meningitis

meningitis

1. Meningitis Presenter – Dr. Vaishali T Moderator – Dr. Shyamala R 1

2. Definition Meningitis is the inflammation of the leptomeninges ( pia and aarchanoid matter) surrounding the brain and spinal cord, with involvement of the subarachnoid space.

3. Types of meningitis Based on the onset Acute meningitis: Progresses in few hours Acute bacterial Acute viral Chronic meningitis: Progressively worsens over weeks (>4 weeks) Bacterial, viral, fungal and parasitic

4. Bacterial meningitis

5. Acute bacterial/pyogenic meningitis Bacterial meningitis is an inflammation of the leptomeninges, usually causing by bacterial infection. Bacterial meningitis may present acutely (symptoms evolving rapidly over 1-24 hours), sub acutely (symptoms evolving over 1-7days), or chronically (symptoms evolving over more than 1 week).

6. E p i dem i o l ogy 6 Annual incidence in the developed countries is approximately 5-10 per 100000 . 30000 infants and children develop bacterial meningitis in United States each year. Approximately 90 per cent of cases occur in children during the first 5 years of life.

7. E p i dem i o l ogy 7 Cases under age 2 years account for almost 75% of all cases and incidence is the highest in early childhood at age 6-12 months than in any other period of life. There are significant difference in the incidence of bacterial meningitis by season.

8. Etiological agents 8 Acute: Streptococcus pneumoniae (38%) Neisseria meningitides (14%) Hemophilus influenza (4%) GNB’s ( E. coli, Klebsiella, Pseudomonas, Acinetobacter) S. agalactiae Listeria Staphylococcus aureus (5%) Chronic: - Mycobacterium tuberculosis

9. Etiology Dr.T.V.Rao MD 9 Elderly and immunocompromised Listeria Monocytogenes Gram negative bacteria Hospital-acquired infections Klebsiella Escherichia coli Pseudomonas Staphylococcus aureus

10. Etiology Dr.T.V.Rao MD 10 Children over 2 months Haemophilus influenza type b Neisseria meningitides Streptococcus pneumoniae Chi l d ren over 12 year s Neisseria meningitides Streptococcus pneumoniae

11. Pathogenesis Mode of transmission – droplets from respiratory secretions Routes of infection : Hematogenous spread – most common, through choroid plexus Direct spread – otitis media, sinusitis, mastoiditis. Anatomical defect in CNS – surgery, trauma, congenital defects.

12. Predisposing factors Age: neonates – highest prevalence d/t Immature immune system Birth canal Increased permeability to BBB 2. Vaccination: reduces meningitis (Hib) 3. Respiratory infections: alcoholism, diabetes, immunosuppression, splenectomy, etc. 4. CSF shunts: staphylococcus, pseudomonas, Acinetobacter. 5. Breach in BBB

13. Patho g enesis Dr.T.V.Rao MD 13 Susceptibility of bacterial infection on CNS in the children Immaturity of immune systems Nonspecific immune Insufficient barrier ( Blood-brain barrier ) Insufficient complement activity Insufficient chemo taxis of neutrophils Insufficient function of monocyte-macrophage system Blood levels of diminished interferon (INF) -γand interleukin -8 ( IL-8 )

14. Patho g enesis Dr.T.V.Rao MD 14 Susceptibility of bacterial infection on CNS in the children Specific immune Immaturity of both the cellular and Humoral immune systems Insufficient antibody-mediated protection Diminished immunologic response Bacterial virulence

15. Patho g enesis Dr.T.V.Rao MD 15 • A offending bacterium from blood invades the leptomeninges. Bacterial toxics and Inflammatory mediators are released. Bacterial toxics Lipopolysaccharide, LPS Teichoic acid Peptidoglycan Inflammatory mediators Tumor necrosis factor, TNF Interleukin-1, IL-1 Prostaglandin E2, PGE2 •

16. Patho g enesis Dr.T.V.Rao MD 16 Bacterial toxics and inflammatory mediators cause Suppurative inflammation. Inflammatory infiltration Vascular permeability alter Tissue edema Blood-brain barrier destroy Thrombosis

