Effect Measure

Bird flu picking up speed

In the first six months of 2006 the number of countries detecting infected birds has doubled. Case fatality remains extraordinarily high. And limited human to human transmission, with at least one moderately large cluster is becoming more evident. WHO continues to say most human infections come from poultry, although the evidence for this is not conclusive. Many cases have scant or no history. The feared easy person to person transmission has yet to occur, but the virus is not standing still. It continues to change genetically and move into wider and more varied niches. Sixty countries are said to be affected.

Southeast asia is said to have made progress controlling the disease and transmission to humans by aggressive programs of culling and vaccination, although the verdict is still out on whether this has truly worked. But meanwhile China, Indonesia and Africa struggle with their veterinary services and the hope of stamping out or controlling the spread in these places is slim. Too many birds, too wide an area, too little resources and public recognition of the problem. The virus is becoming endemic in a variety of bird species in large areas of the globe and is unlikely to go away soon.

The virus is not just a threat to the affected countries but to the world’s population should it spawn a pandemic strain, which seems more and more likely. Yet the wealthy countries are, as always, all talk but little action. At a meeting in Beijing in January $1.9 was pledged by wealthy donor countries to help poorer ones compensate farmers and improve their veterinary, surveillance and public health services. As we noted months ago, only a fraction has been delivered. Slow payments by the World Bank and Asian Development Bank are partly to blame. They have paid out only $4 million of $969 million as of the end of April (Reuters). Other donor countries are also tardy, including the US and the EU. Only Japan has met (and even exceeded) its pledges.

So it’s mid July, now. Soon we will be moving into the northern hemisphere’s colder months and “flu season.” Most observers believe bird flu will also pick up speed.

Which is bad news, because it’s already traveling awfully fast.

Comments

  1. #1 Marissa
    July 11, 2006

    The danger period will be late fall when the northern hemisphere cools down, the virus finds itself in cooler environments and birds are migrating again.

  2. #2 Tom DVM
    July 11, 2006

    There are many class of threats constantly under consideration by Regulators and Governments.

    Unfortunately the flu deniers have recieved greater relative attention then virologists and others who have attempted to offer a balanced estimate of risk.

    Because of the resulting mixed messages, including those by the WHO (Jan 2005), Regulators and Governments have not been able to get their minds around a real and imminent risk of a pandemic.

    A colleague on Flu Wiki, Monotreme observed in Feb/Mar that the virus was being transmitted from human to human more easily than from bird to human. That single fact seems to have been missed by the scientific community and is as good a predictor of future events that I can think of…better saddle-up, we have a problem that is not going away.

  3. #3 Tom DVM
    July 11, 2006

    There are many class of threats constantly under consideration by Regulators and Governments.

    Unfortunately the flu deniers have recieved greater relative attention then virologists and others who have attempted to offer a balanced estimate of risk.

    Because of the resulting mixed messages, including those by the WHO (Jan 2005), Regulators and Governments have not been able to get their minds around a real and imminent risk of a pandemic.

    A colleague on Flu Wiki, Monotreme observed in Feb/Mar that the virus was being transmitted from human to human more easily than from bird to human. That single fact seems to have been missed by the scientific community and is as good a predictor of future events that I can think of…better saddle-up, we have a problem that is not going away.

  4. #4 Name
    July 11, 2006

    Tom, I hadn’t thought of it like that before but the Indonesia cluster does suggest that’s true. This particular strain of H5N1 was transmitted to a single human from a presumably avian source, and then went on from there to infect at least six other humans, for a ratio of 1 B2H: 6 H2H. Granted, there remain many unknowns, but this does present a troubling picture, as you note.

    Despite the apparent calm, my worry meter has been climbing since that cluster and you’ve just gone and set it off again. I wonder what are the thoughts of others who may understand the mechanics of the much feared transition better than I?

  5. #5 mary in hawaii
    July 11, 2006

    I have another question/concern to ask the virologists and epidemiologists out there. Dr. Niman just posted a couple of new items on his recombinomics site which detail how this virus is mutating. My question: is this abnormally rapid? I know viruses by nature, especially RNA viruses, are highly mutagenic but it seems like a very high rate. It also raises concerns in terms of the development of effective vaccines, not just for humans but even birds. That is, what is the point of vaccinating birds if the virus is mutating so rapidly? Will those vaccinations really prevent viral infection or replication in the host animal? Or will they simply mask the worst of the symptoms and allow the newly recombined virus strain to grow? As a matter of fact, could the widespread vaccination of poultry actually be contributing to the evolution of the virus, much as the use – especially inappropriate use – of antibiotics has contributed to the evolution of drug resistant bacteria?

