Swine Flu or Swine Influenza (H1N1 Virus): Symptoms, Signs, Diagnosis, Treatment, Risk Factors

Swine Flu or Swine Influenza or the H1N1 virus is a disorder of the respiratory system that is caused due to an influenza virus in pigs with resultant decreased appetite, lethargy, barking cough. It lasts for about one to two weeks in pigs that are able to survive this disease. In humans, they can be transmitted in people who live in close proximity to pigs like farmers, pork respiratory tract of pigs, pork dealers etc. In a similar way, human infections can also be transmitted to pigs. Until recently, this virus was contained in local areas only and infected mostly pigs, and did not become a nationwide issue, but now it has been seen that this virus has the potential to change and hence researchers named this virus, which was first found in 2009 in Mexico as H1N1 virus, as it mainly infected humans and had the tendency to be transmitted very quickly. It contained two surface antigens namely hemagglutinin 1 and neuraminidase 1. This virus has the potential to spread through coughing of sneezing of an infected person.

The signs and symptoms of swine flu are pretty much the same as found in normal influenza like high fever, cough, lethargy, headache etc. Nausea, vomiting, diarrhea are also noted in some infected people. Some people start having respiratory disorders and may need ventilator support. Pneumonia is also something that can develop in some people. If the virus spreads, death occurs from infection of the lungs. The mortality rate of H1N1 in the USA remained pretty low even though this disease became a pandemic.

A presumptive diagnosis of swine flu is made based on the patient’s history and whether that person has been in proximity to someone already infected and the symptoms that they are experiencing. Typically, nasopharyngeal swab is done to determine if a person is infected with the influenza virus and the exact subtype of the virus i.e., influenza A or influenza B. If the swab is positive type B then it is not a swine flu but if it is positive for type A then it can possibly be swine flu. The center for Disease Control in the United States has developed tests that can detect H1N1 within a matter of hours. To definitively diagnose swine flu, the tests are conducted in specialized laboratories and doctors generally send specimens to these laboratories.

By far the best treatment for influenza infections are vaccinations. For H1N1, the first vaccine was made available in October 2009 and was in the form of a nasal spray. An injectable vaccine was made available soon thereafter which was approved for use in infants of less than a year of age up to the elderly population as well as pregnant females. These vaccines have some common side effects such as redness at the injection site, minor fever, cough wheezing, etc.

With the vaccination in the form of nasal spray, since it is made from a live virus which has lost its potency to replicate, it should not be given to people with compromised immune system. There are also two antiviral drugs that have been used extensively worldwide to treat swine flu and they are Tamiflu and Relenza

According to the Center for Disease Control, people who are at an increased risk for contracting the H1N1 virus are as follows:

• Children between the ages of six months to four years of age.
• People above the age of 50.
• People suffering from asthma, diabetes, and other cardiac, pulmonary, renal disorders.
• Immunosuppressed people.
• Pregnant females.
• Nursing home residents.
• People with obesity.