Thursday, August 6, 2009 at 12:58PM by
Scott McPherson in Politics and government, influenza and infectious diseases | 
1 Comment It has been a few days since I was able to sit down and study the latest news coming from South America. A combination of heavy work and helping my wife through her latest round of chemotherapy combined to distract me for over a week.
Once I was able to concentrate on the latest developments, I was shocked but not surprised. Needless to say, the news is quite disconcerting.
I want to take you back to my blog of July 17th, when I predicted that deaths due to confirmed H1N1v in Argentina would exceed those in the United States by the end of July. It took an extra week, but that gap has finally been closed --depending on how you parse your words.
The latest information coming from the CDC indicates a confirmed total of 353 deaths from swine flu. But Argentina just released new, two-week numbers which raise their death toll to 337.
But wait, there's more. According to the Guardian UK newspaper story, the Argentine government is waiting for positive pathology on another 400 deaths. If even a third of these are confirmed H1N1v, that will catapult Argentina to the top of the world's death list. Hat-tip to Cindy of Nerstrand, MN.
So what, you might ask. Well, two things should leap out at you. First, Argentina has just under 41 million people, according to the CIA. That means Argentina has just over one-seventh the population of the United States, yet it now effectively leads the world in deaths. If the United States had, say, 2,600 deaths from swine flu, that would be a comparable ratio relative to population.
Second, recall that this is Argentina's flu season. The Guardian article discusses that 750,000 confirmed cases of swine H1. I am sure that is just an estimate and not actual swabs. But the number of deaths could be double what is being officially reported, if the 400 unknown results become positive.
This strains further an Argentine government that was the textbook example of how NOT to handle risk communication. In my recent Fox News Channel interview, I was asked if all my warnings could incite panic -- especially my instruction to pregnant women that if they feel anything remotely like flu symptoms, they need to get hold of their doctor, pronto.
No, I responded. It is the absence of information that produces panic, not the presence of honest data. I also reminded the reporter of the work of Dr. Peter Sandman and his advice to treat the American people as adults and give them the skinny exactly as it is.
It was also gratifying when, the very next day, the CDC issued the exact same advice/warning.
Anyway, back to the Argentine government. When H1N1v broke out, they acted as if the virus never existed. No, not here. Move along. When it became painfully apparent the virus was in Argentina and people were dying from it, only then did the government do an about-face and started engaging their pandemic plan.
It is absolutely amazing how governments full of well-educated people can make such terribly dumb decisions.
Further, there seems to be quite the debate raging as to whether or not the virus has indeed mutated in South America. Back in June, the Brazilian research facility Instituto Adolfo Lutz has been in existence since 1892, and was renamed to honor the former University of Bern (Switzerland) scientist. Its core competencies include (from its Website):
Currently, the Adolfo Lutz Institute is recognized internationally for its competence to respond to incidents in their area of expertise, having been accredited by the Ministry of Health and National Public Health Laboratory and Reference Laboratory Macroregional. It Collaborating Center of the Joint FAO / WHO for monitoring of contaminants in food. Reference Center for Analytical Quality Control of Mycotoxins and Residues of Pesticides, National Coordinator of the Program for Monitoring of foreign substances in food, the National Reference Center for Laboratory Diagnosis of AIDS; Collaborating Center of the Pan American Health - OPS areas of arbovirus, influenza virus and production of immunobiological and PAHO Collaborating Center for Cell Cultures.
Anyway, this prestigious WHO collaborating center (think if St. Jude had found such a change!) has typed the first known mutation of the virus' hemagglutinin (the "H" in "H1N1"). Hemagglutinin is what sticks the virus to the cell wall in your respiratory tract (think of those velcro ping-pong balls that stuck to felt dartboards from back in the day). An antigenic change in hemagglutinin could make the virus much easier to catch (search umbrellas and coneson this blogsite for a full description of this phenomenon).