17. Patho l o g y Dr.T.V.Rao MD 17 • Diffuse bacterial infections involve the leptomeninges, arachnoid membrane and superficial cortical structures, and brain parenchyma is also inflamed. Meningeal exudate of varying thickness is found. There is purulent material around veins and venous sinuses, over the convexity of the brain, in the depths of the sulci, within the basal cisterns, and around the cerebellum, and spinal cord may be encased in pus. Ventriculitis (purulent material within the ventricles) has been observed repeatedly in children who have died of their disease. • • •

18. Patho l o g y Dr.T.V.Rao MD 18 • Invasion of the ventricular wall with perivascular collections of purulent material, loss of ependymal lining, and subependymal gliosis may be noted. • • Subdural empyema may occur. Hydrocephalus is an common complication of meningitis. Obstructive hydrocephalus Communicating hydrocephalus

19. Patho l o g y Dr.T.V.Rao MD 19 • Blood vessel walls may infiltrated by inflammatory cells. Endothelial cell injury Vessel stenosis Secondary ischemia and infarction • Ventricle dilatation which ensues may be associated with necrosis of cerebral tissue due to the inflammatory process itself or to occlusion of cerebral veins or arteries.

20. Patho l o g y Dr.T.V.Rao MD 20 • Inflammatory process may result in cerebral edema and damage of the cerebral cortex. Conscious disturbance Convulsion Motor disturbance Sensory disturbance Meningeal irritation sign is found because the spinal nerve root is irritated. Cranial nerve may be damaged • •

21. Symptoms of Meningitis and Septicemia Dr.T.V.Rao MD 21 Meningitis and meningococcal septicemia may not always be easy to detect, in early stages the symptoms can be similar to flu. They may develop over one or two days, but sometimes develop in a matter of hours It is important to remember that symptoms do not appear in any particular order and some may not appear at all.

22. Clinical manifestation Dr.T.V.Rao MD 22 • Bacterial meningitis may present acutely (symptoms evolving rapidly over 1-24 hours) in most cases. Symptoms and signs of upper respiratory or gastrointestinal infection are found before several days when the clinical manifestations of bacterial meningitis happen. Some patients may access suddenly with shock and DIC. • •

23. Clinical manifestation 23 Toxic symptom all over the body Hyperpyrexia Headache Photophobia Painful eye movement Fatigued and weak Malaise, myalgia, anorexia, Vomiting, diarrhea and abdominal pain Cutaneous rash Petechiae, purpura

24. Dr.T.V.Rao MD 24

25. Clinical manifestation Dr.T.V.Rao MD 25 Clinical manifestation of CNS Increased intracranial pressure Headache Projectile vomiting Hypertension Bradycardia Bulging fontanel Cranial sutures diastasis Coma DE cerebrate rigidity Cerebral hernia

26. Clinical manifestation Dr.T.V.Rao MD 26 Clinical manifestation of CNS Meningeal irritation sign Neck stiffness Po s it iv e K e r n i g ’ s s i g n Po s it iv e Brud z i n s k i ’ s s ig n

27. Kernig's sign. Dr.T.V.Rao MD 27 One of the physically demonstrable symptoms of meningitis is Kernig's sign. Severe stiffness of the hamstrings causes an inability to straighten the leg when the hip is flexed to 90 degrees.

28. Brudzinski's sign Another physically demonstrable symptoms of meningitis is Brudzinski's sign. Severe neck stiffness causes a patient's hips and knees to flex when the neck is flexe d . Dr.T.V.Rao MD 31

29. Clinical manifestation Dr.T.V.Rao MD 29 Clinical manifestation of CNS Seizures Seizures occur in about 20%-30% of children with bacterial meningitis. Seizures is often found in Haemophilus influenza and pneumococcal infection. Seizures is correlative with the inflammation of brain parenchyma, cerebral infarction and electrolyte disturbances.

