H1N1 Influenza | Swine Flu

Swine influenza (swine flu) is a respiratory disease of pigs caused by a type of influenza virus. Outbreaks of swine flu happen regularly in pigs. People do not normally get swine flu, but human infections can and do happen. Most commonly, human cases of swine flu happen in people who are around pigs but it’s possible for swine flu viruses to spread from one person to another. In the United States there were 12 cases of swine flu in people from 2006 through 2008. In March and April 2009 there have been many more cases of swine flu than usual in both Mexico and the U.S. and the infections have spread from one person to another.

Swine influenza is a highly contagious respiratory disease in pigs caused by one of several swine influenza A viruses. In addition, influenza C viruses may also cause illness in swine. Current strategies to control swine influenza virus (SIV) in animals typically include one of several commercially available bivalent swine influenza virus vaccines.

Transmission of swine influenza viruses to humans is uncommon. However, the swine influenza virus can be transmitted to humans via contact with infected pigs or environments contaminated with swine influenza viruses. Once a human becomes infected, he or she can then spread the virus to other humans, presumably in the same way as seasonal influenza is spread (ie, via coughing or sneezing).

H1N1 Influenza | Swine Flu History

The ability to trace outbreaks of swine flu in humans dates back to investigation of the 1918 Spanish influenza pandemic, which infected one third of the world’s population (an estimated 500 million people) and caused approximately 50 million deaths. In 1918, the cause of human influenza and its links to avian and swine influenza was not understood. The answers did not begin to emerge until the 1930s, when related influenza viruses (now known as H1N1 viruses) were isolated from pigs and then humans.

In humans, the severity of swine influenza can vary from mild to severe. From 2005 until January 2009, 12 human cases of swine flu were reported in the United States. None were fatal. In 1988, however, a previously healthy 32-year-old pregnant woman in Wisconsin died of pneumonia as a complication of swine influenza.

A 1976 outbreak of swine influenza in Fort Dix, New Jersey, involved more than 200 cases, some of them severe, and one death.2 The first discovered case involved a soldier at Fort Dix who complained of feeling weak and tired. He died the next day.

The fear of an influenza pandemic in 1976 led to a national campaign in the United States designed to immunize nearly the entire population. In October, 1976, approximately 40 million people received the A/NewJersey/1976/H1N1 vaccine (ie, swine flu vaccine) before the immunization initiative was halted because of the strong association between the vaccine and Guillain-Barré syndrome (GBS). About 500 cases of GBS were reported, with 25 deaths due to associated pulmonary complications.

A recent investigation sought to determine the link between GBS and the 1976 swine flu vaccine, since subsequent influenza vaccines did not have this strong association. Nachamkin et al (2008) found that inoculation of the 1976 swine flu vaccine, as well as the 1991-1992 and 2004-2005 influenza vaccines, into mice prompted production of antibodies to antiganglioside (anti-GM1), which are associated with the development of GBS. They proposed that further research regarding influenza vaccine components is warranted to determine how these components elicit antiganglioside effects.

H1N1 Influenza | Swine Flu

Current H1N1 influenza (formerly called swine influenza) outbreak

Human cases of influenza A (H1N1) have been reported worldwide. In 2009, cases of influenzalike illness were first reported in Mexico on March 18; the outbreak was subsequently confirmed as H1N1 influenza A. Investigation is continuing to clarify the spread and severity of H1N1 influenza (swine flu) in Mexico. Suspected clinical cases have been reported in 19 of the country's 32 states. Although only 97 of the Mexican cases have been laboratory-confirmed as Influenza A/H1N1 (12 of them genetically identical to Influenza A/H1N1 viruses from California ). As of May 5th, 2009, nearly 600 H1N1 influenza cases have been confirmed in Mexico, including 25 deaths.

According to the WHO, as of May 4, 2009, H1N1 influenza had been laboratory-confirmed in 20 countries. For an updated tally of affected countries and counts, see WHO's Influenza A (H1N1) Web page. Cases are also suspected in Brazil.

On April 17, 2009, the CDC determined that two cases of febrile respiratory illness in children who resided in adjacent counties in southern California were caused by infection with a swine influenza A (H1N1) virus. By April 26, 2009, the US Department of Health and Human Services declared a national public health emergency involving H1N1 influenza A, citing its significant potential to affect national security.11 By May 6, 2009, 642 cases of H1N1 influenza had been confirmed in nearly all states within the United States and nearly 2000 cases worldwide.

