It’s Professor Dave, let’s check out whooping cough.
Whooping cough is a very serious lung infection caused by a bacteria called Bordetella pertussis.
Sometimes called Pertussis, per meaning very or severe; and tussis meaning a cough, this
disease is notorious for violent, uncontrollable coughing fits that often make it hard to breathe.
In fact, whooping cough gets its name from the gasping breaths you might take after an
intense coughing fit, which make a “whooping” sound.
CDC estimates that there over 24 million cases of pertussis worldwide each year, with over
160,000 of these resulting in death.
While whooping cough can infect people of all ages, and it’s highly contagious, to
boot, it is the most serious, and sometimes deadly, in babies less than a year old, particularly
because of their teeny tiny airways.
Let’s get a closer look at this baby killer now.
So where does it come from?
Whooping cough was first described back in the Middle Ages, and has caused numerous epidemics
over the years.
The causative agent, Bordetella pertussis, was identified in the year 1900 by Belgian
scientists Jules Bordet and Octave Gengou.
Let’s talk more about the bacteria itself: Bordetella is an incredibly small, strictly
aerobic, meaning it needs oxygen or it can’t survive, gram-negative coccobacillus, which
just means its shape is somewhat of an intermediate between cocci, which are spherical bacteria,
and bacilli, which are rod-shaped bacteria.
So basically, think of an oval.
Bordetella pertussis is spread from person-to-person through a sneeze, cough, or just sharing the
same air for an extended period of time.
Once you inhale these bacteria through “infectious aerosols”, they attach to the cilia, the
tiny, hairlike projections, on the epithelial cells of the upper respiratory tract.
The bacteria then proliferate and create toxins that damage the cilia and cause the airways
to swell.
In fact, Bordetella pertussis produces four toxins: pertussis toxin, adenylate cyclase
or hemolysin, dermonecrotic toxin, and tracheal cytotoxin, which collectively trigger both
localized tissue damage and systemic spread of disease.
This bacteria also produces two lipopolysaccharides which can trigger an immune system overreaction
that damages healthy cells.
What this means for an infected individual is this: once the bacteria are inhaled, there’s
typically a seven to ten day incubation period before symptoms set in, though it can take
up to three weeks.
The disease develops in stages, first causing cold-like symptoms, such as runny nose, mild
cough, low-grade fever, or sneezing.
Even though the symptoms are mild, this stage of disease produces the highest number of
bacteria, and therefore has the highest risk of transmission.
After a week or two, the disease progresses and the traditional symptoms associated with
whooping cough set in.
Usually, this means paroxysms, which is just a fancy word for fits, of violent, rapid coughs
until there is no more air in the lungs, which causes an infected individual to sharply inhale
with a loud “whooping” sound.
The extreme coughing can cause vomiting or exhaustion.
For some, complications such as weight loss, bladder control loss, fainting, or rib fractures
might occur.
Even worse, the disease is known to sometimes last up to 10 weeks or more, gaining the nickname
the “hundred day cough”.
Bordetella pertussis can only infect humans, with no known animal or environmental reservoir.
To diagnose the disease, doctors conduct a physical examination, as well as a lab test
of mucus or a blood test.
If caught early, treatment with antibiotics is effective to reduce coughing fits and transmission
to others.
However, treatment after three weeks of illness likely won’t help, as the bacteria have
gone by then, and the damage to the respiratory tract has already been done.
There is, in fact, a vaccine for whooping cough that can protect babies, children, teens,
and adults.
In the U.S., doctors recommend a combination vaccine called DTaP for babies and children,
which protects against three diseases: diphtheria, tetanus, and pertussis in one fell swoop.
There is also a booster, called Tdap, that protects teens and adults from these three
diseases as well, which is very important for anyone to get before visiting a newborn
baby that hasn’t yet been vaccinated.
You’d think since this disease has been around since the Middle Ages, we’d have
eradicated it by now.
However, whooping cough is a common disease in the U.S., and it remains one of the leading
causes of vaccine-preventable deaths worldwide.
One of the best ways to prevent spreading of whooping cough is to cover your mouth and
nose with a tissue when you cough or sneeze, and wash your hands often.
But of course, encouraging people to vaccinate remains a crucial initiative.