jueves, 9 de julio de 2009

Thoughts about H1N1, cytokine storm and public health decisions

Since the first fatalities related to H1N1 that affected young, healthy people, the cytokine storm theory was raised. And it makes sense. In many cases, after a couple of days, patients would develop severe pneumonia and die in a very short period of time.

The cytokine storm is a over-reaction of the immune system when trying to attack the invader ( in this case, the influenza virus ). The hiper-cytokinemia triggers a positive feedback vicious cycle, releasing a huge amount of pro-inflammatory messengers (Tumor Necrosis Factor - TNF -, and other Interleukins ).

These messengers signal leukocytes ( T-cells, neutrophils... ) to go to the site of infection. Since there is a over-reaction, the white cells action produce damage in the area of action. In the case of the H1N1, in the lung parenchyma.

Now, with several months that H1N1 is among us, and with the experience of the H5N1 (avian flu), in which cytokine storm was the cause of most deaths, my questions are :

- Do we have conclusive evidence (histo-pathological, serum TNF levels, ... ) that confirm a cytokine storm in some of the H1N1 patients ?

- Antivirals : They work by inhibiting the virus replication process, so they don't boost an immune reaction (which is good in this case).

Why don't give antivirals as a prophylactic measure ? This would minimize the initial immune reaction, and thus, prevent or minimize the possibility of the cytokine storm.

We also know that antivirals work best within the first 24 / 48 hours of symptoms. The idea is to avoid pneumonia in the first place. Medicine is about promotion and prevention, so we should avoid at all costs H1N1 complications. What I see is that in many cases, they wait until there is a serious condition related to the flu to start medicating. It just seems too bad-to-late to me...

- Government Improvisations : I feel like there is a lot of improvisation on the way that certain governments are dealing with this issue. In my personal experience, a couple of days ago my daughter got sick, with fever, sore throat and was negative to the strep test (was viral). When I knew that she was negative for strep, I asked for the antivirals and it was denied, since she was not part of the "risk group". This of course is not to blame the doctor, but the health officials.

I'm saying this because the same health officials were giving antivirals to everyone that had flu symptoms and, as a prophylactic measure, to their relatives. That was, in my opinion, the right way to go. Unfortunately, that decision lasted only for two days.

So, I had to spend these last two days in a paranoid state checking on my daughter evolution and hoping that it won't spread to his younger brother.

Why do I have the feeling that high government officials and their kids have the antiviral sitting close to them "just in case"... Anyways... better leave it here...

It would be great if any of you want to make comments or have extra information and shed some light on this subject.

Thanks
Luis Falcon