Laboratory preparedness and response with a focus on arboviruses in Europe

Dengue and chikungunya: future threats for Northern Europe?

Arthropod-borne viral diseases are likely to be affected by the consequences of climate change with an increase in their distribution and intensity. Among these infectious diseases, chikungunya and dengue viruses are two (re)emergent arboviruses transmitted by Aedes species mosquitoes and which have recently demonstrated their capacity for rapid expansion. They most often cause mild diseases, but they can both be associated with complications and severe forms. In Europe, following the establishment of invasive Aedes spp, the first outbreaks of autochtonous dengue and chikungunya have already occurred. Northern Europe is currently relatively spared, but climatic projections show that the conditions are permissive for the establishment of Aedes albopictus (also known as the tiger mosquito) in the coming decades. It is therefore essential to question and improve the means of surveillance in northern Europe, at the dawn of inevitable future epidemics.

Drive-through vaccinations prove successful in immunizing mountain communities against tick-borne encephalitis during the COVID-19 pandemic

In March 2020, the COVID-19 pandemic disrupted most of the routine outpatient activities in Italian hospitals and Prevention Departments, including those vaccinations which were not urgent and/or scheduled for children aged 0-6 years. Since June 2020, when the pandemic entered a milder phase, in the alpine Province of Belluno (Veneto, North-Eastern Italy), 12,152 doses of vaccine against tick-borne encephalitis have been administered by means of the innovative “drive-through” modality. No significant adverse events have occurred and popular demand has steadily grown, proving the “drive-through” approach to be safe, efficient and successful.

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

We illustrate the potential for specialist laboratory networks to be used as preparedness and response tool through rapid collection and sharing of data. Here, the Emerging Viral Diseases-Expert Laboratory Network (EVD-LabNet) and a laboratory assessment of chikungunya virus (CHIKV) in returning European travellers related to an ongoing outbreak in Thailand was used for this purpose. EVD-LabNet rapidly collected data on laboratory requests, diagnosed CHIKV imported cases and sequences generated, and shared among its members and with the European Centre for Disease Prevention and Control. Data across the network showed an increase in CHIKV imported cases during 1 October 2018–30 April 2019 vs the same period in 2018 (172 vs 50), particularly an increase in cases known to be related to travel to Thailand (72 vs 1). Moreover, EVD-LabNet showed that strains were imported from Thailand that cluster with strains of the ECSA-IOL E1 A226 variant emerging in Pakistan in 2016 and involved in the 2017 outbreaks in Italy. CHIKV diagnostic requests increased by 23.6% between the two periods. The impact of using EVD-LabNet or similar networks as preparedness and response tool could be improved by standardisation of the collection, quality and mining of data in routine laboratory management systems.

COVID-19 Infection: Data Gaps for Diagnostic Laboratory Preparedness and Tasks on Hand

Emergence of the 2019 novel coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) and its spread, with life-threatening outcomes, have caused a pandemic burden worldwide. Studies of emerging diseases under outbreak conditions have focused on the complete spectrum of pathogens, transmissibility, shedding kinetics in relation to infectivity, epidemiological causes, and interventions to control emergence. During the initial stages of an outbreak, laboratory response capacity focuses on expansion of efficient diagnostic tools for rapid case detection, contact tracing, putting epidemiological findings into sources, mode of transmission, and identification of susceptible groups and reservoirs. It is important for public health diagnostic laboratories to have a fundamental knowledge of viral shedding, antibody response kinetics, assay validation, interpretation, and uncertainties of test results. This study reviewed currently published data from available literature on SARS-CoV-2 infection and compared this with data on viral shedding and antibody response kinetics of other human coronaviruses. Also described are current challenges and comments on some biases and significant data gaps that have limited laboratory preparedness to SARS-CoV-2. Consistent documentation of progress and data gaps from standardized reporting of methods utilized, sampling date, details of test results by specimen type, risk assessments, and symptoms can all be used strategically and provide incentives to governments and their partners to prioritize the development, detection, and response to outbreaks.

Toscana, West Nile, Usutu and tick-borne encephalitis viruses: external quality assessment for molecular detection of emerging neurotropic viruses in Europe, 2017

