NL AVINED: LPAI H3N1 Update (Jul 26th)

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For more than 3 months we've been following the emergence and spread of an LPAI H3N1 virus in Belgium which has produced significant losses (see Belgium: Non-Reportable LPAI H3N1 In Poultry).

Conventional wisdom holds that LPAI H3 viruses aren't supposed to produce serious illness in poultry as only H5 and H7 viruses are considered serious LPAI threats by the OIE (see Terrestrial Animal Code Article 10.4.1.)

As a result, these outbreaks have fallen into a regulatory grey area, and a coordinated response has been slow in coming. Farmers have had to fight for compensation for their lost flocks, and the bulk of the information we've gotten has come from not from Belgium, but from its neighbors, who are worried over its spread.


While the idea had been floated that this virus's toll could be due to some sort of co-infection - five weeks ago, in NL AVINED: LPAI H3N1 - Major Damage And Loss Without Co-infections - Dutch researchers showed this particular LPAI H3N1 virus was fully capable of producing elevated morbidity and mortality in poultry without any outside help.

We've a new (translated) update, published late this week by the Netherland's AVINED, that builds on previous reports (see here, and here), that describe the difficulties in identifying and controlling this LPAI virus.

Symptoms H3N1 barely visible in young animals (updated July 26)

On behalf of the Board of poultry health AVINED Agriculture and the Animal Health Service (GD) a continued study of the low pathogenic H3N1 strain and illness in young animals from five weeks of age.

Interim conclusion: H3N1 also causes disease in young animals, but these are only partly visible. This phenomena practice can easily be missed.

A few weeks ago GD conducted an investigation into the symptoms of H3N1 in laying hens of 35 weeks. This showed that the virus needs no other pathogens to cause major damage in these animals. The clinical picture, to the section, and images the decrease in production by laying hens that correspond to the image that is seen in practice.

Interim results of the follow-up study show animal of 5 weeks old show that young infected animals exhibit very limited disease symptoms.

Think of a less attentive and fevered pitch. The symptoms are so mild that they in practice can be easily overlooked. Symptoms in young animals are therefore only visible during a thorough health assessment. Deaths from the virus may be very limited in young animals.

The research in these animals will be completed soon. An interim report of the study can here find.

What can you do?

To reduce the risk of introduction to the Netherlands, AVINED recommends the following:

Be alert to signs

Be alert to symptoms, so that contamination is detected at the earliest stage possible. If in doubt, contact your veterinarian. And make in consultation with your vet, using the opportunity to submit Early Warning swabs. Especially with young animals, it is important to exclude from non-specific (limited) increase in mortality or hospital avian influenza H3N1. In case of failure of more than 0.5% for two days, or more than 3% per week per coupling mandatory reporting to the NVWA (045-546 3188). 

Sampling poultry flocks from Belgium
 
GD has prepared a roadmap Avian Influenza H3N1 at the request of the sector. GD herein include Recommends that couples make in advance from Belgium show that the couple no virus carrying. In the scenario described, the method of sampling and laboratory tests. The road sector can here find. 

Follow the hygiene protocols
 
to prevent infection and potential spread, we advise you again to follow the hygiene protocols drawn to the situation in Belgium. This includes transport of various poultry (hatching) eggs from Belgium, for visitors from poultry farms, feed transport from Belgium, from Belgium and poultry litter service companies who have worked in Belgium. The protocols can down the page to find.

So we do together our best to keep H3N1 outside our borders.

        (Continue . . .)


While far from the gravest avian flu threat we've seen over the past 20 years, outliers like this upstart LPAI H3N1 remind us that viruses don't always follow our rules or our expectations. 

• Prior to 2013, no one seriously thought that an LPAI H7 virus could ever match HPAI H5N1 as our top avian flu pandemic threat. That is, until LPAI H7N9 emerged in China.

• In early 2014, when the first reports of Ebola emerged from West Africa, conventional wisdom was that the virus was too virulent to spread widely, and that it would `burn itself out'. Two years and 30,000 cases later, we knew better.

• Until 2015, the notion that an arbovirus - transmitted by mosquitoes - could cause an epidemic of severe birth defects was unheard of.  And then Zika came along, with tragic consequences. 

Although comprehensive pandemic planning is essential, our success (or lack, thereof) in combating the next pandemic will depend in large part on our ability to adapt to new situations and quickly adjust our responses.  

As has been pointed out by military experts for more than a century, `No battle plan survives contact with the enemy'.