Background: Worldwide, invasive pneumococcal disease (IPD) causes considerable morbidity and mortality among children, but incidence data in Asia are lacking. This 2-year hospital-based, prospective, surveillance study was conducted at 3 study sites in urban areas of the Philippines to estimate IPD and pneumonia incidence in children and describe the serotype distribution of invasive Streptococcus pneumoniae isolates.
Methods: Children aged 28 days to <60 months residing within the 3 surveillance areas presenting with possible IPD were enrolled. Initial diagnosis, history of pneumococcal vaccine receipt and previous antimicrobial treatment were recorded. Blood specimens were collected for S. pneumoniae identification and serotyping. Final diagnosis was determined for hospitalized subjects, subjects whose culture yielded S. pneumoniae and subjects with clinically suspected meningitis.
Results: A total of 5940 subjects were enrolled, 47 IPD cases identified. IPD site rates were 33.49 per 100,000, 25.38 per 100,000 and 25.85 per 100,000. Chest radiograph-confirmed pneumonia incidence ranged from 633.74 to 1683.59 per 100,000. Highest chest radiograph-confirmed pneumonia incidence occurred in those 28 days to <6 months of age at 2 sites (2166.16 and 3891.94 per 100,000) and those 6–12 months of age at the third site (3847.52 per 100,000). Thirty-five S. pneumoniae isolates were serotyped; most commonly identified were serotypes 1, 2, 5, 6B, 14 and 18F. One serotype 14 isolate was erythromycin resistant. Previous antibiotic therapy was documented in 17–53% of subjects; 2 subjects had received pneumococcal vaccine. At 2 sites, one-third of IPD subjects died.
Conclusions: IPD is an important cause of morbidity and mortality among urban children in the Philippines. Our data support the expectation that widespread immunization would decrease IPD disease burden.
From the *Medical Department, Research Institute for Tropical Medicine, Muntinlupa City, Philippines; †Department of Pediatrics, Philippine General Hospital and National Institutes of Health, University of Philippines Manila, Manila, Philippines; ‡Infectious Diseases Section, Philippine Children’s Medical Center, Quezon City, Philippines; §Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy, Detroit, MI; ¶Translational Research Divison, International Vaccine Institute, Seoul, Republic of Korea; Former Employee of Pfizer Global Research and Development, Paris, France; **Vaccines Clinical Research, ††Clinical Affairs, Specialty Care Business Unit, Pfizer Inc, Collegeville, PA; and ‡‡Former Employee of On Assignment Inc. contracted to Pfizer Inc, Collegeville, PA.
Accepted for publication April 25, 2013.
This study was sponsored by Wyeth, which was acquired by Pfizer Inc in October 2009. Medical writing support was provided by Elaine Santiago, PharmD, at Excerpta Medica and was funded by Pfizer Inc. M.R.C. and L.B. have received speaker honoraria and travel grants from Pfizer Inc, GlaxoSmithKline, Sanofi Pasteur and Novartis. J.S. received speaker honoraria and travel grants from Pfizer Inc, Sanofi Pasteur, Merck and Novartis. R.H. and M.M. are current employees of Pfizer Inc. I.B. was an employee of Pfizer Inc at the time of the study. J.Y. is a former employee of On Assignment Inc, and was a paid contractor to Pfizer to assist with study design, statistical planning, data analysis and manuscripts development. P.E.K. was an employee of International Vaccine Institute and S.A.K. was and still is an employee of International Vaccine Institute which was contracted to Pfizer Inc to assist in conduct of this study.
Address for correspondence: Maria Rosario Capeding, MD, Research Institute for Tropical Medicine, Alabang Medical Clinic, 297 Montillano St., Alabang, Muntinlupa City, Philippines. E-mail: firstname.lastname@example.org.