The H5N1 strain of influenza - often referred to as bird flu - is first known to have jumped from chickens to humans in 1997. Since 2004 it has ripped through poultry and wild bird populations across Eurasia, and had a 53% mortality rate in the first 147 people it is known to have infected. Health authorities fear this strain, or its descendent, could cause a lethal new flu pandemic in people with the potential to kill billions.
Flu has been a regular scourge of humanity for thousands of years. Flu viruses each possess a mere 10 genes encoded in RNA. All of the 16 known genetic subgroups originate in water birds, and especially in ducks.The virus is well adapted to their immune systems, and does not usually make them sick. This leaves the animals free to move around and spread the virus - just what it needs to persist.
But sometimes a bird flu virus jumps to an animal whose immune system it is not adapted to.
The girl's parents, Zainul Arifin and Darsini, said their youngest child ran a high fever for about 10 days.
"We thought it was just common flu and gave her cold medicine," Zainul told The Jakarta Post at his home in Suka Asih village on Thursday.
After a week of treatment at home, when the girl's condition worsened the couple sought treatment for her at two medical clinics in the Pasar Kemis district, both of which refused to admit her.
Declan Butler did a great job of pulling together the geographic information on H5N1 through the middle of 2006. However, everyone should note that the H5N1 plotting data have not been updated in over a year so many human H5N1 cases and recent animal outbreaks are not plotted on these maps.
The Editors of Effect Measure are senior public health scientists and practitioners. Paul Revere was a member of the first local Board of Health in the United States (Boston, 1799). The Editors sign their posts "Revere" to recognize the public service of a professional forerunner better known for other things.
European bird flu: an open book?
Category: Bird flu
Posted on: October 26, 2007 7:30 AM, by revere
Two months ago Germany reported H5N1 in asymptomatic ducks and geese.
Now the UN's Food and Agriculture Organization is saying this may be
a sign that there is already a reservoir of hidden infection in
healthy domestic birds in Europe. The FAO points to a huge popuation
of chicken and waterfowl in the Black Sea area that are similar to
asian bird populations and in contact with them via migration. FAO
wants more surveillance of domestic ducks and geese in some eastern
European countries that have not kept up as much as their western
European neighbors:
"It seems that a new chapter in the evolution of avian influenza may
be unfolding silently in the heart of Europe,'' said Joseph Domenech,
the organization's chief veterinary officer, in the statement.
(Bloomberg) This seems like a very curious thing for FAO to say and
makes me suspect FAO has already been reading the opening of the
new chapter without telling the rest of us. They make it sound like they
are just making a plausible speculation. It's hard not to suspect they know
more than they are telling.
That's what happens when the record of transparency is, well, cloudy.
Declan Butler did a great job of pulling together the geographic information on H5N1 through the middle of 2006. However, everyone should note that the H5N1 plotting data have not been updated in over a year so many human H5N1 cases and recent animal outbreaks are not plotted on these maps.
I have a version of this that has a timeline up at the top of the page that is updated to March 2007. I do not know how to link to it. I probably had help to find it,
and not being very computer savvy, I can not tell you how to get there. There
may even be a later version, but I can't get there so if anyone else can, please
let us know.
It is still very impressive to see the global spread of this virus thru March 07.
All poultry owners in Uganda are required to register their chickens, including indigenous breeds, with the parish chiefs. The measure is meant to prepare for a possible bird flu outbreak now that the disease has spread to South Sudan.
The registers will be used as the basis for compensating farmers in case their stock needs to be destroyed in the event of an outbreak.
Avian influenza H5N1 in Africa: an epidemiological twist
The Qinghai strain, the predominant variant in Africa, has acquired several troubling properties, including respiratory rather than faecal transmission in poultry, increased thermal stability, and a PB2 gene mutation associated with pathogenicity in mammals, including human beings.
Because there are fewer domestic waterfowl in Africa than in Asia, it is unknown whether they can perpetuate the virus through the warm season. It is also not known whether HPA1 H5N1 is being maintained in African birds or periodically reintroduced.
...When avian influenza H5N1 hit the African continent in early 2006... it was not contained for several reasons, including delayed official decisions, inexperience, lack of prompt intervention planning, poor preparedness, corruption, and hesitation by farmers to report outbreaks. Similar factors have been associated with the continued spread in Asia.8 The true situation in most African countries is unknown.
Bird flu outbreaks have occurred in Vietnam's northern Cao Bang Province since Oct. 10, raising the total number of localities currently affected by the disease to three.
The disease has killed or infected 480 ducks and 80 chickens raised by 13 households in Trung Khanh district...To prevent bird flu spread, local veterinary agencies have culled all ill poultry and isolated the affected areas.
Using the guinea pig as a model host, we show that aerosol spread of influenza virus is dependent upon both ambient relative humidity and temperature.
Twenty experiments performed at relative humidities from 20% to 80% and 5ºC, 20ºC, or 30ºC indicated that both cold and dry conditions favor transmission.
