Fatal H5N1 Encephalitis Cluster Raises Concern

Fatal H5N1 Encephalitis Cluster Raises Concern

January 9, 2014
http://www.recombinomics.com/News/01091401/H5N1_Enceph_Cluster.html

There was no cough or other signs of respiratory illness, which is usually the case with influenza, but not always with H5N1. Dr. Talbot said the patient died of meningoencephalitis, or swelling of the brain.

These cases have important clinical, scientific, and public health implications. In both cases, the clinical presentation led to diagnoses of gastrointestinal infection and acute encephalitis, which alone or in combination are common clinical syndromes in southern Vietnam.

Patient 1 had no respiratory symptoms and a normal chest radiograph less than 24 hours before she died. Although Patient 2 showed signs of pneumonia during the last day of his life, a respiratory illness was not considered his most relevant clinical problem.

The above comments (in red) describe the first exported H5N1 case reported to date. The Canadian developed symptoms during a flight from Beijing to Vancouver and was subsequently hospitalized in Edmonton, where she died, after presenting as indicated above.

The above comments (in blue) are from a New England Journal of Medicine paper describing a cluster in Vietnam involving siblings who both developed encephalitis. These two fatal H5N1cases raised concerns that similar cases would go unnoticed because of a focus on cases with respiratory symptoms.

The 2014 case raises similar concerns because China did not report any H5N1 cases in northern China in 2013. Enhance surveillance for H7N9 in China and Taiwan led to the first human case of H6N1, the first fatal case of H10N8, and the detection of an H9N2 case, which is also rare. The failure to detect any H5N1 cases during this surveillance raises concerns that H5N1 is presenting with symptoms similar to the three H5N1 cases described above, and such cases are common, based on the export of H5N1 from China to Canada.

Leave a Reply