Friday, January 11, 2019

Whooping Cough/Pertussis 2019

Whooping Cough/Pertussis
Pertussis has been a steady presence since the early 2000’s, but it has been back in the news recently with a rise in numbers since the fall of 2018. If you watch the news you have heard that there are quite a few cases currently in Marin County.

Commonly known as whooping cough, pertussis is a very contagious respiratory illness caused by a type of bacteria calledBordetella 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.

Despite generally high coverage with childhood pertussis vaccines, pertussis is one of the leading causes of vaccine-preventable deaths worldwide. It is estimated that there are 16 million pertussis cases, and about 195,000 pertussis deaths in children per year. By far, most of the deaths occur in young infants who are either unvaccinated or haven't had at least 2 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 infant deaths. In 2014, 11,209 cases were reported which included two infant deaths and hundreds of hospitalizations. The Public Health department was expecting another peak to happen last summer when in July, California had its first infant death from pertussis since 2016, but no surge of illnesses occurred as anticipated. We may be at the beginning of the next cycle this coming year, as the timing fits.

For the most up to date info from the public health department click this link:



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. Those patients with their little runny nose and not much fever are quite contagious. This is why every effort should be made to keep kids with colds away from young infants. We never know if it is going to turn into something worse. At week two, the cough becomes much more troublesome. 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. Newborns often do not have the intercostal muscles to cough so their symptoms could be cyanosis (lips turning blue) due to lack of oxygen. Patients 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 as the "Hundred day cough" and they aren't kidding. This is a miserable illness for anyone, but for young infants pertussis can be deadly. Babies routinely get their first vaccination for this around 2 months of age. The primary series is given at 2, 4, 6, months and at 12-18 months, and again before kindergarten entry. Significant protection isn't achieved until the 4th shot at the 12-18 month visit. The four doses gets them up to 75% protected. This goes up to ~90% after the 5th dose (known as the booster.) Thankfully, ever since the state law passed requiring vaccination for school entry, we don’t have many patients trying to avoid getting this immunization.

Because babies are so vulnerable to this illness, current practice recommends giving all pregnant moms
a Tdap (Tetanus/Diphtheria/Pertussis) with every pregnancy. The Tdap vaccine was licensed in the US in 2005. This immunization should be done in the third trimester between 27-36 weeks. Studies have found that since this program began there has been a whopping 75 percent reduction of infant pertussis hospitalization and a 46 percent reduction of any infant pertussis cases.

For folks who will have a newborn in their lives,If it has been more than 2- 3 years since you had the shot OR the actual illness you should get another booster. The immunity wanes. Researchers claim that three out of four babies who get pertussis get it directly from family members or caregivers. It is essential that all the family contacts have current vaccine protection. This means partners, grandparents, caregivers and siblings or anyone who anticipates spending any time with your new baby. This way everyone will be able to remember the date of their most recent tetanus shot; it will be right around your baby's birthday!
EXPOSURE

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.

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, depending on the lab, 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 do test positive, the Department of Public Health will be involved to make sure they get all of the contacts treated.

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, although honey might be soothing (no honey for babies less than a year old.)

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. The studies are actually fairly discouraging and see a big drop in protection after the first year or two, but aside from being around an infant, there is currently no plan for requiring a booster dose. There is no current call for routine TDaP boosters if you don't have a newborn in your life, But since everyone should get a Tetanus shot every 10 years, there is no good reason not to make that the Tdap.

A big Thank you to Sheila Zarate from the SF Public Health Department for her input and oversight to make sure I am passing along information that is accurate.


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