19 March 2008

Influenza in Hong Kong, China

Since mid-February 2008 Hong Kong has been experiencing its annual influenza season with influenza strains that are being seen in other areas of the northern hemisphere: influenza A/H3N2, A/H1N1 and B  [1].

Outbreaks of influenza have been reported in schools and community settings, and several people including young children have been admitted to hospital. Three children are reported to have died from influenza-like illness. Two of these cases have been confirmed, one as influenza A/H1N1 and one as A/H3N2. In all three cases avian influenza A/H5N1 and SARS have been excluded.

As a result of outbreaks in schools, Hong Kong authorities have brought forward the Easter closure of all primary schools. The influenza season is expected to last until April.

Seasonal influenza

Influenza is a respiratory illness transmitted via droplet infection or direct contact with respiratory secretions from infected persons. Symptoms include fever, cough, headache and aching joints.

In the northern hemisphere, influenza occurs most often in winter and peaks between December and March. In Hong Kong, influenza is more common between January and March, and during July to August each year [2].

Influenza can have serious complications especially in older persons and those with pre-existing medical conditions. Given the current seasonal influenza activity in Hong Kong, occasional deaths from the illness are to be expected.

Advice for travellers

There are no travel restrictions to Hong Kong, or mainland China.

Travellers should try to avoid crowded conditions as possible and maintain personal hygiene including frequent hand washing.

Certain groups are at particular risk of complications from influenza including those aged 65 years and over, and persons with pre-existing medical conditions such as chest, heart, liver or kidney conditions, a history of splenectomy, or diabetes [3].

Travellers who fall into any of the higher risk categories above should ensure that they have received their annual influenza vaccine.

Returning travellers who become unwell with fever, cough or difficulty in breathing should consult their health care provider, or call NHS Direct on 0845 46 47.

References

1. European Centre for Disease Control and Prevention. Influenza situation in Hong Kong, China. 14 March 2008. [Accessed 19 March 2008]. Available at: http://ecdc.europa.eu/pdf/ECDC_threat_assessment.pdf

2. Hong Kong Centre for Health Protection. Health risks of season influenza, avian influenza, influenza pandemic. November 2005. [Accessed 19March 2008]. Available at: http://www.chp.gov.hk/files/pdf/FluX3_E.pdf

3. Salisbury D, Ramsay M, Noakes K (eds). Immunisation against infectious disease. 2006; Department of Health, London. Available at: http://www.dh.gov.uk/en/Policyandguidance/Healthandsocial

caretopics/Greenbook/DH_4097254

Links and further information

European Centre for Disease Control and Prevention

Hong Kong Centre for Health Protection influenza page

Health Protection Agency seasonal influenza page