Meningitis lecture

1. Meningitis
Prepared by: Jubran Alsaaidy
Supervised by:
DR. MOHAMMED AL-HAKAMY

2. Meningitis
 Introduction:
Meningitis: is the inflammation of
the protective membranes
covering the brain and spinal cord
which are known as the meninges.

3. Meningitis
 The Meninges:
Is the system of membranes
which envelopes the central
nervous system.
It has 3 layers:
1. Dura mater
2. Arachnoid mater
3. Pia mater

4. Meningitis
 Epidemiology:
• Many countries are affected by spread of meningitis and it’s a common disease
worldwide.
• Bacterial meningitis is of particular concern. Around 1 in 10 people who get this type
of meningitis die, and 1 in 5 have severe complication.
• 70% of the cases are of children under 5 years old and people over the age of 60
years old
• Over 1.2 million cases of meningitis are estimated to occur worldwide each year.

5. Meningitis
 Meningitis in Yemen
• In 2017 the Suspected cases of meningitis was reported from Amanat Al-Asimah
governorate with 629 Cases (25.5%); other governorates reporting high number of cases
include:
• Taiz with 355 cases (14.4%),
• Dhamar with 244 cases (9.9%),
• Ibb with 214 cases (8.7%),
• Al Hodeida with 166 cases(6.7%).
• Aden with 141 cases(5.7%).

6. Meningitis
 Meningitis in Yemen
• Total of 1,006 cerebrospinal fluid samples
were collected, from 01 January to 20
August 2017, from 10 sentinel sites of
national bacterial meningitis surveillance
programme spread across the country.
• Of these samples, only 5 samples have
tested positive for Streptococcus
Pneumoniae; 2 for Neisseria Meningitides
W135; and 11 samples were positive for
other bacteria. Almost 80%of the CSF
samples yielded no result.

7. Meningitis
Etiology of Meningitis
• Head injury
• Cretan drugs (mainly NSA’S)
• Cancer
• Middle ear infection
Infectious Non-infectious
• Bacterial
• Viral
• Fungal
• Parasitic/protozoal

8. Meningitis
Etiology of Meningitis

9. Meningitis
Prevailing causes according to age

10. Meningococcal
Meningitis

11. Meningococcal Meningitis
Meningococcal meningitis or cerebrospinal fever is an acute communicable disease
caused by N.Meningitidis and it only affects humans.
There are five main groups of meningococcal bacteria that commonly cause disease,
these are:
• Men A,
• Men B,
• Men C,
• Men W,
• Men Y

12. Meningococcal Meningitis
Epidemiology:
 In the African meningitis belt, the
WHO definition of a meningococcal
epidemic is > 100 cases per 100,000
population per year.

13. Meningococcal Meningitis
Epidemiology:
 In the endemic countries the incidence of: (per 100,000 population)
• > 10 cases per year characterizes High
• 2-10 cases per year characterize Moderate,
• <2 cases per year characterize Low.
 An outbreak outside the meningitis belt may be defined as a substantial increase in
invasive meningococcal disease in a defined population above that which is
expected by place and time.

14. Meningococcal Meningitis
Epidemiology:
 In Europe, the incidence of disease ranges from 0.2 to 14 cases per 100,000
population and majority cases are caused by serogroup B strains.
 In Americas, the incidence of disease is in the range of 0.3 to 4 cases per
100,000 population.
 In United States, the majority cases are caused by serogroups B, C and Y.
 In Asia most meningococcal disease is caused by meningococci belonging to
serogroup A or C.

15. Meningococcal Meningitis
Mode of transmission:
- Direct droplet infection: more frequent with cases and carriers.
- Droplets nuclei and particles are rare, because the organism dies rapidly
outside the body.
Route of Entry:
- Nose and mouth.

