What’s new with the flu?
By Ilene with guest expert Dr. Henry Niman
Tamiflu resistant swine flu virus strains, circulating along with the wild-type (more prevalent, Tamiflu sensitive) viruses, are increasing in numbers, as the pool of viruses continues to expand. This is not due to sporadic point mutations, nor is it to do a nefarious government plot. This is how nature works, and knowledge of viral evolution leads Dr. Niman to predict that the number of Tamiflu-resistant cases will continue to increase.
At the Recombinomics website, today, additional support for Dr. Niman’s theory is presented. Growing numbers in the country of resistant viruses are showing up in clusters, for instance in the Maryland/Virginia area and in Pennsylvania. These clusters of Tamiflu-resistant cases most likely reflect a larger pool of resistant viruses circulating in the U.S. and other countries. "These repeated reports of H274Y [i.e., genetic change causing Tamiflu-resistance] in geographic clusters, as well as transmission clusters, suggest that H274Y has passed a tipping point, and reports of H274Y will increase in the upcoming weeks." H1N1 Tamiflu Resistant Cluster in Pennsylvania,
Separately, the ratio of D225G swine flu virus variant to wild-type variant may also be increasing. As this variant may cause a more severe disease by binding in the lungs, rather than just in the upper airways, this is cause for concern. The more aggressive course of disease apparently occurring in Ukraine may be the result of an increasing ratio of a more virulent D225G virus to the wild-type virus.
Further investigation is needed. Because the wild-type virus binds in the upper respiratory system while the D225G variant binds in the lungs, tissue samples from individual patients should be taken from both regions in order to see more accurately how the virus is evolving.
Here are two of Dr. Niman’s recent updates discussing these developments. For more, visit Dr. Niman at Recombinomics.
H1N1 Tamiflu Resistance Crosses Tipping Point
Recombinomics Commentary 03:07
December 4, 2009
Within the past two weeks, the number of documented cases of oseltamivir resistance in H1N1 viruses has risen from 57 to 96. Around one third of these cases occurred in patients whose immune systems were severely suppressed by haematological malignancy, aggressive chemotherapy for cancer, or post-transplant treatment. The clusters in the two hospital wards should be viewed in the context of these overall trends. Although all incidents of oseltamivir resistance merit investigation, no evidence suggests that events to date constitute a public health threat.
The above comments from the WHO update on transmission of H1N1 with H274Y [genetic change conferring resistance to Tamiflu] in hospitals in Wales and North Carolina, claims no evidence suggests that the sharp spike in cases, or the clear human to human transmission, is a public health threat, but the evidence in the report alone clearly identifies a threat. Moreover, the numbers in the report appear to represent only a subset of associated evidence, which raises concerns that a tipping point has been reached and readily detectable H274Y will be reported in the upcoming weeks, signaling the early stages of fixing H274Y in pandemic H1N1, as happened in seasonal H1N1.
The rapid appearance of H274Y in patients receiving Tamiflu suggested that H274Y was transmitting as a minor species and was largely undetected in untreated cases. However, there was concern that the H274Y level would rise, leading to readily detected transmission. The reports of transmission in clusters of immuno-suppressed patients indicate the concern has been realized, and transmission resembles the early stages of fixing of H274Y in H1N1 seasonal flu…
Thus, the explosion of cases with H274Y is expected to continue to rise and create more problems in the management of patients. H274Y will eliminate Tamiflu and Peramivir and limit anti-virals to Relenza, which will further strain the health care system.
Full article by Dr. Niman here >>.
446 Dead in Ukraine – D225G and Deaths Spread
Recombinomics Commentary 02:20
December 2, 2009
1,937,292 Influenza/ARI
116,982 Hospitalized
446 DeadThe above numbers represent the latest update from the Ukraine Ministry of Health. As the number of cases approach 2 million, the rate of increase has slowed and shifted to the east. The largest daily update was in Donetsk, which rose by 5892 cases to 127,584 (see map). However. Increases in deaths are being report across the eastern border in Russia, were there have been 30 deaths reported in Saratov. Similarly, almost 200 deaths have been reported in Turkey, raising concerns of D225G spread.
The initial data showed strong association of D225G with fatal cases. Of the 9 samples from western Ukraine, all four fatal cases had D225G. In contrast nasal washes from surviving cases were positive for the same sub-clade, but were wild type at position 225, suggesting that infections were mixtures and virus with D225G targeted the lung, while wild type remained in the upper respiratory tract…
The reporting of D225G in all fatal cases in Ukraine should be followed up with additional sequence data on more of the 400+ fatalities…
An increase in the D225G ratio would be cause for concern.
Full article here.>>
