Special Information

Swine Flu

As the virus of the  spine flue is spread from person to person  in United States and    Mexico  triggering global concerns

CNN) -- The World Health Organization has called it a "public health emergency of international concern. Seemingly out of nowhere, the swine flu virus has spread from person to person in Mexico and the United States, triggering global concerns as governments scramble to find ways to prevent further outbreak."Swine Flu FAQ

WebMD Provides Answers to Your Questions About Swine Flu
By Daniel J. DeNoon
WebMD Health News
Reviewed by Louise Chang, MD
The swine flu virus in the U.S. is the same one causing a deadly epidemic in Mexico. What is swine flu? What can we do about it? WebMD answers your questions.

What Is Swine Flu?

Like humans, pigs get the flu. Four different types A swine flu strains commonly circulate among pigs. Most recent swine flu viruses have belonged to the H1N1 and H3N2 subtypes. Pigs typically get sick but usually don't die from swine flu.
The new swine flu virus infecting humans is very unusual. It's somehow acquired genes from swine, bird, and human flu bugs. And it's also got genes from Eurasian swine flu viruses that aren't supposed to be in North America.

Do's & Dont's

Do Humans Get Swine Flu?

Normally, swine flu bugs don't infect people. Historically, there's a case every year or two in the U.S. among people who have contact with live pigs.
But from December 2005 to January 2009 there was an uptick in swine flu cases. There were 12 human swine flu infections during this time. Eleven of these people had direct or indirect contact with pigs; in the twelfth case it was not known whether there was pig contact.
It's possible this uptick was due to improved reporting systems, but the CDC says "genetic changes in swine flu viruses and other factors might also be a factor."
The new swine flu virus is different. It's not yet clear that it's here to stay. But it is infecting humans, and that has world health officials keeping a close eye on it.

What Are the Symptoms of Swine Flu?

Swine flu symptoms are similar to regular flu symptoms and include cough, sore throat, fever, chills, headache, and fatigue. Some patients have also reported nausea and diarrhea. There is no easy way to distinguish swine flu from other types of flu or other germs. It takes a lab test to tell whether it's swine flu.

Can Swine Flu Spread From Person to Person?

The U.S. residents infected with swine flu virus had no direct contact with pigs. The CDC says it's likely that the infections represent widely separated cycles of human-to-human infections.

Have There Been Previous Swine Flu Outbreaks?

If swine flu sounds familiar to you, it's probably because you remember or have read about the 1976 swine flu outbreak at Fort Dix, N.J., among military recruits. It lasted about a month and then went away as mysteriously as it appeared. As many as 240 people were infected; one died.
The swine flu that spread at Fort Dix was the H1N1 strain. That's the same flu strain that caused the disastrous flu pandemic of 1918-1919, resulting in tens of millions of deaths.
Concern that a new H1N1 pandemic might return with winter led to a crash program to create a vaccine and vaccinate all Americans against swine flu. That vaccine program ran into all kinds of problems -- not the least of which was public perception that the vaccine caused excessive rates of dangerous reactions. After more than 40 million people were vaccinated, the effort was abandoned.
As it turned out, there was no swine flu epidemic.

I Got a Flu Shot. Am I Protected Against Swine Flu?

No. There is currently no swine flu vaccine.
It's possible that the seasonal flu vaccine might provide partial protection against H3N2 swine flu bugs. But the strain that appeared in California is the H1N1 swine flu strain. It is very different from the H1N1 human flu strain included in the seasonal flu vaccine.
It's not known whether previous infection with human type A H1N1 flu might provide partial protection against the type A H1N1 swine flu in the current outbreak.
However, the CDC has made a "vaccine seed" from swine flu isolated from an infected person, and has begun the process of developing a vaccine should the need arise. Whether a vaccine could be produced in quantity by next flu season is a huge question.

How Serious Is the Public Health Threat of a Swine Flu Epidemic?

