Pediatrician Intuition – What your pediatrician wants you to know
by Jay S. Rosenbloom MD PhD
Pertussis (also known as whooping cough) is an infection that has received a lot of press in the last few years. It was just a year ago that California was setting records with the number of cases of pertussis, and now it is Washington’s turn. Oregon isn’t far behind.
Background: pertussis gets its name from the bacteria that cause the disease (Bordetella pertussis). It is transmitted from person to person by respiratory droplets; so breathing the air within 6 feet of someone coughing due to the disease is the best way to catch it.
The illness has 3 phases: catarrhal stage (1-2 weeks), paroxysmal cough stage (1-6 weeks), and convalescence (weeks to months). It is often difficult to diagnose pertussis early (when antibiotics will help) because the first stage is quite similar to a common cold. The paroxysmal stage is where the whoop of whooping cough comes. At this time people will have such prolonged coughing spells they feel like they have coughed all of the air out of their lungs and take a long, fast and deep inhaled breath, producing a whooping sound. The cough doesn’t whoop, breathing in does.
It is usually much more obvious that someone has whooping cough when at this stage, but by then antibiotics will not make the infected person better faster, it just makes them no longer contagious. The cough can then linger for weeks or months. When someone has acquired the bacteria it usually takes 7-10 days before they show any signs.
The vast majority of deaths from pertussis occur in the first three months of life Often the younger the child, the more severe the illness.
History: Before the vaccine became available pertussis was much more common. Between 1940 and 1945 over 1,000,000 cases were reported in the US. The vaccine was introduced in the 1940’s and by 1970 there were fewer than 5,000 cases reported. However, we have seen those numbers slowly creeping back up with more than 27,000 last year. So far this year (and it is only May) Washington state has had more than 1,700 cases.
Prevention: From the 1940’s until the late 1990’s the vaccine was made by blasting apart whole Bordatella pertussis bacteria. It was about 85% effective at stimulating the immune system in such a way that the person would be immune to the disease. However, this protection always wanes, and is typically lost by 5 to 10 years after the most recent booster. With the old vaccine high fevers and other side effects were more common. Using cloning techniques the genes for 4 proteins on the surface were put into yeast so high concentrations of vaccine could be made with less material being injected, giving the same level of protection. When you hear about the DTaP (for kids <7 years) or Tdap (for anyone >7 years) the little “a” stands for acellular, which means it offers the same protection with fewer side effects than the old one using the whole cells.
Bottom line: The best way to prevent whooping cough is to make sure you and your children’s vaccines are up to date. The vaccine isn’t perfect, leaving 1 in 7 still susceptible when fully immunized, with even that protection waning over time. It is the best we have to offer, and in fact, the immunity from the vaccine is about the same as one gets even suffering a full blown infection. Even though this is rarely a dangerous disease to older kids and adults it can be deadly to infants. The best way we have to protect them is to have less of this potentially deadly germ circulating in the community (herd immunity).
About the blog
This blog is written by our providers. It is not intended to replace any medical advice, but rather to share our thoughts on a variety of topics we encounter daily as primary care pediatricians in the Portland area. Each entry’s author is named under its title. This content is not based on any commercial product or service, nor is it a recommendation of such. Opinions expressed are our own and are not influenced by any form of compensation.