Detection of Pneumococcal DNA in Blood by Polymerase Chain Reaction for Diagnosing Pneumococcal Pneumonia in Young Children From Low- and Middle-Income Countries

Abstract

Background.We investigated the performance of polymerase chain reaction (PCR) on blood in the diagnosis of pneumococcal pneumonia among children from 7 low- and middle-income countries.Methods.We tested blood by PCR for the pneumococcal autolysin gene in children aged 1–59 months in the Pneumonia Etiology Research for Child Health (PERCH) study. Children had World Health Organization–defined severe or very severe pneumonia or were age-frequency–matched community controls. Additionally, we tested blood from general pediatric admissions in Kilifi, Kenya, a PERCH site. The proportion PCR-positive was compared among cases with microbiologically confirmed pneumococcal pneumonia (MCPP), cases without a confirmed bacterial infection (nonconfirmed), cases confirmed for nonpneumococcal bacteria, and controls.Results.In PERCH, 7.3% (n = 291/3995) of cases and 5.5% (n = 273/4987) of controls were blood pneumococcal PCR-positive (P < .001), compared with 64.3% (n = 36/56) of MCPP cases and 6.3% (n = 243/3832) of nonconfirmed cases (P < .001). Blood pneumococcal PCR positivity was higher in children from the 5 African countries (5.5%–11.5% among cases and 5.3%–10.2% among controls) than from the 2 Asian countries (1.3% and 1.0% among cases and 0.8% and 0.8% among controls). Among Kilifi general pediatric admissions, 3.9% (n = 274/6968) were PCR-positive, including 61.7% (n = 37/60) of those with positive blood cultures for pneumococcus.Discussion.The utility of pneumococcal PCR on blood for diagnosing childhood pneumococcal pneumonia in the 7 low- and middle-income countries studied is limited by poor specificity and by poor sensitivity among MCPP cases.

Intrapleural streptokinase is effective and safe for children with multi‐loculated empyema regardless of the time from disease onset

“…The relative paucity of pneumococcus in bacterial culture despite the absence of a vaccination programme during the study period indirectly suggests that the pneumococcal disease burden was lower than expected. This was also emphasised by the culture data in the Community Acquired Pneumonia Etiology Study from our institution and the Pneumonia Etiology Research for Child Health data from sites in Bangladesh and Thailand . However, a study in South African children reported that polymerase chain reaction analysis of pleural fluid dramatically increased the yield of pneumococcus compared to just cultures .…”

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

“…A study among children and adults hospitalized with acute LRTI in South Africa found that invasive pneumococcal pneumonia was associated with increased colonization density; cases with density >1000 copies/mL had 18 times greater odds of invasive pneumococcal pneumonia than colonized cases with density <1000 copies/mL [10]. The South African study defined invasive pneumococcal pneumonia by detection of S. pneumoniae by PCR in the blood, a diagnostic not used in our study owing to poor specificity [31,32]. We found that the best-performing threshold (6.9 log 10 [10 6.9 ] copies/mL) was much higher than that suggested by the South African study, but comparison of density thresholds between studies is limited by methodologic differences.…”

Advances in the diagnosis of pneumonia in children

“…[107][108][109] However recent results from the multicenter Pneumonia Etiology Research for Child Health (PERCH) study showed both poor sensitivity (64%; 36/56 microbiologically confirmed pneumococcal pneumonia cases were PCR positive) and specificity (5.5%; 273/4987 of non-pneumonia controls were PCR positive). 110 These results illustrate the need for Reducing contamination of samples Samples that are less likely to be contaminated by upper respiratory flora may be less prone to problems of interpretation. Bronchoscopy with bronchoalveolar lavage (BAL) or aspirate may provide a representative sample from the lower respiratory tract but it is invasive and requires specialized skill and sedation of the child.…”

“…Serological testing of blood specimens may be useful for epidemiological studies of the cause of pneumonia, where comparison of acute and convalescent titers may help identify the causative agent, [93][94][95][96][97][98][99][100][101][102][103][104][105][106][107][108][109][110][111][112] although the diagnostic value of a single specimen collected in the acute phase of the illness is generally limited. Pertussis serology may be a useful complementary diagnostic tool in older children and during the later phases of illness.…”