Evaluation of the World Health Organization Global Invasive Bacterial Vaccine-Preventable Disease (IB-VPD) Surveillance Network’s Laboratory External Quality Assessment Programme, 2014–2019

Abstract

Introduction. In 2009, the World Health Organization (WHO) established the Global Invasive Bacterial Vaccine Preventable Disease (IB-VPD) Surveillance Network (GISN) to monitor the global burden and aetiology of bacterial meningitis, pneumonia and sepsis caused by Haemophilus influenzae (Hi), Neisseria meningitidis (Nm) and Streptococcus pneumoniae (Sp). Hypothesis/Gap Statement. The GISN established an external quality assessment (EQA) programme for the characterization of Hi, Nm and Sp by culture and diagnostic PCR. Aim. To assess the performance of sentinel site laboratories (SSLs), national laboratories (NLs) and regional reference laboratories (RRLs) between 2014 and 2019 in the EQA programme. Methodology. Test samples consisted of bacterial smears for Gram-staining, viable isolates for identification and serotyping or serogrouping (ST/SG), plus simulated cerebrospinal fluid (CSF) samples for species detection and ST/SG by PCR. SSLs and NLs were only required to analyse the slides for Gram staining and identify the species of the live isolates. RRLs, and any SLs and NLs that had the additional laboratory capacity, were also required to ST/SG the viable isolates and analyse the simulated CSF samples. Results. Across the period, 69–112 SS/NL labs and eight or nine RRLs participated in the EQA exercise. Most participants correctly identified Nm and Sp in Gram-stained smears but were less successful with Hi and other species. SSLs/NLs identified the Hi, Nm and Sp cultures well and also submitted up to 56 % of Hi, 62 % of Nm and 33 % of Sp optional ST/SG results each year. There was an increasing trend in the proportion of correct results submitted over the 6 years for Nm and Sp. Some SSLs/NLs also performed the optional detection and ST/SG of the three organisms by PCR in simulated CSF from 2015 onwards; 89–100 % of the CSF samples were correctly identified and 76–93 % of Hi-, 90–100 % of Nm- and 75–100 % of Sp-positive samples were also correctly ST/SG across the distributions. The RRLs performed all parts of the EQA to a very high standard, with very few errors across all aspects of the EQA. Conclusion. The EQA has been an important tool in maintaining high standards of laboratory testing and building of laboratory capacity in the GISN.

Evaluation of Laboratories Supporting Invasive Bacterial Vaccine-Preventable Disease (IB-VPD) Surveillance in the World Health Organization African Region, through the Performance of Coordinated External Quality Assessment

“…The majority of the participants experienced problems in identifying bacterial morphologies compatible with H. influenzae on Gram stains, particularly in 2014 and 2017 where <80% of laboratories correctly identified these on Gram stains. Gram staining results for H. influenzae were not scored in the EQA scheme for all laboratories in 2014, 2017, 2018 and 2019, because <80% of all (global) participants reported the correct result [ 17 ]. In 2014, approximately 40% of the laboratories failed to identify Gram stains, and this proportion decreased to 18% in 2016.…”

“…The WHO IB-VPD EQA distribution (provided by the UK NEQAS) was conducted once per calendar year, and each full panel of samples consisted of (i) unstained bacterial smears for Gram-staining, (ii) viable isolates for identification and serotyping/serogrouping (ST/SG) and (iii) simulated CSF samples for PCR-based species detection and ST/SG. Details on sample preparation, quality control, shipping and laboratory testing, reporting to the UK NEQAS and results scoring are detailed elsewhere [ 17 ]. Briefly, three or four bacterial films on glass slides were included in each distribution for Gram staining.…”

“…The scoring scheme for the EQA is described in detail elsewhere [ 17 ]. Briefly, any result matching the intended result for the Gram staining results was given a score of “1”; incorrect results were scored as “0”.…”

“…In general, failure to report an individual result was given a score of “0”. Within each distribution, some Gram staining results from individual samples or identification results from individual viable cultures were excluded from the scoring scheme if <80% of respondents did not achieve the expected result, in accordance with UK NEQAS accreditation standards (ISO17043) [ 17 ]. Each component of the EQA was scored separately and then combined to give an overall score.…”

“…The performance of laboratories supporting the IB-VPD surveillance at a global level was recently published, highlighting the progress and challenges in identifying meningitis-prone pathogens [ 17 ]. However, in that report no regional evaluation was conducted to assess the impact that EQAs had on participating African laboratories and whether they were meeting the priority-defined objectives of improving laboratory performance.…”