Haemophilus influenzae type b (Hib), is a type of bacteria that can cause very serious illness, and even death, especially in infants and children under five years old. Even though it has the word “influenzae” in its name, it has nothing to do with the influenza (flu) virus.

Before the vaccine, Hib was the most common cause for meningitis (infection of the brain) in very young children, which can lead to brain damage, hearing loss, blindness, and learning or developmental difficulties. Hib can also cause epiglottitis (an infection of the tissue in the throat), pneumonia (an infection of the lungs), and bacteremia (an infection of the blood).

The risk of infection in Canada is low, but as long as Hib exists in other countries, there is still a chance of getting it. Getting vaccinated is the best way to protect you and your child from getting Hib.

Hib bacteria enters the body through the nose or mouth. It can spread easily to others through close contact with respiratory droplets of someone who is infected with the bacteria, such as from talking, coughing, or sneezing.

It can take two to four days for people with an infection to show symptoms, and some people may never get symptoms. During this time, they can still pass on the bacteria to others. People with an infection can spread the disease if the Hib bacteria is still in their body, which may be for a long time if they do not receive appropriate antibiotic treatment.

Hib occurs mostly in children under five years old and adults 65 years or older. The symptoms can be mild or severe. The most common infections are in the nose and throat, and sometimes can cause flu-like symptoms. Symptoms of Hib depend on the type of infection and which part of the body is infected.

In rarer cases, the bacteria can enter other parts of the body including the brain, heart, bones and skin. This type of infection may lead to very serious illness including meningitis (an infection of the lining that covers the brain), epiglottitis (an infection of the tissue in the throat), pneumonia (an infection of the lungs), and bacteremia (an infection of the blood).

The most important way to prevent Hib is to make sure you and your child(ren) are vaccinated. In Canada, Hib vaccination is part of Ontario’s Publicly Funded Routine Immunization Schedule.

  • Usually, one vaccine (e.g. DTap-IPV-Hib) is used to protect against diphtheria, tetanus, pertussis, polio and Hib
  • Five doses are given, each at two, four, six, and eighteen months of age, and a booster dose at four to six years of age
  • It’s available from a health care provider’s office (as a single vaccine or a combination vaccine such as DTap-IPV-Hib) or a City Immunization Clinic (through the Dtap-IPV-Hib vaccine that also protects against diphtheria, tetanus, pertussis and polio)

Hib vaccines are safe, are about 95 to 100 percent effective at preventing a Hib infection, and free to eligible groups.

If your child misses a vaccine or is due for their next dose, these vaccines are available from a health care provider’s office. Students in Junior Kindergarten to Grade 12 can also receive vaccines at a City Immunization Clinic.

If you think you or your child might have a Hib infection, call a health care provider right away. You can also call 811  (TTY: 1-866-797-0007) to talk to a registered nurse 24 hours a day, seven days a week. Calls to 811 do not need you to provide your OHIP number and all information is free, secure, and confidential.

Hib is diagnosed by a health care provider based on symptoms and laboratory tests. The most common tests use a sample of blood or spinal fluid to check for Hib bacteria.

People diagnosed with Hib are given antibiotics to treat the infection. Depending on how serious the infection is, some people may need to stay in a hospital. In some cases, close contacts of the case may also be recommended to receive antibiotics to prevent further infection.

For more information, talk to a health care provider or call 811  (TTY: 1-866-797-0007) to talk to a registered nurse 24 hours a day, 7 days a week for information that is free, secure, and confidential. You can also call Toronto Public Health at 416-338-7600.