Here's what you need to know about the transmission and prevention of swine flu.
Transmission and infection
Swine flu is mainly spread via respiratory droplet transmission. Infection occurs when you inhale droplets when an infected person coughs or sneezes. You can also become infected if you have contact with a surface such as doorknobs and even hands that are contaminated with the virus and then touch your mouth, nose or eyes.
According to studies the virus can survive on surfaces and be transmitted by hand contact, so regular hand washing and personal hygiene is an important step in preventing infection.
How H1N1 affects the body is not fully known at present. "In analogy to other influenza strains that affect humans, it will infect cells of the respiratory tract, causing inflammation, fever and an immune reaction," says Professor Wolfgang Preiser, Head of Medical Virology Department of Pathology at Stellenbosch University.
"The symptoms are the same as for seasonal flu: rapid onset fever, malaise, coughing and/or sneezing. You will not be able to distinguish infection with the novel of pandemic influenza A/H1N1 from infection with a seasonal influenza virus strain (mostly A/H3N2 so far during the season with a bit of influenza B Viruses) on clinical grounds alone."
Preiser says the incubation period is short (as short as two and up to a few days at most), and the duration of the symptoms in uncomplicated cases should be around one week.
Who is most at risk?
The NICD advises that unless patients have underlying conditions that could cause complications, swine flu should be treated like a common cold.
"We are fast moving into a situation where we will no longer want to know about each and every case. In other words, no need any more to test all suspect cases, but surveillance (as co-ordinated by NICD) will focus on cases of severe illness and on unusual outbreaks," says Preiser.
People already managing illnesses such as diabetes, emphysema, chronic bronchitis, HIV/Aids, people over 65 and pregnant women should seek medical advice if symptoms which are the same as cold or flu persist.
Symptoms such as persistent vomiting, shortness of breath and chest pains require medical attention.
"One should seek medical advice if the clinical disease becomes more severe than 'ordinary' flu; it could be, for example, bacterial super-infection which must be treated with antibiotics, or it could be (in rare cases only, we believe) a severe course of influenza which may need to be treated with antivirals. In these cases one can test for the novel strain by doing specific PCR tests that are available at different laboratories around the country," says Preiser.
Because flu spreads very easily prevention may be difficult.
"Stay away (if possible) from people who are sick with a flu-like illness, ask them to cover their faces when sneezing or coughing (with a tissue of the sleeve, not their hands unless they wash them afterwards), and wash your own hands regularly before touching your face, eyes, eating and applying cosmetics," advises Preiser.
When providing care to a household member who is sick with influenza, the NICD advises the following:
- Keep the sick person away from other people as much as possible
- Remind the sick person to cover their coughs, and clean their hands with soap and water or an alcohol-based handwash often, especially after coughing and/or sneezing
- Have everyone in the household clean their hands often using soap and water or an alcohol-based handwash
- Household contacts of the sick person who may have chronic health conditions should take antiviral medications to attempt to prevent being infected
(Leandra Engelbrecht, Health24, July 2009)
- Professor Wolfgang Preiser, Head of Medical Virology Department of Pathology at Stellenbosch University
- National Institute for Communicable Diseases
- World Health Organisation
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