Canada: WILD BIRD SURVEY DETECTS AVIAN INFLUENZA IN DUCKS

From the Canadian Food Inspection Agency:

"A national survey of wild migratory birds (ducks) has produced preliminary results indicating the possible presence of Influenza A in 28 wild ducks in Quebec and five wild ducks in Manitoba. To date, preliminary testing has identified H5 influenza. No evidence of H7 influenza has been observed."

The Canadian Government, in collaboration with the Canadian Cooperative Wildlife Health Center has been conducting a survey of wild birds for avian influenza.

It seems unlikely to me that this virus will turn out to be the highly pathogenic avian influenza A(H5N1) circulating in Asia and Eastern Europe. As noted on the web site, low pathogenic avian influenza is commonly found in wild birds, and these birds were apparently healthy.

Goes to show how "you won't find it until you look for it". It would be interesting to know how many tests have been done so far to get an idea of the prevalence. Over 4800 birds were tested in the survey, but all testing is not expected to be complete until November.

In case people are interested, Canada has developed a National Wildlife Disease Strategy, available here.

Damien

H5N1 Timeline

The WHO has put together a timeline of events in the H5N1 panzootic.

Damien

Wave-Like Spread of Ebola Zaire?

A new paper in PLoS by Walsh, Biek, and Real provides pretty good evidence that Ebola Zaire is spreading through Central Africa in a wave-like fashion. However, it is too premature to assume that this "wave" is driven by gorilla-gorilla contact. Gorillas are clearly not the reservoir - they suffer too much mortality for the virus to be maintained in gorilla populations. Insufficient sampling of wild populations has been done to identify the reservoir species for Ebola: the virus may be spreading in a wave-like fashion through any number of species, and outbreaks in great apes and humans are still likely the result of a spill-over from another mammalian host.

Damien

CDC: Mallards and Highly Pathogenic Avian Influenza Ancestral Viruses, Northern Europe

This paper is like many others in the avian influenza literature on wild birds.  Although it makes a very compelling argument for avian influenza surveillance in wild birds, and provides important information on the genetics of influenza isolates, it neglects to provide a numerator (how many birds had the virus) or denominator (out of how many birds were tested).

Risk is estimated (in its simplest terms) by the probability an event will occur, times the magnitude of the event once it occurs.  Without numerator and denominator information, it is impossible to estimate the first part of the risk equation (the probability an event will occur).  This information is critical to developing risk management systems.

Damien

Interesting discussion of the 1976 swine flu "pandemic"

EffectMeaure has an interesting discussion of the 1976 swine flu scare, here.

With that perspective, it makes it even more important that we follow Peter Sandman's advice (here and here) when discussing bird flu.

Damien

H5 in swans in Croatia - what swan?

From ProMED:

Avian influenza in Croatia
---------------------------
Information received on 21 Oct 2005 from Dr. Mate Brstilo, Director of the
Veterinary Administration, Ministry of Agriculture and Forestry, Zagreb:

Report date: 21 Oct 2005.

An outbreak of avian influenza was reported in wild migratory swans in
Zdenci municipality, Viroviticko-Podravska county. Out of approximately
1500 wild migratory swans, 15 birds died.

The OIE should start requiring more information the species of migratory birds that are found with high path avian influenza. Knowing which species were tested (and report negatives AND positives) can go a long way to help us understand the epizootiology of this disease. Where do these swans migrate? How do we know they were really migratory (there are many species of birds that are resident, and even some populations within normally migratory species do not migrate, e.g., Canada geese).

UN task forces battle misconceptions of avian flu, mount Indonesian campaign

An excerpt from a UN task force on routes of spread of avian influenza:

"A new United Nations task force warned today against the "over-simplified" perception that wild birds are the main cause of avian flu, and urged immediate measures be taken among both domestic and wild bird populations to guard against its possible transference, while a UN task force in Indonesia begins a door-to-door campaign to help poultry farmers deal with the pathogen.

