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Swine influenza is a respiratory disease that is caused by type A influenza viruses. It is given the name swine flu because this virus usually causes outbreaks of influenza in pigs. (1)
The H1N1 virus is a strain of the type A influenza virus. The symptoms caused by swine flu are common to seasonal flu. The H1N1 virus is a combination of viruses from pigs, birds, and humans.
The H1N1 virus spreads the disease by infecting the cells that line your respiratory tract, i.e., the nose, throat, and lungs. The virus gains entry into the system via infected droplets that you inhale. It can also enter your body from your eyes and mouth. (2)
Signs and Symptoms of Swine Flu
The symptoms of swine flu (S-OIV influenza) in people are: (3)
- Fever (present in 94% of patients)
- Cough (present in 92% of patients)
- Sore throat (present in 66% of patients)
- Body aches
It is important to note that these symptoms are similar to those of regular human flu. Although there are some symptoms of the new H1N1 flu strain that may distinguish it from other types of flu, they cannot be relied upon for a definitive diagnosis.
One of the ways in which it may differ from seasonal flu is that some individuals may exhibit gastrointestinal symptoms, such as nausea or diarrhea. (4)
Therefore, if you experience any of these symptoms, it is recommended to seek medical advice and follow the recommended precautions to prevent the spread of the virus.
Myths Around Swine Flu
Having a runny nose and a fever means I have the flu
Contrary to popular belief, experiencing symptoms such as a runny nose and fever does not necessarily indicate that an individual has contracted the flu.
In fact, in many cases, these symptoms may be caused by a different viral or bacterial infection. While flu-like symptoms such as body aches, fatigue, and respiratory issues can be associated with the flu, a proper diagnosis can only be made through medical examination and testing.
A flu shot will make me sick
Despite popular misconceptions, getting the flu shot will not result in severe sickness or contracting the flu virus.
However, like with any medical intervention, the flu shot may cause certain side effects, although these are usually mild and short lived.
According to research, the most commonly reported adverse events following an influenza A (H1N1) vaccination were fatigue (11.3%), pain at the injection site (8.38%), and myalgia (6.97%). However, these symptoms were generally mild and did not pose a significant burden on the individuals who received the vaccine.
In conclusion, it is crucial to dispel the myth that the flu shot can give individuals the flu and to encourage people to get vaccinated to protect themselves and others from the potentially severe consequences of the flu. (5)(6)
Antibiotics will cure the flu
There is a common misconception that antibiotics can be used to cure the flu. However, antibiotics are only effective against bacterial infections and are therefore ineffective against viral infections such as the flu.
As the flu is caused by a virus, antibiotics cannot help in treating the condition or preventing its spread. It is essential to use appropriate medications and treatments that are specifically designed to target viral infections, manage the symptoms of the flu, and prevent its spread to others.
Therefore, it is important to consult a healthcare professional to determine the most effective treatment options for the flu. (7)
I can get swine flu from eating pork
It has been widely speculated that swine flu can spread to humans through the consumption of pork or other pig-derived products.
However, numerous studies and scientific research have conclusively demonstrated that properly handled and prepared pork poses no significant risk of transmitting swine flu to humans.
There is no cure for swine flu
It is a common misconception that there is no cure for swine flu. Antiviral drugs are the mainstay of clinical treatment and have been shown to effectively manage the illness.
When administered within the first 48 hours of the onset of clinical signs, antiviral drugs such as oseltamivir and zanamivir can make the illness milder and the patients feel better faster.
However, antiviral drugs are most effective when administered early, and their effectiveness may be reduced in severe or high-risk cases that are not treated promptly. Therefore, prevention of swine influenza remains critical. (10)
You only get swine flu once in your life
It is a common myth that an individual can only contract swine flu once in their lifetime. However, this is not true due to the constantly changing nature of influenza viruses.
Infection with one strain of the virus does not provide complete protection against all strains of the virus that may emerge in the future.
