Pneumococcal infection

Pneumococcal infection - anthroponous infectious disease with airborne droplet transmission of the pathogen, is characterized by the most frequent lesion of ENT organs, lungs and central nervous system.

Streptococcus pneumoniae (pneumococcus) is a gram-positive, aerobic, encapsulated diplococcus. Every year in the US, pneumococcal infection causes 7 million cases of otitis media, 500,000 cases of pneumonia, 50,000 cases of sepsis, 3,000 cases of meningitis, and 40,000 deaths. The diagnosis of pneumococcal infection is based on the Gram staining method. Treatment of pneumococcal infection depends on the profile of resistance and includes beta-lactams, macrolides and fluoroquinolones.

ICD-10 code

A40.3. Septicemia caused by Streptococcus pneumonie.

What causes pneumococcal infection?

Pneumococcal infection is caused by pneumococcus, which has an pneumococcal capsule. It consists of a complex of polysaccharides that determine the serological type and contribute to virulence and pathogenicity. In general, there are more than 91 serotypes, but the most serious diseases are caused by types 4, 6, 9, 14, 18, 19 and 23. These serological types cause 90% of invasive infections in children and 60% of these infections in adults. However, the percentage ratio is slowly changing, which can partly be explained by the widespread use of polyvalent vaccines.

Typically, pneumococci colonize the respiratory tract, especially in the winter and early spring periods. Distribution occurs through the aerosol, which is formed by sneezing. Present epidemics of pneumococcal infection are rare.

People with chronic diseases (chronic cardiorespiratory diseases, diabetes mellitus, liver disease, alcoholism), persons with immunosuppression, functional or anatomic asplenia or sickle cell anemia, prolonged bedridden patients, smokers, Alaska Natives and certain populations of Indians are most susceptible to serious and invasive pneumococcal infections America. In elderly people, even without concomitant pathology, the prognosis is usually unfavorable. Damaged due to chronic bronchitis or common respiratory viruses, the respiratory epithelium may be a favorable background for the development of pneumococcal invasion.

What are the symptoms of pneumococcal infection?

The primary focus of infection is more often in the respiratory tract. Pneumococci can also cause otitis media, rhinosinusitis, meningitis, endocarditis, infectious arthritis, and rarely peritonitis. Pneumococcal bacteremia can be a primary manifestation of the infectious process in susceptible patients, and may also accompany an acute phase of localized pneumococcal infection. Despite the treatment of pneumococcal infection, mortality rates are 15-20% in children and adults and 30-40% in elderly patients.

Pneumococcal pneumonia is the most frequent serious infection caused by pneumococcus. It can be divided or (more rarely) focal (bronchopneumonia). Pleural effusion is found in 10% of cases. She can spontaneously resolve during the treatment. In less than 3% of cases, it is possible to get buffered pleurisy and fibrinous-purulent effusion, which will form pleural empyema. Pulmonary abscesses are rare.

Pneumococcal infection has many clinical options.

Acute otitis media of pneumococcal etiology in infants (after the neonatal period) and children occurs with a frequency of 30-40%. More than a third of children in most populations suffer pneumococcal otitis media at the 2nd year of life. Often recurrent pneumococcal otitis occurs. Mastoiditis and thrombosis of the lateral sinus (the most common complications of otitis media in the preantibiotic era) are rare today.

Rhinosinusitis can also be caused by pneumococci. It can take a chronic course or become polymicrobial. The maxillary and latticed sinuses are most often affected. Infection in the frontal and sphenoid sinuses can spread to the meninges, leading to bacterial meningitis.

Acute purulent meningitis is often caused by pneumococcus, and may also be secondary, due to bacteremia from other foci of infection (in particular, pneumonia), and also with the direct spread of the infectious process from the ear, mastoid process or paranasal sinuses, or in fracture of the base of the skull, in which one of these areas or a trellis plate is damaged.

Rarely the result of bacteremia may be endocarditis, and even in individuals who do not have valvular pathology. Pneumococcal endocarditis causes corrosive damage to valve flaps, which leads to rapid rupture or fenestration, which in turn leads to acute heart failure.

