From the Guidelines
The treatment of Haemophilus parainfluenzae bacteremia should involve ceftriaxone 2g IV daily for 4 weeks, as recommended by the most recent guidelines 1. This recommendation is based on the guidelines for the management of patients with valvular heart disease, which include recommendations for the treatment of HACEK microorganisms, including Haemophilus parainfluenzae 1.
Key Considerations
- Ceftriaxone is the first-line therapy due to its effectiveness against HACEK microorganisms, including Haemophilus parainfluenzae 1.
- Alternative options, such as ampicillin-sulbactam or ciprofloxacin, may be considered in cases of beta-lactam allergy or intolerance, but fluoroquinolones are generally not recommended for patients under 18 years old 1.
- Treatment duration may need to be extended to 6 weeks in cases of prosthetic valve endocarditis or other complicated infections 1.
- Source identification and control are crucial in the management of Haemophilus parainfluenzae bacteremia, as the infection may originate from respiratory, oral, or genitourinary sources.
- Antimicrobial susceptibility testing should guide therapy adjustments, as beta-lactamase production is common in Haemophilus species.
- Supportive care, including fluid management and monitoring for sepsis complications, is essential alongside antimicrobial therapy.
Additional Recommendations
- Blood cultures should be repeated to confirm clearance of bacteremia.
- For uncomplicated cases with good clinical response, transition to oral therapy may be considered after 3-5 days of IV treatment.
- Endocarditis should be ruled out in cases with persistent bacteremia, as H. parainfluenzae can cause endocardial infections requiring longer treatment courses.
From the FDA Drug Label
Ceftriaxone for Injection is indicated for the treatment of the following infections when caused by susceptible organisms: ... BACTERIAL SEPTICEMIA Caused by ... Haemophilus influenzae Levofloxacin tablets are indicated for the treatment of adults (≥ 18 years of age) with mild, moderate, and severe infections caused by susceptible isolates of the designated microorganisms in the conditions listed in this section ... 1. 11 Acute Pyelonephritis: 5 or 10 Day Treatment Regimen Levofloxacin tablets are indicated for the treatment of acute pyelonephritis caused by Escherichia coli, including cases with concurrent bacteremia
- Treatment options:
- Ceftriaxone (2) may be used to treat Haemophilus parainfluenza bacteremia.
- Levofloxacin (3) is indicated for the treatment of infections caused by Haemophilus parainfluenzae, but its use in treating bacteremia is not explicitly stated, except in the case of acute pyelonephritis with concurrent bacteremia caused by Escherichia coli.
- Key consideration: The choice of antibiotic should be guided by susceptibility testing and local epidemiology.
From the Research
Treatment of Haemophilus parainfluenzae Bacteremia
- The treatment of Haemophilus parainfluenzae bacteremia typically involves the use of antibiotics, with the choice of antibiotic depending on the susceptibility of the isolate 4, 5, 6.
- According to a study published in 1979, patients with Haemophilus parainfluenzae infections did well with antibiotic therapy, and there were no deaths 4.
- The same study found that 6% of isolates were resistant to ampicillin, and all were sensitive to chloramphenicol, suggesting that chloramphenicol may be a suitable alternative if the antibiotic sensitivity of the organism is unknown 4.
- A more recent study published in 2004 found that the most active drugs against Haemophilus parainfluenzae were levofloxacin, cefditoren, cefotaxime, cefpodoxime, and amoxicillin/clavulanate 5.
- However, another study published in 2016 reported a clinical isolate of Haemophilus parainfluenzae with cefotaxime resistance and decreased susceptibility to fluoroquinolones, highlighting the need for regular surveillance of resistance patterns 7.
- The 1977 study found that all strains of Haemophilus parainfluenzae tested were susceptible to chloramphenicol, kanamycin, gentamicin, cephalothin, and colistin, but three strains were resistant to ampicillin, and eight were resistant to tetracycline 6.
Antibiotic Resistance
- The emergence of antibiotic-resistant strains of Haemophilus parainfluenzae is a concern, and regular surveys of resistance patterns are necessary to guide treatment decisions 5, 7.
- The 2016 study found that the clinical isolate of Haemophilus parainfluenzae had a β-lactamase-producing amoxicillin-clavulanic acid-resistant (BLPACR) phenotype, and substitutions in the PBP3 and gyrA and parC genes were detected 7.
- The 1977 study found that the three ampicillin-resistant strains of Haemophilus parainfluenzae tested had elevated minimal inhibitory concentrations for penicillin and carbenicillin, and produced beta-lactamase 6.