Governments, local authorities and international agencies need to take a greatly increased role in combating the role of factory-farming, commerce in live poultry, and wildlife markets which provide ideal conditions for the virus to spread and mutate into a more dangerous form, the Task Force convened by the UN Environmental Programme (UNEP) Convention on Migratory Species (CMS) said today."

Read the whole news release here.


Damien

ProMED comments on UK bird flu positive parrot

The ProMED editor "AS" has some interesting commentary (mid-way down the piece) on the recent discovery of an avian influenza-positive parrot in quarantine in the UK:

"Interestingly, H5N1 was detected last week in pet birds smuggled 
from China to Taiwan. This has happened before as well, and is a  
clear indication of significant disease risk related to contacts with 
pet-birds originating or passing through that part of the world. In 
this context, the current call of the UK government for a ban on all 
 wild bird imports into the EU, echoed in European press, makes sense. 
If such policy is applied, it must go hand-in-hand with severe 
measures to prevent smuggling which is expected to increase.

International trade in pet-birds is a multi-billion global industry;  
veterinary inspection upon this trade is a complex, laborious and 
expensive task. Consignments, sometimes, pass through intermediate 
stations where contacts with other consignments might occur.

The parrot died more than 30 days after arrival; the incubation of  
avian influenza is considered to be not longer than 7 days. It is 
thus unlikely that it came to the UK infected. We are looking forward 
to the outcome of the UK investigation into the origin of infection 
in this case. 

Besides the legal trade in wild animals, there is a huge illegal 
trade. National inspection authorities are obliged to deal with 
smuggling attempts, from single travelers hiding one or several pets 
in their personal luggage up to organized crime dealing with  
large-scale smuggled consignments applying sophisticated methods. 
There are daily confiscations everywhere, but -- unfortunately -- 
most illegal consignments are considered to reach their destinations 
undetected. The black market in illegal animal products, estimated by  
Interpol to be worth USD 6 to 10 billion annually (2nd only to the 
illegal drug trade), threatens the health of humans and may lead to 
the extinction of many species of animals. - Mod.AS"

Damien

BBC: Parrot in quarantine tests positive for H5 in UK

A story on the BBC web site today describes a parrot (not sure what species) that died in quarantine tested positive for an H5 avian influenza virus.  Testing is ongoing to see if it is H5N1.

From the story:

"The bird came from South America, and was held with 216 birds from Taiwan."

and

"The bird, from Surinam, was part of a mixed consignment of 148 parrots and "soft bills" that arrived on 16 September. "

H5N1 has never been reported from either Surinam or Taiwan, although Taiwan did have H5N2 last year.  So if this strain turns out to be H5N1, it means it must have been in contact with other, H5N1 birds in the wildlife trade - who knows where those birds are now?

Damien

Bird flu in perspective

Here is a really good article, by Peter Sandman.  Very much worth the read.

Canada has 16 million doses of Tamiflu

If this is true, then Canada is in a pretty decent position to
control, at least for a while, the spread of pandemic influenza if the
pandemic happens. With 16 million doses, enough to treat almost half
the population, Canada will be able to save many lives if combined
with effective isolation of cases.

NY Times: Deadly 1918 Epidemic Linked to Bird Flu, Scientists Say

Deadly 1918 Epidemic Linked to Bird Flu, Scientists Say By GINA KOLATA New York Times Published: October 5, 2005 Two teams of federal and university scientists announced today that they had resurrected the 1918 influenza virus, the cause of one of history's most deadly epidemics, and had found that unlike the viruses that caused more recent flu pandemics of 1957 and 1968, the 1918 virus was actually a bird flu that jumped directly to humans.

<snip snip>

This is very interesting. Previous research suggested that the Spanish Flu was essentially a mammalian virus, although very similar to avian viruses. This is the first evidence to show that the 1918 pandemic was caused by bird flu, apparently the only one out of the last three pandemics.

Damien

UPDATE: The full text of the Nature paper is online here

OIE expert's mission to assess the avian influenza situation of wildlife in Russia

"OIE expert's mission to assess the avian influenza situation of wildlife in Russia

Paris, 4 October - At the request of the OIE delegate of Russia, the World Organisation for Animal Health (OIE) has started yesterday its expert's mission to assess the avian influenza situation of wildlife in Russia and the national measures to be taken to minimize the risk of international spread of the disease. The mission will last one week.

