There are only a few causes of swine flu in humans. They are:
Contact with infected pigs: This is the most common way of catching swine flu. Any contact with infected pigs makes transmission more likely.
Contact with infected humans: This is a much less common way of catching swine flu, but is a risk, especially for those in close contact with an infected person.
In cases where humans have
infected other humans, close contact was necessary with the infected person,
and it nearly always occurred in closed groups of people.
Some people are more at risk of catching swine flu than others; including:
The symptoms of swine flu in humans are quite similar to those of regular flu, and include:
Less commonly, a person with swine flu may experience vomiting and diarrhea
Symptoms can be managed with
similar treatments to regular flu. However, a doctor should examine the patient
for confirmation of swine flu and advise how to relief individual symptoms.
Swine flu is mostly diagnosed through noting the symptoms.
There is also a quick test called the rapid influenza diagnostic test that can help identify swine flu. However, these vary in effectiveness and may show a negative result even though influenza is present. More accurate tests are available in more specialized laboratories.
However, in a similar way to seasonal flu, symptoms are often mild and self-resolve. Most people do not receive a test for swine flu as treatment would be the same, regardless of the outcome.
If symptoms are mild, it is extremely unlikely that any
connection to swine influenza is found, even if the virus is there.
The best treatment for influenza infections in humans is prevention by vaccination. Work by several laboratories has produced vaccines. The first H1N1 vaccine released in early October 2009 was a nasal spray vaccine that was approved for use in healthy individuals ages 2-49. However, the use of nasal spray has not been recommended since 2016. The injectable vaccine, made from killed H1N1, became available in the second week of Oct. 2009. This vaccine was approved for use in ages 6 months to the elderly, including pregnant females. Both of these vaccines were approved by the CDC only after they had conducted clinical trials to prove that the vaccines were safe and effective. A new influenza vaccine preparation is the intradermal (trivalent) vaccine is available; it works like the shot except the administration is less painful. It is approved for ages 18-64 years.
Almost all vaccines have some side effects. Common side effects of H1N1 vaccines (alone or in combination with other flu viral strains) are typical of flu vaccines used over many years and are as follows:
The flu shot (vaccine) is made from killed virus particles so a person cannot get the flu from a flu shot. However, the nasal spray vaccine contains live virus that have been altered to hinder its ability to replicate in human tissue. People with a suppressed immune system should not get vaccinated with the nasal spray. Also, most vaccines that contain flu viral particles are cultivated in eggs, so individuals with an allergy to eggs should not get the vaccine unless tested and advised by their doctor that they are cleared to obtain it. Like all vaccines, rare events may occur in some rare cases (for example, swelling, weakness, or shortness of breath). About one person in a million who gets the vaccine may develop a neurological problem termed Guillain-Barré syndrome, which can cause weakness or paralysis, difficulty breathing, bladder and/or bowel problems, and other nerve problems. If any symptoms like these develop, see a physician immediately.
Two antiviral agents have been reported to help prevent or reduce the effects of swine flu. They are zanamivir (Relenza) and oseltamivir (Tamiflu), both of which are also used to prevent or reduce influenza A and B symptoms. These drugs should not be used indiscriminately, because viral resistance to them can and has occurred. Also, they are not recommended if the flu symptoms already have been present for 48 hours or more, although hospitalized patients may still be treated past the 48-hour guideline. Severe infections in some patients may require additional supportive measures such as ventilation support and treatment of other infections like pneumonia that can occur in patients with a severe flu infection. The CDC has suggested in their guidelines that pregnant females can be treated with the two antiviral agents. Some researchers suggest the data on Tamiflu and Relenza is not correct and suggest the antivirals are not effective.
On Dec. 22, 2014, the FDA approved the first new anti-influenza drug (for H1N1 and other influenza virus types) in 15 years, peramivir injection (Rapivab). It is approved for use in the following settings:
Diarrhea, skin infections, hallucinations, and/or altered behavior may occur as side effects of this drug.
If a person is infected, it is important they follow these rules to prevent any further spread: