Commentary
H1N1 Tamiflu Resistance At 100% in Honduras and Guatemala?
Recombinomics Commentary 20:47
August 31, 2008
With respect to neumonía, Sanchez needed that 260 people died in which goes of the year, among them 127 smaller children of five years and 96 greater adults of 50, the most vulnerable groups to the respiratory affections. Between the diseases that have begun to appear in the last months it appears influenza type AH1 N1, that causes high fevers, cough, muscular pains and in some cases diarrea pictures, it explained.
The above translation describes recent deaths Nicaragua, that were linked to H1N1 infections. The comments expressed concerns that influenza from Honduras was spreading into Nicaragua.
HA sequences from H1N1 isolates from Honduras and Guatamala were recently released at GenBank as part of a US military (Air Force) surveillance program. These sequences were in addition to a large series released a few months. The H1N1 sequences were collected in 2007/2008 season, and the five recent isolates from Honduras and Guatemala listed below are Brisbane/59 and closely related to each other.
Phylogenetic analysis places these isolates on a branch with H1N1 isolates that have H274Y. Recently sequences from South Africa were released, where the frequency of H274Y in H1N1 cases were at 100%, suggesting the sequences provided a selection advantage. The HA sequences from South Africa fell into two major groups. One had a cluster on newly acquired polymorphisms onto a genetic background that was common among H274Y isolates in the United States. The second group was related bur fell onto a branch with H274Y isolates from France.
The isolates from Honduras and Nicaragua form a new branch from the second branch described above. This new branch also has an isolate from France, which has H274Y, strongly suggesting that there recent isolates from Guatemala (collected in early June) and Honduras (collected in early and late July) also have H274Y, raising concern that the frequency of H274Y in recent isolates in Guatemala and Honduras are also near 100% Tamiflu resistant, which may now also be true for Nicaragua.
The NA sequence from these patients as well as additional isolates would be useful. All recent isolates also have K99N, which was also present in sequences from a Siberian Lake, which were closely related to human H1N1 from the 1930’s.
These data raise concerns that high frequencies of Tamiflu resistance have also come to North America. In South Africa, the first 107 H1N1 sequences this season had H274Y, as did the first 10 sequences from Australia.
A/Guatemala/AF1969/2008 01-Jun-2008
A/Guatemala/AF1995/2008 08-Jun-2008
A/Honduras/AF1968/2008 07-Jul-2008
A/Honduras/AF1994/2008 21-Jul-2008
A/Honduras/AF1993/2008 22-Jul-2008
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