Any flu epidemic is worrisome, especially when a new strain of flu bug is involved.
"Influenza A viruses new to the human population that are able to efficiently transmit from person to person and cause illness may represent a pandemic threat," the CDC warns.
It's worrisome that, unlike seasonal flu, the swine flu outbreak in Mexico is attacking healthy young people. That's a hallmark of pandemic flu bugs.
But it takes more than a new virus spreading among humans to make a pandemic. The virus has to be able to spread efficiently from one person to another, and transmission has to be sustained over time. In addition, the virus has to spread geographically.

Is There a Treatment for Swine Flu?

Yes. While the swine flu bug is resistant to older flu medicines, it remains sensitive to Tamiflu and to Relenza.

Can You Get Swine Flu by Eating Pork?

No. You can only catch swine flu from being around an infected pig -- or, if it's the new swine flu virus, from an infected person.
Swine flu symptoms: If you're about to Google "swine flu symptoms," we can save you some trouble. There isn't a special set of symptoms unique to swine flu. It's pretty much flu, and it takes a lab test to tell whether it's swine flu.

Here's what the CDC's web site says about swine flu symptoms: "The symptoms of swine flu in people are expected to be similar to the symptoms of regular human seasonal influenza and include fever, lethargy, lack of appetite and coughing. Some people with swine flu also have reported runny nose, sore throat, nausea, vomiting and diarrhea."

What is the swine flu?

Sporadic swine influenza A virus (SIV) infection of humans may produce a wide range of clinical signs and symptoms. Many human cases of swine influenza A virus infection have had a history of recent direct physical contact with pigs prior to illness onset. However, close (within 6 feet), but not direct contact with pigs, also has been reported among human swine influenza A virus cases. Limited, non sustained human-to-human swine influenza A virus transmission has been documented in the published literature. In addition, some confirmed swine influenza A virus cases have not had a history of exposure to pigs.

What are the symptoms of swine flu?

Although uncomplicated influenza-like illness (fever, cough or sore throat) has been reported in many cases, mild respiratory illness (nasal congestion, rhinorrhea) without fever and occasional severe disease also has been reported. Other symptoms reported with swine influenza A virus infection include vomiting, diarrhea, myalgia, headache, chills, fatigue, and dyspnea. Conjunctivitis is rare, but has been reported. Severe disease (pneumonia, respiratory failure) and fatal outcomes have been reported with swine influenza A virus infection. The potential for exacerbation of underlying chronic medical conditions or invasive bacterial infection with swine influenza A virus infection should be considered.
This document provides interim guidance on infection control, antiviral treatment and chemoprophylaxis, and monitoring of close contacts of cases of swine influenza virus infection, including guidance for health care workers and public health personnel. The guidance will be updated as needed.

Recommendations

For clinical care or collection of respiratory specimens from a symptomatic individual (acute respiratory symptoms with or without fever) who is a confirmed case, or a suspected case (ill close contact of a confirmed case) of swine influenza A virus infection:
Infectious Period
Persons with swine influenza virus infection should be considered potentially contagious for up to 7 days following illness onset. Persons who continue to be ill longer than 7 days after illness onset should be considered potentially contagious until symptoms have resolved. Children, especially younger children, might potentially be contagious for longer periods. The duration of infectiousness might vary by swine influenza A virus strain.
Case definitions
A confirmed case of swine influenza virus infection (SIV) is defined as a person with an acute respiratory illness with laboratory confirmed swine influenza A virus at CDC by one or more of the following tests:

  • real-time RT-PCR
  • viral culture
  • four-fold rise in swine influenza A virus specific neutralizing antibodies

A suspected case of swine influenza A virus is defined as a person with an acute respiratory illness who was a close contact to a confirmed case of swine influenza A virus infection while the case was ill, or is an acutely ill person (acute respiratory illness) with a recent history of contact with an animal with confirmed or suspected swine influenza A virus infection.