Septic arthritis is often the result of pneumococcal bacteremia from another focus of infection. In general, it is similar to septic arthritis caused by other Gram-positive microorganisms.

Spontaneous pneumococcal peritonitis occurs most often in patients with cirrhosis and ascites.

How is pneumococcal disease diagnosed?

Pneumococcal infection is diagnosed by the identification of pneumococci in the early stages according to their typical encapsulated appearance when stained with Gram stain. A characteristic capsule is also visualized when the smears are stained with methylene blue. The culture test and serotyping (in the presence of indications) confirm the identification. Serotyping of isolates of a microorganism can be useful for epidemiological reasons. This allows us to trace the correlation relationships of the distribution of specific MO clones and to trace patterns resistant to antimicrobial drugs. The test for the determination of sensitivity to antibiotics should be carried out on isolated strains. Pneumococci in the joints can be determined by direct smears or by culture examination of aspirate purulent synovial fluid.

How is pneumococcal disease treated?

If the disease is suspected, the initial treatment of pneumococcal infection, before the results of sensitivity to antibiotics, depends on data on local patterns resistant to certain groups of antimicrobial agents. Although the most preferred treatment for pneumococcal infections is beta-lactams and macrolides, treatment can be complicated by the migration of resistant strains. In the world, strains highly resistant to penicillin, ampicillin and other beta-lactams are widespread. The most frequent predisposing factor for the development of resistance is the use of beta-lactam drugs over the past few months. When MO middle resistance is detected, treatment with penicillin G in standard or high doses or other beta-lactams can be prescribed.

Severe patients with non-meningeal infection caused by high-resistant to penicillin MO can often receive treatment for pneumococcal infection with ceftriaxone or cefotaxime. If the minimum inhibitory concentration of the isolate is not high, high doses of parenteral penicillin G (20-40 million units per day for adults) can also be used for treatment. All penicillin-resistant isolates are sensitive to vancomycin, but with parenteral vancomycin it is not always possible to achieve adequate drug concentrations in the cerebrospinal fluid for the treatment of meningitis (especially when SCS is used along with antibiotics). Therefore, ceftriaxone or cefotaxime and / or rifampicin are often used along with vancomycin in patients with meningitis. Recent fluoroquinolones, such as gatifloxacin, hemifloxacin, levofloxacin and moxifloxacin, are effective in treating respiratory infections in adults caused by high-penicillin-resistant pneumococci.

How is pneumococcal disease prevented?

The transferred pneumococcal infection forms type-specific immunity, which does not extend to other serotypes of the pathogen. At present, there are 2 pneumococcal vaccines: a polyvalent polysaccharide vaccine that targets 23 serotypes that cause more than 80% of serious pneumococcal infections and a conjugated vaccine directed against 7 serotypes of the pathogen.

Conjugated vaccination against pneumococcal infection is recommended for all children from 6 weeks to 5 years of age. The vaccination schedule depends on the age and health of the child.
If vaccination is started before the age of 6 months, children should receive 3 inoculations at an interval of approximately 2 months, followed by the 4th vaccine at the age of 12-15 months. The time for the first vaccination is 2 months. If vaccination is started at the age of 7-11 months, then two shots are given, and then a booster dose. At the age of 12-23 months, 2 vaccinations are given without a booster dose. At the age of 24 months and up to 9 years, children receive a single dose.

Polysaccharide vaccine is ineffective in children under 2 years old, but reduces pneumococcal bacteremia in adults by 50%. There are no documented cases of pneumonia reduction. Protection from the use of this vaccine usually lasts for many years, but in highly susceptible people, revaccination is desirable after 5 years. Polysaccharide vaccine is indicated to people aged 65 years, as well as to persons aged 2-65 years with increased susceptibility and before splenectomy. It is not recommended for children under 2 years of age or hypersensitive to vaccine components to individuals.

For children with functional or anatomical asplenia younger than 5 years, penicillin V 125 mg is recommended. The duration of chemoprophylaxis is determined empirically, but some experts continue chemoprophylaxis throughout the childhood period, as well as in the adult period due to the high risk of developing pneumococcal infection in patients with asplenia. Pneumococcal infection in children and adolescents is treated by administering penicillin (250 mg orally) for at least 1 year after splenectomy.