Tag: Influenza A Virus

An Overview of Swine Flu

Swine flu or influenza is a condition caused by strains of subtypes of Influenza A virus called H1N1, H1N2, H3N1, H3N2, and H3N3. These viruses are common in pigs located in midwestern United States, Canada, South America, Mexico, Mainland China, Japan, Taiwan, Europe, and other Eastern Asian countries.

Transmission of influenza virus from swine to humans is relatively uncommon and does not always result to human influenza but often leads to production of antibodies in the blood. When properly cooked, pig meat does not have the potential of passing the virus. Transmission that leads to human influenza is called zoonotic swine flu.

People who work with pigs, particularly those with direct exposure, are at greater risk of being infected with swine flu. Towards the middle of the 20th century, identification of influenza subtypes became likely paving the way for an accurate diagnosis of transmission to humans. Since then, 50 infections have been confirmed and recorded.

It is rare for these strains of swine flu to be transmitted from one human to another. In humans, the symptoms of swine flu are similar to common influenza as well as influenza-like illness such as chills, sore throat, fever, coughing, muscular pains, severe headache, and general discomfort.
The 2009 swine flu outbreak in humans was caused by a new strain of influenza A virus subtype H1N1 which have genes that closely resemble swine influenza. The root of this new strain is not known. According to the World Health Organization for Animal Health, this new strain has not been isolated in pigs. It is capable of human-to-human transmission and manifests the normal symptoms of influenza.

Swine can be infected with human influenza such as the case of the 1918 flu pandemic and the 2009 flu outbreak. Swine flu was first proposed as a disease associated with humans during the 1918 flu pandemic. During that time, pigs became simultaneously sick with humans.

Influenza virus as a cause of disease in pigs was first identified in 1930. For the next six decades, strains of swine influenza became almost exclusively H1N1. From 1997 to 2002, new strains of three varied subtypes and 5 different genotypes were identified as the cause of influenza among pigs in North America.

From 1997-1998, H3N2 strains developed. They included genes acquired through reassortment of human, avian, and swine viruses and have been a principal cause of wine influenza in North America. Reassortment between H1N1 and H3N2 resulted to the development of H1N2. In Canada, a strain of H4N6 resulted from the reassortment of avian and swine flu but was isolated on a single farm.

The H1N1 variant of swine flu is one of the descendants of the strain that brought about the 1918 flu pandemic. While persisting in pigs, the descendants of the 1918 virus have also been transmitted throughout the 20th century which resulted to the usual seasonal influenza outbreaks.
It is interesting to note that direct infection from pigs to humans is rare, with only 12 confirmed cases in the United States since 2005.

However, since the influenza strains remain in the pigs after they have disappeared in the human population can make these pigs a reservoir where the influenza virus could survive and later on transmitted to humans as soon as their immunity to the strain is no longe effective.

Swine flu has been recorded as zoonosis in humans several times, oftentimes with limited distribution and rarely with massive distribution. Swine outbreaks are common and can lead to significant economic losses in the industry, mainly leading to stunting and expanded market time. Swine influneza, for instance, the British meat industry has experienced 65 million of losses annually.

The Lowdown on The 2009 Swine Flu Outbreak

The 2009 outbreak of swine flu or H1N1 virus is recently hugging the limelight due to the potential harm or effects it can have on a patient or on a community. Unfortunately, the source of the virus still cannot be traced.

Before the first case in the United States was discovered, the illness was believed to have started in Mexico which eventually spread to other countries. Recently, the first case of swine flu was reported in
Costa Rica. Alarmed that it could grow into a worldwide flu epidemic, the World Health Organization of the United Nations and the Center for Disease Control Prevention (CDC) in the United States raised its pandemic alert level to Phase 5, which signifies that a “pandemic is imminent.”
While experts believed that the recent outbreak is not as fatal as previous epidemics, such as the SARS virus, health officials believe that the number of cases could go up as the new flu is expected to make its way throughout the United States.

The new swine influenza strain is apparently a new variant of four strains of influenza A virus subtype H1N1. According to the Center for Disease Control and Prevention, one of the strain is endemic in humans and birds and a couple are endemic in pigs.