  • Close contact is defined as: within about 6 feet of an ill person who is a confirmed case of swine influenza A virus infection

Acute respiratory illness is defined as recent onset of at least two of the following: rhinorrhea or nasal congestion, sore throat, cough (with or without fever or feverishness)
Recommendations for public health personnel
For interviews of healthy individuals (i.e. without a current respiratory illness), including close contacts of cases of confirmed swine influenza virus infection, no personal protective equipment or antiviral chemoprophylaxis is needed. See section on antiviral chemoprophylaxis for further guidance.
For interviews of an ill, suspected or confirmed swine influenza A virus case, the following is recommended:

  • Keep a distance of at least 6 feet from the ill person; or
  • Personal protective equipment: fit-tested N95 respirator [if unavailable, wear a medical (surgical mask)].

For collecting respiratory specimens from an ill confirmed or suspected swine influenza A virus case, the following is recommended:

  • Personal protective equipment: fit-tested disposable N95 respirator [if unavailable, wear a medical (surgical mask)], disposable gloves, gown, and goggles.
  • When completed, place all PPE in a biohazard bag for appropriate disposal.
  • Wash hands thoroughly with soap and water or alcohol-based hand gel.

Infection Control

Recommended Infection Control for a non-hospitalized patient (ER, clinic or home visit):

  1. Separation from others in single room if available until asymptomatic. If the ill person needs to move to another part of the house, they should wear a mask. The ill person should be encouraged to wash hand frequently and follow respiratory hygiene practices. Cups and other utensils used by the ill person should be thoroughly washed with soap and water before use by other persons.

Recommended Infection Control for a hospitalized patient:

  1. Standard, Droplet and Contact precautions for 7 days after illness onset or until symptoms have resolved.
  2. In addition, personnel should wear N95 respirators when entering the patient room.
  3. Use an airborne infection isolation room (AIIR) with negative pressure air handling, if available; otherwise use a single patient room with the door kept closed.
  4. For suctioning, bronchoscopy, or intubation, use a procedure room with negative pressure air handling.

Recommended PPE for personnel providing clinical care to ill individuals:

  1. Disposable gown, gloves, goggles, N95 respirator.

Antiviral Treatment

Antiviral treatment for confirmed or suspected ill case of swine influenza virus infection may include either oseltamivir (Tamiflu) or zanamivir, with no preference given at this time. Recommendations for use of antivirals may change as data on antiviral susceptibilities become available.
Initiate treatment as soon as possible after the onset of symptoms.
Oseltamivir (Tamiflu):

  1. The treatment dosing recommendation for children who weigh 15 kg or less is 30 mg twice a day. For children who weigh more than 15 kg and up to 23 kg, the dose is 45 mg twice a day. For children who weigh more than 23 kg and up to 40 kg, the dose is 60 mg twice a day. For children who weigh more than 40 kg, the dose is 75 mg twice a day.
  2. For ages 13 years and older: 75mg twice a day for five days

Zanamivir (Relenza)
Zanamivir (Relenza) is an alternative for treatment of influenza in patients aged 7 years and older; dosage varies by age. This drug is not approved for treatment of influenza in children aged <7 years. It is an orally inhaled drug that is administered using a disk inhaler device twice a day for five days.

  1. The treatment dosing recommendation for persons aged 7 years and older is 2 inhalations twice a day for five days (2 inhalations of 5mg each twice a day for five days)

Antiviral Chemoprophylaxis
Antiviral chemoprophylaxis (pre-exposure or post-exposure) can be considered for close contacts of a confirmed or highly suspected case of swine influenza virus infection.

  • Close contact is defined as: within about 6 feet of an ill person who is a confirmed case of swine influenza A virus infection (e.g. post-exposure chemoprophylaxis following unprotected close exposure).

Duration of antiviral chemoprophylaxis is 7 days after the last known exposure
Oseltamivir: Administered by mouth once a day for seven days following the last known exposure; dosage varies by age and weight for children aged 1 year to 12 years (available in suspension, 30mg, 45mg, 75mg capsules)

  • The chemoprophylaxis dosing recommendation for children who weigh less than 15 kg is 30 mg once a day. For those who weigh more than 15 kg and up to 23 kg, the dose is 45 mg once a day. For children who weigh more than 23 kg and up to 40 kg, the dose is 60 mg once a day. For children who weigh more than 40 kg, the dose is 75 mg once a day.
  • For ages 13 years and older: 75 mg once a day for seven days

Zanamivir is an alternative for chemoprophylaxis for patients aged 5 years and older; dosage varies by age. It is an orally inhaled drug that is administered using a disk inhaler device.