30. Clinical manifestation Dr.T.V.Rao MD 30 Clinical manifestation of CNS Conscious disturbance Drowsiness Clouding of consciousness Coma Psychiatric symptom Irritation Dysphoria dullness

31. Clinical manifestation Dr.T.V.Rao MD 31 Clinical manifestation of CNS Meningeal irritation sign Neck stiffness Po s it iv e K e r n i g ’ s s i g n Po s it iv e Brud z i n s k i ’ s s ig n

32. Clinical manifestation Dr.T.V.Rao MD 32 Clinical manifestation of CNS Transient or permanent paralysis of cranial nerves and limbs may be noted. Deafness or disturbances in vestibular function are relatively common. Involvement of the optic nerve, with blindness, is rare. Paralysis of the 6 th cranial nerve, usually transient, is noted frequently early in the course.

33. Clinical manifestation Symptom and signs of the infant under the age of 3 months In some children, particularly young infants under the age of 3 months, symptom and signs of meningeal inflammation may be minimal. Fever is generally present, but its absence or hypothermia in a infant with meningeal inflammation is common. Only irritability, restlessness, dullness , vomiting, poor feeding, cyanosis, dyspnea, jaundice, seizures, shock and coma may be noted. Bulging fontanel may be found, but there is not meningeal irritation sign. Dr.T.V.Rao MD 33 •

34. Skin rashes Dr.T.V.Rao MD 34 • • • • Is due to small skin bleed All parts of the body are affected The rashes do not fade under pressure Pathogenesis: Septicemia wide spread endothelial damage activation of coagulation thrombosis and platelets aggregation reduction of platelets (consumption ) BLEEDING 1.skin rashes 2.adrenal hemorrhage Adrenal hemorrhage is called Waterhouse-Friderichsen Syndrome.It cause acute adrenal insufficiency and is uaually fatal

35. Skin rashes Dr.T.V.Rao MD 35

36. Dr.T.V.Rao MD 36

37. ‘ Glass Test’ Dr.T.V.Rao MD 37 A rash that does not fade under pressure will still be visible when the side of a clear drinking glass is pressed firmly against the skin. If someone is ill or obviously getting worse, do not wait for a rash. It may appear late or not at all. A fever with a rash that does not fade under pressure is a medical emergency.

38. Co m p li c a t i o n s Dr.T.V.Rao MD 38 Subdural effusion Subdural effusions occur in about 10%-30% of children with bacterial meningitis. Subdural effusions appear to be more frequent in the children under the age of 1 year and in Haemophilus influenza and pneumococcal infection. Clinical manifestations are enlargement in head circumference, bulging fontanel, cranial sutures diastasis and abnormal trans illumination of the skull. Subdural effusions may be diagnosed by the examination of CT or MRI and subdural pricking.

39. Com p li c a t i on Dr.T.V.Rao MD 39 Ependymitis Neonate or infant with meningitis Gram-negative bacterial infection Clinical manifestation Persistent hyperpyrexia, Frequent convulsion Acute respiratory failure Bulging fontanel Ventriculomegaly (CT) Ce r e b r o s p i n a l fl u i d by v e n tri c u l ar p un c t u re – WBC>50×10 9 /L Glucose<1.6mmol/L Protein>o.4g/L

40. Co m p l ic a t i o n s Dr.T.V.Rao MD 40 Cerebellar hyponatremia Syndrem of inappropriate secretion of antidiuretic hormone (SIADH) Hyponatremia Degrade of blood osmotic pressure Aggravated cerebral edema Frequent convulsion Aggravated c onscious disturbance

41. Com p li c a t i on Dr.T.V.Rao MD 41 Hydrocephalus Increased intracranial pressure Bulging fontanel Augmentation of head circumference Brain function disorder Other complication Deafness or blindness Epilepsy Paralysis Mental retardation Behavior disorder

42. Meningococcal Meningitis Dr.T.V.Rao MD 42 Less common bacterial causes of Meningitis, such as Staphylococci, enteric bacteria, group B streptococci and Listeria, occur in sub-populations like the immunocompromised, neonates, or head trauma patients. Patients with Meningococcal Meningitis present with sudden onset of fever, intense headache, nausea, vomiting, stiff neck and, frequently, a petechial rash with pink macules or, very rarely, vesicles. Delirium and coma often appear. Case fatality rate is between 5% and 15%.

