H1N1 virus

What is Influenza A/H1N1 (swine flu)?

Influenza A/H1N1 is a new influenza virus infecting humans. It was first detected in humans in the United States of America (USA) in April 2009, but was probably causing infections in Mexico for a period before this. Initially, this new virus was thought to be a type of flu virus that infects pigs and sometimes spreads to humans (hence the initial name of 'swine flu'). However, further studies have revealed that it is not a virus that came directly from pigs, but rather a new virus formed by the recombination of several different genetic elements from pigs, avian and human species.

Why is there a risk of a pandemic from this virus?

An influenza pandemic occurs when a new flu virus emerges to which the majority of humans are non-immune, and which can spread efficiently and sustainably amongst humans. Thus far, the H1N1 virus appears to meet these criteria and has already affected a large number of countries across the globe. It has therefore been essential to activate global responses.

How do people become infected with swine flu?

Available information on swine flu suggests that it spreads from person to person, much like 'seasonal influenza' (i.e. the common ‘flu'), which is mainly spread via respiratory droplets. Individuals are infected when they breathe in droplets that are released into the air when an infected person coughs or sneezes. Infection can also result if a person is in contact with inanimate surfaces (e.g. door knobs or hands) that are contaminated with the virus, and then touches his/her mouth, nose or eyes.

How long can an infected person spread the virus to others?

It is believed that the swine flu virus has the same properties in terms of spread as seasonal flu viruses. With seasonal flu, studies have shown that people may be contagious from one day before they develop symptoms, to seven days after they become ill. Children, especially younger children, may potentially be contagious for longer periods. It is therefore important for people who have flu-like symptoms to stay at home for at least seven days, to reduce spread to other people.

What kills the influenza virus?

The influenza virus is destroyed by heat (75-100°C), various chemicals, alcohol-containing cleansers and antiseptics.

How long can the influenza virus remain viable on objects (e.g. books and door knobs)?

Studies have shown that the influenza virus can survive on environmental surfaces and can infect a person for up to two to eight hours after being deposited on the surface.

Can I become infected with swine flu from eating or preparing pork?

No. Swine flu has not been shown to be transmissible to people through eating properly handled and prepared pork (or other products derived from pigs).

Should I be alarmed about the increase in cases of swine flu in South Africa?

Experience in other affected countries indicates that the H1N1 virus spreads rapidly through communities. It is not possible to contain this virus by quarantine of contacts and travel restrictions. Social distancing of affected persons (usually by home isolation) may, to some extent, reduce spread, but the spread of swine flu is inevitable. What is most important is to reduce potential complications of the condition by focusing on diagnosis and treatment of persons with severe illness, and those at risk for complications.

What should I do if I fall ill?

If you live in an area where there are confirmed cases of swine flu and you develop flu-like symptoms including fever, body aches, runny or stuffy nose, sore throat, nausea, vomiting or diarrhoea, you should stay home and avoid contact with other people. This means that you should not leave your home, except to seek medical care and avoid normal activities including work, school, travel, shopping, social events and public gatherings.

If you have severe illness or are at high risk for flu complications, contact your healthcare provider or seek medical care. Your healthcare provider will determine whether flu testing or treatment is needed.

If you become ill and experience any of the following warning signs, seek emergency medical care.

In children, emergency warning signs that need urgent medical attention include:

• fast breathing or trouble breathing
• bluish or grey skin color
• not drinking enough fluids
• severe or persistent vomiting
• not waking up or not interacting
• being so irritable that the child does not want to be held
• flu-like symptoms improve, but then return with fever and worse cough.

In adults, emergency warning signs that need urgent medical attention include:

• difficulty breathing or shortness of breath
• pain or pressure in the chest or abdomen
• sudden dizziness
• confusion
• severe or persistent vomiting
• flu-like symptoms improve, but then return with fever and worse cough.

Who is at high risk of severe illness?

