Background: Streptococcus pneumoniae
is the leading cause of childhood pneumonia
worldwide. Isolation of this organism, however, is uncommon in resource-poor countries, in part because of extensive use of prior antibiotics. A rapid, highly sensitive immunochromatographic test
(ICT) for S. pneumoniae
was evaluated for the diagnosis of meningitis
Cerebrospinal fluid (CSF) from 450 children with suspected meningitis
was tested with ICT, and results were compared with CSF culture, latex agglutination test (LAT) and/or polymerase chain reaction
(PCR). Serial CSF specimens from 11 patients were also evaluated for duration of positive results during effective antimicrobial therapy.
All 122 cases of pyogenic pneumococcal meningitis
positive either by culture (N = 87) or PCR (N = 35) were positive by ICT, yielding 100% (122 of 122) sensitivity. All purulent CSF specimens from patients with meningitis
caused by other bacteria by culture (N = 149) or by LAT (N = 48) or those negative by culture, LAT and LytA
and thus of unknown etiology (N = 20), and normal CSF specimens (N = 104) were negative by ICT. Thus the specificity of ICT also was 100% (321 of 321), although negativity of ICT was not confirmed by PCR, if it was positive for other organisms either by culture or LAT. Serotyping of S. pneumoniae
strains revealed 28 different serotypes, indicating that outcome of ICT are independent of diverse capsular serotype of pneumococcus
. Antigen was detected by ICT for at least 10 days after presentation, and 1 was still positive on day 20, which was longer than for either LAT or PCR.
ICT for pneumococcal antigen in CSF is 100% sensitive and specific in diagnosing pyogenic pneumococcal meningitis
and can detect ∼30% more pneumococcal meningitis
cases than with culture alone. The simplicity of the test procedure and the longevity of CSF antigen detection suggest the potential utility of ICT to estimate the true burden of pneumococcal disease, as for Haemophilus influenzae
type b using data from meningitis
, and to guide selection of appropriate antibiotic treatment, especially in resource-poor countries with widespread prehospital antimicrobial use.