RESUMEN
Middle East respiratory syndrome coronavirus (MERS-CoV) was detected in humans in 2012. Since then, sporadic outbreaks with primary transmission through dromedary camels to humans and outbreaks in healthcare settings have shown that MERS-CoV continues to pose a threat to human health. Several serologic assays for MERS-CoV have been developed globally. We describe a collaborative study to investigate the comparability of serologic assays for MERS-CoV and assess any benefit associated with the introduction of a standard reference reagent for MERS-CoV serology. Our study findings indicate that, when possible, laboratories should use a testing algorithm including >2 tests to ensure correct diagnosis of MERS-CoV. We also demonstrate that the use of a reference reagent greatly improves the agreement between assays, enabling more consistent and therefore more meaningful comparisons between results.
Asunto(s)
Infecciones por Coronavirus/diagnóstico , Coronavirus del Síndrome Respiratorio de Oriente Medio , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/inmunología , Ensayo de Inmunoadsorción Enzimática , Técnica del Anticuerpo Fluorescente , Humanos , Coronavirus del Síndrome Respiratorio de Oriente Medio/inmunología , Pruebas de Neutralización , Análisis de Secuencia por Matrices de Oligonucleótidos , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Pruebas Serológicas/métodosRESUMEN
The first reported case of Middle East respiratory syndrome coronavirus (MERS-CoV) infection was identified in Saudi Arabia in September 2012, since which time there have been over 2000 laboratory-confirmed cases, including 750 deaths in 27 countries. Nucleic acid testing (NAT) is the preferred method for the detection of MERS-CoV. A single round of a Proficiency Testing Program (PTP) was used to assess the capability of laboratories globally to accurately detect the presence of MERS-CoV using NAT. A panel of eleven lyophilized specimens containing different viral loads of MERS-CoV, common coronaviruses, and in vitro RNA transcripts was distributed to laboratories in all six World Health Organization regions. A total of 96 laboratories from 79 countries participating in the PTP, with 76 of 96 (79.2%) reporting correct MERS-CoV results for all nine scored specimens. A further 10 laboratories (10.4%) scored correctly in eight of nine specimens of the PTP. The majority of laboratories demonstrated satisfactory performance in detecting the presence of MERS-CoV using NAT. However, some laboratories require improved assay sensitivity, reduced cross contamination of samples, and improved speciation of coronavirus subtypes for potentially complex clinical specimens. Further PTP and enhanced links with expert laboratories globally may improve the laboratory performance.
Asunto(s)
Infecciones por Coronavirus/diagnóstico , Ensayos de Aptitud de Laboratorios , Coronavirus del Síndrome Respiratorio de Oriente Medio/aislamiento & purificación , Salud Global , Humanos , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Arboviruses such as dengue virus, yellow fever virus, Zika virus and chikungunya virus are major threats to human health globally, including countries in the Eastern Mediterranean Region (EMR). AIMS: This study aimed to assess laboratory proficiency in EMR countries for detection of dengue virus, yellow fever virus, Zika virus and chikungunya virus. METHODS: A global external quality assessment programme for arbovirus diagnostics was developed and run in 2016 and 2018. National-level public health laboratories were instructed to apply the polymerase chain reaction detection method on specimen panels containing dengue virus, yellow fever virus, Zika virus and chikungunya virus. RESULTS: Over both rounds of the programme, 100% of participating EMR laboratories correctly detected yellow fever virus and chikungunya virus, ≥ 84.6% detected dengue fever virus and ≥ 76.9% detected Zika virus. CONCLUSION: While participating EMR countries demonstrated good proficiency in detecting arboviruses, only half of them were enrolled in the global external quality assessment programme, providing an incomplete picture of regional capacity. Effort should be put into increasing participation in subsequent rounds.
Asunto(s)
Infecciones por Arbovirus/diagnóstico , Arbovirus , Laboratorios/normas , Garantía de la Calidad de Atención de Salud/normas , Infección por el Virus Zika , Fiebre Chikungunya/diagnóstico , Dengue/diagnóstico , Humanos , Laboratorios/estadística & datos numéricos , Medio Oriente , Garantía de la Calidad de Atención de Salud/estadística & datos numéricos , Organización Mundial de la Salud/organización & administración , Fiebre Amarilla/diagnóstico , Infección por el Virus Zika/diagnósticoRESUMEN
Diagnostics play a central role in the early detection and control of outbreaks and can enable a more nuanced understanding of the disease kinetics and risk factors for the Middle East respiratory syndrome-coronavirus (MERS-CoV), one of the high-priority pathogens identified by the WHO. In this review we identified sources for molecular and serological diagnostic tests used in MERS-CoV detection, case management and outbreak investigations, as well as surveillance for humans and animals (camels), and summarised the performance of currently available tests, diagnostic needs, and associated challenges for diagnostic test development and implementation. A more detailed understanding of the kinetics of infection of MERS-CoV is needed in order to optimise the use of existing assays. Notably, MERS-CoV point-of-care tests are needed in order to optimise supportive care and to minimise transmission risk. However, for new test development, sourcing clinical material continues to be a major challenge to achieving assay validation. Harmonisation and standardisation of laboratory methods are essential for surveillance and for a rapid and effective international response to emerging diseases. Routine external quality assessment, along with well-characterised and up-to-date proficiency panels, would provide insight into MERS-CoV diagnostic performance worldwide. A defined set of Target Product Profiles for diagnostic technologies will be developed by WHO to address these gaps in MERS-CoV outbreak management.
RESUMEN
Background: In 2002, the World Health Organization (WHO) launched a regional microbiology external quality assessment (EQA) programme for national public health laboratories in the African region, initially targeting priority epidemic-prone bacterial diseases, and later including other common bacterial pathogens. Objectives: The aim of this study was to analyse the efficacy of an EQA programme as a laboratory quality system evaluation tool. Methods: We analysed the proficiency of laboratories' performance of bacterial identification and antimicrobial susceptibility testing (AST) for the period 2011-2016. The National Institute for Communicable Diseases of South Africa provided technical coordination following an agreement with WHO, and supplied EQA samples of selected bacterial organisms for microscopy (Gram stain), identification, and antimicrobial susceptibility testing (AST). National public health laboratories, as well as laboratories involved in the Invasive Bacterial Diseases Surveillance Network, were enrolled by the WHO Regional Office for Africa to participate in the EQA programme. We analysed participants' results of 41 surveys, which included the following organisms sent as challenges: Streptococcus pneumonia, Haemophilus influenzae, Neisseria meningitidis, Salmonella Typhi, Salmonella Enteritidis, Shigella flexneri, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus anginosus, Enterococcus faecium, Serratia marcescens, Acinetobacter baumannii, and Enterobacter cloacae. Results: Eighty-one laboratories from 45 countries participated. Overall, 76% of participants obtained acceptable scores for identification, but a substantial proportion of AST scores were not in the acceptable range. Of 663 assessed AST responses, only 42% had acceptable scores. Conclusion: In the African Region, implementation of diagnostic stewardship in clinical bacteriology is generally suboptimal. This report illustrates that AST is poorly done compared to microscopy and identification. It is critically important to make the case for implementation of quality assurance in AST, as it is the cornerstone of antimicrobial resistance surveillance reporting and implementation of the Global Antimicrobial Resistance Surveillance System.