Emerging pathogens may present challenge in choosing acute otitis media treatment

Issue: February 2009

21st Annual IDC NY Symposium

Understanding the shifts in the pathogens that cause otitis media and sinusitis may assist in making better antimicrobial agent choices.

“We clearly are seeing more Haemophilus influenzae and more are beta-lactamase–resistant,” said Michael E. Pichichero, MD, professor of microbiology and immunology, medicine and pediatrics at the University of Rochester School Of Medicine, New York, and an Infectious Diseases in Children Editorial Board member.

In a nine-year, prospective study conducted by Pichichero, Janet Casey, MD, and colleagues, researchers followed 551 children with acute otitis media to examine whether the causative pathogens in persistent AOM had changed in frequency or distribution following the introduction of high-dose amoxicillin therapy and pneumococcal conjugate vaccination.

Results indicated that “H. influenzae has become the predominant pathogen of persistent AOM and AOM treatment failure since universal immunization with the pneumococcal conjugate vaccine [PCV7, Prevnar, Wyeth].” The researchers added that more Streptococcus pneumoniae AOM isolates are becoming penicillin resistant again and more H. influenzae are beta-lactamase–producing.

In another 2007 study conducted by Casey et al, data suggested an emergence in non-PCV7 serotypes since 2003; 80% were penicillin-resistant.

“Although the current AAP/AAFP guidelines endorse amoxicillin high dose (90 mg/kg/day), the better antibiotic selection would be amoxicillin/clavulanate high dose, or if tolerability is an issue, then one of the AAP/AAFP–recommended cephalosporins,” Pichichero said. – by Jennifer Southall

For more information:
Pichichero ME. New research in otitis media and sinusitis 2008. Presented at: 21st Annual IDC NY Symposium; Nov. 22-23, 2008; New York.
Pediatr Infect Dis J. 2004;23:824-828.
JAMA. 2007;298:1772-1778.