Influenza A viruses originating from animals can adapt to infect humans following mutation or gene exchange, according to a report from the United Nations' Food and Agriculture Organisation (FAO) report.

Identification and characterization of such viruses are therefore pre-requisite for pandemic preparedness. Pandemic influenza viruses are those that are capable of causing epidemic spread in human populations over large geographic regions or worldwide. Animal influenza surveillance should be combined with a decision-making process, allowing for appropriate follow-up in case positives are found.

In the framework of the FLURISK project funded by the European Food Safety Authority (EFSA), the FAO, together with the Royal Veterinary College in London, United Kingdom, conducted a cross-sectional survey of national animal influenza surveillance programmes directed at Chief Veterinary Officers (CVOs) from 183 countries.

The aim was to assess the current capacity to detect influenza viruses with zoonotic potential in animals.

Zoonotic influenza viruses are those that can be naturally transmitted between vertebrate animals and humans. Comprehensive and detailed information on influenza surveillance in different animal species, as well as information sharing mechanisms instigated were collected and analysed.

Details of 587 animal influenza surveillance system components implemented during the period 2010-2012 were recorded for 99 countries. A surveillance system component is hereby characterised by:

• surveillance type (active, passive, etc.)
• purpose (national or international surveillance system, research, etc.)
• objective (detection, monitoring, etc.)
• influenza targeted (avian, equine, swine, pandemic influenza), and
• target population (domestic, wild, companion animals).

Results of the analysis revealed that influenza surveillance systems in animals are widely implemented. However, less than one per cent of components analysed were specifically aimed at detecting pandemic influenza viruses in animals, and these exclusively targeted pigs.

The authors note a general integration of these components into national surveillance systems, which is an indication for government leadership and funding and shows the interest and commitment of these governments to invest in pandemic preparedness through targeted surveillance. Such structures would also indicate a minimum level of sustainability of efforts.

Nevertheless, the results reveal the global need for increasing surveillance targeting influenza viruses with pandemic potential in relevant animal species.

Recognising that surveillance in animals is mostly implemented with the objective of safeguarding animal health and international trade, the report's authors suggest how existing efforts may be improved and where existing components could be adapted to inform human pandemic risk. In addition, those countries implementing only few components are encouraged to increase active surveillance efforts in order to identify a wider diversity of influenza viruses from a range of animal populations.

Recommendations include:

• integration of several active-representative or risk-based components
• targeting subtypes with higher zoonotic risk regardless of their importance for animal production and health
• sampling healthy as well as diseased animals
• timely communication of results to the national and international communities, including submission of virus sequences to public databases and sharing of live viruses with the scientific community.

The survey further revealed that the public health sector is only alerted for about half of the components targeting avian, swine and pandemic influenza in the instance that positive animal cases are identified.

Failure to do so may be related to a lack of established communication channels. Communication between veterinary and public health services may also be impaired or non-existent, since they are usually governed by different ministries.

However, when investigating animal influenza viruses that may have severe consequences in the human population, it is of utmost importance that these services inform each other of any findings and promote joint activities. A One Health approach would encourage standardised communication and collaboration between veterinary services and public health officials. Routine operating procedures should be put in place and officials adequately trained. Procedures for emergency response should also be established and regularly tested in simulation exercises.

The authors add their gratitude for the participation of CVOs in the survey.

Reference

Von Dobschuetz S., M. de Nardi, K.A Harris, O. Munoz, C. Breed, B. Wieland, G. Dauphin, J. Lubroth and K.D.C. Stark. 2014. Influenza surveillance in animals: what is our capacity to detect emerging influenza viruses with zoonotic potential?. Epidemiology and Infection, available on CJO2014. doi:10.1017/S0950268814002106

Original source: FAO report