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 spreads from respiratory droplets when an infected person breathes, coughs, sneezes or talks.

An infected person can spread Hib as long as the bacteria is still in their body, which may be for a long time if they do not receive appropriate antibiotic treatment.

A person is usually no longer infectious after 24 to 48 hours of effective antibiotic treatment.

Symptoms may start two to four days after being exposed to the bacteria. Some people may not get symptoms. During this time, they can still pass on the bacteria to others.  

Hib occurs mostly in children under five years of age 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.

Symptoms of serious illness may include: 

  • Sudden fever 
  • Drowsiness 
  • Intense headache 
  • Vomiting 
  • Stiff neck and back 

          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. Hib vaccination is part of Ontario’s Publicly Funded Routine Immunization Schedule. 

          Usually, one vaccine (e.g. DTap-IPV-Hib ) is given at two, four, six and 18 months of age to protect against diphtheria, tetanus, pertussis, polio and haemophilus influenzae type b (Hib). The risk of Hib goes down as a child gets older. 

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

          If you or your child misses a vaccine or is due for the next dose, these vaccines are available from a health care provider’s office (as a single vaccine or combination vaccine such as DTap-IPV-Hib) or at aTPH community vaccine clinic for school-aged children.

          If you or your child(ren) were in close contact with someone with Hib, watch for symptoms for four days after your last contact with that person. 

          If you think you or your child may have a Hib infection, it is important to: 

          • Seek medical care right away. Call before visiting a clinic or hospital so they can prepare for your arrival and stop virus spread. 
          • Stay home and away from others while you are sick to prevent spread.
          • Wear a well-fitting, high-quality mask (e.g. surgical mask, N95) if you need to go out. 
          • Wash or sanitize your hands often and cover your cough or sneeze with your elbow or a tissue. 

              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.