Variable Sensitivity in Molecular Detection of Zika Virus in European Expert Laboratories: External Quality Assessment, November 2016

Abstract

Zika virus (ZIKV) infections are a significant public health concern. A strong capability for ZIKV detection is an absolute requirement for adequate preparedness and response strategies and individual patient care. The objective of this study was to assess and improve the capability of European expert laboratories for molecular testing for ZIKV through an external quality assessment (EQA) scheme. Laboratories were provided a panel of 12 samples which included negative samples, samples containing African-or Asian-lineage ZIKV at various concentrations (10 3 to 10 9 copies/ml), and samples containing dengue virus, yellow fever virus, or chikungunya virus. The results were analyzed on the basis of the outcomes of testing for the samples and the extraction and detection method used. Samples with a ZIKV RNA status scored correctly by Ͼ50% of the laboratories were designated the core sample. A total of 85 panel outcomes were submitted by 50 laboratories in 31 countries. The results designated all samples as core samples. Thirty-three percent (28/85) of the panel outcomes identified all samples. Analysis at the laboratory level showed that only 40% of the laboratories (20/50), representing 45% of the countries, scored sufficiently; i.e., they had at least one test operational that scored all core samples correctly. There is a need for improvement of the molecular detection of ZIKV in 60% of the participating laboratories. While the specificity of the tests was more robust, the results of the EQA showed large variation in test sensitivity. Improvements should focus on both nucleic acid extraction and ZIKV detection methods.

Laboratory readiness and response for novel coronavirus (2019-nCoV) in expert laboratories in 30 EU/EEA countries, January 2020

“…To properly assess the actual capability of the laboratories to detect (sub)clinical 2019-nCoV cases and to provide directions for corrective actions, proficiency testing by external quality assessment (EQA) is essential and urgently needed. The importance of EQA was illustrated in the European ZIKV response where timely implementation was not matched by an overall good capability [17]. Forty of the 47 responding laboratories in this study indicated that they will participate in such an assessment.…”

Specialist laboratory networks as preparedness and response tool - the Emerging Viral Diseases-Expert Laboratory Network and the Chikungunya outbreak, Thailand, 2019

“…EVD-LabNet represents a laboratory and knowledge platform for support of clinical and public health preparedness and response through laboratory capacity and capability building. Moreover it provides access for ECDC, national public health authorities and its member laboratories to reference diagnostics, expertise and knowledge exchange [20,21]. EVD-LabNet comprises 61 expert laboratories in 30 European Union and European Economic Area (EU/EEA) countries, seven laboratories in seven EU pre-accession countries, three in two other European countries and six in six non-European countries.…”

The difficulties in obtaining reliable Zika virus diagnostics

“…2 Furthermore, in 2016, for the first time in documented history, confirmed yellow fever virus was exported in travellers from Africa to Asia, where about 2 billion immunologically naive people live in areas inhabited by the Aedes aegypti mosquito vector and are at risk for transmission. 3 The casefatality rate of yellow fever is among the highest of all arboviral diseases, underscoring the threat of a newly emerging epidemic disease problem in Asia.…”

“…Albeit to a lesser extent, similar problems were also observed in European laboratories, for which the overall risk of false-negative results was 14•5% (8•9-20•1) and the overall risk of false-positive results was 4•4% (2•1-6•8). 3 The similarities between the studies from Brazil and Europe show that adequate laboratory diagnosis of Zika virus infection is universally challenging. Unreliable Zika virus diagnostics have a huge effect on individual and public health, potentially including illegal abortions based on false-positive test results, 4 unwarranted delays of pregnancy, and biased estimates of the absolute risk of congenital disease upon maternal infection during pregnancy.…”