Surveillance
revere | January 28, 2008Everyone knows it's flu season. We see the evidence in birds and people with H5N1. The Indian subcontinent is awash in birds with H5N1. Sometimes here we forget to remind people it is also flu season with the regular circulating subtypes, H1 and H3 and this is shaping up to be a predominantly H1 season in Europe and the US.
In the US:
During week 3 (January 13 - 19, 2008), influenza activity continued to increase in the United States.
Three hundred twenty-nine (11.1%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (…
revere | January 25, 2008You'd think finding that there were some bird flu infections that went undetected would be bad news but it is actually good news. Not tremendous good news but better than no news, and that's unusual in the bird flu world. For some time the absence of mild or inapparent infections has been worrying. It means that the current case fatality ratio of over 60% is the real CFR, not one based on just the most serious cases coming to the attention of the surveillance system. Now scientists gathered in Bangkok at one of the many gatherings of those studying the disease have heard some new data…
revere | January 23, 2008In 2006 there were 115 confirmed cases (WHO case count) of H5N1 in humans with 79 deaths. In 2007 the figures are 86 cases and 59 deaths. Some have taken this as evidence H5N1 is less of a problem (latest data here). That's not how I read it, however. Seasonal flu numbers bounce around from year to year, too, and if this year is better than last year it isn't because flu is disappearing. Still, let's take a look at the numbers a little more closely and see where the differences are. Here's the WHO Table:
21 January 2008
Country
2003
2004
2005
2006
2007
2008
Total
cases
deaths…
revere | January 10, 2008Whenever confirmed human cases of bird flu appear in an area there usually follows heightened sensitivity to new cases of severe pneumonia. Are they bird flu too? Severe pneumonia is pretty common, so you can't automatically assume that "if it quacks like a duck and walks like a duck it must be a duck." It turns out there are a lot of birds that look like ducks that aren't ducks, at least when it comes to influenza-like illnesses. On the other hand, "testing negative" with PCR, which on its own is a pretty sensitive and specific test is also not foolproof. "On its own" means under the best…
revere | January 9, 2008Every year "flu season" comes during which there is a marked uptick in influenza-like illnesses (ILIs) in the community. An ILI is defined to be cough or sore throat together with a fever of over 100 degrees F. (37.8 degrees C.) or self-reported fever and chills as well as no other obvious cause (e.g., strep throat). But are all ILIs influenza? No. They are ILIs. In the absence of lab work (and since most are thought to be of viral origin, only non-specific symptomatic and supportive therapy is recommended and no diagnostic lab work is usually done), an ILI could be from influenza virus or…
revere | January 8, 2008A new study from a glycobiology laboratory at MIT is creating a buzz in the flu community (see the MIT Press Release here). A great deal of molecular biology and virology studies what happens when the virus gets into a cell to use the cell's own machinery to make copies of itself. Glycobiology is a relatively new area, concentrating on the straight and branched chains of sugar units that make up a great deal of the "stuff" one finds outside of a cell. What do these sugars have to do with influenza?
In earlier posts (see here and here and links therein) we showed how the influenza virus…
revere | January 6, 2008The big newswires and health agencies are relatively quiet, but word keeps leaking out of Egypt that there are a lot of suspect bird flu cases:
CAIRO: Hospitals nationwide reportedly quarantined more human cases suspected of being infected with the H5N1 bird flu virus.
