A prospective study of etiology of childhood acute bacterial meningitis, Turkey

Abstract

Determination of the etiology of bacterial meningitis and estimating cost of disease are important in guiding vaccination policies. To determine the incidence and etiology of meningitis in Turkey, cerebrospinal fluid (CSF) samples were obtained prospectively from children (1 month-17 years of age) with a clinical diagnosis of acute bacterial meningitis. Multiplex PCR was used to detect DNA evidence of Streptococcus pneumoniae, Haemophilus influenzae type b (Hib), and Neisseria meningitidis. In total, 408 CSF samples were collected, and bacterial etiology was determined in 243 cases; N. meningitidis was detected in 56.5%, S. pneumoniae in 22.5%, and Hib in 20.5% of the PCR-positive samples. Among N. meningitidis-positive CSF samples, 42.7%, 31.1%, 2.2%, and 0.7% belonged to serogroups W-135, B, Y, and A, respectively. This study highlights the emergence of serogroup W-135 disease in Turkey and concludes that vaccines to prevent meningococcal disease in this region must provide reliable protection against this serogroup.

Figure 1

Meningitis cases by geographic region of Turkey. The number of suspected meningitis cases included in the study per region is shown in boldface, with the region-specific estimated incidence rate of laboratory-confirmed meningitis (per 100,000 population) shown in parentheses. In total, 408 children were diagnosed with suspected acute bacterial meningitis. Bacterial meningitis was confirmed by PCR, culture, or latex agglutination test in 243 cases. Region-specific incidence rates ranged from 1.0 to 10.9/100,000 population.

Figure 2

Distribution of bacteria causing childhood acute bacterial meningitis in different age groups. Neisseria meningitidis was the most common cause of meningitis, and the highest estimated incidence was in children <1 year of age for all 3 bacteria. The number of cases is indicated above each bar. S. pneumoniae, Streptococcus pneumoniae; Hib, Haemophilus influenzae type b.

Figure 3

Distribution of etiology of acute bacterial meningitis in Turkey detected by using PCR analysis. Of 243 PCR-confirmed cases, 138 (56.5%) were attributable to Neisseria meningitidis, 55 (22.5%) to Streptococcus pneumoniae, and 50 (20.5%) to Haemophilus influenzae type b (Hib).

Figure 4

Distribution of predominant Neisseria meningitidis serogroups in different age groups. Serogroups W-135 and B caused 42.7% and 31.1% of all meningococcal infections, respectively. W-135 was the most common cause of meningococcal infection in all but 2 age groups analyzed.

Figure 5

Etiology of confirmed cases of bacterial meningitis in different geographic regions. W-135 was the most prominent Neisseria meningitidis serogroup in the Southeast Anatolia, Aegean, Eastern Anatolia, and Black Sea regions. The percentages of cases caused by Streptococcus pneumoniae and Haemophilus influenzae type b (Hib) are also shown.