Mild H5N1 In Korea Raises Transparency Issues
Recombinomics Commentary 19:42
April 22, 2008
The confirmation of mild H5N1 in a soldier in South Korea raises serious transparency issues. The concerns in South Korea were increased as government agencies issued statements splitting hairs between H5N1 confirmed and HPAI H5 confirmed poultry outbreaks. HPAI H5 is confirmed with a sequence of the HA cleavage site, which for all practical purposes confirms H5N1. The sequences of the HPAI H5 and H5N1 would be virtually identical removing virtually all doubt that the H5 positive cases are H5N1 positive cases.
Now the government is using the same hair splitting approach to delay confirming that the soldier is H5N1 positive with the same H5N1 detected in the birds being culled. The number of infected farms is approximately 50, indicating the H5N1 is easily passed from farm to farm, and these connections are likely linked to migratory birds (see satellite map). The infection of a soldier/culler, who had PPE’s and prophylactic Tamiflu would once again suggest that transmission to humans was efficient. The status of the other hospitalized patients is unclear, but if they are on Tamiflu, the likelihood that they will test negative is high, because Tamiflu lowers viral load to an undetectable level. Moreover, government comments that bird flu symptoms in an H5N1 infected patient are not due to the H5N1 raises serious credibility issues.
Unfortunately, such issues are not limited to South Korea. Japan has announced the implementation of a pre-pandemic vaccine program, even though they have not reported H5N1 since early 2004. The similarity between the H5N1 in South Korea in 2003/2004 and Japan in 2004 strongly suggests that there was H5N1 in Japan in 2006/2007 and 2007/2008, when South Korea reported large poultry outbreaks. Closely related H5N1 was also found in fecal samples from site frequented by migratory bird, which migrate from H5N1 confirmed areas in Mongolia. Thus, the lack of any H5N1 reports in Japan for this season or last season remains suspect.
The level of suspicion is even higher for India, which has reported its largest outbreak to date in West Bengal and Tripura. In both countries, the initial denials of H5N1 infections and suggestions that the dead birds had died from Newcastle Disease was not credible since the dead birds had been vaccinated against Newcastle Disease and dogs, cats, and jackals died after eating the infected birds. In the outbreaks in West Bengal the deaths of resident and migratory birds in proximity to the H5N1 poultry was noted. However, India has never reported an H5N1 case in anything other than poultry, even though migratory birds that winter in India spend the spring and summer in H5N1 positive nature reserves in China and Mongolia.
Moreover, films of dead birds and villagers in West Bengal left little doubt that there were human H5N1 infections. The villagers had no PPE’s and many had eaten the H5N1 positive birds. When these villagers developed symptoms, they were not tested for H5N1, raising concerns of significant levels of mild infections.
The same situation exists in Bangladesh. Migratory birds also fly into Bangladesh because of the Ganges Delta, which is shared with India. Although Bangladesh has confirmed H5N1 in wild birds falling from trees and populating metropolitan areas, Bangladesh has never reported H5N1 in a migratory bird or human. These detection / reporting issues also raise concerns about Bangladesh.
Similarly, Pakistan has acknowledged human to human transmission of H5N1, but reports were withheld for six weeks and released only after two brothers had died and two other brothers had developed pneumonia over an extended time frame. Initially, only one positive was confirmed by WHO because of sample degradation.
Sequences from earlier outbreaks in South Korea, India, Pakistan, and Afghanistan are all clade 2.2.3. The human cases in Pakistan and South Korea suggest all of these countries have had human cases, although only Pakistan has reported a WHO confirmed case.
The H5N1 outbreaks in the above countries have almost certainly caused human infections that have not been reported or confirmed. Many of these cases may have been mild, which increases the likelihood of transmission to humans and the associated adaptation to humans.
Thus, H5N1 is clearly evolving below the radar in these countries and there is little reason to believe that such mild cases are not widespread as was seen last season in Egypt.
Media Links
Recombinomics Presentations
Recombinomics Publications
Recombinomics Paper at Nature Precedings