Fatal necrotizing fasciitis caused by Haemophilus influenzae serotype f

We describe a case of fatal lower limb necrotizing fasciitis in a 65-year-old man who was treated with broad-spectrum
antibiotics, limb amputation and tissue debridement. The causative organism was identified by PCR as Haemophilus
influenzae serotype f, which is a highly unusual cause of necrotizing fasciitis.
J Med Microbiol 57 (2008), 249-251

/Hae·moph·i·lus/ (he-mof´i-lus) a genus of hemophilic gram-negative bacteria (family Pasteurellaceae) including H.
aegyp´ticus, the cause of acute contagious conjunctivitis; H. ducrey´i, the cause of chancroid; H. influen´zae (once
thought to be the cause of epidemic influenza), the cause of lethal meningitis in infants; and H. vagina´lis, associated
with, and possibly the cause of, vaginitis.

Haemophilus genus:  H. influenzae is the most common cause of bacterial meningitis in children between the ages of
five months and five years. The initial respiratory infection can spread to the blood stream and eventually the central
nervous system. A stiff neck, lethargy, and the absence of the sucking reflex are common symptoms in infected babies.
A vaccine is available, but is not always effective in very young children. Adult meningitis is much less common and
usually only occurs in those predisposed to illness.
H. influenzae is the number one cause of Epiglottitisthis, [a] potentially fatal disease, which may cause airway
obstruction in children between the ages of 2 and 4. Haemophilus infection has also been associated with chronic
bronchitis, pneumonia, bacteremia, conjuctivitis, and a host of other illnesses

Crawford SA, Evans JA, Crawford GE. Necrotizing fasciitis associated with Haemophilus aphrophilus. Report of a case.
Arch Intern Med. 1978 Nov;138(11):1714-1715. [PubMed]


Haemophilus sp cause numerous mild and serious infections, including bacteremia, meningitis, pneumonia, otitis media,
cellulitis, and epiglottitis. Diagnosis is by culture and serotyping. Treatment is with antibiotics.

There are several pathogenic species of Haemophilus, the most common of which is H. influenzae, which has 6 distinct
encapsulated strains, a through f, and numerous nonencapsulated, nontypeable strains. Before the use of H.
influenzae type b (Hib) conjugate vaccine, most cases of serious, invasive disease were caused by type b. H. influenzae
causes many childhood infections, including meningitis, bacteremia, septic arthritis, pneumonia, tracheobronchitis, otitis
media, conjunctivitis, sinusitis, and acute epiglottitis. These infections, as well as endocarditis, may occur in adults,
although far less commonly. These illnesses are discussed elsewhere in The Manual. Occasionally, nonencapsulated
strains cause invasive infections.

H. influenzae serotype aegyptius may cause mucopurulent conjunctivitis and bacteremic Brazilian purpuric fever. H.
ducreyi causes chancroid (see Sexually Transmitted Diseases (STD): Chancroid). H. parainfluenzae and H. aphrophilus
are rare causes of bacteremia, endocarditis, and brain abscess.

Many Haemophilus sp are normal flora in the upper respiratory tract and rarely cause illness. Pathogenic strains enter
the upper respiratory tract through droplet inhalation or direct contact. Spread is rapid in nonimmune populations.
Children are at highest risk of serious infection, particularly males, blacks, and Native Americans. Overcrowded living
conditions and day care center attendance predispose to infection, as do immunodeficiency states, asplenia, and sickle
cell disease