43. Laboratory diagnosis Specimen collection: CSF – lumbar puncture in 3 sterile containers 1 - cell count 2 - biochemical analysis 3 bacteriological examination Blood – culture and sensitivity Urine – immunochromatographic test

44. Laboratory Findings Dr.T.V.Rao MD 44 Peripheral hemogram – Total WBC count 20×10 9 /L ～ 40×10 9 /L WBC Decreased WBC count at severe infection – Leukocyte differential count 80% ～ 90% Neutrophils

45. Cytological and biochemical parameters in CSF of normal individuals and in different types of meningitis Characteristics Normal individual Pyogenic meningitis Tuberculous meningitis Viral meningitis CSF pressure (mm of water) Normal (50–150) Highly elevated (>180) Moderately elevated Slightly elevated/normal TLC (per mm3 ) 0–5 100–10,000 10–500 25–500 Predominant cell type Lymphocytes Neutrophils Lymphocytes Lymphocytes Glucose (mg%) 40–70 < 40 mg/Dl 20-40 absent Total proteins 15-45 >45 100–500 mg/dL 20–80 mg/dL ( mg%) (moderately increased) (markedly increased) (mild increase)

46. CSF microscopy ( gram stain): Heaped smear Centrifugation Direct antigen detection : -From CSF: supernatant- latex agglutination test - S. pneumoniae, S.agalactiae , N.meningitidis , H.influenza or E.coli -From urine: ICT – C-polysaccharide antigen of S. pneumoniae. Culture: chocolate agar, blood agar and MacConkey agar.

47. Culture and identification properties of common bacterial agents of pyogenic meningitis Streptococcus pneumoniae: • Culture: It produces α- hemolytic colonies on blood agar, described as draughtsman-shaped or carrom coin appearance • Biochemical identification: It shows bile soluble, ferments inulin and sensitive to optochin. Neisseria meningitidis: It produces non- hemolytic colonies on blood agar, which on smear shows gram-negative diplococci. • Biochemical identification : Meningococci are catalase and oxidase positive. They ferment glucose and maltose but not sucrose • Serogrouping : Slide agglutination serogrouping (SASG) test is done to identify the serogroups of meningococci isolates by using appropriate antisera. Haemophilus influenzae: • Culture: Blood agar with S. aureus streak line shows satellitism. • Biochemical identification: Disk test for X and V factor requirement shows growth surrounding combined XV disk.

48. Streptococcus agalactiae: • Culture: It produces β- hemolytic colonies on blood agar, which on smear shows gram-positive cocci in short chain. • Biochemical identification : It shows CAMP test positive and resistance to bacitracin • Serogrouping with group specific antisera shows Lancefield group B. Gram-negative bacilli meningitis: • Escherichia coli and Klebsiella produce lactose-fermenting colonies on MacConkey agar; identified by ICUT tests • Non-fermenters : Pseudomonas is oxidase positive, whereas Acinetobacter is oxidase negative. They produce non-lactose fermenting colonies; identified by ICUT tests. Listeria monocytogenes: • Motility: It shows tumbling type of motility at 25°C but nonmotile at 37°C (called differential motility, which is due to temperature dependent flagella expression) • Culture: It grows on blood agar ( β- hemolytic colonies), and chocolate agar. Note: Selective media such as PALCAM agar (containing mixture of antibiotics) may be useful for isolation of Listeria from specimens such as food and environmental samples

49. Laboratory Findings Dr.T.V.Rao MD 49 • Rout e xamination of cerebrospinal fluid (CSF) Increased pressure of cerebrospinal fluid Cloudiness Evident Increased total WBC count (>1000×10 9 /L) Evident Increased neutrophils in leukocyte differential count Evident Decreased glucose (<1.1mmol/l) Evident Increased protein level Decreased or normal chlorinate CSF film preparation or cultivation : positive result