For an updated tally and case counts in specific states, see the CDC's H1N1 Flu (Swine Flu) Web page. All affected patients have had mild influenza like illness, with only two requiring brief hospitalization. As of May 1, 2009, only one death attributed to H1N1 flu had been reported in the United States, involving a 23-month-old child from Mexico who was visiting relatives in the United States.

Government and public health officials are monitoring this situation worldwide to assess the threat from H1N1 influenza and to provide guidance to health care professionals and the public. Because the situation is changing rapidly, it is important to check regularly for changes in recommendations as new information becomes available.

Technically, the term "swine flu" refers to influenza in pigs. Occasionally, pigs transmit influenza viruses to people, mainly to hog farmers and veterinarians. Less often, someone infected passes the infection to others.

The human respiratory infection caused by a particular influenza virus H1N1 strain — popularly known as swine flu — was first recognized in spring 2009. A few months after the first swine flu cases were reported, rates of confirmed H1N1-related illness were increasing in much of the world. As a result, the World Health Organization declared the infection a global pandemic.

The pandemic was declared over in August 2010. Currently, H1N1 is still circulating in humans as a seasonal flu virus and is included in the seasonal flu vaccine.

H1N1 Influenza | Swine Flu Morbidity and Mortality

H1N1 influenza (swine flu) tends to cause high morbidity but low mortality rates (1%-4%).

Symptoms Of Swine Flu In People

Swine flu causes symptoms very similar to seasonal (or human) flu. The most common symptoms of swine flu, like seasonal flu, are fever, cough, and sore throat and can include body aches, headache, chills and fatigue. Some people also have diarrhea and vomiting. There have been some people with swine flu who have been sicker and have even died.

Manifestations of H1N1 influenza (swine flu) are similar to those of seasonal influenza. Patients present with symptoms of acute respiratory illness, including at least 2 of the following:

• Fever
• Cough
• Sore throat
• Body aches
• Headache
• Chills and fatigue
• Diarrhea and vomiting (possible)

Persons with these symptoms should call their health care provider promptly. If an antiviral agent is warranted, it should ideally be initiated with 48 hours from the onset of symptoms (see Medications). The duration of illness is typically 4-6 days. The infectious period for a confirmed case is defined as 1 day prior to the onset of symptoms to 7 days after onset.

In children, signs of severe disease include apnea, tachypnea, dyspnea, cyanosis, dehydration, altered mental status, and extreme irritability

When to see a doctor?

It's not necessary to see a doctor if you're generally healthy and develop flu signs and symptoms, such as fever, cough and body aches. Call your doctor, however, if you have flu symptoms and you're pregnant or you have a chronic disease, such as emphysema or a heart condition.

How would I know if I have swine flu?

If you have symptoms of influenza as described above, and especially if you have recently traveled to an area where there have been human cases of swine flu, contact your healthcare provider who will decide what type of testing and treatment is right for you. To diagnose any kind of flu virus, a swab of the inside of your nose needs to be collected by a doctor. Identification of a swine flu virus requires special laboratory testing.

If you think you might have swine flu and you need to see your health care provider, you should call ahead and let them know you might have the flu. That way, precautions can be taken to avoid the spread of flu to others.

H1N1 Influenza | Swine Flu 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.

You can't catch swine flu from eating pork.

• Influenza complications include:
• Worsening of chronic conditions, such as heart disease, diabetes and asthma
• Pneumonia
• Neurological signs and symptoms, ranging from confusion to seizures
• Respiratory failure

H1N1 Influenza | Swine Flu Treatments and drugs

People sick with any type of flu should make sure to drink enough fluids, get plenty of rest, eat healthy foods, wash hands frequently and stay home to avoid spreading the flu to other people. The kinds of drugs used to treat seasonal flu, called antivirals, can also be used to treat swine flu. There have been a few influenza viruses, including the most recent swine flu, that are resistant to some, but not all, of these drugs. Healthcare providers may recommend that people who are sick or appear to be sick with swine flu receive an antiviral medication.

