Meningitis (cerebrospinal meningitis) is an inflammation of the membranes (hard, soft, and arachnoid) that cover the brain and spinal cord. Meningitis affects people of all ages, but most often affects newborns and children under 10 years of age.
Meningitis can be caused by a variety of infectious agents (bacteria, viruses, fungi, yeast, and protozoa) that have penetrated the meninges. The most common bacterial pathogens are meningococcus, tubercle bacillus, Afanasiev-Pfeifer bacillus (Hemophilus influenzae), pneumococcus, hemophilic streptococcus, staphylococcus aureus. Meningococcus causes mass outbreaks of the disease more often than other pathogens, therefore meningococcal meningitis is sometimes called epidemic. The main causative agents of viral meningitis are poliomyelitis viruses, ECHO viruses (human enterocytopathic viruses), Coxsackie viruses. Fungal meningitis is traditionally caused by Cryptococcus.
Pathogens multiply in the meninges and cerebrospinal fluid, getting there from the nasal cavity and pharynx through the middle ear, mastoid process, bony openings or through blood vessels. The source of infection can also be foci in the lungs, bones, skin; from there, the infection enters the brain and its membranes with blood.
Meningitis is manifested by fever, headache, nausea, vomiting, drowsiness, depression of consciousness. Pain and stiffness of the neck and lower back are often noted. The pulse may be fast or slow. Small or large hemorrhages are sometimes found on the skin. If the symptoms listed above appear during an infection of the nose, throat, lungs, meningitis should be suspected and appropriate investigations should be carried out.
The diagnosis of meningitis is confirmed by a lumbar puncture (lumbar puncture) and examination of the cerebrospinal fluid, the characteristic changes of which include an increase in the number of cells (mainly lymphocytes) and, in most cases of bacterial meningitis, the presence of bacteria.
Of all the forms of acute bacterial meningitis, the most impressive progress has been made in the treatment of the epidemic form of meningococcal meningitis. Early diagnosis and treatment with sulfonamides and antibiotics has reduced the mortality rate from 60–70% to 5%. The disease is transmitted from one person to another by airborne droplets or contact (through objects contaminated with the saliva or mucus of the sick person), therefore, in order to prevent the spread of infection, people in contact with the patient are prescribed small doses of sulfonamides (0.5–1.0 g 2 times a day) for three days.
The treatment of other forms of bacterial meningitis is also very effective, with the exception of some cases of tuberculous meningitis and meningitis caused by H. influenzae. In the last decades, mortality from meningitis has decreased significantly, and in many cases there is a complete recovery.
Although the use of sulfonamides and antibiotics has significantly improved the results of the treatment of meningitis, its success largely depends on the early diagnosis of the disease and the identification of its pathogen. Meningococcal and pneumococcal meningitis is currently effectively treated with ampicillin or penicillin G (benzylpenicillin) administered intravenously. For pneumococcal meningitis, penicillin is indicated. For tuberculous meningitis, a combination of rifampicin or streptomycin with isoniazid, pyrazinamide, and ethambutol is prescribed.
Many forms of infrequent fungal infections of the brain and its membranes are difficult to treat. But for some types of fungi, there is still an effective therapy. So, with cryptococcal infection, the antibiotic amphotericin B is successfully used, and in the last time, fluconazole. For the treatment of viral meningitis, acyclovir is used intravenously.