The Super Spreader

The Super Spreader
September 19, 2013 0 Comments

The stakes are still high in search of a dominant cause for infectious disease spread by airborne and fomite contagion.  Finding the cause is the last step to stopping its spread.  Around the time of SARs in 2003, the question loomed very large ‘who is a super spreader’?  It persists and remains largely unanswered.  If answered predictably, the person identified and an epidemic or pandemic averted.

Below are some key questions asked in considering super spreading with the answer to the question, “who is a super spreader” at the end.

What is a super spreader?

A Super-spreader is defined as a person who transmits their infection to 10 others.   In most all epidemics studied, the 90% of the infection was delivered by 10% of the infected.   Since Super spreaders are only identified in the aftermath of an epidemic.  Any and all attempts to identify super spreaders have yielded nothing specific rendering super spreading a numerical curiosity if not a phenomenon.

What makes a super-spreader?

A contagious person is a spreader.  Contagious people are symptomatic people with some exceptions.  Hence while asymptomatic people can be contagious and vice versa, super spreaders are symptomatic.  While it seems obvious, it’s the first and only clue yet in search of identifying super spreaders.

What is super susceptibility?

Many groups are “at risk” of infection.  While some infections are more prevalent in certain groups resistance can be prevalent in others.  Some strains of influenza infections can favor adults.  Elderly, an “at risk” group in have shown formidable resistance to certain strains in other cases.  Super susceptibility occurs based on certain conditions.  International air travel can create super susceptibility as well as very specific weather patterns.  More will be detailed in future blogs.  However just as a dry forest does not mean forest fire, so too does super susceptibility does not mean epidemic.  For that you need contagion.

What is super mucus?

Not a pretty thought.  But that’s what we hopefully do not inhale but do exhale when you are in a common mode of super susceptibility.  Super mucus comes from dehydrated lungs.  This is a condition similar to the daily life of certain lung diseases such as those of a sufferer of cystic fibrosis.  If one is sick and super susceptible their exhalation is particularly virulent in the matter of influenza.  Ten times more virus in such an exhalation will be viable.  On a similar note a sick person presenting in a super susceptible state is also susceptible to secondary infections, let alone highly infectious.

A sick person presenting in a super susceptible state is also susceptible to secondary infections, let alone highly infectious.

A sick person presenting in a super susceptible state is also susceptible to secondary infections, let alone highly infectious.

Is cold temperature a super spreader?

Yes in a way.  Lower temperatures indirectly causes lower RH%.  The lower the RH% under 48% and the more likely super spreading will occur for the worst infectious viruses such as influenza.  RH% that are under 48% causes the virus sick people exhale to last longer and diffuse farther from the point exhalation.  If the virus gets into the return air duct, extreme super spreading occurs.  As with super susceptibility, super spreading does not make people sick.  Contagion does.  No contagion, no disease epidemic.

Where is super-spreading most likely to occur?

Super spreading will occur where there is ample contagion and other factors that are conducive.  The undesired perfect storm of disease is low RH%, high population susceptibility and contagion.  Repeat that cycle over the incubation period (3-5 days for influenza) and an epidemic is born.  Its strength is based on the amount of super susceptibility, the amount of contagion and the degree of super susceptible people.

Answer: A super spreader is a symptomatic almost always fevered person.

 

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