The Coming Influenza Pandemic?

February 11 Flu Update

Sorry, we're a little late today. Big news flu day on an absolutely brilliant winter morning.

The lead story is the ongoing spread of bird flu, covered here by WaPo. Italy, Greece, Bulgaria. Note that an expert notes that it is helpful to date that in these countries, wild birds and not poultry have been found with the disease.

Local Italian report on flu in Sicily.

There's also another bird outbreak suspected in the Danube, Romania.

In Nigeria, there are "suspected cases" near bird outbreaks. It would be completely contrary to the existing pattern if outbreaks of this size were not matched by human cases.

"There are a few suspected cases ... We're trying to locate them but our sources can't provide us with addresses for now," said Abdulsalam Nasidi, who is in charge of the response to bird flu as a threat to humans at the federal Health Ministry.

He said epidemiologists were searching for two people feared to have contracted bird flu in the northern state of Kaduna, close to Sambawa Farms where one of the poultry samples was found that tested positive for H5N1.

Nabarro of WHO reminds us that this spread increases the chances of a mutation, which he says no one has seen happen yet.

We have got bird flu now in southeast Asia, central Asia, eastern Europe, and west Africa," he said. "Compared with eight months ago, this is a major extension of the avian influenza epidemic."

Nabarro said control measures put in place by countries have helped to contain the spread but bird flu is still expanding across the world "putting at risk the health of people who are living intimately with poultry and also adding to the overall load of the H5N1 virus."

He said it is the increase in the quantity of the virus in the world today that has boosted the overall chance of mutations, including a mutation that could cause a disease which could then spread through the human population.

"That's why we get so concerned about the spread of the virus, because we want to do everything we can to reduce the opportunity for mutation," Nabarro said.

He said one of the urgent needs is to establish how avian influenza reached west Africa.

"The likely means is by migrating wild birds traveling from north to south, and one of the main migratory routes passes from Siberia through the Black Sea area, including Crimea and on to west Africa," Nabarro said. "The alternative is that the virus arrived in birds that are being traded — and if that is the case they would have been smuggled as Nigeria had banned import of birds from avian influenza affected areas during the last two years."

The Italian Ag minister says farms are well protected there.

Lee County, Florida, recognizes a pandemic would overwhelm them. If it does, they will, among other things, ask retired medical professionals to come back to work.

Japan is preparing to make generic Tamiflu.

WaPo with an interesting story on flu vaccines. Its about adjuvants being used to "strech" flu vaccine production capacity.

"We believe that the adjuvant may become the holy grail of vaccines," Chrystyna Bedrij, an analyst with Griffin Securities, wrote in November in a review of avian flu-related business.

Must read. Effect Measure on "A trainwreck in slow motion." He cites a study on Influenza Report 2006 that looks at the age distribution of cases of influenza pandemic. 90% of cases are below the age of 39. Revere says this is unheard of. Even in 1918, excess mortality was higher in young people, but the distribution was not this skewed.

It may be we are seeing some kind of reporting bias, i.e., that younger age cases are being recognized but not older ones, although this seems unlikely given the severity of the illness. It is also possible that there is something about exposure that is higher in the young. It has been suggested that it is the youngest who are closest to poultry, either by virtue of having the chore of collecting the eggs in the henhouse in the morning or because they play with the birds as pets. But it has been a puzzling feature of H5N1 outbreaks that adult poultry workers and those involved in culling operations rarely become ill or show signs of infection. It is possible there is some kind of cross immunity in the older age groups or other unidentified biological feature that either protects an older person or makes the younger ones especially susceptible.

As yet this is not a pandemic virus. But it has the hallmarks of one in the making. It is like watching a trainwreck in slow motion.

Here's the actual study.

Effect Measure also has this on the spread of the bird flu.

The evolution of the H5N1 question as a matter of human health now depends on imponderables. We know too little about the biology of host range, transmission and virulence to be able to predict what this subtype can do, much less what it will do and when. But the world is now set up for a pandemic should the virus's biology permit it. Every community should be thinking hard what the consequences would be and begin to prepare.

We ran the source story for this a while ago. Its a paper on how ventilator access should be rationed in a pandemic. Effect Measure weighs in with the moral implications of this. (My note: its this kind of issue that worries me in terms of maintaining order in a pandemic).

ProMed bonanza today.

In addition to the death yesterday in Indonesia, another person is in critical condition. In Shanxi, China, 35 people are under observation after being near a bird death site of 15,000 people. Also includes raw age data used in the analysis above.

ProMed with ongoing data on the spread, including Lagos and Western Europe.

ProMed on the worldwide spread (again). Contains the "positive" story of a single strain. Also, wonders if the question isn't migratory or smuggling, and is migratory and smuggling (mod comment).

ProMed on Italy and Greece.

The International Reference Library posted this note to ProMed. The lab is open 7 days a week--don't listen to countries who claim their results aren't in because the lab is closed.

Recombinomics on a familial cluster in Amara he says has is a bimodal distribution.

Recombinomics on Indonesia, which says that familial clusters are on the increase there, as well.

Recombinomics says that disease onset dates in Turkey were withheld, and that these onset dates reveal human to human transmission.

posted by Orange @ 9:41 AM