BAL HARBOUR, FLA. — One of the most interesting pediatric infectious disease papers in the past year—according to Ralph D. Feigin, M.D.—suggests that cephalosporins are superior to penicillin for the treatment of group A beta-hemolytic streptococcal tonsillopharyngitis in children.
But take a closer look at the metaanalysis before changing your approach to the treatment of this common condition, Dr. Feigin advised at the annual Masters of Pediatrics conference sponsored by the University of Miami.
The authors included 35 trials involving 7,125 patients in their study, and found that the overall odds ratios for bacteriologic and clinical cure rates significantly favored cephalosporins. They concluded that the likelihood of treatment failure is less if an oral cephalosporin is used for treatment (Pediatrics. 2004;113:866-82).
However, the failure to exclude group A beta-hemolytic streptococcus (GABHS) carriers in some of the clinical trials included in the metaanalysis is of concern, said Dr. Feigin, chairman of the department of pediatrics at Baylor College of Medicine, Houston.
Cephalosporins have been shown to be superior to penicillin for eradicating the GABHS carrier states, so the inclusion of a high proportion of carriers would skew the results in favor of cephalosporins in those studies; the statistical analysis used in the metaanalysis fails to adequately address this issue, he said.
Furthermore, only 6 of the 35 studies included were double blinded, and only 9 were investigator blinded. Eleven studies did not include typing of organisms to determine if positive follow-up cultures represented new infection.
The numerous cephalosporins represented in the studies—11 were used in the 35 studies—and lack of compliance testing in 9 of the studies, were also items of concern, Dr. Feigin said.
Penicillin has a narrower spectrum and much lower cost than many of the cephalosporins included in the metaanalysis, and it is effective for shortening disease course and limiting suppurative sequelae and transmission. Studies have shown that penicillin is effective for preventing acute rheumatic fever—even when it is initiated 9 days after onset of acute illness. Therefore, it should not be discounted as a drug of choice for GABHS tonsillopharyngitis, he said.
Other topics among Dr. Feigin's picks for the most interesting papers of the year were:
▸ Linezolid vs. vancomycin for treatment-resistant gram-positive infections in children. Linezolid was shown in this study of more than 300 hospitalized children with serious gram-positive infections to be effective and well tolerated (Pediatr. Infect. Dis. J. 2003;22:677-85).
The children were randomized to receive either 10 mg/kg of intravenous linezolid every 8 hours followed by oral linezolid, or to receive 10-15 mg/kg every 6-24 hours followed by an oral agent as appropriate. The pathogen eradication rates for methicillin-susceptible S. aureus and for methicillin-resistant coagulase-negative staphylococci were high in both groups and did not differ significantly.
Significantly more days of IV therapy were required with vancomycin (10.9 vs. 8.0 days) and significantly more patients had adverse drug-related events with vancomycin (34% vs. 19% of patient).
But if this study has you thinking about using linezolid instead of vancomycin—think again, Dr. Feigin advised. To postpone development of resistance to this newer drug for as long as possible, reserve it for use only in patients with infections for which other agents cannot be used, he said.
▸ Human metapneumovirus and lower respiratory tract disease. A new RNA virus known as human metapneumovirus was identified in 2001, and this 2004 study showed that the virus might be the cause of a considerable number of respiratory illnesses in children. Of 248 specimens from children from whom no virus was previously isolated, 49 were found to be associated with metapneumovirus. About 25% of the infections were in children under age 6 months, and 49% were in those ages 6 months to 1 year (N. Engl. J. Med.2004;350:443-50).
The findings suggest that this is a relatively frequent cause of lower respiratory tract infection in children. It was also found in 15% of children with upper respiratory infections, Dr. Feigin noted.
▸ Monkeypox detection. A series of cases of monkeypox in children and adults in 2003 was traced to prairie dogs, which were shown in an epidemiological investigation to have been infected by exposure to giant Gambian rats. The human infections, as shown in this 2004 study, were associated with direct contact with sick prairies dogs kept or sold as pets (N. Engl. J. Med. 2004;350:342-50).
The study involved five males and six females ranging in age from 3 to 43 years, but a total of 35 cases were confirmed in a 2003 outbreak and another 36 were suspected, Dr. Feigin said.