Saturday, March 31, 2018

Why are Incidents of Whooping Cough Rising?


Yesterday I saw an article posted at Yahoo regarding Whooping Cough:

Maggie Parker (2018, March 29). Whooping cough is making a comeback — here’s what you need to know. Yahoo Lifestyle. https://uk.style.yahoo.com/whooping-cough-making-comeback-heres-need-know-195336764.html
Apparently whooping cough incidents have increased substantially, especially over 2017 and into 2018, calling into question the whooping cough vaccine's efficacy.

Here is a chart from the CDC, which only includes data up to 2016, well before the huge spikes in 2017 and 2018 of formally diagnosed incidents:
  

https://www.cdc.gov/pertussis/images/incidence-graph-age.png

A news article from 2014 describes the then-surging cases of whooping cough:
Jyoti Madhusoodanan (2014, September 17). Persistent Pertussis. The Scientist, https://www.the-scientist.com/?articles.view/articleNo/41029/title/Persistent-Pertussis/
An altered vaccine and parents opting-out of inoculations have contributed to ongoing outbreaks across the U.S. In its most recent tally of California’s continuing whooping cough epidemic, the US Centers for Disease Control and Prevention (CDC) reported nearly 8,000 cases of pertussis in the state this year; 267 of those cases were severe enough to require hospitalization.   And it’s not just California that’s seen a recent surge in pertussis: several Washington, DC-area schools reported more than a dozen cases just last week. Minnesota has reported 708 cases already this year. Nationwide, there have been more than 17,000 reported cases of whooping cough since the start of 2014, according to the CDC.
Why did whooping cough incidents increase during this period? The article above attributes the causes to a changed vaccination and dropping vaccination across the population.

The more current 2018 Yahoo article discusses the various causes cited as responsible for these rising incidents and concludes the following, citing a study from a researchers:
Maggie Parker (2018, March 29). Whooping cough is making a comeback — here’s what you need to know. Yahoo Lifestyle. https://uk.style.yahoo.com/whooping-cough-making-comeback-heres-need-know-195336764.html
“Our results are important because they show that recent trends in pertussis are not necessarily caused by recent changes in epidemiology or biology,” said first author Matthieu Domenech de Cell├Ęs, formerly a UM postdoctoral researcher under King, now at the Institut Pasteur in Paris.

Instead, natural population turnover, incomplete vaccination coverage, and slowly waning protection from a highly effective yet imperfect vaccine best explain the resurgence of whooping cough, according to this research.
Majia here: What does it mean to say that "recent trends" (i.e., increased incidents) are not caused by "recent changes in epidemiology or biology"?

One can try infer what the explanation is after reading the second paragraph but "natural population turnover, incomplete vaccination, and slowly waning protection from an imperfect vaccine" (which is simultaneously represented as highly effective) does not offer closure on why the incidents are increasing so substantially.

This speculation on the cause of rising incidents is not idle.  My son (who is not a small child anymore) developed a severe "whooping cough" last fall and now has it again this spring. He never received a formal diagnosis despite having it twice.

In my son's case, two doctors have been unable to explain his condition despite antibiotic and steroid treatments. His condition is being described as some sort of suddenly-acquired reactive airway disease.  We checked for mold in his room and have been able to rule that out.

His friends have similarly been afflicted with bouts of coughing but no formal diagnoses of pertussis.

Why are our children sicker in this particular way?

Why are their bronchial passages so inflamed?
 
I cannot but wonder whether the "recent changes in epidemiology or biology" are in truth to blame. What recent change in biology can you imagine as possibly contributing to increased incidents of whooping cough?