Rheumatic Fever's Decline
Nonrheumatogenic types of group A streptococcus may be replacing rheumatogenic types in cases of acute streptococcal pharyngitis in children, said Dr. Stanford T. Shulman of Northwestern University and his colleagues.
This change could be contributing to the decline of acute rheumatic fever among children in the United States, based on a comparison of data on M-type isolates from children in Chicago during 1961–1968 with data from children in Chicago and nationwide during 2000–2004 (CID 2006;42:441–7).
Several rheumatic types of group A streptococcus were present in nearly 50% of 468 pharyngeal isolates from the 1961–1968 period, but comprised only 11% of 450 isolates from the Chicago area and 18% of 3,969 isolates nationwide during the 2000–2004 period.
In contrast, the proportion of several nonrheumatogenic types increased significantly between the study periods, from about 5% to nearly 28% of isolates both in Chicago and nationwide.
Rheumatic types 14, 18, 19, and 29 essentially vanished during the years between the two study periods. The other most significant decreases occurred in rheumatic types 3, 5, and 6, which comprised 35% of the Chicago isolates during the first study period, when acute rheumatic fever was still prevalent, but only 10% of Chicago isolates during the second study period, when acute rheumatic fever had become rare.
Predictive Model of Lyme Meningitis
Three conditions—a long-lasting head-ache, the presence of cranial neuritis, and a predominance of cerebral spinal fluid mononuclear cells—can predict Lyme meningitis in children aged 2–13 years, said Dr. Robert A. Avery of the Alfred I. duPont Hospital for Children in Wilmington, Del., and his colleagues.
Data from a study of 27 children with Lyme meningitis (LM) and 148 children with aseptic meningitis (AM) provide the first model to distinguish between the two conditions in areas where Lyme disease is endemic (Pediatrics 2006;117:1–7).
Overall, 16 of the 27 (59%) patients with LM experienced headaches longer than 3 days' duration, compared with 37 of 148 (25%) patients with AM. The average duration of headache was 7.5 days among LM patients vs. 2.8 days among AM patients.
In addition, 15 (56%) of the LM patients had cranial neuritis, compared with 5 (3%) of the AM patients. Finally, the average percentage of mononuclear cells in samples of cerebrospinal fluid was 87% among the LM patients vs. 58% among the AM patients, and 19 (70%) of the LM patients had CSF mononuclear cell levels greater than 86% compared with 42 (28%) of the AM patients.
However, high levels of CSF mononuclear cells are not specific to LM alone, and this finding must be supported by longer-lasting headaches and the presence of cranial neuritis for an LM diagnosis, the researchers noted. All three conditions made statistically significant contributions to the prediction model.
Based on a regression analysis in which all three conditions were considered, the odds ratio for LM for each variable was 2.9 for a patient with a headache lasting 14 days, 3.4 for a patient with 90% CSF mononuclear cells, and 16.9 for a patient with cranial neuritis.
Flu Shots a Must in Kids With NNMD
Flu shots are de rigueur for children with neurologic and neuromuscular diseases given their high risk of influenza-related respiratory failure.
“Children with pulmonary disease, cardiac disease, or NNMD [neurologic and neuromuscular disease] had approximately a 10% probability of respiratory failure” during a hospitalization for influenza, Dr. Ron Keren and colleagues reported. “Having two of the three chronic conditions increased the probability another three- to fourfold” (JAMA 2005;294:2188–94).
Dr. Keren, of the Children's Hospital of Philadelphia, and associates examined rates of respiratory failure in 745 children and adolescents (aged 21 years and younger) in 2000–2004. Eighty-nine (12%) had an NNMD, most commonly cerebral palsy (40%), seizure disorders (42%), and hydrocephalus/cerebrospinal fluid shunt (30%).
During the study period, 32 children developed respiratory failure; 14 of those had an NNMD, a sixfold increased risk compared with those with no chronic health problem. This risk was higher than that associated with pulmonary disease (OR 5.0) or cardiac disease (OR 4.0), both of which are accepted indications for an annual childhood influenza vaccine.