bird flu
revere | September 19, 2007The bird flu influenza subtype, H5N1, that has been infecting humans with high mortality is the highly pathogenic (HPAI) version of a virus that also exists in a low pathogenic form (LPAI). The high and low path designations refer to effects on poultry, not humans, but only the HPAI versions have been of public health importance. On the other hand, the HPAI strains have all come from LPAI ones via a variety of genetic mechanisms and LPAI strains are themselves of importance to the poultry industry where they decrease productivity of the flock. For these and other reasons there is a need to…
revere | September 18, 200710,000 ducks in Guangdong Province in the south of China have died of bird flu and 100,000 more culled in an attempt to stop the spread of the disease. Massive bird flu outbreaks are not exactly a novelty these days but the Chinese incident is noteworthy because it is now reported the ducks were in vaccinated flocks:
According to Guangdong Animal Epidemic Prevention Center director Yu Yedong, the 9,800 ducks that died at Sixian village had been vaccinated. But he added the first vaccination could only be 65 percent effective, while a second shot would have made it 90 percent.
He believed the…
revere | September 14, 2007&In Europe and North America pets -- what veterinarians call companion animals -- are usually dogs or cats. In other countries (e.g., Korea) dogs are raised for food like livestock. Birds are a sort of cross over creature. Birds as companions are fairly common in Europe and America but they are most often exotic. But even people who raise birds for food frequently develop an attachment to them, and having a chicken or turkey as a pet is far from rare. But chickens get bird flu. It turns out that and dogs can also become infected, although at the moment they are not known to be…
revere | September 12, 2007The war in Iraq has been going on in earnest since March of 2003, which is about how long the war on bird flu has been going on. Yes, there were some preliminary skirmishes in the bird flu war in 1997, but it wasn't until it burst out of southern China with a vengeance that full scale hostilities started. In both wars there have been a lot of innocent bystanders. In neither are seeing a lot of progress, despite claims to the contrary. The war in Iraq, at least, is susceptible to human control. The war against H5N1 doesn't seem to be. The number of human casualties in the bird flu war is…
revere | September 11, 2007It's September 11, so time to do a "security" post. Sigh. The current dopiness concerns the lessons we can learned for making das Vaterland safe after the recent Atlanta lawyer TB incident. Since learning the wrong lesson seems to be standard operating procedure for both Republicans and Democrats, not to mention "professional" public health types like the CDC, I'm not surprised to read crap like this:
A congressional investigation into officials' inability to stop a tuberculosis patient from leaving the country found significant security gaps, heightening concern about vulnerability to…
revere | September 7, 2007There's a lot to know about influenza that we don't know. Unfortunately a lot of is things you thought we knew but don't. Like whether there is a risk from influenza virus in drinking water. Admittedly this hasn't been at the top of the list for seasonal flu, since the main reservoir for this virus is other people and that's who you catch it from. But with avian viruses there is the problem of aquatic birds (the main reservoir in the wild) shedding virus into ocean littorals and surface waters, including drinking water reservoirs. In addition, agricultural run-off, including fecal waste from…
revere | September 6, 2007Australia's severe flu season reminds us, in dramatic fashion, that "regular" (seasonal) influenza can still be a severe disease. It's not just the elderly, but children, too. What about children in the developing world? What would you find if you went into one of Bangladesh's urban slums? We now have some information, presented as a Letter to the Editor in CDC's journal, Emerging Infectious Diseases. Children under the age of 13 with fever and symptoms of an influenza-like illness (dengue fever was excluded) in 2001 were tested for acute infection via antibodies to H1N1 or H3N2 influenza,…
revere | September 5, 2007What seemed pretty obvious at first, that wild birds could be and were long distance carriers of H5N1 is, like the birds themselves, still up in the air. The problem is that existing data on migrating wild birds has failed to show convincing evidence they are infected:
FAO officials last year voiced concerns that bird migration patterns might have spread disease Asia and Europe to Africa. But as elsewhere in the world, very few cases have been found among wild birds in Africa.
The Wildlife Conservation Society Field Veterinary Program Director William Karesh is among those attending the…
revere | September 4, 2007Recently we posted on the paper by scientists at Fred Hutchinson Cancer Research Center and University of Washington (Seattle) reporting a new statistical tool for evaluating the likelihood that a cluster of bird flu cases in a small geographic area was spread from person to person or the result of a common source, usually poultry. Two clusters were looked at, one in Turkey and the other in Indonesia (the so-called Karo cluster). It is fairly well established there was human to human transmission in this cluster, as there has been in others. It makes sense. If a person can become infected by…
revere | September 1, 2007There are a lot of industries that will suffer mightily if there were an influenza pandemic so it's hard to single out any one that will be hit harder. But among the most vulnerable certainly must be the travel industry. At the height of a pandemic the problem is probably moot. By that time even the people in the travel industry will have other things to think about. But a pandemic doesn't start in an instant. It starts somewhere and depending upon surveillance systems we will have more or less time to react depending upon where we are. There will also likely be a period of uncertainty when…
revere | August 31, 2007A couple of weeks ago CDC's peer reviewed journal, Emerging Infectious Diseases, published online an ahead-of-print paper by Yang et al., "Detecting Human-to-Human Transmission of Avian Influenza A (H5N1)." The paper has now been published in the journal and predictably, it made news. It's an interesting paper, but we think some people are going beyond what it says. First, the gist according to Reuters:
A mathematical analysis has confirmed that H5N1 avian influenza spread from person to person in Indonesia in April, U.S. researchers reported on Tuesday.
