This strange influenza epidemic is a late-bloomer. Many new swine flu cases keep cropping up in April and running toward May on the North American continent. In Mexico in 2009, there have been well over 1,000 cases and 22 deaths. In the U.S. there are 91 documented cases as of April 29, 2009 and one death. The epidemic is in 10 states in the U.S., and Europe reports more cases in at least 4 countries. Several countries are banning travel to Mexico.
This is like a major snowstorm in springtime. This is a true, life-threatening epidemic, breaking forth on the North American continent and apparently racing outward on planes, cars and trains to other distant points. The Centers for Disease Control (CDC) in the United States and the World Health Organization are geared for pandemic, a world-wide disease outbreak. Wherever a person lives, alertness and attention are priorities. Who are the players in this mind-boggling event called epidemic or pandemic?
Infectious Disease Pandemics and Epidemics – Pathogens, Susceptible, Carrier and Resistant Hosts
The characters in epidemic and pandemic dramas are:
- Influenza virus, an RNA virus with the ability to attack the respiratory tract. The virus is an Orthomyxovirus, literally "myxo" means “slime” exudates, or mucus-inducing caused by the virus.
- Hosts of various animal species include: swine, birds (chickens, geese, ducks) and humans.
- Large populations of the susceptible hosts are available, i.e. hosts with no resistance.
- Large populations of carrier hosts, those who are infected, do not know it, and carry the viruses within them and transmit the viruses to others.
Epidemics and Pandemics Rise, Crest and Decline – Epidemic Curves. Why Is This?
- Viral epidemics feed on susceptible hosts. The epidemic moves forward with increasing victims until there are few, or no more, potential hosts left to infect.
- Host victims respond to the viral attack and produce antibody and cell defense responses that provide host immunity. Then,these hosts are no longer being infected or diseased. These hosts are convalescent, immune hosts. Those who have died are removed from the infected pool.
- All epidemics tend to peak, reach equilibrium (crest) and then decline based on the principles listed above for the natural, disease history. This is the nature of an epidemic curve.
Pandemics and Epidemics, How Are They Stopped and What Can Be Done?
Epidemics have known causes. In times past no one knew what caused plague, cholera, tuberculosis or any other infectious disease. Robert Koch gave postulates to determine how to know the infective microbe.
Today, virtually all pathogens of infectious epidemics are known, or quickly identifiable. By using this information, epidemiologists, physicians, health, local, state and federal officials can take necessary and directed actions. Specific disease protocols, enable officials to know the what, when, where and how of during epidemics and pandemics.
Pandemic, Epidemic and Endemic, What to Watch and Expect.
- Daily and hourly updates on the disease's progress. Updates occur in all media: television, radio, internet, newspaper and magazines.
- Precautions and warnings to heed. For influenza, isolation of flu victims, avoiding crowds and public places, regular hand washing, avoidance of touching hands and fingers directly to the mouth or eyes.
- Vaccination when available (currently not available for H1N1 swine flu 2009).
- Antiviral intervention, when appropriate. CDC recommends oseltamivir (Tamiflu, Registered Name) as effective to treat and prevent swine flu for people 1 year and older; zanamivir (Relenza, Registered Name) is useful to treat and prevent in 7-year-old and older persons, and may be used for prevention in those as young as 5 years old. Each drug is effective against swine flu H1N1. Amantidine and rimatadine are not effective.
- In secondary bacterial infections, appropriate antibiotics are useful for control.
- The epidemic of swine flu H1N1 may slow down and seem to die out (it may be endemic for a period of several months) out only to come back again with a vengeance when schools are packed and people are crowded together in the Fall and Winter seasons of late 2009 and early 2010. Hopefully, by that time, sufficient vaccine will be available for immunization of susceptible hosts, especially youths, respiratory-compromised, and elderly people.
This epidemic/pandemic will be interesting to watch and study. The epidemic may fizzle, or it may sizzle.
Remember, it is important for all to be informed and be proactive in present or future epidemic and pandemic situations!
Sources
CDC (US). 2009. Human Swine Influenza Investigation.
Greenberg, R.S. et al. 2001. Medical Epidemiology. Third Ed., Lange Medical Books/McGraw-Hill, New York. 215pp.
WHO. 2009. Epidemic and Pandemic Alert and Response.
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