50. Laboratory Findings Dr.T.V.Rao MD 50 special examination of CSF Specific bacterial antigen test Countercurrent immuno-electrophoresis Latex agglutination Immunoflorescent test Neisseria meningitides (meningococcus) Haemophilus influenza Streptococcus pneumoniae ( pneumococcus) Group B streptococcus

51. Laboratory Findings Dr.T.V.Rao MD 51 Especial examination of CSF Other test of CSF LDH Lactic acid CRP TNF and Ig Neuron specific enolase (NSE)

52. Differential diagnosis Dr.T.V.Rao MD 52 • Clinical manifestation of bacterial meningitis is similar to clinical manifestation of viral, tuberculosis , fungal and aseptic meningitis. • Differentiation of these disorders depends upon careful examination of cerebrospinal fluid obtained by lumbar puncture and additional immunologic, roentgenographic, and isotope studies.

53. Antibiotic Therapy Dr.T.V.Rao MD 53 Selection of antibiotic No Certainly Bacterium Community-acquired bacterial infection Nosocomial infection acquired in a hospital Broad-spectrum antibiotic coverage as noted below Children under age 3 months » Cefotaxime and ampicillin » Ceftriaxone and ampicillin (children over age 1months) Children over 3 months » Cefotaxime or Ceftriaxone or ampicillin and chloramphenicol

54. Antibiotic Therapy Dr.T.V.Rao MD 54 Certainly Bacterium Once the pathogen has been identified and the antibiotic sensitivities determined, the most appropriate drugs should selected. N meningitides : penicillin, - cephalosporin S pneumoniae: penicillin, - cephalosporin, Vancomycin H influenza: ampicillin, cephalosporin S aureus: penicillin, nefcillin , Vancomycin E coli: ampicillin, chloramphenicol , - cephalosporin

55. Antibiotic Therapy Dr.T.V.Rao MD 55 Course of treatment 7 days for meningococcal infection 10 ～ 14 days for H influenza or S pneumoniae infection More than 21 days for S aureus or E coli infection 14 ～ 21 days for other organisms

56. Treatment Dr.T.V.Rao MD 56 General and Supportive Measures Monitor of vital sign Correcting metabolic imbalances Supplying sufficient heat quantity Correcting hypoglycemia Correcting metabolic academia Correcting fluids and electrolytes disorder Application of cortical hormone Lessening inflammatory reaction Lessening toxic symptom lessening cerebral edema

57. General and Supportive Measures Dr.T.V.Rao MD 57 • Treatment of hyperpyrexia and seizures Pyretolysis by physiotherapy and/or drug Convulsive management Diazepam Phenobarbital Subhibernation therapy Treatment of increased intracranial pressure Dehydration therapy 20%Mannitol 5ml/kg vi q6h Lasix 1-2mg/kg vi •

58. General and Supportive Measures Dr.T.V.Rao MD 58 – Treatment of septic shock and DIC Volume expansion Dopamine Corticosteroids Heparin Fresh frozen plasma Platelet transfusions

59. T r e atm e n t Dr.T.V.Rao MD 59 Complication Measures Subdural effusions Subdural pricking Draw-off effusions on one side is 20-30ml/time. Once daily or every other day is requested. Time cell of pricking may be prolonged after 2 weeks. Ependymitis Ventricular puncture — drainage Pressure in ventricle be depressed. Ventricular puncture may give ventricle an injection of antibiotic. • •

60. Complication Measures Dr.T.V.Rao MD 60 • Hydrocephalus Operative treatment Adhesiolysis By-pass operation of cerebrospinal fluid Dilatation of aqueduct SIADH (Cerebral hyponatremia) Restriction of fluid supplement of serum sodium diuretic •

61. P r o g no s is Dr.T.V.Rao MD 61 Appropriate antibiotic therapy reduces the mortality rate for bacterial meningitis in children, but mortality remain high. Overall mortality in the developed countries ranges between 5% and 30%. 50 percent of the survivors have some sequelae of the disease.

