h3n2

World Press and Vietnam again caused a stir and organizational control disease prevention (CDC) confirmed three more American young people in Iowa mutate flu virus infects a new A (H3N2) derived from pig . As from January 8.2011, the CDC has recorded 12 cases scattered in five northeastern states of the United States. The samples after the tests to detect genetic decoding in the variable new strains of genetic reassortment between H3N2 is circulating in pigs in the United States with M genes of H1N1 pandemic strain in 2009, is S-OTR called H3N2 (swine-origin H3N2 triple reassortant).

Why does the medical world feared H3N2 S-OTR?

Influenza A viruses, including subtypes (subtypes) based on a combination of two proteins, hemagglutinin (H) and Neuraminidase (N). . There are 16 H antigens and nine antigen N.  In nature, each H and N antigens are often distributed in a certain species of animals.  Currently only three H antigen subtypes (H1, H2, H3) and two subtypes N antigens (N1, N2) is regularly circulated in humans. The other subtypes found mostly in animals. Wild birds are natural hosts of the virus.

The most important characteristics of the virus is likely to change frequently antigenic structure through the phenomenon of mutation and genetic recombination.  Meanwhile, strains "new" would escape recognition by the immune system, easily cause major outbreaks and high mortality risk to the community without resistance. History has proven each pandemics were caused by a new virus appears to mutate.

Back at the North American case, which flu strains are circulating in pigs rarely causes human disease.  Since 2005, only 35 cases reported in the United States, but production levels have increased in 2011.  When different strains co-infection in a host body, the genetic material can exchange and create a new strain variables.

At the conference Fourth European Influenza held in Malta (May 9.2011), a scientific discovery has been global shocked Dr. Ron Fouchier and colleagues at Erasmus Medical Center Rotterdam (Netherlands) announced . In the laboratory, they have successfully tested the mutant strains caused by H5N1 virus introduced directly into the respiratory tract to cause infection experiment repeated on civet.  With only five through ten mutant virus experimental phase, they have gained new H5N1 strain can spread easily through the airways from civet to others. Biologically, this means the ability to spread from person - people with respiratory!

A similar result was also published later by Ruben O. Donis and colleagues from the CDC Atlanta, USA mutagenic when carrying sialic acid receptors on antigen H and N antigens on the H5N1 virus.

H5N1 threat there

H5N1 bird flu virus circulating in migratory birds, infected poultry, but no symptoms (especially in species of aquatic birds).  Due to different antigenic structure should only pathogenic H5N1 virus for some people with close contact (slaughter poultry diseases) and not be able to spread from person to person. Diseases caused by H5N1 in humans begins with the outbreak in 1997 in Hong Kong. Up to date 08/02/2012, the world's total was 584 cases with 345 deaths (59%). In Vietnam, since the first cases detected in the hospital as soon 11/01/2004 tropical disease, now has a total of 121 cases (the third highest in the world after Indonesia and Egypt), 61 deaths ( 50%).  After nearly two years absence from the H5N1 Swine Flu, the health ministry announced two deaths from H5N1 in January 1.2012 in Kien Giang and Soc Trang.  Ministry of Agriculture and Rural Development is published on the H5N1 poultry in the provinces of Thanh Hoa, Ha Nam, Hai Duong, Quang Tri, Soc Trang and Kien Giang.

As translated in poultry, the risk of H5N1 infection when exposed and not protected very high and the cases will continue to happen ...

Worst case scenario and how to deal

When infected people continue to have variable influenza virus strains circulating in human capital (such as avian influenza H5N1, H3N2 swine flu ...), viral conditions regular exercise over how to penetrate the human body, the ability to turn adaptive genetic change will have many opportunities to occur and to a certain time, a new varieties with the ability to spread from person - who will appear (this time in natural conditions, repeat the process "of make " was successful in the lab)!

Imagine a new pandemic scenario for the appearance of a human influenza virus can mutate damage the strength of the H5N1 (mortality 50%) combined with the ability to spread from person - person via the respiratory tract of H1N1 each 2009 pandemic (worldwide spread in just three months)!

Before a flu pandemic threat is happening in the future, the medical community should be prepared for questions: when would appear? Any complications? Responding to like? ...

First of all, have solved the bird flu. Spread to humans by blocking the implementation of biosecurity measures in animal husbandry, food processing line clean. Implementation of effective vaccination for poultry and humans. Monitoring, detection and early treatment of cases to be dispersed in the community.

Hopefully, mankind continues to win the race for survival with competing microbial world, which took place millions of years and continues increasingly fierce.

Recombinomics Commentary 23:30
January 13, 2012 St Jude has released full sequences (at Genbank) from four H5N1 avian isolates from Egypt.  The PB1 and/or PB2 sequences from three of the isolates (A/chicken/Egypt/Q1182/2010, A/chicken/Egypt/Q1185/2010, A/chicken/Egypt/Q1011/2010) have extensive regions of identity with seasonal H1N1, seasonal H3N2, or H1N1pdm09, raising serious concerns regarding sequences in internal genes from human H5N1 cases.

NAMRU-3 has not released any H5N1 sequences from any human case since March, 2010. 

Full sequences on human H5N1 should be generated and released as soon as possible. 

The recombination with human sequences seen in the avian isolates strongly suggests serious recombination in human H5N1 cases.

CDC confirms two human infections with novel influenza viruses

December 9, 2011 -- CDC has confirmed two cases of human infection with two different novel influenza A viruses in different states. Both patients have fully recovered. While the viruses infecting both patients have been found in U.S. swine and some of the prior human infections with these viruses have been associated with direct or close swine contact, there are no reports of direct or close contact with swine prior to illness onset in either of these cases. Laboratory testing at CDC has confirmed that both novel viruses are susceptible to the antiviral medications oseltamivir (Tamiflu®) and zanamivir (Relenza®).

