Standardization of Laboratory Methods for the PERCH Study

Abstract

The Pneumonia Etiology Research for Child Health study was conducted across 7 diverse research sites and relied on standardized clinical and laboratory methods for the accurate and meaningful interpretation of pneumonia etiology data. Blood, respiratory specimens, and urine were collected from children aged 1–59 months hospitalized with severe or very severe pneumonia and community controls of the same age without severe pneumonia and were tested with an extensive array of laboratory diagnostic tests. A standardized testing algorithm and standard operating procedures were applied across all study sites. Site laboratories received uniform training, equipment, and reagents for core testing methods. Standardization was further assured by routine teleconferences, in-person meetings, site monitoring visits, and internal and external quality assurance testing. Targeted confirmatory testing and testing by specialized assays were done at a central reference laboratory.

Challenges in the diagnosis of paediatric pneumonia in intervention field trials: recommendations from a pneumonia field trial working group

“…Whenever incorporating ancillary diagnostics into a case definition, the equipment and technologies used should be thoroughly profiled and, ideally, standardised. 87,116 These factors are both particularly important when study personnel are not doing these ancillary tests or diagnostic procedures themselves, such as in passive surveillance. Investigators should aim to homogenise the equipment and diagnostic procedures available across health facilities.…”

“…Future studies should consider a standardised approach for both sample collection and laboratory processing, as described by PERCH investigators. 87 Studies that investigate the causes of pneumonia could help to reduce heterogeneity in pneumonia phenotypes by identifying whether the underlying infection is predominantly bacterial, viral, or a combination of both. One potential complication with these studies is that multiple pathogens are often found in the respiratory tract of both sick and healthy children.…”

Colonization Density of the Upper Respiratory Tract as a Predictor of Pneumonia—Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Pneumocystis jirovecii

“…PERCH employed conventional and molecular diagnostic techniques for the identification of potential pathogens, as described elsewhere [8, 28–31]. In brief, total nucleic acid extraction was performed on respiratory specimens using the NucliSens easy-MAG system (bioMérieux, Marcy l’Etoile, France).…”

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

“…All laboratory methods were standardized across sites [18]. A flocked NP swab (flexible minitip; Copan) and a rayon oropharyngeal (OP) swab specimen were collected from each case and control and were placed into the same vial.…”

“…A second NP specimen for S. pneumoniae culture was collected simultaneously with the first swab specimen; pneumococcal isolates were serotyped using Quellung reaction or latex agglutination, as described elsewhere [18]. Testing was performed at each site, and all sites participated in external quality assurance programs for both pneumococcal PCR and serotyping [18].…”