62. Chronic meningitis

63. Definition It is characterized by persistence of signs and symptoms as well as the CSF abnormality for >4 weeks. Agents of chronic meningitis: Bacterial agents Common bacterial agents • Partially treated suppurative meningitis • Parameningeal infections (e.g. otitis media) • Mycobacterium tuberculosis • Borrelia burgdorferi (Lyme disease) • Treponema pallidum (secondary, tertiary syphilis) Rare bacterial agents: Nocardia, Actinomyces, Tropheryma whipplei , Leptospira, Brucella. Viral agents Some of the agents of acute viral meningitis may also present as chronic meningitis. Examples: Mumps, echoviruses, herpesviruses, HIV and lymphocytic choriomeningitis virus. Parasitic agents • Toxoplasma gondii • Free-living amoebae • Trypanosoma brucei (African sleeping sickness) • Angiostrongylus cantonensis (Eosinophilic meningitis) • Gnathostoma spinigerum • Baylisascaris procyonis • Cysticercosis, schistosomiasis, echinococcal disease • Toxocara canis and Trichinella. Fungal agents • Cryptococcus neoformans • Candida albicans • Blastomyces dermatitidis • Histoplasma capsulatum • Coccidioides immitis • Aspergillus species • Sporothrix schenckii • Pseudallescheria boydii • Cladophialophora bantiana

64. Viral meningitis

65. Aseptic Meningitis It is the inflammation of subarachnoid space due to viral etiology. It is the second most common type of meningitis, next to acute bacterial meningitis. It is often less severe than bacterial meningitis and has a better prognosis. Etiological Agents: -Enteroviruses (Coxsackie's and echovirus): most common. -Adenovirus -Arbovirus -LCM virus -Measles virus -Herpes Simplex Virus -V a r i c e l la 65

66. Vi r al Me n i n gi t is Dr.T.V.Rao MD 66 Reservoirs: -Humans for Enteroviruses, Adenovirus, Measles, Herpes Simplex, and Varicella -Natural reservoir for arbovirus birds, rodents etc. Modes of transmission: -Primarily person to person and arthopod vectors for a rboviruses Incubation Period: -Variable. For enteroviruses 3-6 days, for arboviruses 2-15 days Treatment: No specific treatment available. Most patients recover completely on their own.

67. Non Polio Enteroviruses Dr.T.V.Rao MD 67 Types : 62 different types known: -23 Coxsackie A viruses, -6 Coxsackie B viruses, -28 echoviruses, and 5 other How common? -90% of all viral meningitis is caused by Enteroviruses -Second only to "common cold" viruses, the rhinoviruses. -Estimated 10-15 million/ more symptomatic infections/yr in US How does infection spread? Virus present in the respiratory secretions & stool of a patient. Direct contact with secretions from an infected person. Parents, teachers, and child care center workers may also become infected by contamination of the hands with stool.

68. Arboviral meningitis HIV meningitis Mumps meningitis LCM meningitis

69. Laboratory criteria for diagnosis: CSF showing ≥ 5 WBC/cu mm No evidence of bacterial or fungal meningitis. Case classification Confirmed : a clinically compatible illness diagnosed by a physician as aseptic meningitis, with no laboratory evidence of bacterial or fungal meningitis Aseptic meningitis is a syndrome of multiple etiologies, but most cases are caused by a viral agent

70. Cytological and biochemical parameters in CSF of normal individuals and in different types of meningitis Characteristics Normal individual Pyogenic meningitis Tuberculous meningitis Viral meningitis CSF pressure (mm of water) Normal (50–150) Highly elevated (>180) Moderately elevated Slightly elevated/normal TLC (per mm3 ) 0–5 100–10,000 10–500 25–500 Predominant cell type Lymphocytes Neutrophils Lymphocytes Lymphocytes Glucose (mg%) 40–70 < 40 mg/Dl 20-40 absent Total proteins 15-45 >45 100–500 mg/dL 20–80 mg/dL ( mg%) (moderately increased) (markedly increased) (mild increase)

71. Treatment Treatment of almost all cases of viral meningitis is primarily symptomatic: Analgesics, antipyretics, antiemetics and fluid and electrolyte replacement. Oral or intravenous acyclovir may be of benefit in patients with meningitis caused by HSV-1 or 2 and in cases of severe EBV or VZV infection. Patients with HIV meningitis should receive highly active antiretroviral therapy.

