{
   "source_x": "PMC",
   "title": "Density of Upper Respiratory Colonization With Streptococcus pneumoniae and Its Role in the Diagnosis of Pneumococcal Pneumonia Among Children Aged <5 Years in the PERCH Study",
   "doi": "http://dx.doi.org/10.1093/cid/cix100",
   "pmcid": "PMC5850437",
   "abstract": "BACKGROUND: Previous studies suggested an association between upper airway pneumococcal colonization density and pneumococcal pneumonia, but data in children are limited. Using data from the Pneumonia Etiology Research for Child Health (PERCH) study, we assessed this potential association. METHODS: PERCH is a case-control study in 7 countries: Bangladesh, The Gambia, Kenya, Mali, South Africa, Thailand, and Zambia. Cases were children aged 1\u201359 months hospitalized with World Health Organization\u2013defined severe or very severe pneumonia. Controls were randomly selected from the community. Microbiologically confirmed pneumococcal pneumonia (MCPP) was confirmed by detection of pneumococcus in a relevant normally sterile body fluid. Colonization density was calculated with quantitative polymerase chain reaction analysis of nasopharyngeal/oropharyngeal specimens. RESULTS: Median colonization density among 56 cases with MCPP (MCPP cases; 17.28 \u00d7 10(6) copies/mL) exceeded that of cases without MCPP (non-MCPP cases; 0.75 \u00d7 10(6)) and controls (0.60 \u00d7 10(6)) (each P < .001). The optimal density for discriminating MCPP cases from controls using the Youden index was >6.9 log(10) copies/mL; overall, the sensitivity was 64% and the specificity 92%, with variable performance by site. The threshold was lower (\u22654.4 log(10) copies/mL) when MCPP cases were distinguished from controls who received antibiotics before specimen collection. Among the 4035 non-MCPP cases, 500 (12%) had pneumococcal colonization density >6.9 log(10) copies/mL; above this cutoff was associated with alveolar consolidation at chest radiography, very severe pneumonia, oxygen saturation <92%, C-reactive protein \u226540 mg/L, and lack of antibiotic pretreatment (all P< .001). CONCLUSIONS: Pneumococcal colonization density >6.9 log(10) copies/mL was strongly associated with MCPP and could be used to improve estimates of pneumococcal pneumonia prevalence in childhood pneumonia studies. Our findings do not support its use for individual diagnosis in a clinical setting.",
   "authors": [
      "['Baggett, Henry C', 'Watson, Nora L', 'Deloria Knoll, Maria', 'Brooks, W Abdullah', 'Feikin, Daniel R', 'Hammitt, Laura L', 'Howie, Stephen R C', 'Kotloff, Karen L', 'Levine, Orin S', 'Madhi, Shabir A', 'Murdoch, David R', 'Scott, J Anthony G', 'Thea, Donald M', 'Antonio, Martin', 'Awori, Juliet O', 'Baillie, Vicky L', 'DeLuca, Andrea N', 'Driscoll, Amanda J', 'Duncan, Julie', 'Ebruke, Bernard E', 'Goswami, Doli', 'Higdon, Melissa M', 'Karron, Ruth A', 'Moore, David P', 'Morpeth, Susan C', 'Mulindwa, Justin M', 'Park, Daniel E', 'Paveenkittiporn, Wantana', 'Piralam, Barameht', 'Prosperi, Christine', 'Sow, Samba O', 'Tapia, Milagritos D', 'Zaman, Khalequ', 'Zeger, Scott L', 'O\u2019Brien, Katherine L', None]"
   ],
   "id": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5850437"
}