An acute infectious disease of a bacterial nature caused by influenza bacillus (Haemophilus influenzae) is called hemophilic infection. The disease is characterized by the development of purulent foci in the organs, damage to the respiratory and nervous systems. The bacterium is a coccobacillus with a diameter of up to 1 micron. According to the cultural properties, 7 biotypes of bacilli are distinguished, some of which have a capsule. To date, 6 capsule types of influenza are known, which are designated from A to F. In human pathology, type b hemophilic bacillus is of great importance.
A hemophilic infection is transmitted exclusively from a person, the route of infection is airborne. In 90% of healthy people, a hemophilic bacillus is isolated from the nasopharynx, and in 5% of cases, the type b pathogen occurs.
In the vast majority of cases, hemophilic infection is recorded in children aged six months to five years. Infection is much less common in infants and children over five years of age. Recently, hemophilic infection is increasingly recorded in adults. The peak incidence occurs in February and the spring months.
The entrance gate is the nasopharyngeal mucosa. The causative agent is able to persist asymptomatically for a long time. With weakening of the immune system, the latent form of infection can turn into a manifest one. Hemophilus infection spreads on the surrounding tissues, while causing the development of bronchitis, otitis media, sinusitis, pneumonia. Purulent cellulitis and arthritis, and in some cases damage to internal organs, are also characteristic of a diminished infection. Moreover, a systemic disease occurs only when the pathogen has a capsule. Capsule-free bacteria only cause inflammation of the mucous membranes.
Symptoms of the disease
It is not possible to establish the duration of the incubation period in this disease, since the manifest form of the disease is often a latent consequence. A common cause of generalized infection in children is type b haemophilus influenzae.
A hemophilic infection, as a rule, is acute. In half of the cases, the pessimized form of the disease develops purulent meningitis, pneumonia in 20% of cases, and other focal lesions less often. The following clinical manifestations are characteristic of the disease:
- acute pneumonia;
- purulent meningitis;
- inflammation of the subcutaneous tissue;
- septicemia;
- purulent arthritis ;
- epiglottitis;
- otitis media, sinusitis, pericarditis, other manifestations.
Hemophilus infection is the most common cause of purulent meningitis in children from one year to 4 years. Usually, meningitis begins with symptoms of a respiratory illness. Later, signs characteristic of bacterial meningitis appear. The disease is always severe, in 10% of cases it ends lethally. Sometimes meningitis is accompanied by purulent cellulitis and arthritis. Hemophilic pneumonia can be either croupous or focal, in many cases complicated by purulent pleurisy. Pneumonia can occur in combination with inflammation of the middle ear and purulent pericarditis.
Sepsis develops more often in children up to a year, proceeds with lightning speed with the development of septic shock. Cellulite is also characteristic of children under one year old and begins with symptoms of acute respiratory infections. In older children, cellulite is often localized on the limbs. Epiglottitis (inflammation of the epiglottis) is considered a severe form of infection and is accompanied by bacteremia in 90% of cases. Purulent arthritis is the result of hematogenous introduction of bacteria into the joints and is often accompanied by osteomyelitis.
Diagnosis and treatment
A hemophilic bacillus is isolated from cerebrospinal fluid, sputum and pus of the patient. Using the reaction of counter electrophoresis, it is sometimes possible to detect a bacterium in cerebrospinal fluid or urine.
To treat the disease, tetracycline antibiotics, ampicillin and chloramphenicol are used. Nevertheless, treatment of the infection presents certain difficulties, since the bacillus is highly resistant to many antibacterial drugs. Given the complexity of diagnosis and treatment of the disease, vaccination against HIB infection is becoming increasingly important. Vaccination against hemophilic infection in 95-100% of cases avoids infection. Immunization contributes to a significant reduction in the incidence of, and most importantly, infant mortality from severe infections.