The New York Times is reporting that the State of Washington has been hit by a whooping cough (pertussis) epidemic that has hit 1,284 individuals in 2012, 10 times the 128 seen at this point in 2011. At this rate, there could be over 3000 cases by the end of 2012. Of those infected so far in 2012, 86 infants (under age of 1 year) required hospitalization, including 19 of whom were under 2 months. Pertussis immunization, with the DTaP vaccine, does not confer full immunity to the child until the third vaccination at 6 months of age, during which the infant is susceptible to catching the disease from adults with lapsed immunity or other children who are not vaccinated. However, even children with the first vaccination have some immunity, so the infection could be milder than in a child without any vaccination.
As discussed previously, the State of Washington’s Secretary of Health, Mary Selecky, has access to a special fund, announced by Governor Chris Gregoire last week, to help deal with this epidemic. According to the New York Times, “whooping cough, or pertussis, a highly infectious respiratory disease once considered doomed by science, has struck Washington State this spring with a severity that health officials say could surpass the toll of any year since the 1940s.”
The situation has been made worse by the lack of the funds necessary to battle the epidemic effectively. The New York Times stated:
The response to the epidemic has been hampered by the recession, which has left state and local health departments on the front lines of defense weakened by years of sustained budget cuts. Here in Skagit County, about an hour’s drive north of Seattle — the hardest-hit corner of the state, based on pertussis cases per capita — the local Public Health Department has half the staff it did in 2008. Preventive care programs, intended to keep people healthy, are mostly gone.
Without much insight into Washington State’s politics, taxes and funding options, it is clear that choices were necessary to choose what program could be funded or not. What was important than the health of the state’s children? In addition, the Times reported that:
The county’s top medical officer, Dr. Howard Leibrand, who is also a full-time emergency room physician, said that in the crushing triage of a combined health crisis and budget crisis, he had gone so far as to urge local physicians to stop testing patients to confirm a whooping cough diagnosis.
If the signs are there, he said — especially a persistent, deep cough and indication of contact with a confirmed victim — doctors should simply treat patients with antibiotics. The pertussis test can cost up to $400 and delay treatment by days. About 14.6 percent of Skagit County residents have no health insurance, according to a state study conducted last year, up from 11.6 percent in 2008.
“There has been half a million dollars spent on testing in this county,” Dr. Leibrand said late last week. “Do you know how much vaccination you can buy for half a million dollars?” And testing, he added, benefits only the epidemiologists, not the patients. “It’s an outrageous way to spend your health care dollar.”
Apparently a lot of people are not seeking medical treatment (in adults, the symptoms can be just a lingering cough), and the state health department believes that as few as 20% of pertussis cases are being recorded and tracked, so the epidemic could be substantially larger. Unfortunately, even those with mild symptoms could be infectious for up to 3 or 4 months, if they go untreated. These individuals are the ones at most risk to pass the pertussis bacteria onto infants.
One of the issues that is clearly a cause of the epidemic is the lack of herd immunity, a theory that if sufficient individuals are immune (usually through vaccination), then an infection has only a small chance of causing an epidemic. Usually, depending on the contagiousness of the disease, somewhere between 85-95% of the population should be immune to induce herd immunity. For pertussis, an immunization rate needs to be about 92-94% to keep an outbreak to blossom into a full-fledged epidemic.
Washington used to have one of the easiest opt-out laws for vaccinations, so the legislature implemented a tougher requirement that a parent must consult with a physician before opting out. Of course, some physicians buy into the anti-vaccine rhetoric, so some parents could shop for an anti-vaccine physician (admittedly quite rare). Even with the tougher law, about 6% of parents in the state declined to vaccinate their children, one of the higher rates in the US. If you throw in children who cannot be vaccinated (for example, those who are immune-compromised) and adults with lapsed immunity (adults should get booster shots), the level of non-immune residents could be above 10%, which breaks the herd immunity in the local area. This may be the primary cause of the local epidemic.
Pertussis is fatal to about 1% of children who get the disease. So vaccines absolutely save lives. Let’s hope that the residents of Washington learn a lesson, and that the healthcare system can help lessen the effects of the epidemic, despite the lack of funding.