In many patients, the disease caused by H5N1 may follow an unusually aggressive clinical course, with rapid deterioration and high fatality.
The incubation period is around 2-8 days and possibly as long as 17 days.
Diarrhoea, vomiting and abdominal pain have been reported as early symptoms.
Almost all reported patients develop pneumonia.
To update clinicians on the epidemiology and clinical manifestations, including complications, of avian influenza.
To update on the options for treatment.
Summary To date, all outbreaks of the highly pathogenic form of avian influenza have been caused by viruses of the H5 and H7 subtypes. The virus can improve its transmissibility among humans via reassortment, in which genetic material is exchanged between humans and avian virus during coinfection of a human and a pig. It can also go through a more gradual process of adaptive mutation during subsequent infections of humans. All evidence to date indicates that close contact with dead birds is the principal source of human infection with the H5N1 virus.
Limited evidence suggests that some antiviral drugs, notably oseltamivir, can reduce the duration of viral replication and improve prospects of survival, provided that they are administered within 48 hours, ideally 12 hours, following symptoms onset. This review aims to give an overview of this topical and interesting issue.
- ©ERS 2006
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