It's also important to document vaccine status and to identify coughing family members. In most cases an adult, often the mother, is the vector for infection in a young infant.
Vaccine status had not been recorded for 48% of patients aged 2 months or older. Specific information regarding the number of pertussis-containing vaccine doses received was infrequently recorded. Contact isolation was discussed in just 8% of cases, despite the fact that restriction from school attendance is very important in school-aged children. Household chemoprophylaxis had been provided in just 51%, and of those diagnosed where vaccine status could be ascertained, just 10% were appropriate for age.
Attempts to document vaccine status are notoriously difficult as many parents do not carry an immunization card, and obtaining details from a public health department or primary care office after hours is nearly impossible. A check of the box “vaccines up to date” relies on simply asking the parent who may or may not know for sure the child's vaccine status.
Among those who had been tested for pertussis, correct treatment was prescribed in just 62%. In many cases, therapy was not optimal: In some cases, amoxicillin was prescribed when otitis was concurrently diagnosed, while in others a macrolide was given but in the wrong dose. For pertussis, a correct regimen would be 10–12 mg/kg per day of azithromycin for each of 5 days, as opposed to 10 mg/kg per day on day 1 followed by 5 mg/kg per day for days 2–5 for otitis media.
And we know that pediatricians are often reluctant to write prescriptions for adults, even though pertussis is highly transmissible and the sooner chemoprophylaxis is given, the better the chance to interrupt transmission. An adult with the disease presents a threat to a young infant living in the same household. (The adult dose is 500 mg/day azithromycin for 5 days.)
Indeed, after educating our local pediatricians about treating pertussis presumptively, we have seen a drop in cases thus far in 2005.
Pertussis Case Definition
Clinical Case Definition
▸ A cough illness lasting at least 2 weeks with one of the following: paroxysms of coughing, inspiratory “whoop,” or posttussive vomiting, and without other apparent cause (as reported by a health professional).
Laboratory Criteria for Diagnosis
▸ Isolation of Bordetella pertussis from a clinical specimen or positive polymerase chain reaction (PCR) assay for B. pertussis.
Case Classification
▸ Confirmed: an acute cough illness of any duration associated with B. pertussis isolation; or a case that meets the clinical case definition and is confirmed by PCR; or a case that meets the clinical case definition and is epidemiologically linked directly to a case confirmed by either culture or PCR.
▸ Probable: meets the clinical case definition, is not laboratory confirmed, and is not epidemiologically linked to a laboratory confirmed case.
Both probable and confirmed cases should be reported to the local health department.
Source: Centers for Disease Control and Prevention and the Council of State and Territorial Epidemiologists