National Center for Biotechnology Information NCBI NLM MEDLINE humans pubmed abstract nih national institutes of health national library of medicine research support non-u.s. gov't adult female male adolescent aged middle aged Antibodies sensitivity and specificity pneumonia pneumococcal / diagnosis* streptococcus pneumoniae / isolation & purification* j anthony g scott kenya enzyme-linked immunosorbent assay / methods pmid:12134258 doi:10.1086/341205 validation study jacktone obiero kevin marsh bacterial / blood* bacterial proteins / analysis* immunoglobulin g* / blood pneumococcal / immunology roc curve