West Virginia
One case of human infection with a novel influenza virus was reported by West Virginia and involves infection of a child with the novel influenza A (H3N2) virus with genes from swine, human, and avian lineages with the M gene from the 2009 H1N1 virus that was first identified in August 2011. Ten prior human infections with this virus in four other states have been confirmed. These occurred in Indiana (2), Pennsylvania (3), Maine (2), and Iowa (3).

These novel influenza A (H3N2) viruses are substantially different from currently circulating seasonal (human) influenza A (H3N2) viruses, but are distantly related to human influenza viruses that circulated among people in the 1990s. For that reason, some adults may have some residual immunity against this virus. This might help explain why 10 of the 11 cases that have been detected have occurred in children.

Most human infections with viruses that circulate in swine (but not humans) have been associated with swine exposure, but limited human-to-human transmission associated with these viruses is thought to have occurred as well, most recently in Iowa. While an investigation is ongoing in West Virginia, no direct or indirect contact with swine has been reported, implying that limited human-to-human transmission of this virus may have occurred again.

No ongoing community transmission of this virus has been detected in the United States. However, CDC is taking this situation very seriously. Surveillance surrounding reported cases is being further enhanced and, as a precaution, a vaccine virus has been developed and provided to manufacturers for them to begin vaccine production should that become necessary.

Minnesota
The other case of novel influenza A virus infection was reported by Minnesota, and is associated with a different influenza virus; an influenza A (H1N2) virus that circulates in swine  in the United States, but does not normally infect or cause illness in humans. This case also was in a child. This is only the second case of human infection with this novel influenza A (H1N2) virus reported to CDC since novel influenza virus infections became nationally notifiable in 2007. The first such case was identified in Michigan in 2007. By some characteristics, this H1N2 virus is close to human influenza A (H1N1) viruses called “A/New Caledonia /20/99-like,” which circulated and caused illness among people as recently as 2007. As a result, people who were exposed to A/New Caledonia/20/99-like viruses may have some existing immune protection against the virus detected in Minnesota. Again, no direct or indirect contact with swine has been reported with this case, implying that limited human-to-human transmission may have occurred in this instance as well.

Detection of Swine Influenza Infections in Humans
Human infections with novel influenza A viruses normally found in swine are rare events. Recently, however, the frequency of such detections has increased. This could be occurring for a number of reasons, including one or more of the following factors: First, laboratory methods for testing for these viruses in the United States were improved following the 2009 H1N1 pandemic. These improvements may be resulting in viruses being identified now that would have gone undetected previously. Second, this could be due to increased surveillance in the United States for influenza at this time of year. CDC has requested that states analyze, and then send, their first influenza virus specimens of the season for seasonal influenza surveillance purposes. This practice, coupled with very low levels of seasonal flu activity at this time, could mean that sporadic novel influenza infections are more likely to be tested. Third, it is possible that the increased frequency of detection of novel influenza viruses with swine origins identified by CDC represents a true increase in the number of such cases, possibly occurring from exposure to infected swine  or through subsequent, limited human-to-human transmission.

The novel influenza A (H1N2) virus identified in Minnesota is known to circulate in U.S. swine herds. While the prevalence of the novel influenza A H3N2 virus with the 2009 H1N1 M gene in swine is unknown, the virus has been detected in U.S. swine through the United States Department of Agriculture’s swine influenza surveillance program.

In response to recent human infections with novel influenza viruses, CDC would like to convey the following information:

1. 1. CDC recommends an annual seasonal flu vaccine to protect against seasonal influenza viruses; however, a seasonal flu vaccine is unlikely to protect against flu viruses that normally circulate in swine.
2. There are two FDA–cleared drugs that are expected to be effective in treating illness associated with these viruses. The antiviral drugs oseltamivir and zanamivir – which are used to treat infection with human seasonal influenza viruses – also have shown activity against influenza viruses from swine. (For more information about influenza antiviral medications, please see www.cdc.gov/flu/antivirals/whatyoushould.htm )
3. Influenza has not been shown to be transmissible to people through eating properly handled and prepared pork (pig meat) or other products derived from pigs. For more information about the proper handling and preparation of pork, visit the USDA website fact sheet “Fresh Pork From Farm to Table.”

At this time, CDC recommends the following:

1. People who experience flu symptoms following direct or close contact with swine and who require medical attention (see below) should mention this exposure to their doctor or health care provider. (A list of flu symptoms is available at www.cdc.gov/flu/about/disease/symptoms.htm.)
2. For people who have NOT had exposure to swine and develop ILI, CDC’s recommendations for seeking treatment are the same as they are for seasonal influenza.
   1. If you have symptoms of flu and are very sick or worried about your illness contact your health care provider.
   2. Certain people are at greater risk of serious flu-related complications (including young children, elderly persons, pregnant women and people with certain long-term medical conditions) and this is true both for seasonal flu and novel  flu virus infections. (For a full list of people at higher risk of flu related complications, see www.cdc.gov/flu/about/disease/high_risk.htm.) 
   3. If these people develop ILI, it’s best for them to contact their doctor. (The majority of recent novel influenza A (H3N2) cases have been in children.)
   4. Your doctor may prescribe antiviral drugs that can treat the flu. These drugs work better for treatment the sooner they are started.

More information about swine influenza and links to all previous reports related cases of novel influenza A (H3N2) viruses infections are available on the CDC swine influenza website at www.cdc.gov/flu/swineflu/index.htm.

Source: http://www.cdc.gov/media/haveyouheard/stories/novel_influenza.html