Now the health department is reporting a troubling consequence of that trend.
Yesterday afternoon, the VDH alerted health care providers statewide about an uptick in the number of cases of pertussis, a vaccine-preventable disease more commonly known as whooping cough. According to the VDH, 27 cases of pertussis have been confirmed in Vermont this year alone, including six cases in the past month. Four confirmed cases have been reported in Chittenden County and one each in Washington and Bennington counties — with additional cases pending confirmation in Chittenden, Addison and Windham counties. The patients' ages (for confirmed cases) range from 5 months to 67 years old.
The incidence of pertussis had been on the decline since 2005 following the introduction of a new booster vaccine, recommended for children ages 10 and up. Confirmed cases dropped from 110 in 2006 to 11 in 2009. But last year, that number began creeping up again. Health experts say the rise may be due to the cyclical nature of the disease, which seems to reemerge every three to five years, as well as Vermont's declining rate of childhood vaccinations.
Pertussis is a highly contagious disease of the lungs caused by a bacterial infection. Anyone who has clinical symptoms of pertussis should be evaluated by a health care provider. People with suspected or confirmed cases of pertussis should be kept out of school, work and group activities until five days of antibiotic therapy have been completed.
Household members and other close contacts of someone who has pertussis should receive antibiotics to prevent the illness. Serious complications from pertussis are most common among children under the age of 1. They include pneumonia, encephalopathy (brain inflammation), and in rare cases, death.
"This is a good reminder for everyone to get vaccinated as the best defense against whooping cough, and to look for symptoms of the disease," says Deputy State Epidemiologist Susan Schoenfeld. "We are seeing a resurgence in pertussis cases in other areas of the country, and this is a real concern for public health officials nationwide."
The last widespread outbreak of pertussis in Vermont occurred in 1996 and 1997. A total of 280 cases were identified in 1996, including 171 cases in school-aged children in 69 Vermont schools. In 1997, there were 283 cases.
The earlier that a person, especially an infant, starts on treatment for whooping cough, the better. The infection usually begins with mild upper respiratory symptoms and an irritating cough that gradually worsens to include possible whooping, short periods without breathing, or vomiting.
School and child care entry laws in Vermont require multiple doses of a pertussis-containing vaccine, depending on the age of the child. However, Vermont allows parents to opt out of vaccines on medical, religious or philosophical grounds. When pertussis is identified in a school, letters are often sent to parents to inform them of the illness, describe symptoms of pertussis, and encourage parents to have children with symptoms examined by a health care provider. While immunization is the best protection against pertussis, it's possible for fully vaccinated children to develop the illness, though they often have milder disease.
Immunity to the disease can also wane over time. The adolescent/adult pertussis booster vaccine (Tdap) should be given to all Vermonters ages 10 and older. The health department urges anyone who has close contact with infants to get the Tdap vaccine.
Why is Vermont's rate of childhood vaccinations falling? Health experts suggest that, in one respect, the state's immunization program is a victim of its own success. Most Vermonters, including many health care providers who’ve never treated patients outside the United States, have never seen the painful and often debilitating consequences of vaccine-preventable diseases such as polio, measles, pertussis and diphtheria.
For more details on pertussis, visit the Health Department website at healthvermont.gov.
Top photo courtesy Vermont Department of Health.