They said they had developed a tool to…
revere | August 30, 2007If you want a good snapshot of how poorly prepared Indonesia is for coping with bird flu, look no further than the Letter column of The Jakarta Post:
On Aug. 26 I found a dead wild bird in my yard. I am living in Bali near the area where bird flu related deaths have occurred.
Since I was worried about the possible risk connected with dead birds, I tried to contact some authority to guide me on how to handle this situation.
I tried to reach the main hospital in Bali, Sanglah, and the answer was to go there if sick but they do not know anything regarding dead birds or chickens.
Next I tried to…
revere | August 28, 2007A recent article in TimesOnline (hat tip RobT) raises an inevitable and interesting question about how we are going to ration scarce high tech medical resources in a pandemic. The article reports on a paper by Canadian scientists on SARS patients indicating that certain patterns of protein expression offer clues to clinical prognosis. In particular, the researchers found that protein expression patterns for interferons, known to participate in the innate immune system's reaction to viral infections, seem to indicate that one of two distinct patterns predict a relatively good prognosis, the…
revere | August 24, 2007Pandemic influenza gets its share of headlines but there are other viruses out there that also are good tabloid fodder, most notably Ebola virus which causes Ebola hemorrhagic fever, whose gruesome effects were depicted in Richard Preston's book, The Hot Zone. Ebola has some close relatives in the filovirus family, among them Marburg virus. Like Ebola it can cause a gruesome demise. Marburg has cause several outbreaks in Africa, one of the largest in Angola at the end of 2004, early 2005 (see the Wikipedia article on Marburg for more details). One of the enduring mysteries is where the virus…
revere | August 23, 2007"Protecting the border" is a battle cry for the most reactionary US politicians but when it comes to flu, they are as unlikely to be successful as they are for people. However it might be the Canadians, who have a functioning public health system, who are most at risk from a surge of US citizens fleeing their own poverty-stricken, understaffed and dysfunctional health care society that will be most interested in keeping those American illegal aliens out of their hospitals. This week the heads of state of Mexico, Canada and the US discussed what to do in a pandemic and they all agreed on the…
revere | August 22, 2007[Given our posts (here, here) on the particularly severe flu season in Australia, we thought it useful to remind ourselves that a bad flu season can be really bad -- worse than the 1918 pandemic in some locations. Here is a post we did back in April 2006 about an interesting paper (see link in post) by Cecile Viboud and her colleagues at NIH that looks at historical records on flu mortality. Flu is a bad disease, pandemic strain or not. Why some flu is worse than others we don't know.]
Originally posted Friday, April 7, 2006:
We talk frequently about the H5N1 virus mutating to a form…
revere | August 21, 2007We keep seeing these discussions about the probability of a pandemic next year. Sometimes they center on the "overdue" for a pandemic notion, sometimes on using available data to give an estimate of the rough chances of a pandemic. In the latter category is this little contretemps in the UK:
Contingency plans drawn up by the NHS are based on a 3 per cent chance in any given year that the virus will mutate into a form that infects humans. However, an international review at a summit of avian flu experts put the risk of a pandemic during the next year as between 5 and 20 per cent.
Leading…
revere | August 20, 2007As promised, here is a second post on the situation in Australia, currently struggling through a very bad flu season. In the first post I quoted the late epidemiologist Irving Selikoff who referred to statistics as "people with the tears wiped away." Statistical summaries are the stock in trade of the public health profession but it is important to keep reminding ourselves of the ocean of tears we wipe away when we quote them.
So it's back to Australia:
He kissed her goodnight and she softly whispered: "I love you" so as not to wake their two young sons, fast asleep in her arms.
It was the…
revere | August 20, 2007This is about the particularly severe flu season being endured by our friends in Australia. Southern hemisphere, so the flu season is in full swing there, the reverse of the northern hemisphere. But "full swing" doesn't quite describe it, so I'm going to do this one in two parts ((all links from Flu Wiki Front Page, news for August 18). The great epidemiologist Irving Selikoff once described statistics as people with the tears wiped away. So the first post today will be statistics, or the equivalent, without the tears . Later today I'll do the other part:
As the flu epidemic continues to…
revere | August 19, 2007The big pandemic flu vaccine news of the moment has to be The Lancet report that vaccine maker GlaxoSmithKline has been able to get excellent antibody production against H5N1 with a new adjuvanted preparation that contains remarkably little viral antigen. This is important because the currently the only FDA approved pre-pandemic H5N1 vaccine uses more than 20 times as much (90 micrograms versus 3.8 micrograms) in an unadjuvanted preparation with much worse antibody response.
In today's Lancet, Isabel Leroux-Roels and colleagues report safety and immunogenicity data from a phase-1 dose-sparing…