Dr. Nadia Aziz F.A.B.C.M, Lecturer community medicine department

1-Define what is meningitis 2-Types of meningitis 3-Identification of meningococcal meningitis, the diagnosis, its occurrence & ways of controlling this disease.

Is an inflammatory process of liptomeninges and the CSF

1- Acute pyogenic (bacterial) meningitis 2-Acute aseptic (viral) meningitis 3-Acute focal suppurative infection (brain abscess, subdural and extradural empyema) 4- Chronic bacterial infection (tuberculosis)

1- Neisseria meningitidis 2- Streptococcus pneumoniae and 3- Haemophilus influenzae type b (Hib) Constitute more than 75% of all cases of bacterial meningitis in most studies, and 90% of bacterial meningitis occur in children.

An acute bacterial disease, characterized by: Sudden onset of fever intense headache nausea and vomiting stiff neck and photophobia A petechial rash with pink macules may be observed.

With antibiotics, intensive care units and improved supportive measures have decreased but it remains high at 8%–15%. long-term sequelae : 10 –20% of survivors will suffer mental retardation, hearing loss and loss of limb use.

1- Meningitis (the most common presentation) 2- Bacteremia and 3- Sepsis

Meningococcaemia is the most severe form of infection with petechial rash, hypotension, disseminated intravascular coagulation and multiorgan failure. Other forms of meningococcal disease such as pneumonia, purulent arthritis, and pericarditis are less common.

1-CSF or blood culture: Isolation of meningococci from a sterile site CSF or blood (gold standard). The sensitivity of culture, especially in patients who have received antibiotics, is low. 2-Latex agglutination test: Identification of group-specific meningococcal polysaccharides in CSF by latex agglutination in culture-negative cases

3-Polymerase chain reaction: detecting meningococcal DNA in CSF or plasma and not requiring live organisms is of help but false- negative results are common. 4-Gram-stained smears from petechiae: may show Neisseria.

Neisseria meningitidis, the meningococcus, is a Gram-negative, aerobic diplococcus. Neisseria are divided into serogroups according to their capsular polysaccharide. Group A, B, and C organisms account for at least 90% of cases, although the proportion of groups Y and W135 and X is increasing in several regions.

In Europe and North America the incidence of meningococcal disease is higher during winter and spring In Sub-Saharan Africa (African meningitis belt) the disease classically peaks during the dry season

Infants have the highest risk of meningococcal disease. Rates of disease decrease after infancy and then increase in adolescence and young adulthood.

In addition to age, other risk factors include underlying immune deficiencies, such as asplenia, properdin deficiency. Crowding, low socioeconomic status, active or passive exposure to tobacco smoke and concurrent upper respiratory tract infections In some countries males are at higher risk than females

Reservoir: Humans. Mode of transmission Direct contact, including respiratory droplets from nose and throat of infected people Up to 5%–10% of people may be asymptomatic carriers with nasopharyngeal colonization by N. meningitidis.

2 to 10 days, commonly 3–4 days.

Until live meningococci are no longer present in discharges from nose and mouth. Meningococci usually disappear from the nasopharynx within 24 hours after institution of antimicrobial treatment to which the organisms are sensitive.

Susceptibility to the clinical disease is low and decreases with age; this induces a high ratio of carriers to cases. Persons deficient in certain complement components are especially prone to recurrent disease; splenectomized persons are susceptible to bacteraemic illness.

A. Preventive measures 1) Educate the public on the need to reduce direct contact and exposure to droplet infection. 2) Reduce overcrowding in living quarters and workplaces, barracks, schools and ships. 3) Vaccines containing groups A, C, Y and W-135 meningococcal polysaccharides are been available

Two polysaccharide vaccines: 1- Quadrivalent ACYW-135 vaccine 2- Bivalent AC Polysaccharide meningococcal vaccines against serogroups A and C are safe and effective in adults and children over 2, but do not elicit long-term protection.

Vaccines are effective for: 1- outbreak control 2- prevention among high-risk groups, such as travellers to countries where disease is epidemic, Hajj pilgrims, military groups, and individuals with underlying immune dysfunctions.

Because these vaccines are often poorly immunogenic in young children and have limited duration of efficacy, they are not generally used in routine childhood immunization programs.

1) Isolation: Respiratory isolation for 24 hours after start of treatment. 2) Protection of contacts: Close surveillance of household, daycare, and other intimate contacts for early signs of illness, to initiate appropriate therapy without delay prophylactic administration of chemotherapeutic agent to intimate contacts

Younger children in day care centers, even if not close friends, should all be given prophylaxis after an index case is identified

1- Rifampicin Twice daily for 2 days: adults 600 mg per dose; children over 1month old, 10 mg/kg 2- Ceftriaxone For adults, 250 mg IM, given in a single dose, 125 mg IM for children under Ciprofloxacin 500 mg PO, a single dose to adults.

Penicillin given parenterally in adequate doses is the drug of choice Ampicillin and chloramphenicol are also effective. Ceftriaxone Ciprofloxacin

Penicillin-resistant strains have been reported in many countries, strains resistant to chloramphenicol also have been reported. Treatment should start as soon as the presumptive clinical diagnosis is made, even before menin-gococci have been identified.

In children, until the specific agent has been identified, the drug chosen must be effective against Haemophilus influenzae type b (Hib) as well as Streptococcus pneumoniae.

1) When an outbreak occurs, major emphasis must be placed on: Careful surveillance, early diagnosis and immediate treatment of suspected cases. Thresholds (alert and epidemic) When thresholds are passed, immunization campaigns must be implemented.

1) setting up an epidemic management committee, enhancing surveillance, undertaking field epidemiology and bacteriological investigations, ensuring supplies of drugs and laboratory material mass vaccination

2) Reduce overcrowding and ventilate living and sleeping quarters 3) Intimate contacts should all be considered for prophylaxis

4) The use of vaccine in all age groups affected is strongly recommended if an outbreak occurs in a large institutional or community setting

Thank you & Good luck