Introduction:
Not long ago H influenzae type b (Hib) was the number one cause of bacterial meningitis. More than half of the cases of Hib infection in the United States involve bacterial meningitis. Thankfully, Hib disease has plummeted by more than 99 percent since the Hib vaccine was introduced in 1988 – in countries where the vaccine is used. Nevertheless, Hib remains a major worldwide problem.

What is it?
Haemophilus influenzae (H flu) are common bacteria that cause a wide variety of infections in children. Type b has been the cause of the most serious diseases, but can be effectively prevented by immunization. Other types of H flu, especially non-typable H flu, remain very common.

Although the name of these bacteria sounds similar to the influenza virus, the two are unrelated and very different. When the bacteria were first discovered, they were incorrectly thought to be the cause of influenza. This was disproved a decade before the influenza virus was eventually discovered, but the name for the bacteria had already been in use for a generation, and the name stuck.

Who gets it?
Anyone can get an H flu infection, but infants and young children are at the highest risk.,/p>

What are the symptoms?
H flu is among the most common cause of ear infections and sinus infections. These bacteria can cause many other types of infections including septic arthritis, pneumonia, meningitis, and conjunctivitis.

Is it contagious?
Yes. H flu infections can spread by direct contact, respiratory droplets, and body fluids.

How long does it last?
These tend to be acute, not chronic infections. The length of infection depends on the location of the infection and the type of H flu.

How is it diagnosed?
The diagnosis is often suspected based on the history and the physical exam. It can be confirmed by detecting the bacteria in blood, spinal fluid, or other body fluid.

How is it treated?
These infections are treated with antibiotics. Most of the time the antibiotics are given in tablet or liquid form. For serious infections, IV antibiotics may be needed.

How can it be prevented?
The Hib vaccine can prevent most serious cases of H flu disease. Those in close contact with people with serious H flu disease should receive preventive antibiotics.

General hygiene measures can decrease the spread of H flu. Specific preventive measures are available for some types of infection (see ear infections, for instance).<

In 2008, there has been a shortage of the Hib vaccine. Because of this, the CDC is recommending that physician and other caregivers keep an eye out for serious H flu infections until the shortage is resolved and all children are updated on their vaccinations.