Complications of seasonal flu occur more commonly in persons of 65 years and older, children younger than five years, pregnant women and people of any age with certain chronic medical conditions that increase the risk of flu-related complications (such as asthma and diabetes), as well as any other immuno-suppressive condition. While the overwhelming majority of swine flu patients have experienced mild symptoms, there have been a number of deaths reported to date. Some of these deaths were persons with underlying chronic illnesses or pregnant women, while others were young persons who were otherwise healthy. This is a typical feature of new pandemic virus strains. It is unknown how this virus will affect persons who are immuno-suppressed due to the presence of HIV infection.

Adults older than 60 years may have antibodies against this virus due to previous exposure to a similar strain.

Are swine flu tests available in South Africa?

Yes. The National Influenza Centre at the National Health Laboratory service at the National Institute for Communicable Diseases and Virology Laboratory at University of Stellenbosch are currently providing testing for the virus where indicated. It is likely that additional laboratories will be providing testing in the coming weeks. Private pathologists also do sampling and reporting.

Who should be tested for swine flu?

At present, suspected cases of swine flu will be tested. A suspected case is currently defined as follows:

An individual with recent onset of influenza-like illness, i.e. fever of 38°C plus one or more of the following acute respiratory symptoms: sore throat, runny nose/nasal congestion, cough or muscle pains and gives one of the following histories:

• Travel within seven days prior to onset of symptoms to countries with confirmed community-wide outbreaks.
• Close contact with an individual who is a suspected/confirmed case of swine flu in the seven days prior to onset of symptoms, i.e. having cared for, lived in the same household or had direct contact within two metres of a suspected or confirmed case of swine flu.

There is no indication to test healthy contacts of confirmed cases, unless they develop symptoms. As the numbers of suspected cases increase and community transmission is identified, the testing strategy will change to focus on confirming illness in patients with moderate or severe disease, and there will not be routine testing of persons with mild flu-like conditions. A number of existing monitoring systems for seasonal flu will rather be used for monitoring the general trend of the swine flu outbreak.

Is there any effective treatment for swine flu?

Currently, this pandemic is of moderate severity globally. The majority of patients experience mild symptoms and make a rapid and full recovery, often in the absence of any form of medical treatment.

Oseltamivir (Tamiflu®) is the medication currently recommended in South Africa. It is recommended that treatment be given only to suspected and confirmed cases showing severe symptoms, as well as those at high risk of severe illness.

If I have a family member at home who is ill with swine flu, should I go to work?

Employees who are healthy but who have a family member at home with swine flu can go to work as usual. These employees should monitor their health everyday and take precautions, including washing their hands often with soap and water, especially after they cough or sneeze. Alcohol-based hand cleansers are also effective. If they become ill, they should notify their supervisor and stay home. Employees who have an underlying medical condition or who are pregnant should call their healthcare provider for advice, as they may need to receive influenza antiviral drugs to prevent illness.

Steps to minimise the spread of flu in the home

When providing care to a household member who is ill with flu, the most important ways to protect yourself and others who are not ill are to:

• keep the patient away from other people as much as possible
• remind the patient to cover his/her nose and mouth when coughing, and clean his/her hands with soap and water or an alcohol-based hand cleanser often, especially after coughing and/or sneezing
• have everyone in the household clean their hands often, using soap and water or an alcohol-based hand cleanser
• household contacts of the patient who may have chronic health conditions should take antiviral medication such as oseltamivir (Tamiflu®) in an attempt to prevent the flu.

What can I do to protect myself from becoming ill?

There is no vaccine available right now to protect against swine flu. There are, however, everyday actions that may help prevent the spread of germs that cause respiratory illnesses like influenza. These include:

• Covering the nose and mouth with a tissue when coughing or sneezing. Throw the tissue in the bin after use.
• Washing your hands often with soap and water, especially after coughing or sneezing. Alcohol-based hand cleansers are also effective.
• Avoiding touching the eyes, nose or mouth, as germs spread this way.
• Avoiding close contact with ill people. Keep a distance of at least two metres from people with respiratory symptoms.
• Staying home if you are ill for seven days after your symptoms begin, or until you have been symptom-free for 24 hours, whichever period is longer. This is to keep from infecting others and spreading the virus further.

Are there vaccines against the H1N1 virus?

There is currently no vaccine against this new virus.

Does the current common flu vaccine protect against swine flu?

Available data suggests that there will be little or no protection offered by the common flu vaccine against swine flu.