About swine flu

A/H1N1 influenza is a new human virus resulting of a gene combination of different origins: they come partly from porcine viruses, a bird flu and a human virus. This virus was detected in Mexico at the end of March 2009. The first analyzes show a link with viruses which arise in the pigs in North America and Europe/Asia.

The symptoms are usually similar to the symptoms of the seasonal flu, i.e. a sudden rise of body temperature, muscular pain, tiredness and respiratory symptoms, possibly with diarrhea and general discomfort.

The incubation period (time which runs out between the contamination and the appearance of the primary symptoms) covers from 2 to 7 days after the contamination, up to 10 days maximum.

Within the framework of the current epidemic, the transmission is similar to that of a seasonal flu:

• by air, i.e. the dissemination in the air of the virus via cough, sneeze or spluttering

• by close contact with an infected person (when kissing or shaking hands e.g.)

• by contact with objects contaminated by a sick person (a door handle e.g.).

Most viruses are likely to react to the new antiviral drugs (oseltamivir and zanamivir) and to the older antiviral drugs (amantadanes). Virus A/H1N1 is sensitive to recent antiviral but resists the amantadanes of the old generation.

How are people contaminated by the virus H1N1 treated?

In Belgium, the doctor does not take samples among patients presenting of the flu symptoms. Previously, these samples were analyzed by the laboratory of the Scientific Institute of Public health (ISP) in order to confirm that a patient was affected by influenza A/H1N1. Currently, the general practitionner looks after his patients on a case-by-case basis, according to the symptoms and according to the ordinary treatments for the seasonal flu.

The patients belonging to a group at risk are followed carefully. This concerns the following people: 

• patients with a chronic disease of the respiratory system including those who have received drugs against asthma during the 3 past years

• patients with a chronic cardiac pathology

• patients with renal or hepatic moderate to severe insufficiency

• patients with immunosuppression further to a disease or a treatment

• patients with diabetes

• pregnant women

• people older than 65 years

• children younger than 5 years

• patients hospitalized

There is currently no vaccine on sale to protect against influenza A/H1N1. The various producers are currently manufacturing vaccines but some time is still required before the quantities necessary are available.

It is advised to people intending to travel in the countries affected by influenza A/H1N1 to consult the web site of the World Health Organisation (WHO), the web site of the SPF foreign affairs (www.diplomatie.be) or the web site of the SPF public health (www.health.fgov.be). It is advised to all travellers to follow measures of general hygiene. One should avoid contacts with potential patients who could transmit the influenza. The preventive intake of antiviral drugs is not recommended.

The World Health Organization (WHO) has defined a six-phased alert plan in pandemia, allowing all countries to detect and check quickly the threats which diseases with epidemic tendency and emergent diseases represent, in order to bring an appropriate response enabling to reduce the effects on public health and on the worldwide economy.

In nature, influenza viruses circulate continuously among animals, especially birds. Even though such viruses might theoretically develop into pandemic viruses, in Phase 1 no viruses circulating among animals have been reported to cause infections in humans.

In Phase 2 an animal influenza virus circulating among domesticated or wild animals is known to have caused infection in humans, and is therefore considered a potential pandemic threat.

In Phase 3, an animal or human-animal influenza reassortant virus has caused sporadic cases or small clusters of disease in people, but has not resulted in human-to-human transmission sufficient to sustain community-level outbreaks. Limited human-to-human transmission may occur under some circumstances, for example, when there is close contact between an infected person and an unprotected caregiver. However, limited transmission under such restricted circumstances does not indicate that the virus has gained the level of transmissibility among humans necessary to cause a pandemic.

Phase 4 is characterized by verified human-to-human transmission of an animal or human-animal influenza reassortant virus able to cause “community-level outbreaks.” The ability to cause sustained disease outbreaks in a community marks a significant upwards shift in the risk for a pandemic. Any country that suspects or has verified such an event should urgently consult with WHO so that the situation can be jointly assessed and a decision made by the affected country if implementation of a rapid pandemic containment operation is warranted. Phase 4 indicates a significant increase in risk of a pandemic but does not necessarily mean that a pandemic is a forgone conclusion.

Phase 5 is characterized by human-to-human spread of the virus into at least two countries in one WHO region. While most countries will not be affected at this stage, the declaration of Phase 5 is a strong signal that a pandemic is imminent and that the time to finalize the organization, communication, and implementation of the planned mitigation measures is short.

Phase 6, the pandemic phase, is characterized by community level outbreaks in at least one other country in a different WHO region in addition to the criteria defined in Phase 5. Designation of this phase will indicate that a global pandemic is under way.

Attention: the WHO alert plan is global. The move into phase 6 does not necessarily have a consequence on the situation in Belgium. Since phase 6 was declared - on June 11th, 2009 - the daily life in Belgium has not been affected.

If you want to know more on A/H1N1 flu in our country, we advise you the site set up by the "Commissariat Interministériel Influenza": www.influenza.be.

Other important links:

Technical information for specific target groups: site of the SPF Health, Safety of the Food chain and Environment: www.health.fgov.be

Flu monitoring: technical information on the seasonal flu and influenza A/H1N1: site of the Scientific Institute of Public health, National Center of the Influenza: www.iph.fgov.be/flu-surveillance 

Site of the Head office of Health of the French Community: www.sante.cfwb.be (heading “actualités”)

Portal der Deutschsprachigen Gemeinschaft Belgiens: www.dglive.be

Site of the European Center for Disease Prevention and Control. It is an EU agency with aim to strengthen Europe's defences against infectious diseases such as influenza: http://ecdc.europa.eu/

Site of the World Health Organization, including a follow-up of influenza H1N1 to the international level: www.who.in

Specific instructions for travellers: www.diplomatie.be.