Upcoming Technologies for Early and Rapid Diagnosis of Infectious Diseases Joint FAO/IAEA Consultants’ Meeting, 18-20 May 2011

Purpose: To evaluate progress and recommend future direction for the development of tools used for detection of transboundary animal diseases, including zoonotic agents. The specific objective was to discuss amplification and non-amplification systems, biosensors, nanotechnology and equipment, environmental sampling technologies, remote sensing, communication technologies, administrative and logistical set-ups, networks and partnerships. The goal is to improve early warning systems, global capacity and diagnostic harmonization to enhance livestock production and health and contribute towards uniting pathogen detection technologies as a basis of the global one-world, one-health initiative.

Specific Aims: The main thrust of the meeting was to review the latest technologies for detection of transboundary animal diseases (including zoonoses), exchange experiences and opinions on their current level of development, and to discuss the level of their validation and harmonization. The scope of the discussions covered implementation of the novel technologies into the whole diagnostic process starting from sampling and preparation of samples, to testing and reporting. Development of new information platforms for uptake, storage and data analysis, using multiplex diagnostic platforms was also discussed. Special attention has been given to the specific approaches (solutions) required to implement early and rapid diagnostic technologies in Member States (MS), in order to improve the animal health component of the food security chain.

Overall observations: The global development of improved transport infrastructure has contributed to increased international movement of people and goods, as well as increased global (legal and illegal) trade. Consequently, the risk of unintentional or intentional transfer of pathogens between countries or even between continents has increased. Moreover, human and animal diseases, including zoonoses, such as avian influenza (AI), severe acute respiratory syndrome (SARS) and others, have already shown a devastating impact on public and animal health. In addition, due to global climate changes, diseases endemic for certain areas, such as Blue tongue (BT) in North-western Europe and African swine fever (ASF) in the Caucasus are showing a tendency to move or extend to other geographical areas outside their normal range. In addition, political upheavals are cause for increased concern of potential bio- and agro-terrorism events. From these reasons, potentially pandemic diseases are demanding continuous improvements in early and rapid diagnostic technologies.

The Joint FAO/IAEA Division, as a part of the UN aims to contribute to solving these problems by organizing consultancy meetings has invited top experts in the field of development of diagnostic platforms, whose in-depth knowledge and experience will provide a foundation to evaluate the potential implementation of novel early and rapid diagnostic tools in the MS. Promising technology platforms can then be experimentally incorporated in research activities validating their fitness for purpose and applicability in the MS.

Diagnostic technologies offer great potential for detection of infectious pathogens in animals and humans. These technologies enable the detection of clinical disease, usually after the pathogen has been disseminated in the population. The rapid development and emergence of new diagnostic platforms has provided many opportunities for early detection of emerging and unknown pathogens. An example of a powerful laboratory-based technique is Real-time PCR which in recent years has gained diagnostic acceptance in many laboratories in the developed world. However, it must be noted that this has occurred approximately 20 years after its initial non-Real-time application as primarily a research tool in pathogen or disease investigations. Such molecular approaches have contributed to the rapid increase of global pathogen sequence banks, thereby increasing understanding of pathogen epidemiology and variety. Several other platforms presented during previous meetings, such as isothermal amplification, biosensor and microarrays in solid (gene-chip, protein chips) and liquid (bead-based) format, have continued to evolve through the various stages, from research to diagnostic application. However, test validation for new tests continues to be an important issue and, can be difficult to validate through a traditional assay validation strategies. The FAO/IAEA Division is in a unique position to facilitate international networks in a “One World – One Health” approach in collaboration with WHO, other UN Agencies, NGO’s and other organizations and the MS to transfer, evaluate and validate new technologies.

The technological improvements presented during the current meeting have shown continuation of two common tendencies, namely miniaturization and multiplexing, especially in the field of molecular diagnostics. Several advanced technologies to detect the nucleic acid of pathogens were presented and discussed during the meeting, such as:

The technologies reviewed have significantly contributed towards determination of unresolved (known and unknown) diseases, such as aetiology of acute respiratory diseases in USA, Arenavirus infections related to transplantation of organs in humans, Salmon reovirus infection, Turkey viral hepatitis, death in red squirrels with intestinal intussusceptions, Equine encephalitis virus in Israel, Encephalitis in fattening pigs, severe diarrhoea and death in badger cubs, bovine neonatal pancytopenia, high mortality in geese, porcine teschovirus and others.
Although these novel technologies are increasingly gaining importance, conventional pathogen discovery, such as agent isolation, immunohistochemistry and serology should be used in parallel to the novel technologies, in order to facilitate pathogen characterization and/or for validation/verification purposes.

Two main areas (improvement targets) related to some of the above mentioned technologies were discussed i) consideration of the mass ratio (host vs. pathogen DNA), sample preparation, optimized bioinformatics (software development, BLASTing approach), dealing with sequences having no similarities and protection against misclassifications, and ii) adapting technologies for nucleic acid recovery, amplification, detection, data collection, analysing and evaluation (reporting) using a portable device format.

