Encephalitis
Encephalitis is the direct invasion of the parenchyma of the brain by an infectious agent.
Meningo- encephalitis occurs when both the meninges and parenchymal cells are involved.
Viruses are more likely to cause encephalitis rather than meningitis.
The following are the common etiologic agents causing acute encephalitis and meningo- encephalitis in the Philippines:
1. Viruses: arboviruses, Japanese B encephalitis, St Louis encephalitis, chikungunya, dengue or flaviviruses
2. Enteroviruses – Coxsackie virus, Echovirus, Poliovirus
3. Other viruses – spread from man to man: Measles, rubella, varicella- zoster, adenovirus, herpes simplex, Epstein, Barr, cytomegalovirus, mumps, influenza A and B, hepatitis B, rabies
4. Bacteria: H. Influenza, N. Meningitidis, S. Pneumonia, Salmonella, M. Tb, Spirochetes, B. Pertussis
5. Miscellaneous: Rickettsiae, Fungi, Protozoa, Helminths
Clinical manifestations of encephalitis and its severity depend on the involved anatomic site, the pathogenicity of the causative agent and certain host factors like the immune response and reactive mechanisms of the patient. Encephalitis may present as: fever, myalgia, body malaise, respiratory and gastrointestinal symptoms such as cough, nausea and vomiting, headache, drowsiness, seizures, coma, cranial nerve palsies, hemiplegia, hallucinations, behavioral disturbances, and other neurologic findings
The prognosis of encephalitis is generally guarded since mortality is high especially in very young infants and in specific cases of herpes, measles and arboviral infections.
To avoid this encephalitis it is very important to control vectors specifically mosquitoes as in cases of arbovirus encephalitis.
Protection against vaccine preventable diseases like measles, mumps and rubella MMR) and Japanese encephalitis.