Therefore, it is important to remain vigilant and take appropriate preventive measures such as vaccination, proper hygiene, and avoiding contact with infected individuals to reduce the risk of contracting swine flu. (11)
Healthy people don’t need a flu vaccine
Despite common misconceptions, the flu virus can affect anyone, regardless of age, health status, or physical condition.
While it is true that some individuals may be at a higher risk of developing severe complications from the flu, such as elderly people, pregnant women, or people with certain chronic conditions, it does not mean that healthy people are immune to the virus.
On the contrary, even young and healthy individuals can contract the flu and potentially spread it to others around them.
Therefore, it is highly recommended that all individuals consider getting vaccinated against the flu every year as a preventative measure to limit the spread of the virus and control its impact on the population. (12)
The flu is just a case of a bad cold
There is a common misconception that the flu is just a minor ailment, similar to a common cold. However, the flu is a viral illness that can cause a wide range of symptoms, many of which can be severe and debilitating.
The flu can cause symptoms such as high fever, intense headaches, severe fatigue, and widespread body aches that can significantly impact an individual’s ability to carry out their daily activities.
Mode of Transmission of the Swine Flu Virus
It is important to learn how swine flu spreads to prevent its transmission.
Generally, swine flu spreads from one person to another via respiratory droplets expelled during coughing or sneezing (droplet transmission). Those within 2 meters of the patient are more affected by a cough or sneeze.
Also, swine flu can spread by contact transmission, which is by touching an infected person’s hands or belongings or contaminated surfaces and subsequently touching the face, with the virus being most contagious during the initial 5 days of illness. (2)
How Is Swine Flu Treated?
Here’s what you need to know when it comes to the treatment of swine flu: (2)
- The management of swine flu depends on the severity of the symptoms.
- Mild to moderate cases can be treated at home with rest, oral hydration, and symptomatic treatment with antipyretics, antihistamines, and NSAIDs or paracetamol.
- Patients with progressive or severe symptoms should be admitted to hospitals, preferably in intensive care units (ICU) if respiratory failure, sepsis, or multi-organ dysfunction is suspected.
- Aggressive supportive measures such as intravenous hydration, electrolyte correction, and antibiotics for bacterial infections should be taken.
- Noninvasive or invasive mechanical ventilation should be used for patients developing acute respiratory distress syndrome (ARDS) secondary to influenza, and severe cases may require extracorporeal membrane oxygenation (ECMO).
- Antiviral medications such as zanamivir, oseltamivir, and peramivir can help reduce or prevent the effects of swine flu if taken within 48 hours of the onset of symptoms. (2)
Diagnosing an H1N1 Infection
According to experts, the diagnosis of H1N1 infection is primarily based on clinical features, such as symptoms and the time of year.
A respiratory sample should be collected within the first 4–5 days of illness when an infected person is most likely to be shedding the virus. However, some individuals, especially children, may shed the virus for a longer period of time.
To confirm a diagnosis of swine flu, a respiratory sample such as a nose or throat swab is required. Tests such as the reverse transcriptase-polymerase chain reaction (RT-PCR) test, virus isolation test, and assays are usually ordered.
However, routine tests used to detect human influenza viruses, including rapid test kits, may not always detect zoonotic viruses (zoonotic virus refers to a virus that can be transmitted from animals to humans). (2)
How to Prevent the Spread of Swine Flu
There are three primary components to prevention: preventing the virus from spreading among swine, preventing the transmission of the virus from swine to humans, and preventing the further spread of the virus among humans.
Environmental control measures, including vaccination of high-risk populations and public education, are crucial to controlling swine influenza outbreaks due to the limited treatment options available, the high risk for secondary infections, and the frequent need for intensive care in individuals with H1N1 pneumonia. (10)(2)
Here are some tips to prevent swine flu:
- To prevent the spread of the virus, the Centers for Disease Control and Prevention (CDC) recommends frequent handwashing with soap and water or alcohol-based sanitizers.
