Haemophilus influenzae can be classified into 2 types depending on the presence of a capsule on its outer surface: encapsulated and unencapsulated strains. Of the encapsulated strains, type B (Hib) strains are the most pathogenic. Infection with Hib strains is most commonly seen in children and can cause bacteremia and acute bacterial meningitis, epiglottitis, cellulite, otitis, septic arthritis, and respiratory infections. Unencapsulated strains are more common in adults and can cause pneumonia.
A vaccine for Haemophilus influenzae type B (Hib) strain is now available.
More information
Haemophilus influenzae is a Gram-negative bacterium belonging to the family of Pasteurellaceae. It is a non-motile coccobacillus and has a genome of approximately 1.8 Mbp (millions of base pairs) located in a single circular configuration encoding for 1740 genes and is approximately 1 µm in length.
Haemophilus influenzae can be transmitted by droplets of respiration. Bacteria colonize the nasopharynx through interactions between their outer membrane proteins and the host mucus. Other bacterial proteins that impair the activity of the respiratory ciliated epithelium are then expressed. When the bacteria have entered the mucus, a combination of cilia and proteins on their outer membrane helps them adhere to the host epithelial cells, thereby allowing colonization. Once the bacteria colonize the nasopharynx, they invade the cells and move between the epithelial cells, disrupting the tight junctions between the epithelial cells. Bacteria evade the host's immune system by expressing proteases that destroy the IgA antibodies found in the respiratory system.
Important Note
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. The correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings, and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.
