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Courtesy of teh CDC
The purpose of these series of articles on the mutation of H1N1 is to give our reader the most up to date information which will allow you to make good, sound educated decisions about your H1N1 flu prevention and care. This is part one of an ongoing series of articles on the mutations that are being reported within the H1N1 influenza virus. We want to be clear to our readers that these isolated mutations have not been transmitted human to human. However that does not mean it won’t happen today or tomorrow or that it already has happened but hasn’t been detected. According to the World Health Organization (WHO)
The mutation does not appear to spread and the public health significance of the finding is unclear.
During a web conference on Flu.gov yesterday we asked Dr. Anne Schuchat, Director, National Center for Immunization and Respiratory Diseases CDC the following question:
#FluCast Steve from the Examiner: What is the CDC's thinking on the isolated mutations of H1N1 found in Norway and Ukraine?
Dr. Anne Schuchat answered,
The mutations that were described recently are interesting, they suggest that the virus could mutate to potential changes that could lead to more virulence. The mutations though have been seen in mild cases as well as severe cases in Norway and Ukraine and so the jury is not out yet on whether that mutation is going to be common to spread to a lot of people and lead to differences in the severity of disease. So it’s an important result but doesn’t yet have public health implications.
Both the CDC and WHO have stated these mutations have not spread from human to human. However both agencies have not ruled out that these mutations will begin to spread. Also it has been reported that this mutation causes a more severe illness like bleeding in the lungs which can completely destroy the lungs. The mutation is not inclusive to the severe form of H1N1 infection; these mutations have been found in mild cases.
Reports we are getting out the Ukraine are very concerning, but are not limited to just the Ukraine, Norway, China and Brazil have also isolated the same mutation and have reported similar symptoms. The concerns at this time are 2 fold, the severe symptoms that accompany an H1N1 mutated infection and the location of the mutation itself. First we will discuss the location of the mutation and the significance of that mutation. The WHO has isolated a mutation on receptor binding domain D225G which is the exact same receptor binding domain that had mutated in the Spanish Flu virus of the 1918 pandemic. The 1918 pandemic killed approximately 50 million people with 18 million of these individuals dying in drought stricken India. See El Niño’s influence on the 1918 pandemic. Here is a great site on the 1918 pandemic, The Great Pandemic take some time and read over this site it will put into perspective the risk we face if the pandemic of 2009 mutates into a more virulent type. The D225G mutation in the H1N1 attaches to the same area and affects the virus in the same way as the same mutation in the Spanish Flu of 1918. The question is will this mutated strain be passed on human to human as the 1918 mutated virus did. The biggest concern at this time is the severity of illness the mutated version of H1N1 causes. The main cause of death in the Ukraine D225G mutation has been bleeding on the lung which leads to total destruction of the lung tissue. Similar findings were seen in the 1918 pandemic. The infection gets deep into the bases of the lungs and causes a catastrophic cascading chemical reaction to take place.
Thus, there was and is ample evidence of D225G in severe and fatal cases. Like 1918, it is not in all samples from fatal cases, and as with all infectious disease, not all infections are fatal. If the initial dose is low, or the hosts mounts and effective early defense, the clinical course may be mild, as has been seen with virtually all influenza infections, including H5N1 infections such as those in Egypt.
What we can take from this news is the importance of being vaccinated against the H1N1 influenza. Although the first vaccine does not target the mutated H1N1 strain, it will provide some immune response if you are exposed to a mutated H1N1 strain. This will help individuals mount an early defense to an H1N1 mutated infection and help keep symptoms mild and prevent death. We will have a more detailed explanation on the D225G mutation tomorrow and any breaking news on the pandemic of 2009. See article on Tamiflu resistance.
D225G in Fatal H1N1casesin Norway?
Clusters of Hemorrhagic H1N1 Pneumonia in Ukraine
H1N1 mutation makes swine flu virus resistant to antiviral drugs - Tamiflu doesn't work anymore
H1N1 mutations emerging around the world - Tamiflu-resistant strain of H1N1 virus resists antivirals
Comments
I think you have a balanced story on the whole. However, I do not think you you are on the whole correct that there has been no human to human transmission. According to Dr. Niman's posting on 11/23/09 (Recombinomics) he seems to suggest that the case of two oil rig workers who died mithin 24 hrs. of each other may be a case of D225G gaining traction. Additionally, A report from an Iowa medical examiner states that during several post mortems he has performed, Hemorraghic pneumonia was present. This would suggest that D225G is present in the US. As for the the actual number of D225G hemorraghgic pneumonia cases in the US it is anyones guess. Since most of the deaths are caused by secondary inections, mostly bacterial, and viral pneumonia, and a increasingly larger number of hemorrahgic pneumonia it would be important to know the numbers of patients who have died from secondary infection brought on by the H1N1 virus.
