It's Not "Just the Flu"

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This past month has seen the appearance and peaking of seasonal influenza in the Northern Hemisphere.  This year, a particularly early strain of flu has been causing widespread illness across all 50 of the United States.  The start (or height) of any flu season is a good time to refresh our understanding of the influenza virus, prevention strategies, testing methods, and treatment modalities.  This year, however, we also sit exactly 100 years removed from the most deadly global pandemic ever seen by humanity.  Try your hand at some flu-based trivia and take a listen to the podcast below (or on iTunes).

It's Not "Just the Flu"
Jeffery Hill, MD MEd

1.) The 1918 Influenza Pandemic lasted for how long and killed how many people (globally)?

The pandemic flu of 1918 lasted for 18 months and killed somewhere between 50 and 100 million people globally (3-5% of the world’s population at the time). The death count exceeds the death count from battle in World War I and World War II combined. It is estimated 1/5 of the worlds population (500 million people) became ill with influenza during the pandemic. (1, 2 ,3)

"Demonstration at the Red Cross Emergency Ambulance Station in Washington, D.C., during the influenza pandemic of 1918." - Wikimedia Commons

"Demonstration at the Red Cross Emergency Ambulance Station in Washington, D.C., during the influenza pandemic of 1918." - Wikimedia Commons

2.) Where was the first confirmed outbreak of influenza at the start of the 1918 Influenza Pandemic?

The first confirmed outbreak of influenza occurred in Camp Funston, an Army base in Central Kansas. Based on epidemiologic studies, it is not certain that Central Kansas was the true origin of the antigenic shift and H1N1 influenza virus that caused the 1918 pandemic. However, in January of 1918, a local physician in Haskell County, Kansas reported to the US Public Health Service the appearance of a severe outbreak of influenza in his community (an unusual step as influenza was not, at that time, a reportable illness). Others implicate China as the geographic origin of the illness based on records of a respiratory illness outbreak in November of 1917 which was later cited to be identical to the “Spanish Flu.” (1,2, 3)

Giving treatment to influenza patient at the U.S. Naval Hospital. New Orleans, Louisiana, Circa 1918; NH-60309. https://www.flickr.com/photos/navymedicine/7872322146

Giving treatment to influenza patient at the U.S. Naval Hospital. New Orleans, Louisiana, Circa 1918; NH-60309. https://www.flickr.com/photos/navymedicine/7872322146

3.) Why was the 1918 pandemic flu called the “Spanish flu”?

During wartime there was significant censorship of the reporting of the ravages of the illness. Neutral Spain had no such restrictions so it’s presence was much more widely reported and known leading it to be named the Spanish Flu. (3)

Source - Wikimedia Commons

Source - Wikimedia Commons

 

4.) What is the difference between antigenic shift and antigenic drift?

Antigenic drift refers to the small changes in the influenza virus that occur over time as the virus replicates. The resulting viruses are genetically very similar to one another. Antigenic shift refers to a rapid change in the hemagglutinin and/or hemagglutinin and neuraminidase protein combination. Antigenic shift rarely occurs and results in viruses that are significantly different than previously existing viruses and can lead to pandemic infections. Influenza A changes by both antigenic shift and drift. Influenza B changes by antigenic drift only. (4)

H1N1 Swine Flu - Cybercobra at English Wikipedia

H1N1 Swine Flu - Cybercobra at English Wikipedia

5.) For this year, what has been the most commonly reported subtype of influenza?

Influenza A H3N2 has been the most commonly reported subtype of influenza reported. Weekly updates can be tracked at the CDC’s website

Podcast References

  1. https://www.smithsonianmag.com/history/journal-plague-year-180965222/

  2. Barry JM. The site of origin of the 1918 influenza pandemic and its public health implications. Journal of Translational Medicine. 2004;2:3. doi:10.1186/1479-5876-2-3.

  3. Taubenberger JK, Morens DM. 1918 Influenza: the Mother of All Pandemics. Emerging Infectious Diseases. 2006;12(1):15-22. doi:10.3201/eid1201.050979.

  4. Call, S., Vollenweider, M., Hornung, C., Simel, D., and McKinney, W. P. Does This Patient Have Influenza? JAMA Rational Clinical Examination.

  5. https://www.cdc.gov/flu/professionals/diagnosis/rapidlab.htm

  6. Vaccination Information for Healthcare Professionals. CDC. https://www.cdc.gov/flu/professionals/healthcareworkers.htm?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fflu%2Fhealthcareworkers.htm Accessed 12/8/19

  7. https://en.wikipedia.org/wiki/Influenza_vaccine#History

  8. Jefferson T, Jones MA, Doshi P, et al. Neuraminidase inhibitors for preventing and treating influenza in adults and children. Cochrane Database of Systematic Reviews 2014;19(7425):740–563.

Trivia References

  1. Taubenberger JK, Morens DM. 1918 Influenza: the Mother of All Pandemics. Emerging Infectious Diseases. 2006;12(1):15-22. doi:10.3201/eid1201.050979.

  2. Barry, J. How the Horrific 1918 Flu Spread Across America. Smithsonian Magazine. 11/2017. Retrieved from https://www.smithsonianmag.com/history/journal-plague-year-180965222/ on 1/8/2018.

  3. 1918 flu pandemic. (2018, January 8). In Wikipedia, The Free Encyclopedia. Retrieved 21:31, January 8, 2018, from https://en.wikipedia.org/w/index.php?title=1918_flu_pandemic&oldid=819315839

  4. How the Flu Virus Can Change: “Drift” and “Shift”. Retrieved from https://www.cdc.gov/flu/about/viruses/change.htm on 1/8/2018.