Haemophilus influenzae Agent Information Sheet
Boston University
Research Occupational Health Program (ROHP)
617-358-7647
Agent
Haemophilus influenzae is an anaerobic, Gram negative coccobacillus that is non-motile and non-acid-fast. It is a respiratory tract membrane obligate parasite that requires hemin and NAD for in vitro growth. H .influenzea is classified into six antigenically distinct serotypes (a to f) based on capsular polysaccharide antigen.
Disease/Infection
Invasive disease caused by Haemophilus influenzae can affect many organ systems. causing pneumonia, occult febrile bacteremia, meningitis, epiglottitis, septic arthritis, cellulitis, otitis media, purulent pericarditis, and other less common infections such as endocarditis, and osteomyelitis.
Pathogenicity
Infection with Haemophilus influenzae (type b) can cause meningitis (50% of all cases – adults and children), epiglottitis (17%), pneumonia (15%), septic arthritis (8%), cellulitis (6%), osteomyelitis (2%), or generalized bacteremia (2%). A small proportion of children (0.5-3%) children will have asymptomatic infections. Small percentage of exposed can be colonizers of type b (<1% in vaccinated, 2-4% in unvaccinated).
Biosafety Information
Risk Group/BSL
Risk Group 2
Biosafety Level 2 Practice
Modes of Transmission
| Transmission | |
| Skin Exposure (Needlestick, bite, or scratch): | Yes |
| Mucous Membrane Splash to Eye(s), Nose or Mouth: | Yes, Direct contact with mucous membranes |
| Inhalation: | Yes |
| Ingestion: | Unlikely |
Host Range/Reservoir
Host Range – Hib is a human obligate parasite
Reservoir – Humans are the only known reservoir
Symptoms
Symptoms associated with H. influenza type b may include: edema and inflammation of the epiglottis, severe sore throat, fever, localized tissue inflammation, and pericarditis. Systemic disease can present as meningitis, pneumonia, bacteremia without localized infection and septic arthritis.
Incubation period
2-4 Days
Viability
Phenolic disinfectants, 1% sodium hypochlorite, 70% ethanol, formaldehyde, glutaraldehyde, iodophor and peracetic acid are effective against Hib
Survival Outside Host
Hib does not survive long term in the environment, but can survive more than 18 hrs in mucous and 12 hrs on plastic
Information for Lab Workers
Laboratory PPE
Laboratory coat, gloves, eye protection must be worn when in contact with infectious materials.
Containment
Biosafety Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, and cultures.
In Case of Exposure/Disease
- For injuries in the lab which are major medical emergencies (heart attacks, seizures, etc…):
- Medical Campus: call or have a coworker call the Control Center at 4–4144.
- Charles River Campus: call or have a coworker call campus security at 617-353-2121.
You will be referred to or transported to the appropriate health care location by the emergency response team.
- For lab exposures (needle sticks, bite, cut, scratch, splash, etc…) involving animals or infectious agents, or for unexplained symptoms or illness call the ROHP 24/7 hour number (1-617-414-ROHP (7647); or, 4-ROHP (7647) if calling from an on-campus location) to be connected with the BU Research Occupational Health Program (ROHP) medical officer. ROHP will refer you to the appropriate health care location.
- Under any of these scenarios, always inform the physician of your work in the laboratory and the agent(s) that you work with.
- Provide the wallet-size agent ID card to the physician.
Vaccination
Vaccination targets the PRP antigen and is effective for Haemophilus influenzae (Hib) Type B but not other Haemophilus influenzae serotypes. It is given as part of the child series of vaccinations. The vaccine was introduced in the U.S. in 1987. For people working with Type B Haemophilus influenzae, one dose of Haemophilus Influenzae (Hib) vaccine before work with agent if never vaccinated.
Information for First Responders/Medical Personnel
Public Health Issues
Droplet precautions should be utilized for epiglottitis and meningitis. Hib is not highly contagious person to person, but secondary infection may occur in the case of particularly close contact with patients and is non-communicable 48 h after initiation of efficient antibiotic treatment.
Diagnosis/Surveillance
Monitor for symptoms. Diagnosis is most often confirmed by bacterial culture. Newer techniques include detection of the PRP polysaccharide by latex agglutination or countercurrent immunoelectrophoresis and PCR.
First Aid/ Post Exposure Prophylaxis
Rifampin prophylaxis is indicated for direct contacts). Pregnant women should not receive prophylactic treatment.
Perform one of the following actions:
| Skin Exposure (Needlestick or scratch): | Immediately go to the sink and thoroughly wash the wound with soap and water for 15 minutes. Decontaminate any exposed skin surfaces with an antiseptic scrub solution. |
| Mucous Membrane Splash to Eye(s), Nose or Mouth: | Exposure should be irrigated vigorously. |
| Splash Affecting: Garments: | Remove garments that may have become soiled or contaminated and place them in a double red plastic bag. |
Treatment
The primary treatment for Hib is appropriate antibiotics. Intravenous antibiotics, (cefotaxime and ceftriaxone are preferred) are often required but depending on illness, oral administration may follow for 7-10 days. Adult doses are ceftriaxone, 2 g every 12 hours, or cefotaxime, 2 g every 4 to 6 hours. Patients with complications such as endocarditis, pericarditis, or osteomyelitis may require 3 to 6 weeks of therapy. If airways are blocked, more invasive procedures may be indicated.
References
Public Health Agency of Canada. Material Safety Data Sheets. Infectious Substances.
http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/haemophilus-influenzae-eng.php
CDC – http://www.cdc.gov/hi-disease/index.html
Revised: 3/6/24