The reference laboratory of the country (located in Vladimir) and, if possible, other laboratories will be visited to assess the conditions for the laboratory in Vladimir to be part of the world wide network of OIE reference laboratories. Samples from wild birds will be collected to try to verify if they carry the H5N1. The relevant species of wild birds will also be listed in order to identify their migration routes and thus to allow the countries receiving these birds to be prepared to to develop surveillance activities when relevantl.

This mission will be the first of a series of missions in which the OIE will offer the necessary technical and scientific collaboration to Russia needed in combating and/or preventing the disease.

The OIE/FAO world wide laboratory network on avian influenza (OFFLU) will be in the forefront of these missions."

Lets hope they get there before the birds all go south for the winter ...

NY Times article on CWD

Wasting-Disease Culprit May Be Tongue?

http://www.nytimes.com/2005/10/04/science/04tong.html

Although it's a nice discussion about how prions might move around within an animal, I definetely think shedding of prions by faeces or urine onto feed, and then consumption of contaminated feed is much more likely a route of transmission among animals, not sloughing of tongue skin cells.  I wouldn't discount saliva though.  Even infected carcasses could be a transmission route (see paper by Miller et al.).

New England Journal of Medicine: Review of AI in humans by WHO

The WHO has published a synthesis of the what we know about avian influenza (H5N1) in humans in the New England Journal of Medicine (pdf here).


The summary posted on ProMED is here:

"The authors have drawn the following conclusions. Infected birds have been the primary source of influenza A (H5N1) infections in humans in
Asia. Transmission between humans is very limited at present, but continued monitoring is required to identify any increase in viral
adaptation to human hosts. Avian influenza A (H5N1) in humans differs in multiple ways from influenza due to human viruses, including the
routes of transmission, clinical severity, pathogenesis, and perhaps, response to treatment. Case detection is confounded by the
non-specificity of initial manifestations of illness, so that detailed contact and travel histories and knowledge of viral activity
in poultry are essential. Commercial rapid antigen tests are insensitive, and confirmatory diagnosis requires sophisticated
laboratory support. Unlike human influenza, avian (H5N1) influenza may have higher viral titers in the throat than in the nose, and
hence, analysis of throat swabs or lower respiratory samples may offer more sensitive means of diagnosis. Recent human isolates are
fully resistant to M2 inhibitors, and increased doses of oral oseltamivir may be warranted for the treatment of severe illness.
Despite recent progress, knowledge of the epidemiology, natural history, and management of influenza A (H5N1) disease in humans is
incomplete. There is an urgent need for more coordination in clinical and epidemiologic research among institutions in countries with cases
of influenza A (H5N1) and internationally."

The discussion of the efficiency of case detection, critically important to managing the disease, is particularly interesting.  You can't treat or quarantine someone if you don't know they are infected!

Damien

New bird flu paper in EID: Highly Pathogenic Avian Influenza H5N1, Thailand, 2004

There's a new paper on the avian influenza epizootic in Thailand in Emerging Infectious Diseases.  

Interesting quote in the discussion:

"High numbers of HPAI detections coincided with low temperatures in Thailand from October to February, when wild birds from central and northern Asia migrate into Thailand (7). Therefore, seasonal conditions and bird migration might have contributed to the introduction of HPAI virus. Furthermore, the lower temperature supports survival of the virus in the environment and facilitates transmission (33). In addition, several festivals, which are associated with raising, selling, and transporting poultry, occurred around the end of the year. Illegal transportation and cockfighting may have worsened the HPAI situation."

I suspect the latter explanation (festivals and poultry movement) is probably more important than the former (arrival of migratory birds), given that H5N1 wasn't isolated from wild birds consistently till this year.

Damien

Pandemic Flu Awareness Week

The Reveres over at EffectMeasure are spearheading Pandemic Flu Awareness Week. Read their post and spread the word!