 1). After PCV13 vaccination, serotypes associated with IPD cases had been as follow: Two 22F, and one each by 6A, 18C, 3, 7F, 15, 7B, 35B, 24F and 33F. CONCLUSION: This is the first Mexican study based on active surveillance that shows consistent effectiveness of PCV-13 on reduction of overall IPD, disappearance of pneumococcal serotype 19-A, and strong impact on PPE in children. Effectiveness on PM is still above 50%, however, during 2015–16 there had been three cases, but with particular conditions (immunodeficiencies and no vaccination). Continuous active surveillance is mandatory. DISCLOSURES: All authors: No reported disclosures.