However, according to scientists the 2009 H1N1 outbreak is of swine origin which is associated with the virus isolated in North America in 1998. To hasten understanding of the current outbreak as well as in coming up with a vaccine, scientists from Canada have completed the full genetic sequencing of the H1N1 virus.

The new strain of H1N1 has become widespread in Mexico and the United States with confirmed cases in 18 countries and suspected cases in 42 others. Travelers have been warned not to travel to affected countries such as Iceland, Singapore, Thailand, South Korea, Hong Kong, Singapore, to name a few.

In addition, warnings have also been issued warnings to visitors of countries affected by the outbreak. It is advisable for visitors to see the doctor right away if they experience flu-like symptoms.
In Mexico, schools, universities, and all public events were suspended from April 24 to May 6, 2009. In the United States, over 400 schools were closed as of May 3, 2009, which included schools in Texas and about 250,000 confirmed or probable cases.

Dr. Keiji Fukuda, who is the Assistant Director-General for Health Securiy and Environment of the World Health Organization confirmed that efforts to control the outbreak is already too late and should now focus on lessening the effects of the virus. He also clarified that closing borders or limiting travel to infected areas will do little in stopping the spread of the H1N1 virus.

On April 28, 2009, the Center for Disease Control and Prevention suggested that as much as possible, people should avoid non-important travel to Mexico.

According to Dr. Ira Longini, who is an expert in the mathematics and statistics of epidemics, staying at home, seeking medical care, closing public venues, and making anti-flu medicines accessible can help reduce the sickness by almost two-thirds.

Finally, according to Dr. Longini, the focus of efforts is to slow transmission until there is a vaccine that can be developed and made available for controlling swine flu outbreaks.

Signs And Symptoms Of Swine Flu

Most of the human race is now aware of the news outbreak about Swine Flu but are we aware of the signs and symptoms of swine flu? We already know how to prevent but the signs and symptoms is still a puzzle in our mind. Well, through this article, I will give you insights if you are now a victim of Swine Flu virus.

But before, we proceed let me introduce to you first about Swine Flu. The 3-10% of the global population estimated to affect the yearly influenza epidemics that can be a result in severe illness in 34 million patients and causing 200,000400,000 deaths worldwide. Severe illness and deaths occur mainly in the high-risk populations of infants, the elderly, pregnant women and chronically ill patients in industrialized nations.

In addition to these yearly epidemics, the influenza A virus has caused three major global pandemics during the 20th century: there was the Spanish flu in 1918, the Asian flu in 1957 and in 196869 was the Hong Kong flu. These pandemics were caused by an Influenza A virus that had undergone major genetic changes, due to which the population did not possess significant immunity.

In pigs influenza infection produces lethargy, sneezing, fever, coughing, difficulty breathing and decreased appetite. In some cases especially the pregnant women, the infection can cause abortion. Although mortality is usually low (around 1-3%), the virus can produce weight loss and poor growth, causing economic loss to farmers. Infected pigs can lose up to 10 pounds of body weight over a 2 to 3 week period.

Main symptoms of swine flu in humans can be a direct transmission of a swine flu virus from pigs to humans is occasionally possible (called zoonotic swine flu). Under phase one, an animal outbreak of flu symptoms in your hog race backyard.

In phase two considered when the owner within the hog race backyard got infected with a flu from their animal symptoms.

Phase 3 reviewed when a child within the hog race backyard got infected together with his father, his mother and his siblings. The fourth phase, there is a cause of community-level outbreaks of human-to-human transmission of an animal or human-animal flu virus. This phase will focus to contain the spreading of the virus.

Countries will be informed asking to advice their people such as traveling to containment areas. All countries with infected with the swine flu must also consider in deploying a pandemic vaccine. (e.g. when the infected family member went out from their backyard decided to talk to his friends and unaware that hes spreading the virus.)

Second to the last phase, when a man-infected virus either a family member or any of his friends travel to another neighboring country. You will know if there your country is in a phase 5 dominant when there is an announcement suspension of classes because of flu spread out.

This final and a pandemic phase is just like when an unaware man-infected virus travel to another continent unaware that he spread out the Swine Flu virus to another races. Now with the above mentioned signs and symptoms, you are now ready to plan and prepare immediately of the possible attacks of the Swine Flu virus. Consult to different agencies that concerns with the Swine Flu pandemics.