Viral Meningitis

VIRAL MENINGITIS

Definition: An infection that causes inflammation of the membranes that surround the brain and the spinal cord. These membranes are called the meninges.



  • It’s more common than bacterial meningitis and although rarely life-threatening. It can make people very unwell.
  • Most people have a good recovery but for some recovery can be slow and effects long lasting.
  • Many different viruses can cause meningitis, the most common are a group called enteroviruses.
  • Virus cause majority cases of aseptic meningitis.
Causes


  1. Enteroviruses in areas where vaccination has been widely covered e.g. Polio, echovirus, coxsackie virus
  2. Paramyxoviruses e.g. Mumps and Measles
  3. Herpes viruses e.g. herpes simplex, Epstein Barr virus, varicella zoster
  4. Adenoviruses


Risk Factors 
  • Children under sears
  • People with immune suppuration by diseases by diseases, drugs etc


Modes of Spread
  1. Direct spread with saliva, nasal mucus or feces
  2. Coughing or sneezing
  • Direct or indirect with an infected person increases the risk of getting infected with the same virus.


(adsbygoogle = window.adsbygoogle || []).push({});

Pathophysiology
  • Occasionally viruses defeat the body’s defenses and cause infection. If this occurs the virus can spread through the body to the meninges and cause meningitis
  • When the meningitis are infected, tiny blood vessels in the membranes are damaged. This allows the viruses to break through and infect the cerebrospinal fluid. The meninges become inflamed and pressure around the brain can cause nerve damage. Pressure on the brain can produce the specific symptoms associated with meningitis.


Clinical features
  • Headache
  • Neck stiffness
  • Photophobia

The above are present in older children and may be absent in younger ones

  • Fever –           Irritability
  • Seizures –           Poor feeding
  • Non Specific symptoms
  • Arthralgia
  • Myalgia
  • Sore throat

 

  • Anorexia, nausea, and vomiting are common
  • Rare symptoms include:-
    • Pericarditis
    • Myocarditis
    • Conjunctivitis


On Physical Examination
  • Findings vary widely depending on:- patients age, and the organism.
  • Younger patients have less specific signs.
  • Febrile or hypothermic
  • Lymphadenopathy
  • Building of the tontaneite
  • Diastasis of the Sutures
  • Nuchal rigidity

N.B:- Focal neurological signs present in 15% and are associated with poor prognosis

 

Complications
  1. Unilateral deafness after mumps meningitis
  2. Hydrocephalus
  3. Chronic enterovirus meningitis
  4. Seizures disorder, behavioral problems and speech delay.
Investigations
  1. Lumbar puncture and cerebrospinal fluid analysis
    • Most important test
    • Evaluation should include opening and closing pressures


Typical Findings are:-
  1. CSF pressure within normal reference range or increased
  2. LBC < 50dµL; Lymphocytes > 50%, Lymphocytic predominance is typical, neutrophils can predominate in early stages
  3. CSF glucose that is within the reference range (> 66% blood glucose level) or low.
  4. Negative gram stain results

 



  1. Blood glucose – To compare with CSF glucose
  2. CBC – To R/O bacterial infection
  3. Blood culture to exclude bacterial meningitis
  4. PCR assay for enteroviruses
  5. Viral culture of a throat swab, nasopharyngeal aspirate and stool sample
Treatment
  • The disease is self-limiting
  • Mostly supportive
  • Adequate analgesia
  • Treatment of seizures
  • Referral to pediatric ICU if there is an inappropriate level of consciousness and airway cannot be maintained.
  • Rest is advised
  • Steroids are not recommended for use in aseptic meningitis
  • Antiviral medications should be considered if viral encephalitis cannot be excluded
  • Acyclovir is used.


Contradictions of Lumbar Puncture
  1. Clinical or radiology signs of increased intracranial pressure
  2. Shock
  3. After convulsions until stabilized
  4. Clothing study outside normal range
  5. Platelets count below 100 x 109 /L
  6. On anti-coagulant therapy
  7. Papilledema
  8. Hypertension
  9. Abnormal posture on the spine
  10. Respiratory insufficiency
  11. Local superficial infection at Lumbar Puncture site.
  12. Focal neurological signs (will need imaging before considering the safety of the Lumbar Puncture)


Prognosis
  • Most people who get mild viral meningitis completely recur on their own usually within 7 – 10 days. However, people with meningitis caused by certain viruses such as herpes virus and influenza will usually need and get better from treatment such as an antiviral drug.
Preventions
  • No vaccines to protect against non-polio enteroviruses which are the most common cause of viral meningitis.
  • The following help in reducing infected or spreading to other people.
    1. Wash your hands often with soap and water especially after changing diapers, using the toilet or coughing or blowing your nose
    2. Avoid touching your face with unwashed hands
  • Avoid close contact such as kissing, hugging or sharing cups or eating utensils with people who are sick
  1. Stay at home when you are sick


Read Also: Restaurant Equipment