Neurotropic Bird Flu Kills Two Children in Vietnam
Recombinomics Commentary
February 16, 2005
>> We report a fatal case of influenza A (H5N1) in a child who presented with severe diarrhea, followed by convulsions and coma, and who received a diagnosis of acute encephalitis. The diagnosis of influenza H5N1 was established by isolating the virus from stored cerebrospinal fluid, serum, throat, and rectal specimens. <<
The death of two children in Vietnam in February of 2004 by a neurotropic H5N1 should not be a surprise. Neurological complications in the 1918 pandemic are well known. The first human influenza virus isolated in 1933 (WS/33) was passaged through mice to isolated WSN/33 in 1940 to study neurological problems associated with pandemic influenza.
H5N1 is known to have a broad tissue tropism and as been isolated from mouse brains. Moreover, the 2004 isolate from Vietnam that is being used to create a pandemic vaccine causes hind leg paralysis in ferrets.
This year there were reports of chickens with neurological problems in Thailand as well as ducks in Vietnam.
However, the deaths of 2 children in Vietnam who did not develop respiratory symptoms, but were positive for H5N1 are cause for concern. These two children from Dong Thap represent the 10th reported H5N1 familial case cluster in Vietnam, Thailand, and Cambodia and all have a bimodal time of disease onset, strongly implicating human to human transmission.
Moreover, there have been outbreaks of neurological diseases such as
meningococcemia and meningitis in the Philippines or the meningitis outbreaks in mainland China.
The 1918 pandemic flu was frequently misdiagnosed as cholera, dengue fever, and typhoid, diseases which are common in eastern and southeast Asia. The number of misdiagnosed cases is unknown because of a lack of testing for H5N1.
Monitoring of avian influenza in 2004 and 2005 remains scandalous, as preparedness is inadequate and history appears to be destined to repeat.
Media link