BackgroundNeurotropic arboviruses are increasingly recognised as causative agents of neurological disease in Europe but underdiagnosis is still suspected. Capability for accurate diagnosis is a prerequisite for adequate clinical and public health response.AimTo improve diagnostic capability in EVD-LabNet laboratories, we organised an external quality assessment (EQA) focusing on molecular detection of Toscana (TOSV), Usutu (USUV), West Nile (WNV) and tick-borne encephalitis viruses (TBEV).MethodsSixty-nine laboratories were invited. The EQA panel included two WNV RNA-positive samples (lineages 1 and 2), two TOSV RNA-positive samples (lineages A and B), one TBEV RNA-positive sample (Western subtype), one USUV RNA-positive sample and four negative samples. The EQA focused on overall capability rather than sensitivity of the used techniques. Only detection of one, clinically relevant, concentration per virus species and lineage was assessed.ResultsThe final EQA analysis included 51 laboratories from 35 countries; 44 of these laboratories were from 28 of 31 countries in the European Union/European Economic Area (EU/EEA). USUV diagnostic capability was lowest (28 laboratories in 18 countries), WNV detection capacity was highest (48 laboratories in 32 countries). Twenty-five laboratories were able to test the whole EQA panel, of which only 11 provided completely correct results. The highest scores were observed for WNV and TOSV (92%), followed by TBEV (86%) and USUV (75%).ConclusionWe observed wide variety in extraction methods and RT-PCR tests, showing a profound absence of standardisation across European laboratories. Overall, the results were not satisfactory; capacity and capability need to be improved in 40 laboratories.

Emerging Aedes-borne infections in southern Switzerland: Preparedness planning for surveillance and intervention

BACKGROUND

The Preparedness Plan for Surveillance and Interventions on Emerging Vector-Borne Diseases (VBDs) in Southern Switzerland outlines the strategy for preventing and managing potential outbreaks, as well as the surveillance and control activities with a specific focus on Aedes-borne diseases transmitted by Aedes albopictus mosquitoes. The objective of the plan is to provide Public Health Authorities with a framework of preventive and control measures according to the situation and level of epidemic risks.

MATERIAL AND METHODS

The plan is divided into various phases representing the different steps for all potential situations, ranging from no vectors and no transmission risk to epidemic levels with multiple autochthonous/local cases of hospitalization (and deaths) until the end of the epidemic. An algorithm presents how decisions are taken to move from one phase of the plan to another, with detailed activities for different partners and strategies for each specific phase.

RESULTS

The different phases of the plan include activities on disease surveillance and clinical case management, on vector surveillance and control, communication and coordination of activities. The plan is divided into five phases of activities and decision levels. From phase 0 (no cases) to phase 1 (low number of local cases, less than 5), phase 2 (small outbreak with more than 5 local cases), phase 3 (epidemic) and phase 4 (return to no more cases).

CONCLUSION

The plan has been approved by the cantonal authorities and will be submitted to federal authorities. The required implementation tests will begin shortly.

Preparedness of European diagnostic microbiology labs for detection of SARS-CoV-2, March 2020

BACKGROUND

To track the European spread of SARS-CoV-2, decentralized testing became necessary and test capacity needed to be expanded outside reference laboratories rapidly.

METHODS

We assessed via an online questionnaire the preparedness of European hospital laboratories for detection of SARS-CoV-2 and listed the main drawbacks for implementation.

RESULTS

Forty-five percent of the surveyed labs had a test in place by March 26th which is well into the first wave of the pandemic in most countries.

CONCLUSIONS

The main implementation barriers for introduction of a SARSCoV-2 molecular assay in European diagnostic laboratories were availability of positive controls and a specificity panel.

Importation of dengue, Zika and chikungunya infections in Europe: the current situation in Greece

Although several arboviruses-such as dengue (DENV), Zika (ZIKV) and chikungunya (CHIKV) viruses-are not endemic in Europe, they have the potential to emerge following importation of the virus, taking advantage of the favourable climate and ecosystem. DENV, ZIKV and CHIKV are transmitted by Aedes species mosquitoes and are amongst the most common travel-associated arboviruses. Furthermore, they are linked to sporadic, local outbreaks, especially in the southern parts of Europe. In this review we present in brief the DENV, ZIKV and CHIKV cases imported to Greece during the last 6 years (2013-2018), and we describe the recent laboratory data obtained from the Hellenic Pasteur Institute and the National Reference Centre for Arboviruses. We report 21 imported cases of DENV, ZIKV and CHIKV infections in travellers arriving in Greece. The probable origins were south-eastern Asian (71%) and north-central American (29%) countries. Furthermore, we stress the importance of early and accurate diagnosis in spite of a plethora of diagnostic challenges that clinicians and virologists have to face. Altogether, with the authorities' awareness and the preventive measures to be applied, local transmission events can be successfully avoided, especially in summer when the temperature is favourable for mosquito-borne infections.

2019 meeting of the global virus network

The Global Virus Network (GVN) was established in 2011 to strengthen research and responses to emerging viral causes of human disease and to prepare against new viral pandemics. There are now 52 GVN Centers of Excellence and 9 Affiliate laboratories in 32 countries. The 11th International GVN meeting was held from June 9-11, 2019 in Barcelona, Spain and was jointly organized with the Spanish Society of Virology. A common theme throughout the meeting was globalization and climate change. This report highlights the recent accomplishments of GVN researchers in several important areas of medical virology, including severe virus epidemics, anticipation and preparedness for changing disease dynamics, host-pathogen interactions, zoonotic virus infections, ethical preparedness for epidemics and pandemics, one health and antivirals.

