The Clinical Features of Pertussis in Infancy / 소아감염

ABSTRACT

PURPOSE: Pertussis was very common in the past, but reported cases have dramatically decreased. The improvement of vaccination programs and unreadiness of laboratory confirmation seems to have developed this situation. This study investigated the frequency of pertussis among infants with a paroxysmal cough and compared the clinical characteristics between infants with and without pertussis. METHODS: Between June and November 2006, 27 infants admitted to the hospital that were 15-90 days old with a history of a cough for more than seven days were enrolled. The cough was described as paroxysmal, whooping, and post-tussive vomiting. PCR and cultures for Bordetella pertussis with nasopharyngeal aspirates were obtained. The patients were divided into two groups (1) the pertussis group that had positive results by PCR or culture; (2) the control group that had negative results by PCR and culture. Clinical and laboratory characteristics were compared between the two groups. RESULTS: Among the 27 cases, five (18.5%) were finally diagnosed with pertussis. Only one out of the five pertussis cases was initially diagnosed with a pertussis-like syndrome on admission. Compared to the group without pertussis, the pertussis group had a significantly higher frequency of no fever (P=0.043), a paroxysmal cough (P=0.040), cyanosis (P=0.001), non-immunized status for DTaP (P=0.047), normal auscultation (P=0.028), normal chest X-ray findings (P=0.027), high absolute lymphocyte count (P=0.039), and low CRP (P=0.046). The patients with the diagnosis of pertussis had a significantly longer duration of coughing (27.2+/-10.6 vs. 12.6+/-5.6 days, P=0.039). CONCLUSION: Pertussis should be suspected in any infant with typical symptoms of pertussis in addition to a persistent cough without fever, accompanied by paroxysms or cyanosis prior to the age of DTaP immunization. Active laboratory confirmation should be carried out to confirm more cases with pertussis.