  1. Dosing is 2 oral inhalations once a day for seven days (2 inhalations of 5mg each once a day for seven days)

Follow-up Monitoring of Exposed Close Contacts

Close contacts are defined as persons who were within about 6 feet of the confirmed swine influenza case while the case was ill up to 7 days after the case's illness onset. Examples include household members, social contacts, public health care workers, medical health care workers, and others.

  1. Close contacts should be monitored daily for fever (temp ≥38.0 C; ≥100.4 F) and/or any respiratory symptoms up to 7 days following the last known exposure to an ill person who is a confirmed case of swine influenza virus infection.
  2. Close contacts of an ill person who is a confirmed case of swine influenza virus infection should be educated about the signs and symptoms of swine influenza virus infection and advised to contact public health staff if fever or feverishness or any respiratory tract symptoms occur up to 7 days following the last known exposure to the ill case.

Swine Flu Index

Featured: Swine Flu Main Article
Sporadic swine influenza A virus (SIV) infection (swine flu) is an infection that generally is transferred from an infected pig to a human, however there have been reported cases where infection has occured with no contact with infected pigs. Symptoms of swine flu are "flu-like" for example fever, cough, or sore throat. Treatment is generally with the antibiotics oseltamivir (Tamiflu) or zanamivir (Relenza).

Medications

  • oseltamivir, Tamiflu
  • zanamivir, Relenza

Procedures & Tests

  • Bronchoscopy

View All 7 Swine Flu Related Diseases & Conditions »

FDA Drug Labels on RxList.com

  • Tamiflu (oseltamivir phosphate) Capsules And For Oral Suspension )
  • Relenza(zanamivir) Inhalation Powder, for oral inhalation

Swine Flu
Related Conditions

  • Diarrhoea
  • Fever
  • Headache
  • Headaches in Children
  • Pink Eye
  • Sore Throat (Pharyngitis)
  • Chronic cough

Q. What is swine flu?

A. Swine influenza, or flu, is a contagious respiratory disease that affects pigs. It is caused by a type-A influenza virus. Outbreaks in pigs occur year-round.
The most common version is H1N1. The current strain is a new variation of an H1N1 virus, which is a mix of human and animal versions.

Q.
Does swine flu affect humans?
A. While the virus causes regular outbreaks in pigs, people usually are not struck by swine flu. However, there have been instances of the virus spreading to people -- and then from one person to another. The only difference is, says the CDC, transmission in the past did not spread beyond three people -- as it has done this time.

Q.
What is behind the spread of the virus this time?

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A. Researchers do not know yet know. People usually get swine flu from infected pigs. For example, farmers handling infected pigs can contract the virus. However, some human cases have occurred without contact with pigs or places they inhabited.

Q.
What are the symptoms of swine flu?
A. The symptoms are similar to the common flu. They include fever, lethargy, lack of appetite, coughing, runny nose, sore throat, nausea, vomiting and diarrhea.

Q.
How does the virus spread?
A. The virus spreads the same way the seasonal flu does. When an infected person coughs or sneezes around another person, the latter is put at risk. People can become infected by touching something with the flu virus on it and then touching their mouth, nose or eyes. An infected person can pass the virus to another before any symptoms even develop.

Q.
Why is this spread troubling?
A. Scientists are concerned whenever a new virus is able to jump from an animal to a person -- and then spread from person to person. When the flu spreads person to person, it can continue to mutate, making it harder to treat or fight off.
The World Health Organization has said the current outbreak has "pandemic potential," and has urged governments to take precautions to prevent its spread. If the virus continues to mutate, drug makers won't be able to come up with vaccines fast enough.

Q.
Can swine flu be fatal?
A. Just like the regular flu, swine flu worsens pre-existing medical conditions in people. So people with already compromised immune systems can die after contracting it.

