As an avid reader of DKos, and since my specialty is in molecular virology, I take it upon myself to clarify to this community, which I rely on for astute and accurate political analyses, the details and significance of the current Swine flu scare. Since my mind is daily tuned into the life cycles of various viruses, I am irked when I read diaries that incorrectly describe the molecular events that take place during viral infections The virus in all of us: It's Normal!. Please follow me below the fold so that I can correct the record...
Viruses are complicated. Even considering the high mean IQ of readers of the DKos, there is no possible way all of the details will be understood. My job, as an academic research scientist, should be to perform basic science research, and most importantly, inform the public as to the work their tax dollars are purchasing. This is my humble attempt.
All organisms need to be classified. Large organisms are easy because characteristics are easily observed with our own two eyes. In the case of microbes (bacteria, protazoa, and viruses), classification is dependent on more indirect observations. For instance, different species of bacteria are largely characterized based on their metabolic activities rather than their appearances. Viruses also come in many flavors, and since they are so small, they are described based on their life cycle strategies.
The life cycle of viruses is dependent on the type of nucleic acid they contain. We all know that humans replicate through the transmission of double-stranded deoxyribonucleic acid (DNA). The dogma of molecular biology used to state that double-stranded DNA is transcribed into single-stranded ribonucleic acid (RNA), and then translated into a three-dimensional protein. We now know, thanks to viruses, that this isn't always the case. Instead of replicating through the transmission of double-stranded DNA, as do all 3 domains of life (i.e. eukaryotes, prokaryotes, and archaea), viruses can replicate through single-stranded DNA, double-stranded DNA, single-stranded RNA, double-stranded RNA, hybrid DNA/RNA, incompletely double-stranded DNA, cirucular double-stranded DNA, etc. To make things more complicated, these genomes can also be negative or positive sense which basically means that it is written in English (left to right) or Mandarin Chinese (right to left). I won't go into the molecular details there. I'm sure the list of complexity will grow in the near future as many more virulent/avirulent or disease-causing/not causing viruses are discovered.
In the case of influenza viruses, which are members of the orthomyxovirus (sort of mucous-like virus) family, the virus transmits a multi-partite genome, meaning that it contains multiple strands of nucleic acid. Each of the eight strands are made of negative sense single-stranded RNA which is sometimes called vRNA (v for viral). This vRNA enters into the host cell after the virion binds to the cell surface via interactions between its hemagglutinin protein and a cellular receptor (think lock and key).
Figure 2 General influenza virus life cycle
You can see in the life cycle diagram in Figure 2 how complicated the microscopic virus truly is. While much information is listed in this diagram (of which I am not going to describe in entirety), the majority of the influenza virus life cycle is a scientific "black box". Academic research is occuring around the globe with leaders such as Yoshihiro Kawaoka at the University of Wisconsin/Madison pioneering methods to elucidate the detailed molecular events that occur during an influenza virus infection.
Of course, a detailed understanding of influenza virus infection is important for academic and corporate researchers for the production of novel therapeutics and vaccines, but this deep understanding is not important for all voters, politicians, etc. What scientists do need to stress to its most important funding agency (i.e. the American tax payer, and the politicians who dish out the cash) are the implications of widespread influenza virus infections and what can be done to stop it.
Everyone already knows the basics about influenza -- mostly because we have all spent many a night with our heads in the toilet. We know that it is a seasonal disease. We know that the elderly and young are more susceptible and that approximately 40,000 Americans die each year from run-of-the-mill seasonal flu. We know that washing hands and staying away from crowds are the most effective methods to prevent disease. We also hear information about the influenza virus vaccine and how it must be reformulated each year in order to protect us against next season's flu outbreak. Sometimes researchers are correct in the reformulation, and the vaccine protects, sometimes not...
Well... Why not? Why can't researchers get the reformulation correct each year and protect each of the 40,000 Americans statistics? The answer is evolution. If you want to anthropomorphize influenza virus, you could say that they are smarter than us. Of course, they don't have a brain (only strands of nucleic acid surrounded by protein and a lipid envelope), but they are subject to the same Darwinian processes that all living organisms are. In fact, influenza viruses are so adept at evolving and evading extinction that they utilize techniques that Darwin himself had not thought about. Influenza virus RNA not only undergoes spontaneous mutations as does our DNA, but the mutation rate of RNA is faster than DNA so it more quickly evolves. If you remember from above, influenza virus RNA is also made of eight segments. These segments can be traded amongst other influenza virus types in order to quickly change and exploit new environments. In one example, the hemagglutinin gene from one influenza virus type allows infection of swine, while another allows infection of humans. These genes can be traded so that individual influenza virus types can cross the species barrier. This is a phenomenon called reassortment (1).
What we have in Mexico, the United States, and beyond is an influenza virus that has acquired the ability to jump from swine to human. It just happens to be that this new influenza virus appears to be a bit more deadly than the seasonal flu virus. At this point, officials at the CDC, etc., are not sure how dangerous the virus is. They don't know how far it will spread, and they don't know how many people it has to statistically infect before a person is killed. In my opinion, the world's population probably doesn't need to be on high alert about this -- just the world's medical and political institutions. Getting regular folks riled up about an unknown danger has its own consequences. For instance, elderly citizens may be less apt to go to a hospital if they think they might contract the virus there, and everyone else may be less apt to enjoy the beautiful weather we are having... So, the bottom-line is, understand the threat, but please don't worry yourselves sick.