Need for additional capacity and improved capability for molecular detection of yellow fever virus in European Expert Laboratories: External Quality Assessment, March 2018

An external quality assessment of yellow fever virus (YFV) molecular detection in European laboratories was organised in rapid response to an increase in human cases in Brazil in 2018 with risk of import to Europe. Detection of YFV was assessed among 32 laboratories in 23/31 European Union (EU) and European Economic Area (EEA) countries and two laboratories in one non-EU/EEA country. Adequate capabilities were lacking in 10/23 countries; five did not participate as they lacked implemented assays.

An evaluation of serological methods to diagnose tick-borne encephalitis from serum and cerebrospinal fluid

BACKGROUND

Tick-borne encephalitis (TBE) is an infectious disease endemic to large parts of Europe and Asia. Diagnosing TBE often relies on the detection of TBEV-specific antibodies in serum and cerebrospinal fluid (CSF) as viral genome is mostly not detectable once neurological symptoms occur.

OBJECTIVES

We evaluated the performance of TBEV IgM and IgG ELISAs in both serum and CSF of confirmed TBEV patients and discuss the role of (CSF) serology in TBEV diagnostics.

STUDY DESIGN

For the assay evaluation we collected specimen from confirmed TBEV patients. Assay specificity was assessed using sera from patients with a related flavivirus infection or other acute infection. A selected ELISA assay was used to analyze TBEV-specific antibodies in CSF and to evaluate the use in confirming TBE diagnosis.

RESULTS

In this study the overall sensitivity of the IgM TBEV ELISAs was acceptable (94 -100 %). Four out of five IgM ELISA's demonstrated an excellent overall specificity from 94 -100% whereas a low overall specificity was observed for the IgG TBEV ELISAs (30-71%). Intrathecal antibody production against TBEV was demonstrated in a subset of TBE patients.

CONCLUSIONS

In four out of five ELISAs, IgM testing in serum and CSF of TBE patients is specific and confirmative. The lack of IgG specificity in all ELISAs emphasizes the need of confirmatory testing by virus neutralisation, depending on the patient's background and the geographic location of exposure to TBEV. A CSF-serum IgG antibody index can support the diagnosis specifically in chronic disease or once IgM has disappeared.

Familiar barriers still unresolved-a perspective on the Zika virus outbreak research response

Research is an important component of an effective response to the increasing frequency of widespread infectious disease outbreaks. In turn, the ability to do such studies relies on willingness of partners in different regions to collaborate and the capacity to mount a rapid research response. The EU-funded ZIKAlliance Consortium has initiated a multicountry epidemiological, clinical, and laboratory research agenda to determine the incidence, risk factors, and outcomes of Zika virus infection in pregnant women and their children. We reviewed the timeline of patient cohort initiation in relation to the Zika virus epidemic and mapped key events regarding funding, regulatory approvals, and site preparation during this timeline. We then assessed barriers and delays that the international research team experienced through a systematic telephone interview. We have identified three major bottlenecks in the implementation of a swift response: the absence of a timeline for the funding process, delays in regulatory and ethical approval, and the challenging logistics of laboratory support, including diagnostics. These bottlenecks illustrate the clear and urgent need for implementing a strong and permanent global emerging infectious diseases research capacity that has structured funding, enables long-term partnerships, and develops basic clinical and laboratorial research and a response infrastructure that is ready to deploy.

Ongoing and emerging arbovirus threats in Europe

During the last decades, arboviruses that are endemic in Europe have expanded their geographic range and caused an increasing number of human outbreaks. These viruses include West Nile virus, which is expanding its area of circulation in central and southern Europe; Usutu virus, with increasing evidence of a role in human disease; tick-borne encephalitis virus, which is being detected in northern areas and at higher altitudes as a consequence of climate warming; Crimean-Congo hemorrhagic fever virus, which is endemic in Eastern Europe and the Middle East, but has been recently detected in Spain; other viruses, such as California encephalitis virus antigenic group, which circulate in northern and central Europe but whose relevance for human disease in largely unknown. In addition, the rise in global travel and trade has posed Europe to an increased risk of introduction and expansion of exotic arthropod vectors and autochthonous transmission of arboviruses, like dengue and chikungunya viruses, following new introductions from endemic areas. Implementation of integrated arbovirus surveillance programs has been crucial to adopt proper control measures. The identification of emerging outbreaks is however challenging and requires a high degree of awareness and laboratory capacity, especially for the most neglected but potentially threatening pathogens.