Haemophilus influenzae (Hif) is an aerobic and facultatively anaerobic gram-negative coccobacillary microorganism which exists in encapsulated and nonencapsulated forms, both of which are capable of producing beta-lactamase. Although Hif constitutes part of the normal flora of many adults and children, it is capable of producing both limited severity infections such as otitis media and extremely serious diseases such as meningitis and pneumonia. Resistance of Hif to ampicillin and certain other antibiotics has been increasing in the United States. Beta lactamase production, the most common cause of Hif resistance, now occurs in approximately 20% of strains isolated (greater in serotype b than in non-type b strains). The incidence of resistance varies by geograhic region and even among individual institutions in a region. Due to these trends, the National Committee for Clinical Laboratory Standards now recommends that all clinical strains of Hif be tested for the presence of beta-lactamase. The mainstays of empiric treatment of serious Hif infections have been ampicillin and chloramphenicol. Due to increasing ampicillin resistance and toxicities that can occur with chloramphenicol, many clinicians are beginning to utilize newer agents such as cefotaxime, cefuroxime, and ceftriaxone intravenously for serious infections, and cefaclor, cefuroxime axetil, tetracycline (except in children < 8), amoxicillin with clavulanate, erythromycin/sulfisoxazole, and cefixime for oral therapy of less serious infections. The use of vaccines against Hif are now generally recommended for children greater than 18 months old. Hif is recognized as a major cause of infection in both adults and children. Problems of varying resistance patterns and the difficulties associated with obtaining culture results have prompted reevaluations of treatment recommendations for Hif infections. Knowledge of local resistance patterns and choice of antibiotics and appropriate doses will help reduce the risks of treatment failures.
|Original language||English (US)|
|Number of pages||6|
|State||Published - Jan 1 1990|
ASJC Scopus subject areas
- Pharmacology (medical)