Why No Pandemic WildFire Yet
A thoughtful piece by Monotreme, a scientist who blogs over at PFI:
Regular readers will know that I think the role of the environment in pandemic onset has been greatly underestimated by most observers. As I argued here, newer, and more realistic (imo), models suggest that pandemics are very hard to get going, even after a pandemic strain has evolved. I have argued that pandemic-capable strains have already evolved, perhaps many times. If this is correct, then the environmental conditions have not been right in any of these cases. Yet, we have seen cluster after cluster in Indonesia. Can we really have been that lucky?
A recent study suggests that cold, dry air is the best environment for the spread of influenza. You know, when I think of Indonesia, I don't think cold, I don't think dry.
... how many remember the pattern of spread in Turkey back in December 2005/January 2006? We never did get all the information on the relationship between the different cases, but Dr. Niman put together a set of dates consistent with cluster to cluster spread of H5N1... The number of cases found in a short amount of time was staggering...
Why were there so many cases in Turkey? Did I mention that it occurred in January; in a mountainous region; where it was cold and dry?
So, why didn't a pandemic start then? There was a massive response, from Turkey and the WHO. And there was Tamiflu, lots and lots of Tamiflu.
New findings, reported in today in the online open access journal Respiratory Research, about how the virus binds to the respiratory tract and lung suggest children may be particularly susceptible to avian influenza. The results also mean that previous receptor distribution studies may have to be re-evaluated.
Sialic acid molecules on the cell surface act as chemical beacons for the influenza virus. Once the virus finds sialic acid, it can attach and infect the cell, although the precise distribution of sialic acid molecules affects how easily the virus can find host cells to infect.
...The researchers used an improved staining technique to see how well two lectins, Sambucus nigra agglutinin (SNA) and Maackia amurensis agglutinin (MAA), bind to different forms of sialic acid on respiratory tract cells in healthy adults and children. SNA is particularly good at identifying the receptor for human influenza viruses while MAA identifies the receptor for avian viruses - including H5N1.
The researchers found that a particular form of MAA (MAA1) displayed widespread binding throughout the respiratory tract, but was particularly good at binding to children's cells in the lower respiratory tract as well as the upper respiratory tract of adults.
Although this MAA1 binding is not unique for avian influenza receptors, these findings could explain how avian influenza infects children more readily than it does adults. This may explain previous findings from this group that avian H5N1 viruses can infect the human upper respiratory tract, even though these tissues were thought to lack receptors for these viruses.
Tangerang is just west of the Indonesian capital of Jakarta.
The victim, a three-year old boy, lives in the same neighborhood as Dewi Aprilliani, the five-year old girl who died of H5N1 last week. There appears to be no contact between the two children, however. Poultry is again suspected as the vector. Roughly twenty contacts of the young boy are also being tested, according to multiflusite poster and lay translators Commonground and Dutchy.
The boy, despite receiving delayed treatment (he came down with symptoms the 22nd of October but went to hospital five days later), is responding well to Tamiflu. Bird flu has killed three children in Tangerang this month alone
While the CDC has urged that schools be closed early in a pandemic, I keep hearing `hedging' from local officials. Talk of waiting until a certain percentage of students are out with the flu during a pandemic, before closing down.
Once pandemic influenza has been reported anywhere in this country, all schools should be preparing to shut down. Parents, if they are smart, will pull their kids out of any school that doesn't close when the first case is reported in their state. It's that serious.
Another Suspect Pediatric Case
This 9 yr old girl, is a new suspected case in Batam, a location on a group of islands between Sumatra (Riau) and Singapore.
Singapore has been one of the few countries in the area to remain free of bird flu. This location is only 20 kilometers from the coastline of Singapore.
Indonesia is in the wet season now, and an increase in cases should be
Vietnam's southern Tra Vinh province and northern Nam Dinh province have recently been hit by bird flu, raising the total number of affected localities in the country to four, a local veterinary agency confirmed Thursday.
Bird flu outbreaks in Vietnam, starting in December 2003, have killed and led to the forced culling of dozens of millions of fowls in the country.
Over 45 thousands chicks were burnt and buried by Buttle Ehtsham Breeder Farm after having confirmed that they were suffering from Bird Flu
Later after receiving positive reports, over 45 thousands chicks were burnt and buried so that the virus might not affect other poultry farms. The farm manager informed the media people about the loss and said that if the poultry farms owners do not take proper measures, the virus can cause huge losses.
Bangladesh culled some 6,000 chickens after bird flu infected three more farms in the northern part of the country, officials said on Friday.
Nineteen out of Bangladesh's 64 districts have been affected by the virus, forcing authorities to cull 268,000 chickens and destroy nearly three million eggs.
indigo girl
5,173 Posts
You can access Google Earth to visualize the spread of H5N1, avian flu
across the globe. You can choose to look at the spread in birds or in
human/mammlian cases with this technology. It is an amazing thing
to see.
It's a big planet, and the virus is spreading.
http://www.nature.com/nature/multimedia/googleearth/index.html