Bird flu: Treating early, treating late, but treating

New scientific information travels in various ways. The internet is the lastest. Sometimes it's the quickest, too, but often the old ways also work. The oldest method of communication between scientists used to be correspondence. Leibniz was famous for his extensive letter writing to other scientists during the scientific revolution of the 18th century. Even before the appearance of scientific journals, there were local or regional meetings, where scientist would gather periodically and exchange ideas and information through presentations, debate and discussion. These meetings are still important venues for information exchange (in fact, I'm at one now). Often it is informal exchanges over coffee or in the corridor that are the most interesting.

We posted today on new information on which end of the bird to sample for H5N1 virus, information presented and discussed at a gathering of scientists on H5N2 now going on in Singapore. Here is another report from the same meeting gathered by the Reuters reporter Tan Ee Lyn, "from the sidelines." It is another case of this virus behaving differently than the human seasonal flu virus we are most familiar with, but in this case the differences might be in our favor:

An expert who treated numerous bird flu victims in Vietnam has urged doctors not to lose hope with patients who are admitted late to hospital as there is still a good chance that they can survive.

The medical community believes anti-virals such as Tamiflu are only effective in fighting the H5N1 bird flu virus if they are administered within 48 hours of the onset of symptoms. But virologist Menno de Jong said this assumption might only hold true for human flu viruses.

H5N1 behaves differently from human flu viruses and has been observed to be replicating in its human hosts even on the seventh or eighth day, he said.

"In my experience, there is a clear suggestion that there was still virus replication (when we made) a late start in treatment. In four of my patients, there was very rapid clearance of the virus from the throat and all 4 survived," he told Reuters on the sidelines of a conference on avian flu and other infectious diseases in Singapore. (Reuters)

In De Jong's view is that decreasing the viral load with drugs (where? in the respiratory tract?) can lead to a good outcome. In his experience this can still be done after the 48 hour window has closed if the virus is still replicating, although clearly treatment should be initiated at the earliest possible time.

He is reported to have said that early treatment may not only prevent tissue damage from replicating virus, however, but also the "cytokine storm" that is the hallmark of many of the most virulent and rapidly fatal infections. I'm not sure what the evidence for this is, however. Cytokine storm is often portrayed as an over active immune system that has run out of control in fighting the infection. I think it is also possible it is a causal effect of the virus, one of the many ways the it creates havoc by subverting the body's defense mechanisms to improve its own reproducibility. This effect may be the result of some sub-strains or variants that carry mutations on internal genes that have yet to be examined in this regard.

In any event, you don't treat people with influenza antivirals if you don't know they have influenza, so developing a quick test that can be deployed in rural areas has become a priority.

"If the community has a small lab or regional hospital, probably these patients would have been diagnosed earlier and treatment would have been given early," he said.

There is a lot of work being done in this area now. Let's hope some of it can come online quickly. We don't know if a pandemic will happen this year, next year or never, but developing cheap, reliable and easy to use means to diagnose subtypes of influenza A in the field will be valuable no matter what happens and in many places besides the rural areas of Indonesia or Vietnam.