- Disinfecting household, hospital, and public settings by cleaning with a diluted bleach solution is also recommended.
- Anyone who resides in an area where the disease is prevalent and suspects an infection or presents with flu-like symptoms should stay away from work and public transportation and immediately see a doctor.
- The best-known prevention method against swine flu is getting the H1N1 swine flu vaccine. (2)
- Cover your nose and mouth when you sneeze or cough, throw the tissue away in a bin afterward, and then clean your hands.
- Maintain proper personal hygiene.
- Keep your hands away from your face, eyes, mouth, and nose.
- Maintain a safe distance when visiting a sick person.
- Don’t share personal items such as utensils, towels, and others with a sick person.
- Wearing masks is not a foolproof solution to avoid getting sick. While a mask may not entirely prevent the spread of the virus when worn by a sick person, it can offer some level of protection to those around them. Therefore, it is recommended for sick individuals to wear masks to prevent the spread of illness. (13)
- Those who are at higher risk of complications from illness, such as individuals with chronic conditions or pregnant women, should take extra precautions to avoid getting sick. It is advisable for such individuals to stay in a separate room away from the sick person to reduce the risk of infection.
- For children who are infected, special care should be taken to provide them with appropriate care and treatment.
Who Is at Risk for Swine Flu?
Those who are at risk of swine flu include: (2)
- Children younger than 5 years of age
- Elderly (65+ years)
- Pregnant women
- People with COPD
- People with asthma
- People with obesity
- People on immunosuppressants
- People who have impaired kidney functions
- People with heart disorders
- People with diabetes
When to See a Doctor
Seeking medical attention for general flu symptoms such as fever, cough, and body aches isn’t usually necessary. However, you should call your doctor if you have these symptoms when you’re pregnant or suffer from: (2)
- Heart disease
You should also see a doctor if you suffer from emergency signs and symptoms which include:
- Difficulty breathing
- Shortness of breath
- Chest pain
- Muscle pain
Most-Asked Questions About Swine Flu (H1N1)
When do swine flu symptoms appear?
The swine flu or H1N1 symptoms start to appear 3–5 days after exposure to the virus.
Is swine flu contagious?
Yes, swine flu is contagious as it can spread from an infected person to a healthy person.
When was H1N1 a pandemic?
In 2009, the World Health Organization (WHO) declared the H1N1 or swine flu pandemic because many people around the world suffered from it. The pandemic was declared to be over in August 2010.
In April 2009, the United States reported the first two cases of the current strain of pandemic swine influenza caused by a previously unidentified swine virus.
The virus was found to have genetic material from the triple-reassortant swine virus and the Eurasian influenza A (H1N1) swine virus lineage. The newly emerged pandemic swine flu virus has weak genetic similarity to the circulating seasonal H1N1 virus.
What are the signs of swine flu in pigs?
In pigs, influenza A typically lasts for 6–7 days with symptoms including fever, respiratory distress, and weakness, but is usually mild and seldom fatal. Nonetheless, the economic impact can be significant due to weight loss in growing pigs and reproductive failure in sows caused by the fever. (16)
How many swine flu viruses are there?
Swine flu viruses, much like those in humans and other animals, undergo constant change. They can be infected by influenza viruses from different species, including avian and human influenza viruses, leading to the emergence of new viruses through reassortment.
These new viruses are a combination of swine, human, and/or avian influenza viruses.
Over the years, there have been various strains of swine flu viruses identified, with the three main subtypes isolated in pigs in the United States being H1N1, H1N2, and H3N2. (8)
Swine flu is caused by the H1N1 virus, which is a type A influenza virus that once caused a pandemic in 2009. Although it has been brought under control, people can still get very sick from it.
Therefore, it is important to get your vaccination or flu shot, to protect yourself from H1N1 and other viral strains. Remember, prevention is always better than cure!