27 January 2005: Avian influenza in Viet Nam - update

The Ministry of Health in Viet Nam have confirmed two further cases of human infection with H5N1 avian influenza.

The first is a 35 year old woman from the southern province of Dong Thap; the second is a 17 year old boy from Bac Lieu province, also in southern Viet Nam. Both patients have died.

In addition, the World Health Organization is assisting in investigations into a family cluster in northern Viet Nam. Avian influenza H5 virus subtype has been laboratory confirmed in two brothers from Thai Binh province. One of the brothers died in hospital on 9 January, the other is currently recovering. A third brother was hospitalised for observation and remains well.

Health authorities in Viet Nam are investigating the source of infection as the recovering brother is known to have provided care to his sick sibling. This raises the possibility of direct human-to-human transmission. However, it is also possible that transmission occurred through exposure to poultry during a family meal that contained raw duck blood and organs. Limited, un-sustained human-to-human transmission has been known to occur in previous outbreaks of human avian influenza (NaTHNaC clinical update 29 September 2004) (1).

These new cases bring the total number of human cases in Viet Nam since December 2004 to 10, nine of whom have died.

Most human cases of avian influenza have been linked to contact with dead or diseased birds. Evidence suggests that slaughtering, defeathering and preparation of poultry for cooking is particularly risky. Proper cooking destroys the H5N1 virus.

There continue to be no travel restrictions to Viet Nam. The risk to travellers of acquiring avian influenza remains low.

Travellers are reminded of the following precautions:

• Avoid visiting live animal markets and poultry farms
• Avoid contact with surfaces contaminated with animal faeces
• Do not eat or handle undercooked or raw poultry, egg and duck dishes
• Do not attempt to bring any live poultry products back to the UK

Reference

1. Ungchusak K, Auewarakul P, Dowell SF, et al. Probable person-to-person transmission of avian influenza A (H5N1). N Engl J Med 2005;352:333-340

Links

World Health Organization Avian influenza - situation in Viet Nam - update 6

World Health Organization Avian influenza - situation in Viet Nam - update 5

World Health Organization Avian influenza: food safety issues