Sunday, June 16, 2019

Belgium: ASFCA Update On LPAI H3N1














#14,133


Six weeks ago we began following reports of a low path H3N1 avian flu spreading among poultry farms in West Flanders (see Belgium: Non-Reportable LPAI H3N1 In Poultry). 
At the time Agriholland reported LPAI H3N1 On 16 Belgium Poultry Farms, a number that - according to recent media reports - now approaches 70 farms.
Since H5 and H7 are the only LPAI viruses considered reportable by the OIE (see Terrestrial Animal Code Article 10.4.1.), this outbreak would have likely gone unnoticed were it not for its unusually high mortality rate (said to be as high as 60%) in poultry.

Since H3N1 falls into a legal grey area, government agencies have been slow to step in with compensation and to recommend containment protocols. It was less than a week ago that an agreement in principle was finally reached on compensating farmers for their losses.

Thus far, we've yet to see a good explanation for the unusually high mortality rates being reported, and official statements on losses and on how the virus is being spread have been in short supply.
All of this has led to considerable debate in the industry over what the government should have done, and when (see pluimveeweb's Belgium should have acted as HPAI).
Given some of the evolutionary strides we're seeing in other LPAI viruses (i.e. H6N1, H9N2, H4N6, etc.), having enough flexibility to respond quickly to `atypical' outbreaks - even those not covered by the OIE's Terrestrial Animal Code - may become more important over time.  
J. Gen. Virology: Mutations in PB2 and HA Enhanced Pathogenicity of H4N6 Avian Influenza Virus in Mice 

Trans. Emerg, Dis: Continued Reassortment of Avian H6 viruses - Southern China, 2014-2016.


Virology: Receptor Binding Specificity Of H9N2 Avian Influenza Viruses
This week, Belgium's Federal Agency for the Safety of the Food Chain (ASFCA) has released revised protocols for the control of H3N1.  I've only included the opening summary, so follow the link to read it in its entirety.
   
Infections with influenza type H3

News update June 12, 2019

Since early April 2019, dozens of poultry farms were affected by the influenza virus H3. Most of the infected farms are located in West Flanders, some are located in East Flanders, two farms in the province of Antwerp and so far only infected farm was discovered in the provinces of Liege and Luxembourg. The most common symptoms are depression, pale eggs, a rapid decline in egg production (20% to 100%), a decrease in water consumption and food and a high mortality rate (sometimes up to 50% and more).

What influenza H3?


The influenza virus type H3 is a typical avian virus that is completely harmless to humans and the food chain. It has all the characteristics of a low pathogenic virus, which means that the virus itself can not be held responsible for the symptoms or the mortality of the poultry. Of course, it can, however, help to reinforce symptoms caused by other pathogens.

Although originally native to wild birds, it has since adapted to chickens, which explains its increased multiplication and transmission.

In addition, research has shown that this virus has some preference for the laying apparatus, which can contribute to the identified clinical problems and also explains why laying hens are mainly affected.

The virus is transmitted primarily through contact with contaminated materials and between animals, making the application of biosecurity more than strictly mandatory.
Measures

In the new Ministerial Decree of 6 June 2019 concerning emergency measures to prevent the spread of the virus H3-type influenza ( NUMAC number - 2019013193 - to view the consolidated version ), additional general preventive measures are imposed and that additional specific measures for farms where the H3 virus was detected.

In addition, this includes the AM measures of the previous MD of 16 May 2019 concerning emergency measures to prevent the spread of avian influenza H3.

The measures apply from Thursday, June 13, 2019.
        (Continue . . . )