In summary, although there is a slight increase in injection site events with decreasing interval since a previous immunization, Tdap can be safely administered at intervals of greater than or equal to 18 months since a previous TD/Td vaccine.—LC
Viral Occurrences in Young Children
Wolf DG, Greenberg D, Kalkstein D, et al. Comparison of human metapneumovirus, respiratory syncytial virus and influenza A virus lower respiratory tract infections in hospitalized young children. Pediatr Infect Dis J. 2006;25(4):320-324.
The authors compared the clinical and demographic features of children with lower respiratory tract infection (LRI) caused by human metapneumovirus (HMPV), respiratory syncytial virus (RSV), and influenza A virus and sought to determine whether coinfection by HMPV and other respiratory viruses leads to increased disease severity.
This prospective study enrolled 516 children <5 years old who were admitted with LRI at the Soroka University Medical Center in Israel during a one-year period from November 2001 through October 2002. At least one virus was detected in 57% of the enrolled patients.
Of those 293 patients, the viral breakdown was as follows: HMPV (13%), RSV (20%), influenza A (15%), parainfluenza (7%), and adenovirus (2%). The seasonal distribution of HMPV infections resembled those of RSV and influenza with peak incidence between November and March. Twenty-four percent of the HMPV children had co-infections with other respiratory viruses, most commonly RSV.
HMPV patients were older than RSV patients (17.6 +/- 16.8 months versus 10.5 +/- 11.8 months). HMPV was associated with wheezing and hypoxemia at a rate similar to that of RSV and higher than that of influenza A. Atelectasis was more common among HMPV (40%) than among RSV and influenza patients (13%). HMPV was more often associated with a diagnosis of pneumonia than RSV and influenza. HMPV was also more often associated with a diagnosis of asthma and less often with a diagnosis of bronchiolitis than RSV, even when corrected for age. Children who had a co-infection with HMPV had a higher rate of gastrointestinal symptoms but did not show a more severe respiratory picture.
In conclusion, the clinical pattern of HMPV (wheezing, hypoxemia) more closely resembles that of RSV than that of influenza A LRI. Additionally, there was no difference in disease severity between children with HMPV and RSV infection. However, the differences in age, radiographic findings, and clinical diagnosis suggest that HMPV pathogenesis may differ from that of RSV.—LC
Kawasaki Disease in Infants Younger Than Six Months
By Judith Waldman, DO
Chang FY, Hwang B, Chen SJ, et al. Characteristics of Kawasaki disease in infants younger than six months of age. Pediatr Infect Dis J. 2006 Mar;25(3):241-244.
Pi-Chang Lee, MD, and colleagues compared the clinical manifestations, laboratory results, echocardiographic findings, treatment, and outcome between two groups of patients hospitalized with Kawasaki disease. Group one consisted of 20 patients younger than six months. Group two consisted of 100 patients older than six months. The data was collected by chart review.
Researchers found that the time from onset of disease to diagnosis was longer in infants younger than six months. Patients less than six months of age had a higher incidence of incomplete Kawasaki disease. A presentation of full diagnostic criteria within 10 days occurred more frequently in patients greater than six months of age. There was no significant difference in major clinical manifestations between the two groups. However, the frequency of gallbladder hydrops was higher in patients older than six months of age.
Group one had higher white blood cell counts, platelet counts, and triglyceride concentrations and lower hemoglobin values. Group one had higher incidence of coronary involvement, including irregular surface and/or perivascular brightness of coronary artery wall, coronary dilatation, and aneurysm formation. There was no significant difference in giant aneurysm formation between the two groups. Group one had a higher incidence of pericardial effusion and tricuspid regurgitation/mitral regurgitation. Fewer patients received IVIG within 10 days in the younger age group. Diagnostic delay and incomplete presentation postponed IVIG in the patients less than six months of age.