You can protect yourself and others from swine flu the same way that you can protect yourself from seasonal flu. Avoid holding, hugging, kissing, or shaking hands with anyone who has a cold or the flu. Wash your hands often with soap and warm water, or use an alcohol-based hand sanitizer. Avoid touching your nose, mouth or eyes. Clean things that are touched often like door handles, telephones, etc. If you get sick with a flu-like illness say home from work and school and avoid contact with others so the virus does not spread.

 

H1N1 Influenza | Swine Flu Treatment Recommendations 

Treatment is largely supportive and consists of bedrest, increased fluid consumption, cough suppressants, and antipyretics and analgesics (eg, acetaminophen, nonsteroidal anti-inflammatory drugs) for fever and myalgias. Severe cases may require intravenous hydration and other supportive measures. Antiviral agents may also be considered for treatment or prophylaxis (see Medications).

Patients should be encouraged to stay home if they become ill, to avoid close contact with people who are sick, to wash their hands often, and to avoid touching their eyes, nose, and mouth. The CDC recommends the following actions when human infection with H1N1 influenza (swine flu) is confirmed in a community:

 

Home isolation

• Patients who develop flulike illness (ie, fever with either cough or sore throat) should be strongly encouraged to self-isolate in their home for 7 days after the onset of illness or at least 24 hours after symptoms have resolved, whichever is longer.

• To seek medical care, patient should contact their health care providers to report illness (by telephone or other remote means) before seeking care at a clinic, physician's office, or hospital.

• Patients who have difficulty breathing or shortness of breath or who are believed to be severely ill should seek immediate medical attention.

• If the patient must go into the community (eg, to seek medical care), he or she should wear a face mask to reduce the risk of spreading the virus in the community when coughing, sneezing, talking, or breathing. If a face mask is unavailable, ill persons who need to go into the community should use tissues to cover their mouth and nose while coughing.

• While in home isolation, patients and other household members should be given infection control instructions, including frequent hand washing with soap and water. Use alcohol-based hand gels (containing at least 60% alcohol) when soap and water are not available and hands are not visibly dirty. Patients with H1N1 influenza should wear a face mask when within 6 feet of others at home.

Household contacts who are not ill

• Remain home at the earliest sign of illness.

• Minimize contact in the community to the extent possible.

• Designate a single household family member as caregiver for the patient to minimize interactions with asymptomatic persons.

School dismissal and childcare facility closure 

• Strong consideration should be given to close schools upon a confirmed case of H1N1 flu or a suspected case epidemiologically linked to a confirmed case.

• Decisions regarding broader school dismissal within these communities should be left to local authorities, taking into account the extent of influenzalike illness within the community.

• Cancelation of all school or childcare related gatherings should also be announced.

• Encourage parents and students to avoid congregating outside of the school if school is canceled.

• Duration of schools and childcare facilities closings should be evaluated on an ongoing basis depending on epidemiological findings.

• Consultation with local or state health departments is essential for guidance concerning when to reopen schools. If no additional confirmed or suspected cases are identified among students (or school-based personnel) for a period of 7 days, schools may consider reopening.

• Schools and childcare facilities in unaffected areas should begin preparation for possible school closure.

Social distancing 

• Large gatherings linked to settings or institutions with laboratory-confirmed cases should be canceled (eg, sporting events or concerts linked to a school with cases); other large gatherings in the community may not need to be canceled at this time.

• Additional social distancing measures are currently not recommended.

• Persons with underlying medical conditions who are at high risk for complications of influenza should consider avoiding large gatherings.

Preventive measures for health care personnel

The CDC has issued interim recommendations for controlling the spread of H1N1 influenza in health care settings. Recommended measures for care of patients with suspected or confirmed H1N1 influenza include the following:

• Place patients in a single-patient room with the door kept closed. An airborne-infection isolation room with negative-pressure air handling can be used, if available. Air can be exhausted directly outside or can be recirculated after filtration by a high efficiency particulate air (HEPA) filter.

• Suctioning, bronchoscopy, or intubation should be performed in a procedure room with negative-pressure air handling.

• Patients should wear a surgical mask when outside their room.

• Encourage patients to wash their hands frequently and to follow respiratory hygiene practices. Cups and other utensils used by the ill person should be washed with soap and water before use by other persons.

• Routine cleaning and disinfection strategies used during influenza seasons can be applied.

• Standard, droplet, and contact precautions should be used for all patient care activities and maintained for 7 days after illness onset or until symptoms have resolved.

