Epidemiology of invasive pneumococcal infection in children aged five years and under in Saudi Arabia: a five-year retrospective surveillance study

Abstract

The epidemiology of invasive pneumococcal disease (IPD) in children aged <or=5 years in Saudi Arabia has not been described. We conducted a retrospective surveillance study to describe the epidemiology of IPD in the population of children aged <or=5 years served by the National Guard Health Affairs hospitals in central and western regions of Saudi Arabia. We reviewed the medical records of children <or=5 years old admitted to the King Abdulaziz Medical City hospitals in Riyadh and Jeddah with pneumococcal infections for the period January 1999 through December 2003. Only microbiologically confirmed IPD cases (meningitis or bacteremia) were included in the analysis. A total of 82 IPD cases, 19 (23.2%) meningitis and 63 (76.8%) bacteremia, were diagnosed during the five-year period. Of these, 12.2% (10/82) died, with a case-fatality slightly but insignificantly higher in cases of meningitis (15.8%) than bacteremia (11.1%). The average annual IPD incidence was 17.4 per 100,000 (4.0 for meningitis and 13.4 for bacteremia). The incidence was roughly similar in males and females (18.3 and 16.6, respectively; p=0.663) and was almost 4-fold higher in the first year of life compared to the next four years (40.6 and 11.5, respectively; p<0.001). The average annual IPD mortality was 2.1 per 100,000 and was higher in the first year of life compared to the next four years (5.2 and 1.3 , respectively; p=0.043). In the pre-vaccination era (1999-2003) in Saudi Arabia, IPD incidence was comparable to the pre-vaccination incidence rates from many industrialized countries, with children aged <or=1 year suffering the highest IPD risk among those aged <or=5 years.