Saliva swabs for bird flu virus more effective than faecal samples

[LMonty]

This is a surprise- kinda turns the usual process "upside down"!

Saliva swabs for bird flu virus more effective than faecal samples


dpa German Press Agency
Published: Monday December 11, 2006

Singapore- Scientists looking for indications of the bird flu virus have been taking swabs from the wrong end of the duck, a flu expert said in a published report Tuesday. US and British scientists have found that respiratory samples taken from migratory ducks and domestic birds contain more of the bird flu virus than the usual faecal samples, said Dr Robert Webster, from St Jude's Children's Research Hospital.

Saliva swabs from the birds' beaks are much better for detecting bird flu virus particles, while faecal samples are the "least sensitive," The Straits Times quoted Webster as saying at the five- day Keystone Symposia in Singapore, which winds up on Thursday.

Faecal samples were regarded as easier to obtain.

Webster urged researchers to look towards oral swabs, or samples from water pans of domestic birds, provided they are not contaminated with faeces.

Another expert stressed that much more scientific research needs to be done to manage a human outbreak of the bird flu.

Dr Scott Dowell, who has spent the last four years helping fight infectious diseases in Thailand, told 200 clinicians and scientists on Monday that surveys in Thai villages, which had human outbreaks show "a possibility that the virus is food-borne."

"We need more rigorous studies to help us find out what are the risk factors that cause bird flu to be spread to humans," said Dowell, from the US Centres for Disease Control and Prevention.

The focus during this year's event is on respiratory diseases such as bird flu. Nine researchers from the US, Britain and Asian are presenting their findings.

With 258 cases of human H5N1 infections detected so far, of which 158 have been fatal, Dowell said the mortality rate of more than 60 per cent "makes it one of the most deadly infectious diseases."

© 2006 dpa German Press Agency
http://rawstory.com/news/2006/Saliva_swabs_for_bird_flu_virus_mor_12112006.html

 

[Ganseerpel]

Re: Saliva swabs for bird flu virus more effective than faecal samples

Saliva swabs from the birds' beaks are much better for detecting bird flu virus particles, while faecal samples are the "least sensitive," The Straits Times quoted Webster as saying at the five- day Keystone Symposia in Singapore, which winds up on Thursday.

This is consistent with an information I received from a German Journalist.
During the 2006 outbreak in Germany the the national reference labor (FLI) had to stop for some time collection of fecal samples on the level of local vet administration because of lack of specifity.

 

[AlaskaDenise]

Re: Saliva swabs for bird flu virus more effective than faecal samples

If this explains why wild bird testing is failing to find H5N1, I assume their procedures will change ASAP.

.

 

[Mellie]

Re: Saliva swabs for bird flu virus more effective than faecal samples

Anyone have the original scientific reference for this? It would be good to get it to those doing the sampling.

Also referenced by Webster here but no original source is cited:
http://www.asm.org/microbe/index.asp?bid=47152
(Provides only "Suggested Reading" section at the end.)

 

[HenryN]

Re: Saliva swabs for bird flu virus more effective than faecal samples

If this explains why wild bird testing is failing to find H5N1, I assume their procedures will change ASAP.

.

The protocol for screening birds in Alaska for clade 2.2 H5N1 is to take cloacal swabs and fecal samples. ASAP is not an operative concept.

 

[canagica]

Re: Saliva swabs for bird flu virus more effective than faecal samples

Anyone have the original scientific reference for this? It would be good to get it to those doing the sampling.

Also referenced by Webster here but no original source is cited:
http://www.asm.org/microbe/index.asp?bid=47152
(Provides only "Suggested Reading" section at the end.)

I'm assuming that he was referring to the recent paper in EID:
Wild Ducks as Long-Distance Vectors of Highly Pathogenic Avian Influenza Virus (H5N1)

This is really the first paper published that looks at the issue of cloacal and tracheal swabbing in wild birds; it also had interesting information about viral shedding in symptomatic and asymptomatic individuals. There was a forum discussion about the paper here in FluTrackers.

 

[canagica]

Re: Saliva swabs for bird flu virus more effective than faecal samples

The protocol for screening birds in Alaska for clade 2.2 H5N1 is to take cloacal swabs and fecal samples. ASAP is not an operative concept.

You can probably imagine why it's not an ASAP concept-everything for this year has already been bought and people are already heading out to the field. Dry-nitrogen shippers have already been stocked accordingly, and testing labs are set up to receive and process the cloacal samples. Field staff have been trained to get cloacal samples. etc. etc. etc.

Hopefully this will change on the next go-round, but I wouldn't expect much this year.

 

[canagica]

Re: Saliva swabs for bird flu virus more effective than faecal samples

I'm assuming that he was referring to the recent paper in EID:
Wild Ducks as Long-Distance Vectors of Highly Pathogenic Avian Influenza Virus (H5N1)
.

Whoops! Just noticed that the date on that news report was 2006! He probably isn't referring to that recent EID paper...em

 

[HenryN]

Re: Saliva swabs for bird flu virus more effective than faecal samples

You can probably imagine why it's not an ASAP concept-everything for this year has already been bought and people are already heading out to the field. Dry-nitrogen shippers have already been stocked accordingly, and testing labs are set up to receive and process the cloacal samples. Field staff have been trained to get cloacal samples. etc. etc. etc.

Hopefully this will change on the next go-round, but I wouldn't expect much this year.

The differences in sampling has been known for MANY years.

 

[HenryN]

Re: Saliva swabs for bird flu virus more effective than faecal samples

You can probably imagine why it's not an ASAP concept-everything for this year has already been bought and people are already heading out to the field. Dry-nitrogen shippers have already been stocked accordingly, and testing labs are set up to receive and process the cloacal samples. Field staff have been trained to get cloacal samples. etc. etc. etc.

Hopefully this will change on the next go-round, but I wouldn't expect much this year.

From 2006 report

When collecting samples from live or hunter-killed birds, tracheal and cloacal swabs are preferred. Most AI strains tend to replicate more efficiently in the intestinal tract than in the respiratory tract of natural host species (i.e., waterfowl and shorebirds). Consequently, cloacal swabs are generally preferred. However, recent isolations of highly pathogenic H5N1 avian influenza virus in wild birds have documented higher levels of virus in tracheal samples. Therefore, it is recommended that both samples be collected from birds when possible. While the collection of cloacal swabs is a relatively easy procedure, obtaining proper tracheal swabs can be problematic and requires personnel trained in the sampling technique. Examples of tracheal/cloacal swab collection protocols can be found in Attachment 9. Tracheal and cloacal swabs should be placed in separate tubes, and swabs should not be pooled across individuals.
http://alaska.usgs.gov/science/biology/avian_influenza/pdfs/Final_Wild_Bird_Stategic_Plan_3-17a.pdf