Q.
But doesn't the common flu kill more people?
A. Yes, common seasonal flu kills 250,000 to 500,000 people every year. But what worries officials is that a new strain of the flu virus can spread fast because people do not have natural immunity and vaccines can take months to develop.

Q.
Have there been swine flu outbreaks in the past?
A. From 2005 to January 2009, 12 human cases of swine flu were detected in the United States, without deaths occurring, the CDC said. In September 1988, a healthy 32-year-old pregnant woman in Wisconsin was hospitalized for pneumonia after being infected with swine flu and died a week later. And in 1976, a swine flu outbreak in Fort Dix, New Jersey, caused more than 200 illnesses and one death.

Q.
What does the World Health Organization mean when it says swine flu has "pandemic potential"?
A. If the virus spreads over a wide geographic area and affects a large segment of the population, it is upgraded from an "epidemic" to a "pandemic."

Q.
How deadly have pandemics been in the past?
A. In 1968, a "Hong Kong" flu pandemic killed about 1 million people worldwide. And in 1918, a "Spanish" flu pandemic killed as many as 100 million people.

Q.
How can one keep from getting swine flu?
A. There are no vaccines available. But several everyday steps can help prevent the spread of germs: Washing hands frequently; avoiding close contact with people who are sick; and avoiding touching surfaces that might be contaminated.


Health Library

  • MayoClinic.com: Influenza (flu)

Q. Are there medicines to treat swine flu?
A. Yes, the CDC recommends using anti-viral drugs. They keep the virus from reproducing inside the body. And in an infected person, the drugs make the illness milder.

Q. Can one contract swine flu from eating or preparing pork?

A. No. Pork and other pig-derived products, if properly handled and cooked, do not transmit swine flu. The flu virus is killed by cooking temperatures of 160°F (70°C).

Definition

Swine flu is a respiratory infection caused by influenza A viruses. The outbreak of what is popularly called swine flu involves a new H1N1 type A influenza strain that's a genetic combination of swine, avian and human influenza viruses. It can spread from human to human.
True swine flu ordinarily causes illness in pigs. Pig-to-human transmission is unusual, and human-to-human transmission of true swine flu is also possible but infrequent.
Based on its wide spread, the World Health Organization has declared the 2009 outbreak of the new H1N1 flu a global pandemic.
The new swine flu strain is being called by various names: swine-origin influenza A, swine influenza A (H1N1), influenza A/California/H1N1, swine origin influenza virus, North American flu and influenza A (H1N1).
The best approach you can take is to avoid infection. If you develop symptoms of swine flu, seek prompt medical attention to give yourself the best chance of antiviral drugs being effective.
Symptoms 
Swine flu symptoms in humans are similar to those of infection with other flu strains:

  • Fever
  • Cough
  • Sore throat
  • Body aches
  • Headache
  • Chills
  • Fatigue
  • Diarrhea
  • Vomiting

Swine flu symptoms develop three to five days after you're exposed to the virus and continue for about eight days, starting one day before you get sick and continuing until you've recovered.
When to see a doctor
See your doctor immediately if you develop swine flu symptoms, such as fever, cough and body aches, and you have recently traveled to an area where H1N1 swine flu has been reported. Be sure to let your doctor know when and where you traveled.
Also see your doctor if you develop what appear to be swine flu symptoms after you've been in close contact with someone who may have been exposed to H1N1 swine flu.
Doctors have rapid tests to identify the flu virus, but there is no rapid test to differentiate swine influenza A H1N1 from other influenza A subtypes.
Causes
Influenza viruses infect the cells lining your nose, throat and lungs. The virus enters your body when you inhale contaminated droplets or transfer live virus from a contaminated surface to your eyes, nose or mouth on your hand.

Risk Factors
If you've traveled to an area where lots of people are affected by human swine flu H1N1, you may have been exposed to the virus, particularly if you spent time in large crowds.
Swine farmers and veterinarians have the highest risk of true swine flu because of their exposure to pigs.
Complications
Influenza complications include:

  • Worsening of chronic conditions, such as heart disease, diabetes and asthma
  • Pneumonia
  • Respiratory failure

Severe complications of human swine flu H1N1 seem to develop and progress rapidly.

