Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatmentPrevention
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Prevention
Haemophilus influenzae type b (Hib)—not to be confused withseasonal influenza—is a vaccine-preventable disease that is particularly dangerous for young children. Advanced infections can cause potentially serious complications like meningitis, pneumonia, and sepsis.
Hib disease is now rare in the United States, but it continues to be a serious childhood illness in areas where the vaccine isn’t widely available.
FatCamera / Getty Images
Hib bacteria get into the body through the nose and mouth, where it can linger for a while without causing any symptoms. In some cases, however, the bacteria spread to the bloodstream and to other parts of the body. This is called invasive Hib disease.
Invasive Hib disease can affect multiple organ systems and lead to serious complications including meningitis, epiglottitis, pneumonia, septic arthritis, cellulitis, and bacteremia.
Meningitis
The most common mark of invasive Hib disease isbacterial meningitis, or inflammation around the brain and spine. Prior to widespread vaccination, Hib meningitis occurred in50 to 65%of cases and was the most commoncause of bacterial meningitisin kids under five years old.
Symptoms of Hib meningitis include:
Most people with Hib meningitis survive, but the disease can permanently affect their health and development. In the prevaccine era, about15 to 30%of survivors experienced hearing loss or brain damage, and about3 to 6%died—even with appropriate treatment.
Epiglottitis
Hibepiglottitisis when the bacteria infect the epiglottis (the throat tissue that keeps food and liquids from getting into the respiratory tract), sometimes causing swelling so severe it blocks the airway. Epiglottitis occurred in about17%of Hib cases prior to widespread vaccination.
Some symptoms of epiglottitis include:
Pneumonia
Pneumonia(an infection of the lungs) is another common complication of invasive Hib disease, occurring in about15%of cases in the prevaccine era.
Signs and symptoms of pneumonia can vary, but they generally include flu-like symptoms like chills, fever, and nasal congestion, productive cough, chest pain, fast breathing (in children), body aches, fatigue, vomiting (in children), and bluish skin color.
Septic Arthritis
Septic arthritis is a joint infection that happened in roughly 8% of Hib cases prior to the introduction of the vaccine.This happens when Hib bacteria infect the joint (typically a large one like a knee or hip), causing significant discomfort.
Cellulitis
Skin infections (orcellulitis) are another common complication of invasive Hib disease. This occurred in roughly 6% of pre-vaccination era cases—most often in young children—and typically affected the face, head, or neck. The most common symptom of cellulitis is red, tender, and/or swollen skin.
Bacteremia
Infections that spread to the bloodstream are calledbacteremia(also called sepsis). Symptoms of Hib bacteremia include flu-like symptoms, like fever, chills, and fatigue, abdominal pain, nausea and/or vomiting, anxiety, difficulty breathing, and confusion.
There are multiple types ofHaemophilus influenzae, but type b (commonly referred to as Hib), has historically been the most severe.
Before the development of an effective vaccine, Hib caused the overwhelming majority—roughly 95%—of seriousHaemophilus influenzaeinfections.
It’s uncertain exactly how Hib bacteria spread, but scientists think it passes from one person to the next through respiratory droplets (through coughing or sneezing). As a result, people are generally exposed to Hib after being in close contact with someone who is infected, such as at home or in a childcare setting.
While it’s not exactly clear what causes some cases to jump from a mild infection to an invasive one, it’s possible that other respiratory diseases play a role. For example, if someone is already trying to fight off a virus like influenza, the Hib bacteria might have an easier time spreading in the body. In fact, Hib disease has been acommon co-infectionduring past flu pandemics.
At-Risk Populations
Certain individuals are more like to get invasive Hib disease than others. Like many vaccine-preventable diseases, Hib mainly affects young children. Prior to widespread vaccination, Hib accounted for 50 to 65% of cases of meningitis in kids under five years old and was the most common cause of bacterial meningitis in these kids.
Those most likely to get Hib include unvaccinated children and people close to them, as well as individuals with weakened immune systems, including those with certain medical conditions like:
Because Hib can look like a lot of other bacterial infections, healthcare providers often rely on lab tests, in addition to a person’s medical history and physical exam, to diagnose the disease and recommend treatment. If positive for Haemophilus influenzae, local health officials might also want to run tests to figure out if the infection is due to type b or some other subtype.
Physical Exam
Before diagnosing Hib, healthcare providers will first take a medical history and look for signs or symptoms of invasive Hib disease or any of its complications. For young children, in particular, practitioners will likely check vaccination records to see if the child has received any or all of therecommended doses of the Hib vaccine.
The healthcare provider might also ask about any contact the child might have had with someone (especially household contacts or caregivers) with a known Hib infection.
Lab Tests
One of the most common ways labs test samples for Hib bacteria is through a culture, where the sample fluid is placed in a special kind of container to see if Haemophilus influenzaebacteria grow.
Serotyping
Hib disease can be treated effectively with antibiotics, but additional care might be needed to help manage symptoms related to complications. People with invasive Hib disease (especially young children) are often hospitalized as a result of the infection.
Antibiotics
The most common medication used to treat Hib is a 10-day course of a third-generation cephalosporin (such as cefotaxime or ceftriaxone) or a combination of chloramphenicol and ampicillin.
Additional Support
Depending on the severity of the infection, individuals with Hib disease might also need treatment to help with symptoms or subsequent complications. These can include breathing support, blood pressure medication, wound care (due to skin infections), amputations (due to bacteremia), or long-term rehabilitation for brain damage or hearing loss (due to meningitis).
The Centers for Disease Control and Prevention recommends the following groups receive theHib vaccine:
While it’s rare, there are some people who shouldn’t be vaccinated against Hib.Those who have had a life-threatening allergic reaction to the Hib vaccine or any of its components shouldn’t get the vaccine, and those experiencing moderate to severe illnesses should wait until they get better before receiving a dose.
If you aren’t sure if you or your child should be vaccinated against Hib, talk to your healthcare provider or healthcare provider before vaccination.
A Word From Verywell
50 Anti-Vaccine Myths
2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Centers for Disease Control and Prevention.The Pink Book:Haemophilus influenzaetype b.
Centers for Disease Control and Prevention. About Haemophilus influenzae Disease.Centers for Disease Control and Prevention. Haemophilus influenzae type b. In: Epidemiology and Prevention of Vaccine-Preventable Diseases. Hamborsky J, Kroger A, Wolfe S, eds. 13th ed. Washington D.C. Public Health Foundation: 119-131.Centers for Disease Control and Prevention. Recommended Child and Adolescent Immunization Schedule for ages 18 years or younger, United States.
Centers for Disease Control and Prevention. About Haemophilus influenzae Disease.
Centers for Disease Control and Prevention. Haemophilus influenzae type b. In: Epidemiology and Prevention of Vaccine-Preventable Diseases. Hamborsky J, Kroger A, Wolfe S, eds. 13th ed. Washington D.C. Public Health Foundation: 119-131.
Centers for Disease Control and Prevention. Recommended Child and Adolescent Immunization Schedule for ages 18 years or younger, United States.
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
