Rabes Flashcards
(8 cards)
Risk factors
Animal bite, usually strays dogs with virus in their saliva.
Symptoms
*I.P. (Incubation Period) :2-4 weeks, it is proportional to the distance that the virus travels through the peripheral nerve.
1-Initial Symptoms: Fever, malaise, headache
2- Encephalitic Form:
* Intermittent episodes of confusion, agitation, and aggression with periods of calm in between.
* Copious saliva is characteristic (froth from mouth).
*Hydrophobia (fear of water)
*Aerophobia (fear of air drafts)
* Painful spasm on throat muscle.
* Spasm becomes more widespread and involves diaphragm & respiratory muscles.
* Death within a week of respiratory & bulbar palsy.
* Some patients have ascending paralysis .
Diagnosis
1-Mainly is clinical.
* Diagnostic antibody tests don’t become positive except after the 8th day.
* Abs are difficult to interpret in vaccinated persons
2-Laboratory tests.
a) RT-PCR (Reverse Transcription Polymerase Chain Reaction)
Detects rabies virus RNA.
Performed on saliva, CSF, or skin biopsy.
High sensitivity and specificity.
b) Direct Fluorescent Antibody Test (DFA)
*Performed on skin biopsy.
*Detects rabies viral antigens in nerve endings at the base of hair follicles.
c) Rabies Virus Neutralizing Antibody (RVNA) Testing
Treatment
A-Pre-exposure immunization:
* Active immunization of tissue culture or embryo tissue vaccine.
* 3 doses at 0, 7, 28 for travelers to endemic, high-risk groups.
Treatment
B-Post-exposure:
1-Ist aids:
* Wash & flush the wound vigorously by water and soap.
* Ethanol 70%.
* Topical application of rabies Ig.
* Avoid suturing of wound.
* Anti-tetanus toxoid.
Treatment
2-Post-exposure immunization (Active & Passive):
* Passive: 20 IU/kg for Human RIG (Rabies Immunoglobulin) and 40 IU/kg For equine RIG
* ½ dose infiltrated in & around wound, ½ dose IM in deltoid.
* Active: vaccines of 5 doses at 0, 3, 7, 14, 28 IM in deltoid.
DD
1-Guillain-Barré syndrome (GBS) – ascending paralysis, areflexia, no fever or encephalopathy.
2–Myasthenia gravis (in children)
3-Transverse myelitis – motor and sensory deficits below the lesion.
4-Acute disseminated encephalomyelitis (ADEM) – post-infectious or post-vaccination demyelination.
5-Poliomyelitis – asymmetric flaccid paralysis, often with fever.
6-Botulism – descending paralysis, cranial nerve involvement
7-Brucella: Neurobrucellosis
. A 21-year-old male college student is bitten on his left index finger by a dog. The man is urged by his friends to seek medical treatment for the bite, but he refuses to do so. After a few days he develops fever, which is accompanied by occasional headaches, malaise, fatigue, nausea, and an itching sensation on his left hand. Several days later, the man starts to experience episodes of rigidity, hallucinations, breath holding, and difficulty in swallowing.
a) What is your diagnosis?
b) What is the management immediately after bite?
