A whooping cough “outbreak” remains widespread in western Nevada County with more than 40 cases reported since the beginning of the year and 22 reported in the past three weeks, according to county health officials.
“As compared to the last couple years, it is high,” said Tex Ritter, interim director of the Nevada County Public Health Department. “Compared to the 2010 outbreak, we haven’t seen those numbers yet. But it is spreading. The numbers are becoming widespread.”
In 2010, more than 9,000 cases were reported in the state. No county hospitalizations or deaths have been reported with this year’s outbreak of whooping cough, also known as pertussis. But with patients ranging from seniors to 3 months old, county health officials are cautioning that the protection of infants is critical.
“Infants are at the greatest risk of contracting pertussis and having severe complications from it,” noted the health department in an announcement Tuesday.
Most babies who get ill with pertussis contract it from a household contact, often the mother or a brother or sister attending school, health officials said. That is why they say those who are pregnant or live with or care for babies or with children in school are all high priorities for vaccinations.
“Immunizations do decrease the severity and can blunt the spread,” Ritter said. “No immunization is 100 percent effective … however, a vaccination lessens the symptoms.”
Pertussis vaccines, which are about 80 percent effective, are recommended for people of all ages, Ritter said.
“The idea is that if 80 percent of the population is vaccinated, you are less likely to have an outbreak,” he said.
Infants and children should receive five doses of DTaP for protection, county officials recommended. Infant vaccination can start as early as 6 weeks of age, but county officials said doses are usually given at 2, 4 and 6 months, then between 15-18 months and again at 4-6 years of age.
A DTaP booster is given to pre-teens 10-12 years of age. Almost all adolescents or adults who did not receive DTaP as a pre-teen are recommended to receive one. DTaP is particularly important for pregnant women and others who care for infants. A new recommendation is that pregnant women receive a vaccination with each pregnancy.
Nevada County has had a traditionally low immunization rate relative to the state. When reached by phone Wednesday afternoon, Ritter said his department would not be able to provide comparative numbers of how many cases were reported by mid-May in previous years. He said those numbers could be disseminated Thursday.
He did say, though, that Nevada County’s estimated portion of entering first-grade students with required vaccinations was about 70 percent, compared to 93 percent statewide.
However, as Ritter pointed out, that figure includes parents who are pursuing their own schedules for vaccines or who have not filed appropriate paperwork by certain deadlines.
Of the 41 reported county cases this year, 28 cases have been confirmed by laboratory testing or are closely linked to someone confirmed by testing. The health department continues to work with local healthcare providers to identify additional cases.
Most adults in the United States have not been recently vaccinated against pertussis, as many Americans don’t know that immunity from the vaccine (or from the illness) wanes with time, and a booster is recommended.
In outbreaks, cases of whooping cough occur in vaccinated and unvaccinated individuals. However, unvaccinated children are at least eight times more likely than fully vaccinated children to get pertussis, according to the Centers for Disease Control and Prevention.
While the health department recommends immunization and said that it can lesson outbreaks, Ritter would not say that Nevada County’s low vaccination rate was the cause of this year’s pertussis outbreak.
“It does contribute to the spread, but it is not the cause of the spread,” he said.
Other factors contribute, Ritter said, noting that pertussis follows a three-to-five year cycle.
“So this outbreak is not wholly unexpected,” he said.
Pertussis is a bacterium that spreads easily from person-to-person through coughing and sneezing. Outbreaks are difficult to manage because pertussis starts off looking like a common cold before the characteristic whoop or coughing fits appear, health officials said.
“People mistake its symptoms for something else, and people often assume it is allergies. Then they start getting the cough with a whoop,” Ritter said.
Patients with pertussis are considered contagious from the onset of symptoms until three weeks of cough or five days of effective antibiotics.
“If they are showing symptoms, they should see a medical practitioner,” Ritter said. “Antibiotics will lessen the severity and will decrease the exposure.”
After exposure, pertussis can incubate in the body for up to three weeks before symptoms start. Post-exposure antibiotics are recommended for household contacts of contagious patients, as well as close contacts who are at high risk of more severe disease (such as pregnant women, infants and those with weakened immune systems).
As part of its investigation, the health department has been referring household and high-risk contacts to their regular health care providers for care.
“Pertussis is dangerous,” Ritter said.
To contact Staff Writer Christopher Rosacker, email firstname.lastname@example.org or call 530-477-4236.
“People mistake its symptoms for something else, and people often assume it is allergies. Then they start getting the cough with a whoop.”
— Tex Ritter, interim director of the Nevada County Public Health Department