Swine influenza or flu is a respiratory disorder observed in pigs caused by the type A influenza virus. A recent study in the US enlightens that the main strain of virus circulating in the pigs were swine triple reassortant (tr) H1N1, (tr) H3N2 and (tr) H1N2.

But What is Swine Flu in Humans?

As an answer to what H1N1 is, scientists and researchers explained that it is a new strain of virus originating from pigs but spreads from person to person. It is comparatively a more potent strain.

In this piece, you will find everything you need to know about swine flu symptoms, their causes, treatment and preventive measures.

Read on!

Swine flu causes flu-like symptoms in pigs, making it endemic among them. Unlike other diseases like typhus, which is transmitted by ticks or lice, swine flu spreads from person to person, and not animal to person.

Therefore, one should get rid of the notion that swine flu is caused by eating pork.

When asked swine flu is caused by which virus, a study after the 2009 swine flu pandemic shows that the Swine Influenza Virus contains influenza C and influenza A subtypes, namely, H1N1, H1N2, H2N1, H3N1, H3N2, and H2N3. H1N1 is the most virulent form in humans.

The transmission from animal to human is not common because individuals exposed to pigs often generate antibodies in their blood against human flu. Therefore, you might wonder what caused swine flu in humans. Simply put, after proper examination, it was found that the subtype H1N1 is highly contagious and has a higher transmission rate among persons.

This flu virus can be contracted in the following manner:

• Coughing and sneezing that is caused by droplet infection.
• Touching any surface that has been in contact with the virus and if individuals touch their eyes or nose after that.

Those affected by this virus can spread this disease to others, starting from a day before showing the first signs and a maximum of seven days after they have been diagnosed. Children might spread it for more than 10 days.

After learning in detail about the causes, it is vital to go through swine flu symptoms.

Swine flu results in a low mortality rate in pigs- around 1-4%. However, it affects their weight and growth, which is a huge economic loss for farmers. Furthermore, pigs have receptors for both avian and mammalian influenza viruses, leading to mutation of the virus to different forms.

Generally, in humans, the virus is supposed to show flu-like symptoms. Although the infection rate is higher, it results in mild symptoms. According to the United States CDC (Centre for Disease Control and Prevention), here are some of the symptoms of the Swine Influenza Virus:

• Fever
• Cough
• Sore throat
• Body and joint aches
• Headache 
• Shortness of breath
• Chills 
• Watery eyes and runny nose
• Lack of appetite and fatigue
• Abdominal pain

In the 2009 outbreak, some people also reported having diarrhoea and vomiting, inclusive of other signs.

Considering the risk factors, conditions like respiratory failure, pneumonia, high fever leading to neurological problems, dehydration, kidney failure and electrolyte imbalance results in death. Young children and elders are prone to fatality.

As the above symptoms are similar to those of influenza, the swine flu diagnosis becomes difficult.

Take a look at how physicians carry out diagnostic tests for swine flu.

Doctors will perform lab diagnoses of swine flu by taking respiratory fluid from a patient's body. They will collect the fluids by carrying out swab tests of the nose and throat. Sample analysis takes place in the laboratory using genetic techniques.

As per the CDC's recommendations, real-time PCR is the ideal diagnostic test for swine flu. Another way of detecting the swine flu virus is by using an RNA virus-preserving filter-paper card, which is commercially available. This technique results in the proper distinction of the novel swine flu virus from seasonal influenza.

Additionally, some other tests like near-patient point-of-care tests are still in a developmental stage.

Some tests like rapid influenza diagnostic tests, which yield results in just 30 minutes, are not advisable due to their high rate of false negatives and chances of public health risk. 

Owing to that, CDC rolled out a new test, "CDC Influenza 2009 A (H1N1) pdm Real-Time RT-PCR Panel (IVD)", which will replace the conventional RT-PCR tests as it detects the Influenza A virus and specifically the new H1N1 strain of 2009 pandemic by using molecular biology techniques. This test takes four hours to generate results. These findings are 96% accurate.

After diagnosing the swine flu symptoms, one needs to know the treatment options available.

Mostly, patients do not require medications depending on the complication of swine flu. One should focus on relieving the symptoms and preventing the spread of H1N1.

Oral drugs like oseltamivir and zanamivir may be given to patients who are at high risk. However, viruses tend to become resistant to these antiviral drugs. Healthy individuals can fight the infection on their own.

In pigs, one can control the infection by opting for vaccination and proper animal management techniques. Various commercial vaccines are available in the market, including the vaccine against the recent strain of the 2009 virus.

The swine flu treatment for humans majorly focuses on reducing the symptoms like fever, weakness, cough etc. Ingesting antiviral and antibacterial medicines is one way of fighting the swine flu virus. However, the 2009 H1N1 strain has shown resistance to drugs like amantadine and rimantadine. Therefore, it is advisable to let the virus subside on its own and go for medications in case of severe infections.

Now, it is crucial to identify the risk factors of swine flu.

Most mild cases of the Spanish flu would experience typical influenza symptoms like sore throat, headache, and fever. 

But more serious cases would also experience nosebleeds and bleeding from the mouth or ears, hair fall, delirium, dizziness, loss of hearing or smell, and hands and feet turning blue.

Swine flu was common in five years or older children and adults during its emergence. This was not normal, given the elders and very young children are under high-risk groups. However, a study in the US explains that children are more susceptible to this virus than adults are because of the exposure time to this virus. Adults seemed to develop antibodies meaning that they have been infected by the virus before.

After considering several factors, scientists have arrived at the conclusion that the following groups of people are at higher risk than others have:

• Adults who are over 65 years
• Children who are younger than 5 years of age
• Some young adults and children who are undergoing aspirin therapy for a long time 
• Individuals suffering from immune-deficiency conditions, including AIDS
• Women who will give childbirth
• Any person having comorbidity like asthma, diabetes, heart disease, neuromuscular disease, etc.

However, anyone can contract this disease on exposure. It is recommended to look out for swine flu symptoms.

Therefore, it is necessary to keep a tab on H1N1 prevention.

The ideal preventive measure of the Swine Influenza Virus is vaccination. There are three components of preventing this virus- prevention in swine, prevention of human transmission, and prevention of human spread.

• Prevention in Pigs: The most productive way of doing this is vaccination, herd management and farm management. However, due to the evolving virus strain, vaccination has become increasingly difficult. The viruses are unlikely to survive in the environment for over two weeks. Therefore, proper use of disinfectants and control of temperature in the farms is vital. In case any animal is infected, it should be quarantined.
• Prevention in Pigs to Human Transmission: As pigs can contract both the avian, mammalian strain of influenza virus, it becomes a host of antigenic shifts; that is, it leaves room for the formation of new strains. Although the transmission from pigs to humans is unlikely, it is advisable to wear a mask while tending infected animals.
• Prevention in the Human Spread: Some basic ways to stop the widespread of this disease is to follow certain protocols like-
• Washing hands frequently with soap and using hand sanitizer.
• Refrain from touching your nose, mouth and eyes. The virus can be exposed to any surface, including your hands.
• On contracting illness, make sure to stay at home from work or school.
• Avoid going to large gatherings during the flu season.

Furthermore, one should get plenty of rest, drink plenty of fluids to keep the body dehydrated and take over-the-counter medicines to get relief from the symptoms of H1N1.