72. Parasitic infections of central nervous system Protozoan infections of CNS • Free-living amoebae infections of CNS* • Toxoplasma encephalitis* • Cerebral malaria (Plasmodium falciparum)* • African sleeping sickness (Trypanosoma brucei)* • Chagas’ disease (meningoencephalitis, Trypanosoma cruzi ) • Cerebral amoebiasis (E. histolytica) Cestode infections of CNS • Neurocysticercosis (Taenia solium )* • Others: Taenia multiceps , Spirometra and Echinococcus Trematode infections of CNS • Schistosoma mansoni and S. japonicum infections • Cerebral paragonimiasis Nematode infections of CNS • Hyperstrongyloidiasis syndrome ( Strongyloides ) • Eosinophilic meningitis ( Angiostrongylus cantonensis ) • Others: Loa loa (meningoencephalitis), Trichinella spiralis, Toxocara , Baylisascaris procyonis and Gnathostoma infections

73. Fungal agents causing CNS infections Primary CNS pathogen: Cryptococcus neoformans Fungi which primarily cause infections of other body sites, rarely cause CNS infections • Agents of systemic mycoses: Blastomyces dermatitidis, Histoplasma capsulatum and Coccidioides immitis • Agents of subcutaneous mycoses: Sporothrix schenckii , Pseudallescheria boydii and Cladophialophora bantiana • Opportunistic fungal agents : Candida albicans, Aspergillus species and Mucor ( rhinocereberal mucromycosis ) • Others: Microsporidia

74. Cryptococcal meningitis

75. Cryptococcal meningitis Cryptococcal meningitis is caused by a capsulated yeast called Cryptococcus neoformans, which is capable of producing potentially fatal meningitis in HIV infected people. C.Neoformans C.Gattii

76. Pathogenesis and Virulence factors Infection is acquired by inhalation of aerosolized forms of Cryptococcus. Polysaccharide capsule—It is the principal virulence factor of the fungus. It is antiphagocytic and also inhibits the host’s local immune responses Ability to make melanin by producing an enzyme called phenyl oxidase Production of other enzymes such as phospholipase and urease. CNS spread: The unique feature of Cryptococcus is its ability to cross blood-brain barrier which occurs by the yeast cells either they migrate directly across the endothelium or carried inside the macrophages as “Trojan horse”

77. Lab diagnosis Specimens: CSF, blood or skin scrapings. Direct Detection Methods Negative staining: Modified India ink stain (added with 2% mercurochrome) and nigrosin stain - demonstrate the capsule - refractile delineated clear space surrounding the round budding yeast cells against black background. Gram staining may show gram-positive round budding yeast cells. Other stains include: Mucicarmine stain : It stains the carminophilic cell wall of C. neoformans Masson-Fontana stain: It demonstrates the production of melanin Alcian blue stain: To demonstrate the capsule. 4. Antigen detection: The capsular antigens can be detected from CSF or serum by latex agglutination test. It is a rapid and sensitive (95% sensitivity) and specific method.

78. CULTURE Negative staining SDA agar

79. Confirmation of Cryptococcus species is made by: Niger seed agar and bird seed agar: They are used to demonstrate melanin production (brown colored colonies). Growth at 37°C . Urease test is positive Assimilation of inositol and nitrate Mouse pathogenicity test Automated identification system such as MALDI-TOF

80. TREATMENT Treatment depends upon the type of cryptococcosis. Cryptococcosis without CNS involvement: Fluconazole is the drug of choice HIV-infected patients with CNS involvement: The recommended regimen is induction phase for two weeks (amphotericin B ± flucytosine) followed by oral fluconazole therapy till CD4 T cell count raises >200 /µL for 6 months.