Rabies is a viral infection of domestic and wild mammals, transmitted to humans by the saliva of infected animals on the occasion of bites, scratches, licks on injured / a mucosal skin. Any mammal can carry rabies but human cases are due, mostly, to dog bites.
Once declared, rabies is fatal encephalitis. There is no cure, treatment is palliative. As long as it is not declared, rabies can be prevented by post-exposure prophylaxis.
– The incubation period is on average 20 to 90 days after exposure (75% of patients) but may be shorter (in cases of severe exposure, ie face to bite at. the head, hands multiple bites) or longer (20% of patients develop the disease between 90 days and one year after exposure and 5% after more than a year).
– Phase prodromal pruritus or paresthesia at the site of exposure and unspecific symptoms (malaise, fever, etc.).
– Neurological phase:
• Furious form: psychomotor agitation crises or hydrophobia (spasm of the larynx and panic triggered by an attempt to drink the patient or the
sight / sound / touch water) and aerophobia (same reaction triggered by a breath of air); sometimes convulsions. The patient is lucid and calm between crises.
• paralytic form (rarer, 20% of cases): upward progressive paralysis like Guillain-Barré syndrome.
Diagnosis is often difficult: the concept of bite / scratch can miss (exposure through licking) or the wound can be healed; the examination can be difficult and unreliable.
– In all cases
Prolonged washing of the wound or point of contact for locally eliminate the virus is crucial and must be done as soon as possible after exposure.
For the skin, use soap, rinse with running water, removing foreign bodies; the application of povidone-iodine 10% or 70% ethanol is an additional precaution does not replace the washing of the wound. For mucous membranes (eyes, mouth, etc.), rinse with water or saline. Local cleaning remains indicated even if the patient presents late.
– Depending on the type / condition of the wound
Not to promote the penetration of the virus, the wounds are not sutured at all (superficial wounds, not mutilating or puncture p. Ex.) Or left open and re-evaluated in 48-72 hours for any decision to suture. Lesions particularly soiled or likely to cause functional impairment require care in a surgical environment (exploration, removal of foreign bodies, excision of necrotic tissue, copious irrigation with sterile saline or Ringer’s lactate, under local or general anesthesia).When suturing is unavoidable, rabies immune globulin must be administered several hours or days before closing the wound (see below). Infected wounds are sutured and are reviewed daily.
Passive and active immunization:
Given the variable incubation period, the administration of vaccine / immunoglobulin is always an emergency, including in patients exposed several months ago.
– Serotherapy rabies
Rabies immunoglobulin (IGR) is indicated for exhibitions Category III 2 and for exhibitions Category II and III in immunocompromised patients.
It aims to neutralize the virus at the site of inoculation and is administered in a single dose on day 0 at the same time as the first dose of rabies vaccine.
Children and adults: rabies human immunoglobulin, 20 IU / kg or fragments of equine purified immunoglobulin F (ab ‘) 2, 40 IU / kg.
Infiltrate the greatest possible amount in and around the (the) wound (s) 3. The
surplus is injected IM in a region remote from the injection site of the vaccine. In case of multiple wounds, the dose is diluted 2 to 3 times with a sterile solution of sodium chloride at 0.9% to infiltrate all exposed sites.
If the TMF is not available at D0, the first dose of rabies vaccine is administered alone. IGR may also be administered as soon as possible within days but it is not recommended to administer the vaccine when the first dose was given 7 days or more, because the vaccine has already begun to induce protective antibodies.
2* Unless it is established that the patient was properly vaccinated against rabies before exposure (complete pre-exposure vaccination with 3 doses of a VCC).
3* Infiltrate the IGR even if the wound is healed. For wounds finger, infiltrate very carefully to avoid a compartment syndrome. When it is not possible to infiltrate the site (mucous membranes), the entire dose is administered by IM.
– Vaccination post exposure rabies
A complete rabies vaccination is indicated for exhibitions category
II and III. She started at D0 and pursued to term if the risk of rabies has been eliminated 4. There are several types of vaccines. The vaccines prepared in cell cultures (VCC), p. ex. human diploid cells (HDCV), Vero cells (VPCV) or chicken embryo (VPCEP) should replace the vaccines of nerve tissue (VTN). There are several vaccination schedules, learn and follow national recommendations. Shorter regimens recommended by WHO are indicative:
* An incorrect administration technique leads to a failure of PEP. If the injection technique ID unchecked, use the IM regimen.
4* Either by observing the captured animal (whether domestic) or by laboratory diagnosis of the animal killed.
WHO recommends 10 days to observe the animal captured. If at the end of the observation period, the animal has not developed signs of rabies, rabies risk is spread and rabies vaccination is interrupted. Laboratory diagnosis of the slaughtered animal involves sending his head to a specialized laboratory that excludes or confirmed rabies in animals.Rabies vaccination is interrupted if the review is negative.
– Antibiotic / antimicrobial prophylaxis
• A 7-day PO antibiotic therapy is indicated for infected wounds (redness, edema, sero-purulent or bloody discharge, localized cellulitis, lymphangitis, lymphadenopathy, fever). The treatment may be longer and / or parenteral for severe infection.
• Antibiotic prophylaxis PO 5 to 7 days is recommended for deep puncture wounds, wounds of the face or hands, wounds next joint, tendon, ligament, fracture; Heavily soiled wounds and / or requiring debridement; in immunocompromised patients.
• It is not recommended to prescribe an antibiotic for superficial wounds or wounds over 24 to 48 hours in patients without evidence of local or systemic infection.
The dosage is the same for antibiotics or antibiotic prophylaxis:
amoxicillin + clavulanic acid (co-amoxiclav) PO 5 (dose expressed in amoxicillin):
Children: 50 mg / kg / day in 3 divided doses; adults: 1.5 g / day in 3 divided doses
– Vaccination and anti-tetanus serum therapy
Always check the vaccination status. If unknown or if the tetanus vaccination is outdated.
5* The co-amoxiclav is the antibiotic of choice. Doxycycline (200 mg / day in 2 divided doses, except pregnant women and children <8 years) may be used in patients allergic to penicillin.