In this article, we will discuss yhe the Management of Rabies Infection. So, let’s get started.
Management
1. Once the disease is established, therapy is symptomatic: The patient should be nursed in a quiet, isolated, darkened room with all facilities.
• Nutritional, respiratory and cardiovascular support to be provided.
• To reduce psychomotor excitation,
morphine, diazepam and chlorprom-
azine should be used liberally in such
patients.
• Maintain water and salt balance because dehydration results due to aversion to drinking water and excessive perspiration. Intravenous fluids are to be administered liberally.
• Prednisolone and mannitol may be
given in patients with raised intracranial pressure.
2. Prevention of rabies:
A. Post-exposure prophylaxis: Dramatic clinical features and fatal outcome in rabies make the prevention of rabies essential. The steps of prophylaxis include:
• To decide whether post-exposure
prophylaxis is warranted.
• If animal remains healthy during
observed period, no need for prophylaxis.
• If animal develops signs of rabies
(abnormal behaviour), it should be euthanised immediately, the head
should be transported to laboratory
under refrigeration, rabies virus
should be sought by direct fluorescent antibody (DFA) test and virus should be isolated by culture/mouse inoculation. In high risk exposures and in areas where canine rabies is endemic, post-exposure prophylaxis should be initiated. If laboratory test is negative, immunisation should be discontinued. If animal escapes after exposure, prophylaxis must be instituted.
• Local treatment of the wound
Immunisation (active and passive).
i. Local treatment of the wound: It
consists of:
• Wound toilet with soap and water:
The wound is scrubbed with soap and flushed with water so as to remove the saliva from the wound.
• Chemical cleansing of the wound:
After removal of soap with water,
chemical cleansing is done by any
quaternary ammonium compound
(1-4% benzalkonium chloride or 1% cetrimonium bromide) to inactivate the rabies virus.
• Tetanus toxoid and antibiotics should be administered.
• Wound must not be stitched.
ii. Passive immunisation with antirabies serum of either equine or human origin: The antirabies serum provides passive immunity in the form of ready-made antibodies against rabies virus. Human rabies immunoglobulin (HRIG) is preferred because equine antiserum may cause serum sickness.
Dose: Total dose of HRIG is 20 units/kg, and equine antiserum is 40 units/kg. Half the dose is infiltrated
around the wound and remaining
half is given by deep intramuscular
injection into the gluteal region. The
antirabies serum needs sensitivity
test; while HRIG does not require
any prior sensitivity testing.
Warning: When a person is re-exposed to rabies virus after administration of antirabies vaccines, antirabies strum should not be injected.
iii. Active immunisation with antirabies vaccine: In the developed world, human diploid cell vaccine (HDCV) is recommended which is least antigenic and systemic (1-4%)
and local reactions (15-20%) are
uncommon.
In the developing world, several other
rabies vaccines have seen licenced and used extensively. These include vaccines made in chick embryonic cells, vero-cells and duct embryonic cells. These preparations are safe but immunogenic and are effective for post-exposure prophylaxis. In India, HDCV is not
available. Other tissue culture vaccines are; primary chick-embryo cell vaccine (PCECV) and purified vero-cells rabies vaccine (PVRV).