• Health care personnel should wash their hands with soap and water or use hand sanitizer immediately after removing gloves and other equipment and after any contact with respiratory secretions.

• Personnel providing care to or collecting clinical specimens from patients should wear disposable nonsterile gloves, gowns, and eye protection (eg, goggles) to prevent conjunctival exposure.

• As per previous recommendations regarding mask and respirator use during influenza pandemics, personnel engaged in aerosol-generating activities (eg, collection of clinical specimens, endotracheal intubation, nebulizer treatment, bronchoscopy) and/or resuscitation involving emergency intubation or cardiac pulmonary resuscitation should wear a fit-tested disposable N95 respirator.

• Pending clarification of transmission patterns for the 2009 H1N1 influenza A (swine flu) virus, personnel providing direct patient care for suspected or confirmed cases should wear a fit-tested disposable N95 respirator when entering the patient's room.

H1N1 influenza in pregnancy

Pregnant women with suspected H1N1 influenza should receive empiric antiviral treatment.

Most cases of flu, including H1N1 flu, require only symptom relief. If you have a chronic respiratory disease, your doctor may prescribe additional medication to help relieve your symptoms.

The antiviral drugs oseltamivir (Tamiflu) and zanamivir (Relenza) are sometimes prescribed to reduce the severity of symptoms, but flu viruses can develop resistance to them. Some researchers recommend further study on both of these drugs due to uncertainty about their effects beyond the initial reduction in symptoms.

To make development of resistance less likely and maintain supplies of these drugs for those who need them most, antivirals are reserved for people at high risk of complications.


High-risk groups are those who: 

• Are hospitalized

• Are younger than 5 years of age, particularly children younger than 2 years

• Are 65 years and older

• Are pregnant or within two weeks of delivery, including women who have had pregnancy loss

• Are younger than 19 years of age and are receiving long-term aspirin therapy, because of an increased risk for Reye's syndrome, a rare but potentially fatal disease

• Have certain chronic medical conditions, including asthma, emphysema, heart disease, diabetes, neuromuscular disease, obesity, and kidney, liver or blood disease

• Are immunosuppressed due to certain medications or HIV

H1N1 Influenza | Swine Flu Medications

Laboratory testing has found the H1N1 influenza A (swine flu) virus susceptible to the prescription antiviral drugs oseltamivir and zanamivir, and the CDC has issued interim guidance for the use of these drugs to treat and prevent infection with swine influenza viruses. As part of its preparation for the emergency, the US Department of Homeland Security is releasing 25% of stockpiled antiviral agents (ie, oseltamivir [Tamiflu], zanamivir [Relenza]).

The usual vaccine for influenza administered at the beginning of the flu season is not effective for this viral strain. Also, other antiviral agents (eg, amantadine, rimantadine) are not recommended because of recent resistance to other influenza strains documented over the past several years.

Basic supportive care (ie, hydration, analgesics, cough suppressants) should be prescribed. Empiric antiviral treatment should be considered for confirmed, probable, or suspected cases of H1N1 influenza. Treatment of hospitalized patients and patients at higher risk for influenza complications should be prioritized.

Initiation of antiviral agents within 48 hours of symptom onset is imperative for providing treatment efficacy against influenza virus. In studies of seasonal influenza, evidence for benefits of treatment is strongest when treatment is started within 48 hours of illness onset. However, some studies of treatment of seasonal influenza have indicated benefit, including reductions in mortality or duration of hospitalization, even in patients in whom treatment was started more than 48 hours after illness onset. The recommended duration of treatment is 5 days.

• Prophylaxis with antiviral agents should also be considered in the following individuals (pre-exposure or postexposure):
  
  
  • Close household contacts of a confirmed or suspected case who are at high risk for complications (eg, chronic medical conditions, persons >65 y or <5 y, pregnant women)
  • School children at high risk for complications who have been in close contact with a confirmed or suspected case
  • Travelers to Mexico who are at high risk for complications (eg, chronic medical conditions, persons >65 y or <5 y, pregnant women)
  • Health care providers or public health workers who were not using appropriate personal protective equipment during close contact with a confirmed or suspected case.
   

