Pertussis and Walking Pneumonia/ Both of these are making the rounds

 Dr. Ted has been seeing quite a few patients with nasty coughs this season.

We decided to address two of the main culprits here; walking pneumonia and whooping cough. (There is a trifecta of sorts going around. RSV numbers are also up, Here is the link to the post we did on that just a couple of years ago)

Pertussis and walking pneumonia are similar in that they are both very long lasting and very annoying. They do have some key differences.

Pertussis

Commonly known as whooping cough, pertussis 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.

Historically there is a population-level cycle associated with whooping cough. It seems to peak every 3-5 years or so, and we are currently seeing a bump in numbers. Preliminary data show that more than six times as many cases have been reported as of November 23. 2024 compared to the same time in 2023.

Vaccination

Fortunately most kids are vaccinated. It is routinely given as part of the standard shot schedule. The P in the Dtap and then later in the Tdap stands for Pertussis.

The vaccine does a pretty good job of preventing death and severe disease. Unfortunately it only partially decreases transmission and vaccinated people can still get sick, but it is usually a much milder case.

Even though most kids in the USA get the protection, it remains one of the leading causes of vaccine-preventable deaths worldwide. According to a CDC 2014 publication, there were an estimated 24.1 million pertussis cases and 160,700 deaths in children younger than 5 worldwide. 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.

Babies routinely get their first vaccination for this around 2 months of age. The primary series is given at the ages of 2, 4, 6 and 12-18 months, and again before kindergarten entry. Unfortunately, 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 imposed vaccination entry requirements for school, we don’t have many patients trying to avoid getting this immunization. Back in the day, I did have some parents opt out for a variety of reasons. Most of them deeply regretted it and confessed that watching their kids suffer with the months of coughing spasms was torture. The shot is well tolerated and it makes no sense to pass on it. I have deep concerns if the vaccination ever stops being required.

The Tdap (Tetanus/Diphtheria/Pertussis) vaccine was licensed in the US in 2005 for people over the age of seven. Because babies are so vulnerable to this illness, current practice recommends giving all pregnant moms a Tdap (with every pregnancy). 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 75 percent reduction of infant pertussis hospitalization and a 46 percent reduction of any infant pertussis cases. That is enormous progress.

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 close family contacts have current vaccine protection. This means partners, grandparents, caregivers and siblings or anyone who anticipates spending lots of 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!

If you have family members giving you push back about this, (sigh, people can be so disappointing) they are welcome to keep a mask on at all times. Unlike COVID, which is airborne, pertussis is spread by respiratory droplets, so masks actually work to slow the spread.

Symptoms

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 little snot nosed kids don’t always look terribly sick, but they are quite contagious.

This is why, when you have the option, please keep anyone with a cold from being around your infant. 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.

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 or pop blood vessels in their face. Sweating, gagging and choking episodes are common. Some people cough so hard from this that they can break ribs.

Remember, these symptoms may all be much more mild in people who have been vaccinated, but the overall pattern of the coughs coming in deep sporadic fits throughout the day (not just at night) remains the same.

Babies often don’t whoop because young infants often do not have the intercostal (rib) muscles required to cough. Instead, they might just stop breathing briefly or seem really lethargic. They can look cyanotic from the lack of oxygen. It is scary!

For both the vaccinated and unvaccinated, 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, but for young infants pertussis can be deadly.

Plenty of adults get this and don’t get a diagnosis. It is not on the radar for many adult doctors.

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. Remember, this disease is spread by respiratory droplets, so mask wearing and hand washing are very effective at decreasing exposure.

Testing

Unfortunately, testing is far from perfect. There isn’t a rapid test that will give you immediate answers, and waiting for results is not ideal. Testing requires a deep nasal swab (nasopharyngeal), and results often take 3-5 days to come back. Most doctors who suspect Pertussis are likely to start treatment right away, especially if there is a young baby in the household. But according to public health departments, it’s recommended that anybody with a high enough suspicion for a test should be treated automatically (before results come back). Then, presuming they might have the disease, it’s recommended that they stay home from school or work until they’re done with the course of antibiotics. More on treatment below.

Treatment

Treatment usually involves 5 days of antibiotics like azithromycin or clarithromycin, but these are mainly to prevent the spread to others since antibiotics don’t do much to shorten the course of illness once the cough has set in. The good news is that after you’ve finished 5 days of antibiotics or you’ve had symptoms for 21 days (whichever comes first), you’re no longer contagious to others. Therefore, if you’ve been sick for 22 days, you can probably skip the testing as well as the antibiotics. Testing is simply for data purposes, it won’t really change anything. The stick up the nose is not particularly comfortable.

Symptomatic treatment is similar to what you would do with other coughs. This includes a cool mist humidifier and drinking plenty of fluids. The extra moisture in the air can really make a difference with the pertussis cough, so if you don’t have one, a humidifier is a good investment. Smaller more frequent meals may help make vomiting less of an issue.

Inhalers, steroids and cough medicines don't seem to be of much use alas, although honey (Manuka if you can get that) might be soothing. Remember that babies who are less than a year old can’t have honey yet.

Smoke exposure will make things much worse. Skip the campfires.

Walking Pneumonia/Mycoplasma Pneumoniae

We wanted to include a section on walking pneumonia, because it’s another reason you might have a months-long deep cough that doesn’t seem to be getting better. The numbers for it are also up enough that it is getting some media attention.

Symptoms

This is more of a slow-burn infection that settles deeper in the lungs. It typically causes a lingering, dry cough, fatigue, and sometimes low-grade fever. It can leave you feeling out of breath. Unlike pertussis, it doesn’t release toxins but instead, it directly invades the respiratory lining.

Testing

If the section above about pertussis testing left you feeling unsatisfied, then get ready for the ultimate disappointment. There are very, very few commercially available tests for the causative agent, mycoplasma. Physical exams will sometimes show little signs through the stethoscope, but that’s not consistent. You can get an x-ray of the lungs, but that also doesn’t always pick it up. So we’re left with the story, symptoms, exposures, and good guesses.

Treatment

Like pertussis, treatment usually involves antibiotics like azithromycin or doxycycline, which actively target the bacteria and usually help symptoms resolve faster (unlike pertussis). For those who really resist taking antibiotics, time is the great healer and it will go away on its own…eventually. While the vast majority of cases resolve without treatment, immunocompromised individuals can have some serious sequelae.

Whooping Cough vs Walking Pneumonia

How can you tell the difference between these two diseases? In summary, from a physiological standpoint, the big difference is that pertussis mostly affects the upper airways and is toxin-driven, while mycoplasma pneumonia targets the lower airways and works by directly infecting cells. Both can be annoying, but walking pneumonia tends to be less dramatic and more sneaky. The patients don’t always feel super sick but just kind of ‘off’. The cough here is more nagging and dry, usually without the violent fits of pertussis. Your child might seem tired, have a sore throat, or complain about mild chest pain. Fever tends to be low-grade or not even there. It’s actually most common in older kids and teens because mycoplasma pneumoniae, the causative agent, likes to circulate where kids are packed together—schools, sports teams, etc. Kids with asthma or other chronic respiratory issues are more likely to get hit harder if they catch it.

While vaccines exist to prevent pertussis (hello, Tdap!), as of yet there are no vaccines available for Mycoplasma pneumoniae.

Dr. Ted’s advice:

If your child’s cough has been dragging on, especially if it’s dry and disruptive at night or after activity, or if they’re looking more tired or out of breath than usual, those are good reasons to check in. Whooping cough can feel more urgent because of how intense it gets. Always worth a quick listen to those lungs or a swab to rule things out. Follow up with your pediatrician if you think something’s up!