This decade marks the 200th anniversary of Darwin’s birth and the 150th of the publication of The Origin of Species. He believed natural selection has had a fundamental impact on the way we view the evolution of pathogens, who have histories as much as humans. As of today the WHO reports 15,510 official cases of RNA virus novel-H1N1 in 53 countries and with new countries regularly reporting in. This pandemic influenza could have not happened at a better time.
As we move ahead to a boundariless society, free mixing of commerce and trade comes with itself the package of misery. Modern-day flu epidemics are fueled in part by the ubiquity of global air travel (both commodites and humans). Influenza is not new to us, but the 1918 outbreak restated its impact and redefined its pandemicity. Epidemics like cholera and plague had been there but this flu scare revealed the “pan” or panic quotient of the epidemic, globally.
Roughly three times per century, a pandemic occurs, which infects a large proportion of the world’s population. Every year seasonal flu causes about a half-million deaths in vulnerable, and otherwise healthy people. Seasonal H1N1 influenzas may be in fundamental ways different from their 1918 ancestors. Compared to the regular flu, H1N1 seems more deadly (0.25% as opossed to 0.1% fatality). So, yes, swine-origin H1N1 2009, as transmissible as any human influenza, is worse than seasonal flu. A case fatality rate clocking in at 5%— can kill 50-100 million people.
So, if the flu is so similar to the seasonal variety and the earliest conjectured vaccines will arrive in market not before October 2009, that too in limited numbers, the best preventive measure as of now should be our normal flu shots, even though we had it already. More because we are approaching the autumn flu season and that we know of the 1918 pandemic proved mild in its spring incarnation and apocalyptic the following fall.
Countries like Singapore have shown how able management and proper surveillance can prevent such mass havoc. Here there is no fall season and a controllable, co-operative population size with a faith in the government and a cent percent hospitalization. And as we document the first H1N1 death in this island nation, we know measures have been taken, and in the right direction.
The very first step for any governing agency is educating the people by and large. To the more knowledgable populace the level of polymerase CpG may be one explanation for the difference in nature of this flu with its 1918 ancestors. More so, because for the RNA virus’ virulence alone isn’t our sole concern. It’s virulence and transmissibility in tandem that’s keeping scientists up at night. But even then there remained great variation in the pathogen’s effects across the population: some people were exposed but not infected, some were infected but suffered only a seasonal-like flu, and then, of course, there were those whose viscera melted from the inside out. The pathogen can get away with being virulent because it can successfully infect the next susceptible in the chain before it kills its host. Hence, time tested antiviral chemoprophylaxis of oseltamivir (Tamiflu®) and zanamivir (Relenza®), if taken within 48 hrs of exposure, are still the best to bring down transmissibility and viral shedding.
Respiratory hygiene/cough etiquette are major factors in transmissibility as this vairus can travel by only this means. The isolation distance for SARS had been 1.1 meters, but in this case a 3-6 feet distance for coughing individuals in a must. Subsidised sale of face masks can be a profitable resort to augment this droplet precaution and hence, transmissibilty.
World-wide this H1N1 scare has led a more massive depression than the global recession and job-loss could have done till now. Daily news reports come flying in about various immuno compromised individuals getting infected. So, pregnant, asthmatic, cardiac impaired, HIV infected, obese, stem cell transplanted individuals are all in the viable lot. Performing rapid influenza tests at the stightest fever or severe cough (more pronounced in asian population) confirm the causative agent and should be done within 5 days from the onset.
Plus, other standard measures like thermal scanners, full PPE, daily temperature taking in public places, prohibiting large gatherings, travel restrictions and home quarantine orders help the containment strategy as well as the mitigation approach. Social responsibilities and ethical concerns in reporting a temperature rise as well as staying indoors if feeling unwell have helped the cause in a very big way among citizens. Plus, the adage of investing is precautionary scientific resorts much before the actual pandemic have once again been reinstated.
There have been more politics with this influenza than science. Swine flu H1N1 appears at one and the same time moving full-boar and on its cloven heels “la manera mexicana”. The closest ancestral gene for each of the eight gene segments is of swine origin. “Swine flu”, as it is known, is a misnomer. This influenza is a ’swine-bird-human’ triple reassortant. World Organization for Animal Health (OIE) reports that this strain has not been isolated in swine. And there is Mexico, which appearsto be the ground zero for this outbreak of deadly human-specific H1N1. However, the gowth of the internet and social networking sites have helped the awareness and hence the cause of the pig and Mexico responsively as much as the WHO has in deciding the nomenclature of this flu to the hemagglutinin and neuraminidase antigen subtypes.
One very interesting analogy outlines the similarity of this flu with its 1918 counterpart. The gross age of affecetd individuals for both cases were below 50 years. While people above 50 already had a partial immunity from the exposure to previous outbreaks in this 2009 pandemic, the average mortality of 48.5 years in the early twentieth century explains it in the 1918 pandemic. Not many people live to be a fifty to let get infected by the flu virus then.
Few questions still remain about the vaccine. With such short time left and an otherwise slow egg method for vaccine production (the cell culture method for such huge production is yet to be validated), how can the clinical trials be conducted and who gets the prefernce once the vaccines do arrive in the market? What if the virus mutate and reassort again by then?
H1N1 influenza is a urban disease. Human migration to large cities have once again proven the Darwinian notion of graduation in evolution. The US pork industry justifiably have defended themselves in not allowing it to be called a swine flu. Healthy pigs are safe. But two other flu viruses spread all over the world since 1918 – Asian flu in 1957 and the Hong Kong flu in 1968 – and both mutated in pigs. Everyone knows pigs are fed antibiotics. Are they fed antivirals?
I’m not a vegetarian. I love my salami as much as I love my cornish chicken platter. I’m not an animal rights activist. I’m not opposed to big farming on first principles. And yet by way of my epidemiological work and my exposure to this very informative course on influenza I’ve apparently arrived at this conclusion. If we have to prevent one more HN subtype from emerging —– factory farming (as we know it) of livestock must end.
