Chief Executive's Comment - November 2017
Now is the time that we start watching weather patterns, and wildfowl migratory movements, to assess when the HPAI risk to commercial flocks in the country is set to rise from the current ‘LOW’ risk ( “rare but does occur”).
The report of a dead mallard with H5N8 on the Dutch/German border is a concern given that it is on the likely migration route to the UK, so Defra has increased the risk level for an incursion in wild birds for the UK to “MEDIUM” (that is “event occurs regularly”). The UK flyway is shown within the purple dotted line in the map above (the East Atlantic flyway) whereas most of the outbreaks this autumn has occurred within the white line (Black Sea Med flyway).
The weather this month has been in our favour of delaying the onset of infection from migratory birds on the UK flyway. We have had a succession of southerly and south-westerly winds which are pushing against the direction of travel of the migratory wildfowl heading south and west from their Arctic breeding grounds. As a result they have taken a path of least resistance and headed south and east, either side of the Alps, into Bulgaria and Italy on the Black Sea Med flyway. Both these countries have had H5N8 outbreaks in recent weeks.
Over the last month, Italy has reported seventeen more outbreaks of H5N8 HPAI in Bergamo, Brescia, Ferrara, Sondrio, Vicenza and Cremona (see map on next page). The poultry involved included fattening turkeys and layers and seven smallholdings. In all cases, disease control measures are in place; most introductions are primary incursions with little secondary spread observed. One of the outbreaks was reported in one of the largest layer farms in Italy, with over 850,000 birds to be destroyed. Wild birds positive for H5N8 HPAI have been reported in 3 separate cases of mute swans.
While the current weather pattern contrasts markedly with that in October 2016 when the prevailing wind was easterly, helping waterfowl hop across the channel from the Continent, that could change any time. If the weather this November mirrors November 2016, when we had a northerly airflow during the first half of the month, this well help waterfowl move down to the UK from breeding grounds in the Scandinavian arctic. These sorts of weather patterns bring a larger density of waterfowl to our shores and will increase the disease risk to free-range flocks.
A new factor this year is the reservoir of contamination in resident birds carrying the virus which heightens the current risk. The virus is still thought to be surviving in the bottom of ponds infecting resident waterfowl, such as non-migratory mute swans. We have to assume that virus is still present in our wild birds even if the vast majority have died out as a result of the disease. This means that in addition to the higher status migratory bird risk in winter, biosecurity remains as important as ever all year round.
Defra tells us that the risk for poultry remains “LOW” for introduction of infection onto individual premises, but this will depend on levels of biosecurity which must now be increased to a high alert. It is only a matter of time that the ‘MEDIUM’ level of status for wild bird incursions is transferred to a ‘MEDIUM’ level of risk for free-range flocks. That will probably happen when infected waterfowl are found on the west coast of the Netherlands.
Next month I will cover the changes in the HPAI legislative and policy environment, as compared to last year. There have been no indications to date from policy-makers in Brussels that the Commission proposal to extend the free-range derogation during a housing order from 12 to 16 weeks will not be ratified. We are expecting both the Agriculture Council and the European Parliament to rubber stamp the draft legislation as a formality at the end of November or early December and I hope to be able to confirm this in the next edition of the Ranger.
In the meantime please heighten your biosecurity and refer back to the guidance booklets that BFREPA and the Poultry Health and Welfare Group produced last year, including the AI Contingency Planning Workbook.