d. Signs/Symptoms.
(1) Prodromal period. In the classical picture, viral encephalitis is often
preceded by a 1- to 4-day prodromal period. During this stage, the patient usually
complains of malaise, low-grade fever, headache, muscular pain, and sometimes
symptoms suggesting a mild upper respiratory infection.
(2) Later symptoms. These early symptoms may, but usually do not, subside
prior to:
Rather abrupt increase in fever (103-105 F)
Development of a much more severe headache
Symptoms of CNS involvement including:
-- Marked rigidity of the neck and spine
-- Mental confusion
-- Disorientation
-- Delirium or coma
-- Generalized convulsions
-- Speech disturbances
-- Purposeless movements or tremors
-- Other signs and symptoms referable to the CNS
e. Treatment. The survivor of an attack, whether it is inapparent, mild, or
severe, is immune to the specific agent causing the infection. There is no specific
therapy for any of the arthropod-borne virus encephalitides.
f. Prevention. Vaccines, both formalinized mouse brain and chick embryo
types, have had wide experimental use, but they are not, at present, generally available.
Use of such vaccines requires special authorization of The Surgeon General.
Prevention must be directed primarily at the effective control of the vectors or the
safeguarding of the individual from bites of the vector by proper wearing of the uniform
and use of repellents (para 5-13).
Section VI. MOSQUITO-BORNE DISEASES - FILARIASIS
5-24. GENERAL
Causative agents for filariasis are two species of nematodes
(roundworms), Wuchereria bancrofti and Brugia malayi. The adult worms
live in the lymph nodes and subcutaneous tissue of the human host
reservoir, where they produce microfilariae, which find their way into the
bloodstream and are picked up by a mosquito vector (Table 5-1) taking a
blood meal. The microfilariae penetrate the gut wall of the mosquito,
migrate to the thoracic muscles, and change into infective larvae that migrate to the
MD0152
5-27
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