16. Meningococcal Meningitis
Epidemiological features:
(a) AGENT:
N. meningitidis is a gram-negative diplococci. 12 serotypes have been identified,
viz. Groups A, B, C, 29E, H, I. K, L, W135, X, Y, Z. Among all serotype, subgroup A has
been the most important cause of disease.
N. meningitidis dies rapidly on exposure to heat and cold.
(b) SOURCE OF INFECTION:
N. meningitidis is found in the nasopharynx of:
- Cases
- Carriers: the most important source of infection.
*The mean duration of temporary carriers is about 10 months

17. Meningococcal Meningitis
Case-Fatality Ratio by Serogroup and Age-Group

18. Meningococcal Meningitis
Epidemiological features:
(c) PERIOD OF COMMUNICABILITY:
 Until meningococci are no longer present in discharges from nose and throat.
 Cases rapidly lose their infectiousness within 24 hours of specific treatment.
(d) AGE AND SEX:
 Meningococcal meningitis is predominantly a disease of children and young
adults of both sexes with highest attack rate in infants aged 3-12 months.
(e) IMMUNITY
 Immunity is acquired by subclinical infection (mostly), clinical disease or
vaccination.
 Infants derive passive immunity from the mother.

19. Meningococcal Meningitis
Epidemiological features:
(f) ENVIRONMENTAL FACTORS:
 Outbreaks occur more frequently in the dry and cold months.
 Overcrowding, as occurs in schools, barracks, refugee and other camps, is an
important predisposing factor.
 Incidence is greater in the low socio-economic groups living under poor
housing conditions, with exposure to tobacco smoke, HIV infection and travel
to endemic areas.

20. Meningococcal Meningitis
Clinical presentation:
 Asymptomatic: most cases.
 Sudden onset of:
- Headache,
- fever,
- nausea,
- vomiting,
- photophobia,
- stiff neck and various neurological signs.

21. Meningococcal Meningitis
Prevention and control
 General prevention
- Good ventilation
- Avoidance of overcrowding
Specific prevention:
- Chemoprophylaxis (Mass): by
rifampicin 600mg daily for three days.
- Vaccination: are the only real way to
prevent meningitis, but vaccines are
not available for all types of
meningitis.

22. Meningococcal Meningitis
Prevention and control
 CASES:
- Isolation of cases is of limited usefulness in controlling epidemics, because the
carriers outnumber cases.
- Treatment with antibiotics can save the lives of 95% of patients provide that it
is started during the first 2 days of illness
- Penicillin is the drug of choice, if penicillin-allergic patients, ampicillin,
ceftriaxone and other third generation should be substituted.
- A single dose of long-acting chloramphenicol or ceftriaxone is used for
treatment of epidemic meningococcal meningitis in Sub-Saharan African.

23. Meningococcal Meningitis
Prevention and control
 CARRIRS:
- Treatment with more powerful antibiotics such as rifampicin to eradicate the
carrier state because the penicillin doesn’t eradicate it.
 CONTACTS :
- In outbreaks, those with direct, prolonged contact with a case of
meningococcal disease may also be offered clearance treatment.
- Ideally, where indicated, treatment should be started within 24 hours of
identification of the index case.
- Antibiotics effective for this purpose include rifampicin, ciprofloxacin,
ceftriaxone or azithromycin.

24. Meningococcal Meningitis
Prevention and control
 VACCINES:

25. Meningococcal Meningitis
Prevention and control
 VACCINES:
There are three types of vaccine available:
1- Polysaccharide-protein conjugate vaccines (given as intramuscular injection):
- Effective in protecting children under two years of age.
- Safe when used during pregnancy.
- Available in different formulations:
- Monovalent vaccines (serogroup A or C)
- Tetravalent vaccines (serogroups A, C, W, Y).
- In combination (serogroup C and Haemophilus influenzae type b)
- Quadrivalent (A- C-Y-W135)

26. Meningococcal Meningitis
Prevention and control
 VACCINES:
2- Protein based vaccines against serogroup B.
- Used against Serogroup B.
- Protect against meningitis in all ages.
- Not thought to prevent carriage and transmission (not lead to herd protection).
3- Polysaccharide vaccines (given subcutaneously):
- Safe and effective in children and adults, but weakly protective in infants.
- Protection is short-lived and they do not lead to herd protection.
- Still used for outbreak control but are being replaced by conjugate vaccines.
- Safe when used during pregnancy.