Hello Charlie and thanks. You are correct on Dr. Niman's findings however they are not yet official.If we look at the Ukraine data from the 2 cities of Ternopil and Lviv we do find evidence of some polymorphism via recombination which seems to be common.However is it spontaneous mutation? I think more data is needed from these areas to rule out human to human transmission. However I do feel there is a high probability this has already happened since we are seeing an increase in fatal cases of hemorrhagic pneumonia especially in the 2 cities in the Ukraine.Is it an isolated event?We are seeing areas added by the day to the D225G mutation list and more postmortem reports of hemorrhagic pneumonia as the cause of death.So we could have isolated events of spontaneous mutation and transmission,but I'm afraid over time we will see this mutation be a significant part of H1N1 circulation.With that said immunization,good hygiene and better control on antivirals will help slow its progress.
One of the ca 40 German fatal cases had recently returned from a trip to the Ukraine. Maybe it's pure chance, but it does make me wonder whether the mutated virus isn't spreading from person to person at least the Ukraine. If I remember rightly, at the beginning of the epidemic in the US, there was what seemed like a cluster of fatal cases in Utah even though the state as whole didn't count that many confirmed cases. THat anomaly could also have been caused by a mutated strain which spread reagionally .
Hi Stefan.We had cases like this during the Asian avian flu H5N1 scare, where small clusters of individuals mostly family members were infected.They also lived with or worked with poultry.The spread of H5N1 did not go out of the cluster.CDC reports:While most people in these clusters have been infected with H5N1 virus through direct contact with sick or dead poultry or wild birds, limited human-to-human transmission of H5N1 virus cannot be excluded in some clusters.We need more info on the individual who died in Germany.Epidemiologist will try to discover their contacts and movements while in the Ukraine.Just like the 2 oil rig workers that died from H1N1 with 24 hours of each other, they were roommates and spent a lot of time in close quarters.This could be a case of spontaneous mutation with limited rate of transmission.Today's article (Part2 )will focus on these issues.
First of all, I agree with your final statement that everyone should get the H1N1 vaccine. That is one sure way to mount a defense against this virus, and if many people get the vaccine it will contribute to reducing the viruses ability to spread.
However, associating the D225G with the H1N1 strain of 1918 is very irresponsible. There were many factors that contributed to the virulence of the 1918 strain, and D225G may or may not have been only one of them. While the D225G mutation might allow the virus to replicate lower in the lungs, it also reduces transmissibility of the virus. Further, there is no evidence to suggest that the current H1N1 strain cannot replicate lower in the lungs without this mutation, and in fact this has been shown to occur in ferrets. For a alternative, science based view see the virology blog (www.virology.ws). I think we know far too little at the present time to start saying that H1N1 of 2009 is acquiring the virulence mutations of 1918.
Hello viralnerd. My next article will cite the article written by Vincent Racaniello. The association between the D225G mutation in H1N1 of 2009 is the same D225G mutation found in the 1918 virus. The virulence of this mutation in 2009 seems to cause the same hemorrhagic pneumonia that was witnessed in 1918. yes there were many factors in 1918 that we do not face now that contributed to the virulence of the 1918 strain.Also if the data is accurate and a D225G mutation helps to inhibit transmission it still doesn't mean the mutated H1N1 cannot be transmitted.The case of 2 oil worker roommates seems to be a good example.Take for instance we have a population of 10 million and a virus that has a transmission rate of 10% and a death rate of 1% that would mean 10000 deaths. Now a mutated virus within the same population has a transmission rate of 2% and a death rate of 5% that would mean 10000 deaths.So a low transmission rate doesn't allows mean less death.You are correct we need more data
As a retired pathologist, pure hemorrhagic pneumonitis is a rather rare finding. Many pathologists believe that it is almost
pathognomic for viral pneumonia.
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