Haemophilus influenzae is a highly contagious bacterium that is spread through direct contact with infected people. Bacteria can cause problems with the lungs and sinuses, and occasionally result in severe brain, bone, and blood infections. Haemophilus influenzae strains are found worldwide and are a significant cause of illness and death in underdeveloped, poor countries. Most people in developed countries have access to childhood vaccinations against the pathogen. Treatment with oral or intravenous antibiotics is usually effective at clearing up active infections and preventing major, life-threatening complications.
There are six recognizable strains of Haemophilus influenzae, all of which can potentially cause health problems in humans. The most common strain, accounting for about 90 percent of infections, is Haemophilus influenzae type B. Infants and children under the age of 10 are at the highest risk of infection because their immune systems are not yet strong enough to fight off type B pathogens. Adults who have weak immune systems because of chronic diseases or chemotherapy cancer treatments are also at risk. Healthy adolescents and adults are not likely to experience active infections when they are exposed to bacteria.
Most Haemophilus influenzae infections begin in the respiratory tract after breathing in pathogens from an infected person's coughs or sneezes. Sinusitis or pneumonia can develop within a week of coming into contact with bacteria. A person also may have a fever, chills, breathing difficulties, sinus congestion, and muscle aches. Without treatment, it is possible for bacteria to spread to other parts of the body. Some individuals develop painful skin rashes, digestive tract problems, and urinary tract infections as well.
Meningitis, a type of brain infection, is an uncommon but potentially deadly complication of Haemophilus influenzae infestation. An infant or young child who develops meningitis can experience severe headaches, vision problems, nausea, vomiting, and mental confusion. A systemic infection can also occur once bacteria make their way into blood circulation, resulting in full-body aches and extreme fatigue.
Treatment for minor infections usually consists of a two-week to one-month course of oral antibiotics. After blood tests confirm that Haemophilus influenzae is responsible for symptoms, a doctor can prescribe cefotaxime, ceftriaxone, or a similar antibiotic. Hospitalization and critical care measures may be needed if complications such as meningitis arise.
Mandatory government vaccination efforts have all but eradicated Haemophilus influenzae diseases in most parts of the world. People who live in poor, unsanitary conditions with little or no access to quality health care still experience high mortality rates, however. There are efforts underway by government agencies and nonprofit goodwill organizations to provide underprivileged people with the education and medicines they need to prevent widespread epidemics.