According to Al-Masry Al-Youm newspaper, Damietta -- where the latest Bird Flu victim Hanem Atwa Ibrahim, 50, died late on Monday Dec. 31 in a Cairo hospital -- hosts the largest number of cases with five people suspected of carrying the virus, while the Upper Egyptian city of Qena came next, with two cases, followed by El-…
revere | January 2, 2008Egypt continues to be the country outside of Asia with the highest case total of H5N1 disease. Last year there were 23 cases, 18 the year before. A year ago there were 3 confirmed cases each in December and January, with the big month being later, March (7 cases). Flu season (including bird flu) is starting again there with four deaths at the end of December, the first since July. The flu sites newshounds are doing their usually diligent job and they report an additional confirmed but still living case. In addition there are the usual spate of "suspect" cases, a fluctuating number that can…
revere | December 31, 2007Everyone seems to have an opinion about whether bird flu will be the next terrible global pandemic. In current parlance "bird flu" means human infection with the highly pathogenic avian influenza/A subtype H5N1. There is no doubt that this is the 800 pound gorilla in the global health room at the moment, but not because it is more likely to become a pandemic (NB: pandemic by definition is a globally dispersed sudden increase in infection among humans; the same situation for animals is called a panzootic, and it is plausible to say we have an H5N1 panzootic for birds now). On the basis of…
revere | December 27, 2007Bird flu is still flu and one expects an uptick of cases during "flu season" which usually gets underway in earnest in December. So from that perspective it isn't a surprise that December has seen human fatalities from bird flu in six countries: Pakistan, China, Vietnam, Egypt, Burma and, of course, Indonesia. Once the Pakistani cases are officially confirmed and added to the December tally for this flu season it will make it the worst December yet, but we shouldn't read too much into this. Flu seasons are notoriously variable and the numbers bounce around a lot from year to year. But . . .…
revere | December 22, 2007WHO [World Health Organization] is now saying that human to human (H2H) transmission has not been ruled out in China or Pakistan:
China:
The World Health Organization said Friday it was impossible to say whether a case of bird flu in China involving a 52- year-old man was due to human-to-human transmission - but, even if it was, it was down to very close contact between the victims.
The Assistant Director-General for Health Security at WHO, Dr David Heymann, said the only proven transmission of this nature so far, in Indonesia and Thailand, had been as a result of very 'close contact' in a '…
revere | December 21, 2007It's been less than a week since the first reports out of Pakistan that cases of bird flu were appearing there. At the time we warned that the coming of flu season meant these kinds of reports were to be expected, but by the weekend concern increased as a family cluster appeared. As common in the early days of an outbreak news reports were contradictory and confusing. We elected to wait. By Sunday, some excellent reporting by Helen Branswell and diligent combing of the news by flusites allowed us to make a preliminary summary. We fully expected more surprises.
The biggest surprise so far is…
revere | December 18, 2007I don't know much about the West African state of Benin, but the newswires have made sure to alert me to the fact it is the home of ritual Voodoo sacrifice. Which, it turns out, is relevant to bird flu because Benin is having a poultry outbreak with H5N1. This is not much of a surprise, as it is surrounded by neighbors that already have reported infected poultry: Nigeria, Togo, Niger and Burkina Faso. A bit farther afield but still in the region are Ghana, Ivory Coast and Cameroon, all with reported poultry outbreaks. Nigeria has also had a human fatality.
But back to Voodoo. In the US we…
revere | December 16, 2007If I knew for sure what was going on with the reported human bird flu outbreak in Pakistan's northwest border region I'd tell you. At this point it appears no one knows for sure -- not WHO, not CDC, not even the Pakistani authorities. The region where the cases are reported is near the Afghan border and is not under firm government control. The unsettled political situation merely adds to the usual confusion inevitable in the early days of any outbreak. We are all looking for a pandemic signal embedded in a lot of noise, difficult enough, but we don't even know what the signal sounds or looks…
revere | December 10, 2007The debate about how much wild migratory birds contribute to the spread of highly pathogenic influenza/A H5N1 goes on. According to a sensible Commentary in Nature (Dec. 6) it needn't. We should have taken steps some time ago to answer an answerable question. But we didn't and still haven't initiated those steps:
Two years ago, some believed that H5N1 viruses were poised to spread around the globe on the wings of migrating wild birds. A massive effort was mounted to track their movement but, as of September 2007, very few positive birds have been found in tests of over 300,000 healthy wild…
revere | September 10, 2007In the last five years the Veterans Administration has figured out a way to decrease cancer cases amongst veterans by a lot: 40,000 to 70,000 are the estimates. The breakthrough was initiated by the Bush administration, which has used the same technique to make an impact on other problems, from military casualties to the environment: they just don't bother to tell anyone about the cases. Presto: they disappear:
Stonewalling by the Veterans Administration is putting U.S. cancer surveillance and research in jeopardy, according to many of the researchers involved in those fields.
After decades…