Bacterial Meningitis

Bacterial meningitis is an acute infection of the meninges may be complicated by brain damage and irreversible neurological and auditory effects.

Bacterial meningitis is a medical emergency. The treatment relies on early parenteral antibiotic well penetrating the cerebrospinal fluid. Antibiotic therapy is probabilistic in the absence of identification of the organism or pending results found.

The most common causative organisms vary according to age and / or context:

– Isolated cases of meningitis:

• Children from 0 to 3 months:

Child </ = 7 days: Gram-negative bacilli (Klebsiella, E. coli, S. marscesens, Pseudomonas sp, Salmonella sp) and group B streptococci

Children> 7 days: S. pneumoniae (50% of bacterial meningitis) L. monocytogenes is occasionally responsible for meningitis during this period.

• Children from 3 months to 5 years: S. pneumoniae, H. Influenza B and N. meningitidis

• Children over 5 years and adults: S. pneumoniae and N. meningitidis

Special situations:

• Patient immunocompromised (HIV, malnutrition): proportion of Gram-negative bacilli (including Salmonella sp) but also Mr. tuberculosis

• Sickle cell disease: Salmonella sp. and S. aureus is the most common germs.

• If meningitis is associated with a skin infection or a skull fracture, infection with S. aureus is possible.

– Meningitis in an epidemic:

In the Sahelian region 1 during the dry season, meningitis epidemic meningitis (Neisseria meningitidis A or C or W135) affect children from the age of 6 months, adolescents and adults. During and outside of these periods, all germs usually meningitis officials may also be involved, especially in young children.

Clinical signs:

The clinical picture depends on the patient’s age:

Children over one year and adults:

– Fever, severe headache, photophobia, neck stiffness

– Signs Brudzinski and Kernig: the patient lying flexes involuntarily knees when he flexes the neck or when raising her legs upright, knees extended.

– Petechial or ecchymotic purpura (often related to meningococcal infection)

– In severe forms: coma, seizures, focal signs, purpura

fulminans

1 * but not exclusively, p. ex. Rwanda, Angola, Brazil.

Children under one year:

The classic signs are absent rule.

– Irritability, fever or hypothermia, impaired general condition, refusal to eat / suck or vomiting

– Other signs may include: seizures, apnea, loss of consciousness, bulging fontanelle (when not crying); occasionally: stiff neck and purpuric rash.

Laboratory:

– Lumbar puncture (LP):

• Macroscopic examination of cerebrospinal fluid (CSF); immediately begin antibiotic therapy if the PL brings disorder CSF.

• Microscopy: Gram stain (a Gram negative does not eliminate the diagnosis) and leukocyte count.

• In an epidemic context, once the meningococcal aetiology confirmed, the PL is not systematic for new cases.

– Rapid test for identifying soluble antigens.

NOTE: In areas where malaria is endemic, eliminate severe malaria (rapid test or thin and thick films).

Processing a single case of meningitis:

Anti-biotherapy:

For the choice of antibiotic therapy and dosages according to age.

Duration of antibiotic therapy:

1) Depending on the germ:

• Haemophilus influenzae: 7 days

• Streptococcus pneumoniae: 10-14 days

• Streptococcus Group B and Listeria: 14-21 days

• Gram-negative bacilli 21 days

• Neisseria meningitidis See antibiotic therapy in an epidemic

2) If the etiology is unknown:

Children <3 months 2 weeks after sterilization of CSF or 21 days

Children> 3 months and adult: 10 days. Consider extending the treatment -or to reconsider the diagnosis- if fever persists beyond 10 days. In contrast, a 7-day treatment with ceftriaxone enough patients responding quickly to treatment.

Additional treatments:

– Early administration of dexamethasone reduces the risk of hearing loss in meningitis patients with H. influenzae or S.pneumoniae. It is indicated in meningitis caused by these germs or when the bacterial agent involved is unknown, except among the newborn (and suspected meningitis epidemic in méningocciques context).

dexamethasone IV:

Children> 1 month and adult: 0.15 mg / kg (max. 10 mg) every 6 hours for 2 days. Treatment should be started before or with the first dose of antibiotic, otherwise it is of no benefit.

– Ensure a good diet and proper hydration (infusions or nasogastric tube if necessary).

– Seizures.

– Coma: prevention of pressure sores, mouth care, eye care, etc.

Treatment of a meningitis epidemic in the context of 2:

Anti-biotherapy:

N. meningitidis is the most likely germ. The first-line treatment (dispensary) is either oily chloramphenicol or ceftriaxone administered (e) as a single dose IM.

* 2 For more information, see the guide What to do in case of meningococcal meningitis epidemic, MSF.

Children over 2 years and adults (except pregnant or lactating women):

oily chloramphenicol IM: 100 mg / kg single dose without exceeding 3 g. Administering half the dose in each buttock if necessary. Do not exceed the dose indicated.

ceftriaxone IM: 100 mg / kg single dose, without exceeding 4 g. Administering half the dose in each buttock if necessary.

In the absence of improvement (ie of repeated convulsions, fever> 38.5 ° C, onset / worsening of consciousness or neurological signs disorders.) 24 hours after the first injection: remake a second dose the same antibiotic.

In the absence of improvement (same signs as above) 48 hours after the start of treatment (ie d. After 2 doses of oily chloramphenicol or ceftriaxone to 24 hours apart), reconsider the diagnosis . If no differential diagnosis was made (p. Ex. Malaria), treated with ceftriaxone by injection daily for 5 days.