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Influenza: H5N1 Updates

I’ve been neglecting influenza recently, and although the media may have lost interest in H5N1, people are still dying (latest data) and the threat of a pandemic has not gone away. So Maria Zambon’s review article in Nature Biotechnology is required reading (Lessons from the 1918 influenza. 2007 Nature Biotechnology 25: 433-434 subscription):

Finding a final common cellular pathway that explains the virulence of different influenza A subtypes in humans will be important for understanding the severity of human or zoonotic infections. Although a unifying hypothesis is some way off, identification of specific host genes switched on early in infection is essential for pinpointing prognostic indicators of disease severity. Immune intervention strategies are badly needed for treatment of zoonotic H5N1 and may ultimately be simpler to apply than antiviral regimes, which are currently the only countermeasure available for severe influenza infections, whether human or animal in origin.

Influenza H5N1 is still centered in the Far East, and so in the absence of an effective vaccine, antiviral drugs such as Tamiflu (Oseltamivir) are the main weapon against the virus. Unfortunately, there are some problems with using Tamiflu, particularly in Asia (Side effects of Tamiflu: clues from an Asian single nucleotide polymorphism. 2007 Cell Research 17: 309–310):

Tamiflu (Oseltamivir phosphate) seems to be a double-edged sword to some in Asia. While it is counted on against influenza and a feared avian influenza pandemic, the drug is also associated with side effects, ranging from neuropsychiatric, gastrointestinal, to hyperthermia and skin problems. According to a document from US Food and Drug Administration in 2005, 1184 cases of side effects have been reported. Interestingly 69 out of the 75 pediatric cases were from Japan, including two teen suicides. The situation seemed to have made a gloomier turn recently. It was reported in February, 2007 that two Japanese teenagers jumped from apartment buildings after taking Tamiflu and died, bringing the total number of deaths after taking Tamiflu in Japan to 54. Although no direct causal relationship had been established yet, the Japan Health Ministry warned doctors about giving the drug to teenagers. In comparison, relatively few cases of severe side effects were reported from America and European countries.

Are interactions with a single nucleotide polymorphism (SNP) in human cytosolic sialidase (HsNEU2) which occurs in 9.2% of Asian populations and, in striking contrast, not in Europeans and African Americans, responsible? The jury is still out at present…
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This entry was posted on Wednesday, June 6th, 2007 at 7:22 am and is filed under Biology, Health, Influenza, Medicine, Microbiology, Science, Virology. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

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