  6. #6 Patch
    July 11, 2006

    I’ve been following things pretty closely and while I still get this sick feeling in my stomach at times, I must say that BF must be lurking rather quietly at the moment. Off season? Probably. Will it pick up again? I hope not, but probably. But I don’t think your title conveys the current situation.

    Picking up speed from 2 years ago…yes. Picking up speed as of late…maybe not.

  7. #7 lindsey
    July 11, 2006

    A nice visual aid, if you haven’t yet seen it:

    http://news.bbc.co.uk/2/shared/spl/hi/world/05/bird_flu_map/html/1.stm

  8. #8 revere
    July 11, 2006

    mary: Haven’t seen Henry’s post (just got off the plane) but flu viruses mutate very quickly. It is not uncommmon to have them mutate within an infected patient. Most of mutations are unfavorable and the virus cannot replicate, but it makes billions of copies in a person and hence mutation potential is high.

  9. #9 revere
    July 11, 2006

    Patch: Picking up speed in the last 6 months. Remember we are supposedly in the “off” season.

  10. #10 Marissa
    July 12, 2006

    Mary, it’s evolving at a perfectly normal rate typical of single-strand RNA viruses. yes, this will affect vaccines for sure and make them far less effective, but we’ve been saying that all along.

  11. #11 respiratorytherapist
    July 12, 2006

    Reveres,
    I am impressed with SE Asia, Vietnam’s efforts and success. Certainly, compliance by the people to government policies and directives plays a part here. PolSci is not my area, but having spent a little time there in 1972, I have always had the idea that when told to do something there, You Complied. Period.
    In the USA, if the government made the same policies and directives, do you think we would have the same level of compliance and no questions cooperation?

  12. #12 revere
    July 12, 2006

    respiratory therapist: I agree with you that cultural factors loom large in compliance issues with gov’t policies. It is one reason Vietnam is complying and Indon isn’t. Indon is a huge and ethnically diverse country, Vietnam much less so on both scores. It remains to be seen how much Vietnam has succeeded, however, as there is suspicion the vaccination policy is masking birdflu, not eliminating it. We’ll see, I guess.

  13. #13 Kevin
    July 12, 2006

    Thailand seems to manage the situation well via culling without vaccination. Not sure of the cultural factors vs Vietnam and Indonesia? Less authoritarian than Vietnam, better organized than Indonesia?

  14. #14 revere
    July 12, 2006

    Kevin: I think the surveillance question in Thailand is still open, so knowing how well they are doing is also. Between Vietnam and Indon there are numerous issues of the number of ethnic groups and their relation to the government, how things are structured socially in relation to the government and their attitude towards culling.

  15. #15 mary in hawaii
    July 12, 2006

    Marissa and Revere: You both say the virus is evolving at a perfectly normal rate for single strand rna viruses, but I just read this article in CIDRAP regarding the mutations in the Indonesian family cluster that seems to indicate, in that case at least, that the number of mutations was unusually high. Or am I just misreading their intent? Here’s the link.
    http://www.cidrap.umn.edu/cidrap/content/influenza/avianflu/news/jul1206mutate.html

  16. #16 revere
    July 12, 2006

    mary: That’s from Declan Butler’s article in Nature which I have written a post on for tomorrow. I have the same data Declan does. One virologist expressed surprise at the number of mutations in the father’s isolate and suggested it might be another strain, not a mutated virus. I think that is unlikely. There are a couple of issues here, the big one for me being that thee sequences haen’t been curated and errors in sequencing are quite common. Counting up the nucleotide differences isn’t the best way to do this with raw sequence data like this. So the answer to your questio is that there did seem to be a lot of mutations in this one isolate, for reasons that are not clear at the moment.

  17. #17 Marissa
    July 13, 2006

    Mary, I probably disagree with Revere here in that I think another flu strain might be in play (Henry thinks a recombination event occurred, and I agree with him), but the only way to know for sure is by comparing sequences, which we cannot do since we don’t have them.