1. Meningitis

2. Meningitis is clinical syndrome characterized by inflammation of the meninges, that envelope the brain and spinal cord .
Types of meningitis

3. Most common bacteria causing meningitis:
Streptococcus pneumoniae (pneumococcus)
Neisseria meningitidis (meningococcus)
Haemophilus influenzae (haemophilus)
Listeria monocytogenes) (listeria

4. Extremes of age (< 5 or >60 years)
Diabetes mellitus, chronic kidney failure, adrenal insufficiency, hypoparathyroidism, or cystic fibrosis.
Compromised immune system like AIDS, alcoholism ,use of immunosuppressant drugs.
Recent exposure to others with meningitis, with or without prophylaxis.
Malignancy.
Pregnancy.

5. Pathophysiology
Most cases of meningitis are caused by infectious agents that colonized in the host.
What are the main sites of colonization ?

6. These infectious agents like bacteria can arrive the CNS via 3 ways :-
Invasion of the bloodstream and subsequent hematogenous seeding of the CNS.
A retrograde neuronal (e.g., olfactory and peripheral nerves) pathway .
Direct contiguous spread.
The migration pathways to meninges by:
Blood stream , Preformed tissue planes, window membranes of
the labyrinths.

7. Meningitis in newborn can be transmitted either vertically e. g
Meningitis in newborn can be transmitted either vertically e.g. pathogens that have colonized the maternal intestinal or genital tract, or horizontally, via nursery personnel or caregivers at home.

8. Invading to brain -How bacteria invade the brain ??
Factors that immortalize the infectious process in meningitis are :-
Replicating bacteria
Increasing numbers of inflammatory cells
cytokine-induced disruptions in membrane transport
and increased vascular and membrane permeability
All of these process make change in CSF cell count, pH, lactate, protein, and glucose in patients.

9. Etiology and Epidemiology
There are many microorganisms that can cause meningitis including bacteria, viruses, fungi, parasites; also drugs may be a cause (e.g., NSAIDs, metronidazole, and IV immunoglobulin).

10. Bacteria that cause meningitis include :
Pachymeningitis.
Haemophilus influenzae meningitis.
Pneumococcal meningitis.
Streptococcus agalactiae meningitis
Meningococcal meningitis.
Listeria monocytogenes meningitis.
Gram-negative bacilli.
Staphylococcal meningitis: it colonized in the normal skin flora. S epidermidis is the most common cause of meningitis in patients with CNS shunt (ventriculoperitoneal).
Additional causes of meningitis: Congenital malformation of the stapedial footplate, Head and neck surgery, penetrating head injury, comminuted skull fracture, and osteomyelitic erosion, Skull fractures.

11. H. influenzae meningitis primarily affects infants younger than 2 years. S agalactiaemeningitis occurs principally during the first 12 weeks of life but has also been reported in adults, primarily affecting individuals older than age 60 years. The overall case-fatality rate in adults is 34%. Among the bacterial agents that cause meningitis, S pneumoniae is associated with one of the highest mortalities (19-26%).

12. How bacteria reach meninges
Pachymeningitis reach the meninges by skull defect, or an infection from paranasal sinuses.
Pneumococcal meningitis: it is the most common bacterial agent in meningitis associated with basilar skull fracture and CSF leak.
Listeria monocytogenes meningitis: it is widespread in nature and a common food contaminant, most human cases was food borne.

13. Prognosis
Patients who presented with an impaired level of consciousness or seizures, have increase risk of death and neurologic sequelae.
In bacterial meningitis , a score was set to predict
outcome including several variables. Including:
Older age , Increased heart rate.
Lower Glasgow Coma Scale score.
Cranial nerve palsies.

14. What is the most important complication? And what is the percentage ?
Bacterial meningitis is fatal in 1 in 10 cases and 1 of every 7 survivors left with impediment like defenses.

