Friday, March 7, 2014

Pertussis/ Whooping cough

* Please see the updated Pertussis post for current numbers (4/2015)
This week I am going to talk about yet another very relevant and nasty disease. My loyal readers are going to be afraid to go outside! Sorry about that, in my next post I will try to take a break from things that are contagious or itch producing.

Pertussis, commonly known as whooping cough, is a very contagious respiratory illness caused by a type of bacteria called Bordetella pertussis. These bacteria attach to the cilia (tiny, hair-like extensions) that line part of the upper respiratory system. The bacteria release toxins, which damage the cilia and cause inflammation.

Worldwide, it is estimated that there are 16 million pertussis cases and about 195,000 pertussis deaths in children per year. Despite generally high coverage with childhood pertussis vaccines, pertussis is one of the leading causes of vaccine-preventable deaths worldwide. Most deaths occur in young infants who are either unvaccinated or haven't had at least 3 shots in the series.

Historically there is a cycle associated with whooping cough. It seems to peak every 3-5 years.
In 2010, here in California there were more than 9,100 reported cases and at least 10 deaths.
Last  month the first infant death from pertussis was reported for the first time since 2010. We may be at the beginning of the next cycle. The timing fits.

This illness usually starts with a week or two of a runny nose and cough. There may or may not be a low grade fever. At week two, the cough gets much worse. The patient will often have coughing fits...and I mean FITS!! This is spasms of coughing for minutes at time that make even the hardiest person feel like they can't catch their breath.
They may or may not have a high pitched "Whooping" sound with the cough (hence the name). Some folks will vomit after these coughing fits
Sweating, gagging and choking episodes are common.
Some people cough so hard from this that they can break ribs.
This cough lasts and lasts...and then lasts some more.
In Chinese medicine this is referred to  as the "Hundred day cough" and they aren't kidding.
This is a miserable illness for anyone.
I have spoken to parents who had chosen not to vaccinate and had to deal with several months of this horrid illness. Every one of them says they rued the decision to pass on the protection.
For young infants Pertussis can be deadly.
Babies routinely get their first vaccination for this around 2 months of age.
The initial series is given at 2 4 and 6 months* There is a booster dose given at 12 months and again before kindergarten entry.
They don't seem to have adequate protection until they have received the 3rd shot at the 6 month visit.
Once they have had 3 doses they are roughly 75% protected. This goes up to ~90% after the 4th  dose.  (Doses 1 2 3 are the initial series. Doses 4 and 5 are referred to a boosters)

*In our office, the vaccine that we use is the Diphtheria/Tetanus/Pertussis combined with Hib and Polio in a shot called Pentacel.

Hib, Polio and DTaP are all available as separate vaccines.
The Pertussis component of the vaccine does not come separately.

Because babies are so vulnerable to this illness, A fairly new and current practice recommends giving all pregnant moms a TDAP  (Tetanus/Diphtheria/Pertussis) with every pregnancy. This should be done in the third trimester between 27-36 weeks. Please talk to your OB if you have questions about that.
It is also essential that all the family contacts have current vaccine protection. This means Dads, grandparents, caregivers and siblings or anyone who anticipates spending any time with your new baby.
If you had the shot OR the actual illness more than 5 years ago the immunity wanes. You should get another booster.

People who have been exposed to Whooping cough will usually start showing symptoms 7-10 days after the exposure and are contagious by the time they give that first sneeze.
If someone is diagnosed, a course of antibiotics will help limit the spread and may minimize the symptoms. It won't make your cough go away, but the illness won't be quite as severe and you won't be contagious. 

On a similar note, as I noted earlier the vaccine is not 100% effective, but folks who are vaccinated tend to get a much milder case than those who have no protection.

Testing for Pertussis is far from perfect. We usually send a culture obtained by a swab stuck up the nose. (as pleasant as it sounds)
The results may take more than a week, so the decision about whether or not to treat often needs to be made based on the clinical history and symptoms rather than a lab result.

If you have Pertussis, symptomatic treatment includes a cool mist humidifier and drinking plenty of fluids.
Smaller more frequent meals may help make vomiting less of an issue.
Smoke exposure will make things much worse.
Cough medicines don't seem to be of much use, alas.
For older kids, honey might be soothing.

I wouldn't wish this one on anyone....even that grumpy woman at the DMV who seriously waited until I stopped smiling to take my drivers license photo. 

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