Paradigm Shift Intervention Monitoring
twitter
Live feed of underlying pandemic map data here
Commentary
Tamiflu Resistance
Spike in US Raises Transparency Concerns
Recombinomics
Commentary 01:20
December 14, 2009
The above paragraph from the week's CDC report (week 48) announces three more cases of Tamiflu resistance in the US. This number matches the increases for each of the past 3 weeks and brings the total for the past 4 weeks to 16, which is much higher than previous weeks, which usually had 0 or 1 new cases. This recent spike in cases has also been reported by WHO and raises concerns that H274Y is efficiently transmitting. Moreover, recent deaths of patients with H274Y in the US (four of ten) and the Netherlands (four of eleven) have raised concerns that patients with H274Y also have D225G, which has been associated with fatal cases in the US, Ukraine, Norway, Brazil, and France. Moreover, patients with D225G coupled with H274Y have been reported in France and the United States.
However, the CDC report does address those concerns because critical data has been withheld. In week 48 the number of samples tested for H274Y spiked higher, but there is no indication of these are recent samples or an update of surveillance done on samples collected in the spring or summer. Similarly, the location of these cases or outcomes are not given, and there is no indication that patients who developed resistance during treatment are distinguished from patients who were resistant prior to treatment, but fell into the "suspect" category because they failed to respond to Tamiflu.
The Vietnam cluster described in this week's New England Journal of Medicine that would represent such cases. Seven passengers on a train developed H1N1 infections that had H274Y. However, like most patients worldwide, the resistance was not discovered until long after treatment and discharge. The infections were in July, but the first lab confirmations were in September. Although Tamiflu treatment is not effective against H1N1 with H274Y, all patients recovered, but clearly represented infections of a fit and readily transmissible H1N1 with h274Y.
However, using the CDC classification system, these patients would have "documented exposure to Tamiflu" but would not be examples of resistance that developed due to treatment.
Although this is the CDC's largest category, they have yet to show a single example of a case that developed resistance after prolog treatment with Tamiflu. They have described two immuno-compromised patients in Seattle who initially tested as wild type and became H274Y positive during treatment, but one developed resistance between day 4 and 11 of treatment, while the second became positive between days 1 and 18. Results on samples collected on days 3 and 6 were not disclosed, leving open the possibility that resistance was present on day 2 of treatment, supporting the transmission of a significant sub-population, which is easily detected after a few days of Tamiflu treatment. This was seen in the first H274Y patient in Singapore, whi converted to H274Y positive after two days of treatment, as well as prophylactic patients who developed symptoms 5-6 days after the start of treatment.
The failure of the CDC to report any patients who developed H274Y after prolonged treatment, and the efficient transmission of H274Y in Vietnam in July, raise concerns that the weekly reports by the CDC are carefully designed to withhold key information such as the H274Y status prior to treatment, the dates and locations of samples, as well as outcomes of patients who are H274Y positive.
This lack of transparency continues to be hazardous to the world's health.
Media Links
Recombinomics
Presentations
Recombinomics
Publications
Recombinomics
Paper
at Nature Precedings