Swine flu is an infection caused by swine flu influenza virus which is common throughout the population worldwide. The disease affects the respiratory tract of pigs and is transmitted to humans.
THE SWINE FLU VIRUS
The influenza virus is a negative sense RNA virus of the family Orthomyxoviridae with three genera Influenza A, B, C.
Swine influenza is known to be caused by Influenza A subtypes. H1N1, H1N2, H3N1 H3N2. In pigs Influenza A virus are divided into subtypes based on 2proteins on surface of virus the haemagglutinin(H) and the neuraminidase (N). There are various types of subtypes of H and N.
Every year new strains of virus evade host defenses.
Another characteristic of type A influenza is that the virus has segmented genome with eight single stranded RNA segments. When the host cell is infected with more than one influenza virus, the genes have the opportunity to get ressorted and produce a different strain altogether. The antigenic shift is responsible for pandemic of influenza which has been observed in the past. Virus acquires the ability to not only infect but spread within the human host.
Influenza B viruses are only known to infect human and seals causing influenza
Influenza C virus infect both human and pigs and does not infect birds.
HISTORY OF SWINE FLU
Swine origin influenza A H1N1 virus was first recognised in the border area of Mexico and United states in April 2009 and during the span of 2 months and was spread with travellers wordlwide resulting in 1st influenza pandemic since 1968. Around mid 20th century identification of influenza sub types became possible allowing accurate diagnosis of transmission to humans. In 2010 the World Health Organisation declared Swine flu pandemic officially.
The term pandemic means that an infection has spread to many countries around the world causing widespread human suffering. This pandemic has become a worldwide concern. A new strain of Swine flu was detected in 2011, it did not affect a large number of people. In 2015-2016 a large outbreak of swine flu killed a huge number of people. Another outbreak 2017 affecting various people at different places and most recent is 2018 outbreak
The influenza virus is a negative sense RNA virus of the family Orthomyxoviridae with three genera Influenza A, B, C.
Swine influenza is known to be caused by Influenza A subtypes. H1N1, H1N2, H3N1 H3N2. In pigs Influenza A virus are divided into subtypes based on 2proteins on surface of virus the haemagglutinin(H) and the neuraminidase (N). There are various types of subtypes of H and N.
Every year new strains of virus evade host defenses.
Another characteristic of type A influenza is that the virus has segmented genome with eight single stranded RNA segments. When the host cell is infected with more than one influenza virus, the genes have the opportunity to get ressorted and produce a different strain altogether. The antigenic shift is responsible for pandemic of influenza which has been observed in the past. Virus acquires the ability to not only infect but spread within the human host.
Influenza B viruses are only known to infect human and seals causing influenza
Influenza C virus infect both human and pigs and does not infect birds.
EPIDEMOLOGY AND HISTORY OF SWINE FLU VIRUS INFECTION OUTBREAKS
HISTORY
Swine origin influenza A H1N1 virus was first recognised in the border area of Mexico and United states in April 2009 and during the span of 2 months and was spread with travellers wordlwide resulting in 1st influenza pandemic since 1968. Around mid 20th century identification of influenza sub types became possible allowing accurate diagnosis of transmission to humans. In 2010 the World Health Organisation declared Swine flu pandemic officially.
The term pandemic means that an infection has spread to many countries around the world causing widespread human suffering. This pandemic has become a worldwide concern. A new strain of Swine flu was detected in 2011, it did not affect a large number of people. In 2015-2016 a large outbreak of swine flu killed a huge number of people. Another outbreak 2017 affecting various people at different places and most recent is 2018 outbreak.
Influenza A outbreaks occur almost every year although their extent and severity vary.
In the last century, influenza virus caused 3 pandemics, the 1918 spanish flu, 1957 Asian flu, 1968 Hong kong flu. The out breaks differ in extent of spread.
The H1N1 strain responsible for current outbreak of swine origin influenza was first recognised at Mexico and US in 2009, and during a very short spam Swine flu became the 1st pandemic of 21st century. The outbreak has been pandemic in true sense involving more than 170 countries spread all over continents.
As per WHO there is a high risk of overall transmission of Swine flu globally.
SWINE FLU TRANSMISSION
As Swine flu is a viral disease it usully spreads from person to person by inhalation or ingestion of droplets containing virus from affected people who sneeze or cough leading to contamination of air with millions of virus in air.
CLINICAL REPRESENTATION OF SWINE FLU.
Signs and symptoms are similar to seasonal influenza virus or similar to other viral respiratory illness.
A common element of swine flu is upper respiratory symptoms. The patient presents with severe cold, stuffy or running nose combined with head congestion along with watery eyes associated with itching. Sore throat.
Severe bodyache, includes muscle weakness. Feeling of general malaise or weakness are very common with overall discomfort. The patient usually feels so weak that it hampers his daily activities. Presents with continous drowsiness.
In some cases of swine flu, gastrointestinal symptoms like stomach ache, cramps, nausea, vomiting and diarrhoea occur.
PREVENTION
- Patients affected with swine flu should take necesary precautions.
- Stay at home if you are sick.
- Maintain distance from people so that you do not pass the infection to others.
- Always wear a well fitted masks in public places.
- Cover your mouth and nose while coughing and sneezing.
- Wash your hands with soap. Make sure you wash your hand for atleast 15 sec. Use an alcohol based gels or foam sanitizers.
- Use disposable tissues
- Take proper rest.
- Necesary preventive measures in people who are travelling or residing in areas where a swine flu outbreak have occured
- Avoid close contact with people who have been affected with swine flu.
- Always cover your mouth while coughing or sneezing.
- Wash hands frequently as chances of infection through contact.
- Maintiain proper hygeine.
- Practice a healthy lifestyle habits such as nutritious diet, proper sleep, excercise.
- Drink plenty of fluids.
DIAGNOSIS OF SWINE FLU
Swine flu is diagnosed based on the clinical representation of patient. Diagnosis can be made if the person has recently travelled to an area where there is Swine flu outbreak in humans.
If you residing in locality where there is epidemic of Swine flu, or if you come in contact with the influenza virus and symptoms of flu appears.
First thing you need to do is Rapid Influenza Diagnostic Test.. It is a blood test which detects whether the flu is of type A or type B. If type A turns to be positive then you should further go for PCR test for confirmation of subtype. It is advisable to straight away go with PCR in high risk group and in epidemic prone areas.