Treatments and drugs

Most cases of flu, including human swine flu, need no treatment other than symptom relief. If you have a chronic respiratory disease, your doctor may prescribe additional medication to decrease inflammation, open your airways and help clear lung secretions.
Antiviral drugs can reduce the severity of symptoms. Two classes of antiviral medications are used to reduce symptoms and duration of the flu — adamantane antivirals and neuraminidase inhibitors — but flu viruses can develop resistance to them.
Human swine flu H1N1 is sensitive to oseltamivir (Tamiflu) and zanamivir (Relenza), both of which are neuraminidase inhibitors. It's important to start treatment as soon as possible after you become ill. These antiviral medications are most effective if treatment begins within 48 hours of developing symptoms.

Lifestyle and home remedies

If you come down with any type of flu, these measures may help ease your symptoms:

  • Drink plenty of liquids. Choose water, juice and warm soups to prevent dehydration. Drink enough so that your urine is clear or pale yellow.
  • Rest. Get more sleep to help your immune system fight infection.
  • Consider pain relievers. Use Paracetamol if  needed.

Remember, pain relievers may make you more comfortable, but they won't make your symptoms go away any faster and may have side effects. Ibuprofen may cause stomach pain, bleeding and ulcers. If taken for a long period or in higher than recommended doses, acetaminophen can be toxic to your liver.
Talk to your doctor before giving acetaminophen to children. And don't give aspirin to children or teens because of the risk of Reye's syndrome, a rare but potentially fatal disease.

Prevention

These measures may help prevent flu:

  • Stay home if you're sick. If you do have swine flu, you can give it to others starting about 24 hours before you develop symptoms and ending about seven days later.
  • Wash your hands thoroughly and frequently. Use soap and water, or if they're unavailable, use an alcohol-based hand sanitizer. Flu viruses can survive for two hours or longer on surfaces, such as doorknobs and countertops.
  • Avoid contact. Stay away from crowds if possible.
  • Reduce exposure within your household. If a member of your household has swine flu, designate one other household member to be responsible for the ill person's close personal care.

H1N1 Flu (Swine Flu)
Also called: Swine flu
Swine flu is an infection caused by a virus. It's named for a virus that pigs can get. People do not normally get swine flu, but human infections can and do happen. The virus is contagious and can spread from human to human. Symptoms of swine flu in people are similar to the symptoms of regular human flu and include fever, cough, sore throat, body aches, headache, chills and fatigue.
There are antiviral medicines you can take to prevent or treat swine flu. There is no vaccine available right now to protect against swine flu. You can help prevent the spread of germs that cause respiratory illnesses like influenza by

  • Covering your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
  • Washing your hands often with soap and water, especially after you cough or sneeze. You can also use alcohol-based hand cleaners.
  • Avoiding touching your eyes, nose or mouth. Germs spread this way.
  • Trying to avoid close contact with sick people.
  • Staying home from work or school if you are sick.

How many swine flu viruses are there?
Like all influenza viruses, swine flu viruses change constantly. Pigs can be infected by avian influenza and human influenza viruses as well as swine influenza viruses. When influenza viruses from different species infect pigs, the viruses can reassort (i.e. swap genes) and new viruses that are a mix of swine, human and/or avian influenza viruses can emerge. Over the years, different variations of swine flu viruses have emerged. At this time, there are four main influenza type A virus subtypes that have been isolated in pigs: H1N1, H1N2, H3N2, and H3N1. However, most of the recently isolated influenza viruses from pigs have been H1N1 viruses.

