Tuesday, April 28, 2009

It takes a worried man...

To sing a worried song.  And we have lots of worried folks singing right now.  To be of minimal help, I've tried to round up some good, on-going sites that can address your swine-flu worries.

For example, this science blog by public health officials.
The other sense of news is about the current situation. The growing list of US states, and now countries, is relevant to understanding where we are at the moment. Similarly, the growing list of suspected cases will grow, probably very quickly. You should expect it. Those of you follow the H5N1 ("bird flu") story will recognize what is happening here. Flu of any kind has very non specific symptoms (cough, sore throat, fever, etc.) that are caused by numerous respiratory viruses (adenovirus, metapneumovirus, respiratory syncytial virus, parainfluenza, influenza B, etc). They are all circulating at this time of year. Some of them can cause severe disease, although mostly they just produce "spring" (or "summer") colds or flu (most of which isn't flu in the strict sense). In the context of this outbreak each of these respiratory virus cases has the potential to become a "suspect" case. Mexico City has 1614 "cases" and 103 deaths. Not all, or even most, of the cases have been confirmed by laboratory. They are really suspect cases. Some have been confirmed, most not. Confused? Expect that, too. In the opening days and weeks of an outbreak, everyone is confused. That's why we pool our information and try to sort it out. [More]
To keep an eye on where swine flu is occurring and get an epidemiologist's view, here's another good source.

For those of you looking to follow new cases (most of them suspected at this point, not confirmed), a great resource is HealthMap. Reports are popping up of possible infections worldwide: Scotland, Spain, Australia, and New Zealand. Certainly additional possible cases will be showing up over the coming days as well.
One thing I've seen mentioned (including here in the comments) is a question about the unlikelihood of a flu outbreak in Mexico in late April. Isn't influenza a cold-weather bug? Well, yes and no. Influenza circulates year-round at a low level, but it lasts longer in the environment in colder temperatures with lower humidity, meaning more people can potentially be infected by each infected person, leading to our seasonal outbreaks. However, recall that in 1918 the first cases began in winter/spring 1918, and then it came back with a vengeance beginning in August, and really taking off by October. Additionally, we essentially have no barriers to worldwide spread, and there are already potential cases in New Zealand and Australia (where winter is setting in). [More]

She refers to the low-humidy/virus connection.  I remember something about this from this winter, when I came down with the worst case I have ever had.  It seems viruses in higher humidity are attracted to water vapor molecules which weighs them down and they hit the dirt, so to speak.  In winter, the story is different.
In this new study, the Oregon team re-analyzed data from a 2007 Mount Sinai School of Medicine study that identified a weak relationship between flu transmission and relative humidity. The re-analysis revealed a strong link between absolute humidity and flu virus survival and transmission.
"The correlations were surprisingly strong. When absolute humidity is low, influenza virus survival is prolonged, and transmission rates go up," study author Jeffrey Shaman, an atmospheric scientist at OSU who specializes in ties between climate and disease transmission, said in the news release.
Shaman and colleague Melvin Kohn, an epidemiologist with the Oregon Department of Health Services, concluded that relative humidity explains only about 36 percent of flu virus survival and 12 percent of transmission, while absolute humidity explains 90 percent of flu virus survival and 50 percent of transmission. [More]

So given that we're soaking wet here - and totally unable to plant - that should be good news.

I guess.


Anonymous said...

North - american human influenza is proper name for swine flu--John will e-mail you on it as i can't cut-paste--regards-kevin

Ol James said...

I knew that this high humidity was good for something besides making you sweat like a _____<(insert example here).
For some reason when I saw the Sec. of Homeland Security and Sec. of Ag on TV today I got a flashback, of sorts. I remembered the scene in "Animal House" when the crowd at the parade was running. I saw Kevin Bacon's character screaming,"... Remain Calm!!! All is Well!!!"...
They call it something like- H1-N1 ??

Anonymous said...

Now... will the USDA & executive branch use the swine flu outbreak to advance government agendas i.e. manadatory animal ID and national healthcare ?