A specific topic of concern was the advantages and disadvantages and the scope of application of existing lateral flow devices for detection of AI virus and the development of alternative rapid diagnostic tools, such as penside molecular testing, label-free detection of nucleic acids and peptide aptamers for detection of AI. Objective validation data are required to recognize the advantages and indeed the limitations of any new technology. Assuming that a realistic application is then established which brings benefits compared to other technologies, a continuing programme of work is important to establish harmonized use of tests through e.g. Ring Trails and Proficiency Testing schemes. This will enable ready comparison of data from different national laboratories in scenarios where e.g. a given disease’s epidemiological pattern involves spread across national boundaries.

In the field of protein detection assays, two main streams of development were presented: alternative labelling of photometrically measured ligands and alternative generation/concentration of the signal, as follows:

Application of novel early and rapid diagnostic technologies, due to their multiplex format and rapidity of reporting results will change the conventional approach to sampling and data reporting. For this reason, the merits of different approaches to sampling (active and passive sample collection, non-invasive sampling, on-site sample processing/testing and sample stabilization for transport) were discussed. Special emphasis was given to data collection, storage and analysis, as well as the use of international database platforms as a means for providing transparent information/knowledge exchange.

Requirement of on-the-spot (mobile) laboratories, in support of the “on-the-spot” testing were also discussed. Essential advantages of such laboratories are in the early detection of health threats and facilitation of basic and translational research. Such facilities that should encompass a modular design and self-containment would assist clinicians and public health practitioners to manage outbreaks more efficiently.

Last not least the group discussed the needs for national and international support (reference) laboratories to which unresolved cases could be referred and the need for training scientists and field staff to achieve the aims from testing to epidemiological conclusions.

Conclusions and recommendations

  1. Taking into account that there are different levels of expertise, training and detection requirements, different assays and technologies are required for diagnosis and surveillance from field laboratories up to international reference laboratories.
  2. There is a basic requirement for database systems for capturing and integration of diagnostic data on national, regional and global scale. This will require capacity building for sampling, processing and data collection. Encouraging the sharing of clinical, diagnostic and pathogen data will facilitate the implementation and impact of the current and new technologies. This should be considered a high priority because it is advantageous independent of available technology.
  3. There are needs and options for on-site (front line) disease detection and early warning tools. These tests should be used for preliminary diagnosis / assessment of defined diseases using technologies appropriate to the situation and operate in various scenarios:
    • Devices not requiring sample preparation, such as reagent-less biosensors.
    • Devices requiring minimal or limited sample preparation, such as hand held amplification tools or lateral flow.
    • Devices requiring mobile laboratories which can potentially provide qPCR.
    • Protection from early information release of the potential detection of notifiable diseases.
    • Early warning of an emerging, zoonotic and/or unknown disease, before the onset of clinical signs.
  4. Local and national laboratories can perform broad set of tests to target defined diseases and carry out confirmatory tests for selected pathogens. Furthermore they can perform investigative analysis to resolve cases in which known pathogens were not detected, in the above approach. Tools that could be applied at this level include multiplex or syndromic assays such as microarrays (nucleic acid, peptide detection or sequences), next generation sequencing, real time PCR.
  5. In order to facilitate the sustainable implementation of the current and the new technologies, the creation of regional centers of excellence should be encouraged to provide technical capacity and support, capacity building and technology transfer to the local laboratories. Training is important, not only in how to run a given test, but also how to interpret the results correctly in a given disease setting. This will enhance the understanding of how an assay may be used appropriately in (i) disease diagnosis and (ii) relevant surveillance programs. This will link the new technology to the broader benefits which it should bring to outbreak management and control policies that are ultimately approved by the OIE.
  6. Proper application of the above mentioned technologies, including the appropriate information technologies, will contribute to rapid response and action by appropriate competent authorities.
  7. Standard procedures should be established for referral of samples to regional and international reference laboratories and the ownership of results.
  8. Bottom-up communication from the local laboratories, to the international reference laboratories should be established, in order to facilitate the continuous evaluation of current and new technologies. The logistics to source “real world” clinical specimens are crucial in order to evaluate / validate new technologies.
  9. The FAO, FAO/IAEA and WHO should continue to encourage communication links between veterinary and human health laboratories and ministries encouraging the “One World – One Health” concept.
  10. This continuous evaluation and comparison of the above mentioned technologies will aid in enabling their proper interpretation and establishing confidence in the results.

The Joint FAO/IAEA Division has a track record in exploring, evaluating and implementing new diagnostic technologies, to better address the needs of MS. The Joint FAO/IAEA Division is therefore encouraged to continue the evaluation and distribution of up to date technologies and provide opportunities for exploring new technologies for the early detection of pathogens, including multiplex platforms, next generation sequencing and upcoming technologies, in order to support MS in an informed decision taking on the most suitable techniques to address their needs. The Joint FAO/IAEA Division is encouraged to continue to invite the WHO and other international organizations to these consultancy meeting and facilitate global “One Health” evaluation of these promising new technologies.