A recent rise in illnesses due to pertussis, commonly known as whooping cough, should serve as a call to action to ensure all age groups are appropriately vaccinated against this disease to protect the most vulnerable, particularly very young infants, Dr. Mark Horton, director of the California Department of Public Health (CDPH), said today.
“Pertussis is a highly contagious disease,” Horton said. "Unimmunized or incompletely immunized young infants are particularly vulnerable. Illness in this age group frequently leads to hospitalization and can be fatal."
Almost twice as many pertussis cases have been reported in California in the first quarter of 2010 compared with the same time period last year. Two infants have died. The incidence of pertussis tends to peak every two to five years, Horton said. The last peak occurred in 2005 when California reported 3,182 cases, with 574 hospitalizations and seven deaths. The greatest number of cases occur in August and September of each year. Over the past decade, the disease has led to the deaths of between three and four infants annually in California. All were under three months of age. Many more became seriously ill and were hospitalized with complications, including pneumonia and brain damage.
Among vaccine-preventable diseases, pertussis is the most common. Although most children receive five doses of pertussis vaccine (DTaP) before kindergarten, immunization does not provide lifetime immunity. Most children are susceptible again by middle school age and remain susceptible into adulthood.
“Because pertussis vaccination does not begin until two months of age and infants are not fully immune until after six months of age, the only way to protect young infants from the disease is to do everything we can to minimize their exposure,” Horton said. "This means ensuring that their parents and caregivers are immunized.”
Studies have shown that half of the infants with pertussis are infected by their parents, particularly their mothers. Therefore, vaccinating parents and caregivers for pertussis before or at the birth of the child is the most important way to protect infants. In addition to the five doses of pertussis vaccine recommended before kindergarten, a booster dose of the vaccine is recommended for all adolescents between 11 and 18 years of age, and for all persons who will have close contact with young infants.
Pregnant women may be vaccinated with Tdap, which includes pertussis, before pregnancy, during pregnancy, or after giving birth. Fathers may be vaccinated at any time, but preferably before the birth of their baby. CDPH encourages birthing hospitals to implement policies to vaccinate new mothers and fathers before discharge home with their baby. Others who may have contact with infants, including other family members, healthcare workers, and childcare workers should also be vaccinated.
A typical case of pertussis in children and adults starts with a cough and runny nose for one-to-two weeks, followed by weeks to months of rapid coughing fits that sometimes end with a whooping sound. Fever is rare. Symptoms and disease characteristics in young infants are more variable.