The (236 year-old) patient was hospitalized on April 24 at the Institute of Infectious Diseases Emilio Ribas (Brazil) and is fully recovered.
Respiratory secretion sample of this patient was subjected to molecular rt PCR methodology (§ reaÃthe polymerase chain in real time) with probe specific for the new subtype H1N1 by the team of molecular biologist Claudio Sacchi, and the result for the new viral subtype .
Following the research the team of virology Terezinha Maria de Paiva, the Institute Adolfo Lutz, São Paulo, isolated at the end of April that the new strain is now known as A / Paulo/1454/H1N1 are following the rules of the World Health Organization . The virus isolation was performed in cell culture using the MDCK cells successfully in the first passage. In section electron microscopy of the Adolfo Lutz, Marli Ueda and Jonas Kisielius identified several virus particles from the infected culture. also the first observation.
The isolation of the virus provided the sequence of the genetic material of the Brazilian strain, experiments being performed by Dr. Cecília Luiza Simões dos Santos of the Instituto Adolfo Lutz.
The initial molecular characterization of strain A / Paulo/1454/H1N1 are involved the determination of complete sequences of two gene segments, segment 4, which encodes a protein Hemaglutina (HA) responsible for viral infectivity and for which antibodies are produced protectors, and segment 7, which encodes the matrix protein (MP) M1 and M2. The complete sequences of the genes HA and HB, the first determined for strains isolated in Brazil, are available in GenBank, a database that U.S. shared sequences obtained worldwide, which can be consulted by their respective numbers of access: GQ247724 (HA gene) and GQ250156 (MP gene). Molecular analysis indicated that while the virus segment 7 of A / Paulo/1454/H1N1 are shown to be completely conserved when compared to the reference strain A/Califórnia/04/H1N1, segment 4 showed a discrete number of nucleotide changes and of amino acids, with similar rates of around 99, 7% and 99.5% respectively. Detection of amantadine-resistance marker, comprising the amino acid asparagine (N) located at position 31 (N31) of the M2 protein in strain A / San Paulo/1454/H1N1, corroborates the literature that point be the new virus resistant to this class of antiviral compounds.
The debate started just after the sequencing of this new substrain of H1N1v was announced, and it continues to rage on flu sites such as Flutrackers to this very hour. The issue is this: Do these changes have a lot in common with the hemagglutinin from 1918? At first glance, the answer is yes. There was a lot of swine involvement in the 1918 virus, and so it would not be surprising to see this unique virus sort of "run home to Momma" when it comes to picking up mutations. Swine flu is a much closer antigenic descendant to the 1918 pandemic strain than is our seasonal H1N1! The fact that some of these mutations were first typed in the "Brevig Mission, Alaska" trip of Johan Hultin, circa 1997-98, and came conclusively from the 1918 virus, are somewhat unsettling.
It remains to be seen if this Brazilian mutation is responsible for the larger numbers of infected and dead in Latin America relative to population. Sao Paulo is Brazil's southernmost metropolis. It is about 800 miles from Buenos Aires, the capital of Argentina. The area also borders the capitals of Uruguay and Paraguay.
Let us shift to Mexico, which is reporting a new spike in human H1 cases. Are these cases the vanguard, the herald of the Second Wave? Or are these outbreaks simply vestiges of the first wave of the virus? Nobody knows yet, but there are more reports coming from the border region with Texas which indicates more Tamiflu resistance than originally thought.
This can be explained by the sudden and massive insertion of Tamiflu into the region in the Spring. Remember that Tamiflu does not break down in groundwater, nor does it break down in water treatment plants. So it is not surprising that the massive administration of Tamiflu in towns on both sides of the Mexican border might produce NA 274Y Tamiflu resistance.
We have seen this antiviral resistance many times before, both in seasonal H1N1 and in some cases of H5N1 human infection. Of course, the seasonal strain's resistance is far, far more prevalent.
One thing is sure: South America has suffered the most of all the regions of the world in this, the first wave of the H1N1v swine flu pandemic.
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