• Pre-exposure prophylaxis can be considered in the following persons:
  
  
  • Any health care provider who is at high risk for complications (eg, persons with chronic medical conditions, adults >65 y, pregnant women)
  • Individuals not considered to be at high risk but who are nonetheless traveling to Mexico, first responders, or border workers who are working in areas with confirmed cases 
   

H1N1 Influenza | Swine Flu Antiviral Agents

Drugs indicated for treatment of H1N1 influenza A virus include neuraminidase inhibitors (ie, oseltamivir and zanamivir).

Oseltamivir (Tamiflu)

Oseltamivir inhibits neuraminidase, which is a glycoprotein on the surface of influenza virus that destroys an infected cell's receptor for viral hemagglutinin. By inhibiting viral neuraminidase, this agent decreases the release of viruses from infected cells and, thus, viral spread. Oseltamivir is effective in the treatment of influenza A or B and must be administered within 48 hours of symptom onset to provide optimal treatment. The sooner the drug is administered after symptom onset, the better the likelihood of a good outcome. However, some studies of treatment of seasonal influenza have indicated benefit, including reductions in mortality or duration of hospitalization even for patients whose treatment was started more than 48 hours after illness onset. Oseltamivir reduces the length of illness by an average of 1.5 days. (In a subgroup of high-risk patients, illness was reduced by 2.5 d.) In addition, the severity of symptoms is also reduced.

Duration of administration for treatment is 5 days. Postexposure prophylaxis should be initiated within 7 d of exposure and continued for at least 10 days. Pre-exposure prophylaxis should be initiated during potential exposure period and continue for 10 days after last known exposure.

Oseltamivir is available as 30-mg, 45-mg, and 75-mg oral capsules and as a powder for suspension that contains 12 mg/mL after reconstitution.

• Adult dose
  
  
  • Treatment for acute illness: 75 mg PO bid for 5 d
  • Prophylaxis: 75 mg PO qd (Please refer to duration of prophylaxis specific for postexposure.)
   

• Pediatric dose
  
  
  • Treatment for acute illness and age <1 year
    
    • <3 months: 12 mg PO bid for 5 d
    • 3-5 months: 20 mg PO bid for 5 d
    • 6-11 months: 25 mg PO bid for 5 d
     
  • Treatment for acute illness and age >1 year
    
    • <15 kg: 30 mg PO bid for 5 d
    • 15-23 kg: 45 mg PO bid for 5 d
    • 23-40 kg: 60 mg PO bid for 5 d
    • >40 kg: Administer as in adults
     
  • Prophylaxis and age <1 year
    
    • <3 months: Data limited; not recommended unless situation judged critical
    • 3-5 months: 20 mg PO qd
    • 6-11 months: 25 mg PO qd
    • Prophylaxis and age >1 year
    • <15 kg: 30 mg PO qd
    • 15-23 kg: 45 mg PO qd
    • 23-40 kg: 60 mg PO qd
    • >40 kg: Administer as in adults

Zanamivir (Relenza)

Zanamivir inhibits neuraminidase, which is a glycoprotein on the surface of the influenza virus that destroys the infected cell's receptor for viral hemagglutinin. By inhibiting viral neuraminidase, release of viruses from infected cells and viral spread are decreased. Zanamivir is effective against both influenza A and B. The preparation of zanamivir is in powder form for inhalation via the Diskhaler oral inhalation device. Circular foil discs that contain 5-mg blisters of drug are inserted into the supplied inhalation device. Individuals with asthma or other respiratory conditions that may decrease ability to inhale drug should be given oseltamivir.

• Adult dose
  
  
  • Treatment for acute illness: 10 mg inhaled orally bid for 5 d
  • Prophylaxis of household contact: 10 mg inhaled orally qd for 10 d (initiate within 36 h)
  • Prophylaxis for community outbreak: 10 mg inhaled orally qd for 28 d (initiate within 5 d of outbreak)

• Pediatric dose
  
  
  • Treatment for acute illness
    
    • <7 years: Not established
    • >7 years: Administer as in adults
     
  • Prophylaxis in household contact
    • <5 years: Not established
    • >5 years: Administer as in adults
     
  • Prophylaxis in community outbreak
    • Adolescents 12-16 years: Administer as in adults

Additional pediatric considerations

Aspirin or aspirin-containing products (eg, bismuth subsalicylate [Pepto Bismol]) should not be included in the treatment of confirmed or suspected viral infection in persons aged 18 years or younger because of the risk of Reye syndrome. For relief of fever, other antipyretic medications (eg, acetaminophen, nonsteroidal anti-inflammatory drugs) are recommended.