15. Characteristic clinical signs and symptoms can be absent
Diagnosis
physical exam
certain diagnostic tests
Characteristic clinical signs and symptoms can be absent
Blood cultures
Imaging
Spinal tap (lumbar puncture)

16. Blood cultures Cranial Imaging
 Blood samples are placed in a special dish to see if it grows microorganisms, particularly bacteria
limitation : Pretreatment with antibiotics decreases the yield.
Cranial Imaging
(Normally computed tomography, CT) scans of the head may show swelling or inflammation.
May lead to a substantial delay in the initiation of antibiotic treatment, which leads to poor outcome.

17. Spinal tap (lumbar puncture)
This fluid is sent to the lab and analyzed to determine if there is an infection. “We determine:” 1- WBC(leukocyte) count 2- protein concentration 3- glucose concentration then we perform CSF culture and Gram stain.
Is the procedure of taking fluid from the spine (CSF) in the lower back through a hollow needle.
Limitation : Pretreatment with antibiotics decreases the yield.

18. Signs and symptoms
infants (<2years)
older than 2 years

19. Complications
Advanced bacterial meningitis may cause brain damage and death. 50% of patients may have a serious complications within a week, however in 30% of survivors long term sequlae are seen.
Complications include hearing loss, cortical blindness, other cranial nerve dysfunction, paralysis, muscular hypertonia, ataxia, multiple seizures, mental motor retardation, focal paralysis, subdural effusions, hydrocephalus and cerebral atrophy.

20. New Biomarker
The differentiation between acute bacterial and non bacterial meningitis is challenging because they share many similar clinical symptoms, such as fever and headache.
A new biomarker (Procalcitonin) has been studied for the diagnosis of bacterial meningitis.

21. Procalcitonin (PCT) is a 116-amino-acid protein that is produced primarily by the C cells of the thyroid gland and secreted from leukocytes in the peripheral blood.
In healthy individuals, PCT is secreted at levels that are below the detectable limit. However, serum PCT levels increase markedly in patients suffering from bacterial infections.

22. Comparison of the serum and CSF PCT levels between the BM and non-BM patients.
Gram stain of N. meningitidis in CSF has high specificity but the sensitivity is poor.  Furthermore, bacterial culture is time-consuming.

23. The results of the meta-analysis indicated that CSF PCT and blood PCT were both effective biomarkers for BM diagnosis. The diagnostic accuracy of elevated blood PCT appeared to be superior to CSF PCT.  We also found that blood PCT was associated with a higher pooled sensitivity and specificity when compared with CSF PCT.
ROC curves of the serum and CSF PCT for the diagnosis of BM.

24. Management
 Delay in treatment has been associated with a poorer outcome.
  After identification of the pathogen antibiotic therapy as appropriate for patient age and condition
First:
we should start treatment with wide-spectrum antibiotics while confirmatory tests
Rapid transport to the emergency department (ED) because of the early severe complications.

25. Treatment

26. Vaccination Pneumococcal Vaccination.
Hib Vaccination (Haemophilus influenzae type b (Hib)).
Three types of Meningococcal Vaccines used:
Meningococcal conjugate vaccine (MCV4).
Meningococcal polysaccharide vaccine (MPSV4) .
Serogroup B Meningococcal B.

27. New vaccines were developed against Group A Neisseria meningitidis :
MenAfriVac 10 µg of purified Men A polysaccharide antigen conjugated with tetanus toxoid (PsA-TT) per dose . ( 1-29 years ).
MenAfriVac 5 µg for use in infants and children (3–24 months).

28. Patient Education
Meningitis may require education regarding the need for prophylaxis. All contacts should be instructed to come to the emergency department immediately at the first sign of fever, sore throat, rash, or symptoms of meningitis.

29. These steps can help prevent meningitis: 1. Wash your hands. 2
These steps can help prevent meningitis: 1. Wash your hands. 2. Practice good hygiene.  3. Stay healthy.  4. Cover your mouth.  5. If you're pregnant, take care with food.

30. Done by
Lina Wahbeh
Dania Al Shafeey
Maysoon Najdawi
Mohammad Jud
Lama Diab
Hadeel ma’ani