Swine Flu in Humans

Can humans catch swine flu?
Swine flu viruses do not normally infect humans. However, sporadic human infections with swine flu have occurred. Most commonly, these cases occur in persons with direct exposure to pigs (e.g. children near pigs at a fair or workers in the swine industry). In addition, there have been documented cases of one person spreading swine flu to others. For example, an outbreak of apparent swine flu infection in pigs in Wisconsin in 1988 resulted in multiple human infections, and, although no community outbreak resulted, there was antibody evidence of virus transmission from the patient to health care workers who had close contact with the patient.
How common is swine flu infection in humans?
In the past, CDC received reports of approximately one human swine influenza virus infection every one to two years in the U.S., but from December 2005 through February 2009, 12 cases of human infection with swine influenza have been reported.
What are the symptoms of swine flu in humans?
The symptoms of swine flu in people are expected to be similar to the symptoms of regular human seasonal influenza and include fever, lethargy, lack of appetite and coughing. Some people with swine flu also have reported runny nose, sore throat, nausea, vomiting and diarrhea.
How does swine flu spread?
Influenza viruses can be directly transmitted from pigs to people and from people to pigs. Human infection with flu viruses from pigs are most likely to occur when people are in close proximity to infected pigs, such as in pig barns and livestock exhibits housing pigs at fairs. Human-to-human transmission of swine flu can also occur. This is thought to occur in the same way as seasonal flu occurs in people, which is mainly person-to-person transmission through coughing or sneezing of people infected with the influenza virus. People may become infected by touching something with flu viruses on it and then touching their mouth or nose.
What do we know about human-to-human spread of swine flu?
In September 1988, a previously healthy 32-year-old pregnant woman was hospitalized for pneumonia and died 8 days later. A swine H1N1 flu virus was detected. Four days before getting sick, the patient visited a county fair swine exhibition where there was widespread influenza-like illness among the swine.
In follow-up studies, 76% of swine exhibitors tested had antibody evidence of swine flu infection but no serious illnesses were detected among this group. Additional studies suggest that one to three health care personnel who had contact with the patient developed mild influenza-like illnesses with antibody evidence of swine flu infection.
How can human infections with swine influenza be diagnosed?
To diagnose swine influenza A infection, a respiratory specimen would generally need to be collected within the first 4 to 5 days of illness (when an infected person is most likely to be shedding virus). However, some persons, especially children, may shed virus for 10 days or longer. Identification as a swine flu influenza A virus requires sending the specimen to CDC for laboratory testing.
What medications are available to treat swine flu infections in humans?
There are four different antiviral drugs that are licensed for use in the US for the treatment of influenza: amantadine, rimantadine, oseltamivir and zanamivir. While most swine influenza viruses have been susceptible to all four drugs, the most recent seven swine influenza viruses isolated from humans are resistant to amantadine and rimantadine. At this time, CDC recommends the use of oseltamivir or zanamivir for the treatment and/or prevention of infection with swine influenza viruses. More information on treatment recommendations can be found at www.cdc.gov/flu/swine/recommendations.htm.
What other examples of swine flu outbreaks are there?
Probably the most well known is an outbreak of swine flu among soldiers in Fort Dix, New Jersey in 1976. The virus caused disease with x-ray evidence of pneumonia in at least 4 soldiers and 1 death; all of these patients had previously been healthy. The virus was transmitted to close contacts in a basic training environment, with limited transmission outside the basic training group. The virus is thought to have circulated for a month and disappeared. The source of the virus, the exact time of its introduction into Fort Dix, and factors limiting its spread and duration are unknown. The Fort Dix outbreak may have been caused by introduction of an animal virus into a stressed human population in close contact in crowded facilities during the winter. The swine influenza A virus collected from a Fort Dix soldier was named A/New Jersey/76 (Hsw1N1).
Is the H1N1 swine flu virus the same as human H1N1 viruses?
No. The H1N1 swine flu viruses are antigenically very different from human H1N1 viruses and, therefore, vaccines for human seasonal flu would not provide protection from H1N1 swine flu viruses.
Is there a vaccine for swine flu?
Vaccines are available to be given to pigs to prevent swine influenza. There is no vaccine to protect humans from swine flu. The seasonal influenza vaccine will likely help provide partial protection against swine H3N2, but not swine H1N1 viruses.