Swine Infuenza

What is Swine Influenza(H1N1):

Swine influenza is common in pigs in the mid western United States, Mexico, Canada, South America, Europe, UK, Sweden, and Italy, Kenya, Mainland China, Taiwan, Japan and othe Asia. It’s thought that novel influenza A swine flu spreads in the same way that regular seasonal influenza viruses spread; mainly through the fever, coughing, headache and sneezes of people who are sick with the virus.
Swine influenza (swine flu, hog flu, and pig flu) refers to the influenza caused by those strains of influenza virus that are usually infect pigs and called swine influenza virus (SIV).

Transmission of swine influenza from pigs to humans is not common. People who's work with pigs, specially people with intense exposures, are at risk of catching swine flu. There will be more cases, more hospitalization and more deaths associated with this new virus. These strains of swine flu can pass from human to human. In humans, the symptoms of swine flu are similar to those of influenza and of influenza-like illness in general, namely chills, fever, sore throat, muscle pains, severe headache, coughing, weakness and general discomfort.

The 2009 flu outbreak in humans that is widely known as "swine flu" This strain of influenza virus is unique. These new strain of influenza A virus subtype H1N1 that was produced by re assortment from one strain of human influenza virus, one strain of avian influenza virus, and two separate strains of swine influenza. because it is a combination of genes from swine, bird, and human influenza viruses. The origin of this new strain is unknown, and the World Organization for Animal Health that this strain has not been isolated in pigs. Infected individuals report flu-like symptoms of fever, aches and pains, sore throats, coughing, and trouble breathing. It passes with apparent ease from human to human, an ability attributed to an as-yet unidentified mutation. Some people have also reported diarrhea and vomiting.

influenza A(H1N1):
H1N1 is a new influenza (flu) virus first seen in the United States in April 2009. It is called "novel" H1N1 because the virus has never been identified before and is new. Novel H1N1 was initially called "swine flu" by health officials because many of the genes are similar to some flu viruses that pigs in North America can get. However, further study showed that this new virus contains genes from flu viruses that circulate in pigs in Europe and Asia as well as genes from birds and humans. Scientists call this a "quadruple re assortant" influenza virus.

Influenza A virus subtype H1N1, also known as A(H1N1), is a subtype of influenza virus A and the most common cause of influenza (flu) in humans. Some strains of H1N1 are endemic in humans, including the strain(s) responsible for the 1918 flu pandemic which killed 50–100 million people worldwide. Less virulent H1N1 strains still exist in the wild today, worldwide, causing a small fraction of all influenza-like illness and a large fraction of all seasonal influenza. H1N1 strains caused roughly half of all flu infections in 2006. Other strains of H1N1 are endemic in pigs and in birds.

In March and April 2009, hundreds of laboratory-confirmed infections and a number of deaths were caused by an outbreak of a new strain of H1N1..



What exactly is swine flu?
Swine influenza is a highly contagious respiratory disease that emanates from pigs. Pigs are unique because these animals accommodate influenza virus from two other major hosts: humans and birds. Swine flu is a type A influenza virus.
Type A influenza viruses are sub-typed according to 1) their respective Hemagglutinin (H), which is a surface protein that allows the virus to attach to host cells and 2) a viral surface associated neuraminidase (N), which allows the virus to enter the host cell. All influenza A subtypes have been identified from birds. The current swine flu is type A subtype H1N1.


How bad is this strain?
This strain is unique for several reasons. First, as previously mentioned, the combination of avian and human influenza gene sequences is worrisome because of the possible species jumping of the avian virus to that of humans. Second, the H is sufficiently different from the current vaccine strain H such that humans will have little or no protection. Third, unlike the H5N1 bird influenza virus, this current swine influenza virus is effectively passed from human to human and has made its debut well in advanced of the typical influenza season typically kills 36,000 people in the United States. However, it is still too early to tell the full extent of the current viral infection.



How is the virus transmitted ?
Influenza spreads primarily through aerosolization (coughing and sneezing) and direct contact by touching contaminated surfaces. Although the virus requires a living cell to survive/thrive, influenza virus has been shown to persist on surfaces like tabletops for up to 24 hours. The virus is not transmitted by eating cooked pork products.


How can we kill the virus?
Like many viruses, influenza is very heat sensitive. Furthermore, influenza is an envelope virus, which means the genetic material (RNA) is contained within a membrane. Once the membrane is compromised, the viral RNA genome is subject to degradation and thus the virus cannot replicate/survive. There are a number of hand hygiene products that are available that disrupt viral membranes. Additionally, drugs such as Tamiflu (an inhibitor of the viral N) are very effective against the current circulating virus. The antiviral drug Amantadine (an inhibitor of the viral proton pump) has been shown to be ineffective against the current circulating swine influenza.


How can we prevent getting the virus?
Covering the nose and mouth with a surgical mask can be of some help but good hand hygiene, staying away from sick individuals and avoiding crowds will also help greatly.


How can we diagnose Swine Flu in human?
In human, Swine Flu is usually transmitted through the Respiratory Tract. Droplets of infected body fluids may carry flu when people cough or sneeze. Therefore, a respiratory specimen generally needs to be collected within the first 4 to 5 days of illness (when an infected person is most likely to be shedding virus). However, especially children may shed virus for 10 days or longer. The collected specimen is then sent to the identified laboratories in the country for confirmation.



Who is at risk?
Typically, the very young and the very old tend to be at greatest risk, but for two very different reasons. In small children, the immune system is very alert and when activated in response to entities such as an influenza virus, literally goes into overdrive creating a cytokine storm. The result is extensive damage in the lungs akin to drowning in one's own fluids. In the elderly, the immune system is not as alert and does not go into an overdrive as it does with young hosts. Due to aging a compromised immune system gives rise to secondary bacterial infections such as pneumonia.


What are the symptoms of Swine in Human?
It takes about 4 (four) days for the onset of symptoms when a person is infected. The symptoms are usually:-
1. Coughing and sneezing
2. Headache and Body ache
3. Fever and chills
4. Sometimes vomiting and diarrhea
Severe cases of Flu that leads to death are normally seen in very young and very old people whose immune systems are too weak to fight off the virus.


Can a vaccine be created ?
Creating a vaccine is no trivial issue. A vaccine can be created, but to make the number of doses needed to protect the entire community may take a minimum of 6-9 months with the participation of large pharmaceutical firms.

Now that the pandemic alert level is phase 5 imminent pandemic, what should I do?

Pandemic implies that the virus is widespread. It does not necessarily mean that the virus is extremely virulent. However, since the verdict is still out with regard to the current virus, the bottom line is:

• Wash your hands frequently.
• Stay away from those who are ill.
• Avoid large crowds of people.
• Wash hands thoroughly with soap and warm water
• Use hand sanitizer regularly
• Cough and sneeze in your arm or sleeve and refrain from any close contact with your colleagues if you suspect you may be sick
• Get your annual flu shot
• Keep doing what you normally do, but stay home if sick
• Talk to a health professional if you experience flu-like symptoms: fever, cough, runny nose, sore throat, body aches, fatigue and lack of appetite.