1. Meningitis Sorokhan MD, PhD Bukovinian State Medical University Department of the infectious diseases and epidemiology

8. Acute bacterial meningitis caused by S. pneumoniae S. pneumoniae, a gram-positive coccus, remains an important bacterial pathogen in humans. It is a common colonizer of the human. It causes meningitis by escaping the local host defenses and phagocytic mechanisms, either through choroid plexus seeding from bacteremia or through direct extension from sinusitis or otitis media. Presently, it is the most common bacterial cause of meningitis. It may be associated with other foci of infection, such as pneumonia, sinusitis, or endocarditis. Patients with hyposplenism, hypogammaglobulinemia, multiple myeloma, glucocorticoid treatment, defective complement (C1-C4), diabetes mellitus, renal insufficiency, alcoholism, malnutrition, and chronic liver disease are at increased risk. Pneumococcal meningitis in a patient with alcoholism. Courtesy of the CDC/Dr. Edwin P. Ewing, Jr.

9. Pneumococci organism

10. N. meningitis is a gram-negative diplococcus that is carried in the nasopharynx of otherwise healthy individuals. It initiates invasion by penetrating the airway epithelial surface. Presently, it is the leading cause of bacterial meningitis and meningococcemia in children and young adults. Risk factors include (1) deficiencies in terminal complement components (C5-C9); (2) properdin defects that increase the risk of invasive disease; (3) household crowding, chronic medical illness, corticosteroid use, and active or passive smoking; and (4) overcrowding, as is observed in college dormitories and military facilities, which has been reported for a clustering of cases. Acute bacterial meningitis caused by N. meningitis

21. S. agalactiae (group B streptococci) is a gram-positive coccus that is isolated from the lower gastrointestinal tract. It also colonizes the female genital, which explains why it is the most common agent of neonatal meningitis. It has also been reported in adults, primarily affecting individuals older than 60 years. Predisposing risks in adults include diabetes mellitus, pregnancy, alcoholism, hepatic failure, renal failure, and corticosteroid treatment. Acute bacterial meningitis caused by S. agalactiae

22. Aerobic gram-negative bacilli (eg, E. coli, Klebsiella pneumoniae, Serratia marcescens, P. aeruginosa, Salmonella species) can cause meningitis in certain groups of patients. E. coli is a common agent of meningitis among neonates. Other predisposing risk factors include (1) neurosurgical procedures or intracranial manipulation; (2) old age; (3) immunosuppression; (4) high-grade gram-negative bacillary bacteremia; and (5) disseminated strongyloidiasis, which has been reported as a classic cause of gram-negative bacillary bacteremia. Acute bacterial meningitis caused by Aerobic gram-negative bacilli

23. Staphylococcus species ( S. aureus and coagulase-negative staphylococci) are gram-positive cocci that are part of the normal skin flora. Meningitis caused by staphylococci is associated with the following risk factors: (1) status postneurosurgery and posttrauma, (2) presence of CSF shunts, and (3) infective endocarditis and paraspinal infection. Staphylococcus epidermidis is the most common cause of meningitis in patients with CNS (ie, ventriculoperitoneal) shunts. Acute bacterial meningitis caused by Staphylococcus species

24. Aseptic meningitis is the most common infectious syndrome affecting the CNS. Most episodes are caused by a viral pathogen, but they can also be caused by bacteria, fungi, or parasites. Importantly, partially treated bacterial meningitis accounts for a large number of meningitis cases with a negative microbiologic workup. Aseptic meningitis syndrome

25. Infectious Agents Causing Aseptic Meningitis Syndrome Partially-treated bacterial meningitis: L. monocytogenes Brucella species Rickettsia rickettsii Ehrlichia species Mycoplasma pneumoniae B. burgdorferi Treponema pallidum Leptospira species Mycobacterium tuberculosis Nocardia species Bacteria Agent Category

26. Infectious Agents Causing Aseptic Meningitis Syndrome Acanthamoeba species Angiostrongylus cantonensis Taenia solium (cysticercosis) Parasites Cryptococcus neoformans Candida species Aspergillus species Fungi Agent Category

27. Infectious Agents Causing Aseptic Meningitis Syndrome Enterovirus, Herpesvirus, Paramyxovirus, Togavirus, Flavivirus, Bunyavirus, Alphavirus, Reovirus, Arenavirus Rhabdovirus , Retrovirus Viruses Agent Category

29. The Herpesviridae family consists of large DNA-containing enveloped viruses. Eight members are known to cause human infections, and all have been implicated in meningitis syndromes. HSV-1 is a cause of encephalitis, while HSV-2 more commonly causes meningitis. EBV, or HHV-4, and CMV, or HHV-5, may manifest as meningitis during the mononucleosis syndrome. Varicella zoster virus (VZV), or HHV-3, and CMV are causes of meningitis in immunocompromised hosts, especially patients with AIDS. Acute viral meningitis

30. Aseptic meningitis syndrome may be the presenting symptom in a patient with acute HIV infection. This usually is part of the mononucleosislike acute seroconversion phenomenon. Always suspect HIV as a cause of aseptic meningitis in a patient with risk factors such as intravenous drug use and in individuals who practice high-risk sexual behaviors. Acute viral meningitis

31. Patients with meningitis caused by the mumps virus usually present with the triad of fever, vomiting, and headache. It follows the onset of parotitis, which clinically resolves in 7-10 days. Adenovirus (serotypes 1, 6, 7, and 12) has been associated with cases of meningoencephalitis. Chronic meningoencephalitis has been reported with serotypes 7, 12, and 32. The infection is usually acquired through a respiratory route. Acute viral meningitis

32. Chronic meningitis M. tuberculosis, B. burgdorferi, T. pallidum, Brucella species, Francisella tularensis, Nocardia species, Actinomyces species. Bacteria C. neoformans, C. immitis, H. capsulatum, Candida albicans, Aspergillus species, Sporothrix schenckii. Fungi Acanthamoeba species, Angiostrongylus cantonensis, Schistosoma species, Echinococcus granulosus Parasites Agent Category

43. Signs and symptoms

45. CSF findings in different forms of meningitis usually mononucle high low Malignant < 300/mm³ high low Fungal mononuclear and PMNs, < 300/mm³ high low Tuberculous mononuclear , < 300/mm³ normal or high normal Acute viral PMNs , often > 300/mm³ high low Acute bacterial Cells Protein Glucose Type of meningitis

51. Thank you for your attention!