Pregnant women

Oseltamivir and zanamivir are "Pregnancy Category C" medications, indicating that no clinical studies have been conducted to assess the safety of these medications in pregnant women.


Because of the unknown effects of influenza antiviral drugs on pregnant women and their fetuses, oseltamivir or zanamivir should be used during pregnancy only if the potential benefit justifies the potential risk to the embryo or fetus; the manufacturers' package inserts should be consulted. However, no adverse effects have been reported among women who received seltamivir or zanamivir during pregnancy or among infants born to women who have received oseltamivir or zanamivir. Pregnancy should not be considered a contraindication to oseltamivir or zanamivir use. Because zanamivir is an inhaled medication and has less systemic absorption, some experts prefer zanamivir over oseltamivir for use in pregnant women, when feasible.

All people with swine flu who are not hospitalized, and their household and other close contacts, will need to stay at home to prevent spread of illness to other people.  

If I have swine flu, can I stay at home? 

People with mild or moderate illness can and should be cared for at home to prevent spread. Things people who have swine flu who are cared for at home should do include:

• check with their health care provider about any special care they might need if they are pregnant or have a health condition such as diabetes, heart disease, asthma, or emphysema
•  check with their health care provider about whether they should take antiviral medications  
• stay home for at least 7 days after onset of illness; or until free of symptoms (including fever) for 24 hours, which ever is longer  
• get plenty of rest 
• drink clear fluids (such as water, broth, sports drinks, electrolyte beverages for infants) to keep from being dehydrated 
• cover coughs and sneezes. Clean hands with soap and water or an alcohol-based hand rub often and especially after using tissues and after coughing or sneezing into hands. 
• Never cough in the direction of someone else. 
• avoid close contact with others – do not go to work or school while ill  
• be watchful for emergency warning signs (see below) that might indicate you need to seek medical attention 

Get medical care right away if the sick person at home:  

• has difficulty breathing or chest pain
• has purple or blue discoloration of the lips  
• is vomiting and unable to keep liquids down 
• has signs of dehydration such as dizziness when standing, absence of urination, or in infants, a lack of tears when they cry  
• has seizures (for example, uncontrolled convulsions) is less responsive than normal or becomes confused

Is there a vaccine for swine flu?

No. Right now there is no vaccine for swine flu. According to CDC, it is unlikely that the vaccine for seasonal flu will prevent swine flu.

Is it safe to cook and eat pork and pork products?

Yes. It is safe to eat properly handled and cooked pork and pork products. Swine flu viruses are not spread by food. You cannot get swine flu from eating pork or pork products.

Why is swine flu important?

Approximately every 20-40 years, a new strain of the flu virus appears which is very different from the ordinary seasonal flu virus. When this happens most people do not have immunity to this new strain of flu virus and it can spread to many people, across the world, over a short period of time. This is called an influenza pandemic. Some people think that swine flu viruses might play a role in the start of the next pandemic.

H1N1 Influenza | Swine Flu Prevention 

The Centers for Disease Control and Prevention recommends flu vaccination for all people older than 6 months of age. An H1N1 virus is one component of the seasonal flu shot for 2013-2014. The flu shot also protects against two or three other influenza viruses that are expected to be the most common during the 2013-2014 flu season.

The vaccine will be available as an injection or a nasal spray. The nasal spray is approved for use in healthy people 2 through 49 years of age who are not pregnant.

These measures also help prevent swine flu (H1N1 flu) and limit its spread:

• Stay home if you're sick. If you do have swine flu (H1N1 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.

• Contain your coughs and sneezes. Cover your mouth and nose when you sneeze or cough. To avoid contaminating your hands, cough or sneeze into a tissue or the inner crook of your elbow.

• Avoid contact. Stay away from crowds if possible. And if you're at high risk of complications from the flu — for example, you're younger than 5 or you're 65 or older, you're pregnant, or you have a chronic medical condition such as asthma — consider avoiding swine barns at seasonal fairs and elsewhere.

• Reduce exposure within your household. If a member of your household has swine flu, designate only one household member to be responsible for the ill person's personal care.