Rabies

PRESENTATION ON RABIESBY TEJINDER KAURMASTER OF PUBLIC HEALTH (1st Sem.) : 

PRESENTATION ON RABIESBY TEJINDER KAURMASTER OF PUBLIC HEALTH (1st Sem.)

SALUTE TO LOUIS PASTEURPIONEER INVENTOR OF RABIES VACCINE : 

SALUTE TO LOUIS PASTEURPIONEER INVENTOR OF RABIES VACCINE

INTRODUCTION : 

INTRODUCTION Rabies, also known as hydrophobia is an acute, highly fatal viral disease of the central nervous system, caused by Lascivious type 1. It is primarily a zoonotic disease of warm-blooded animals, particularly carnivorous such as dogs, cats, jackals and wolves. It is transmitted to man usually by bites or licks of rabid animals. Classical hydrophobia is clinically characterized by a long and variable incubation period, a short period of illness due to encephalomyelitis ending in death, despite intensive care. It is the only communicable disease of man that is always fatal.

PROBLEM STATEMENT : 

PROBLEM STATEMENT In India, Rabies occurs in all the parts of the country with exception of Lakshadweep and Andman and Nicobar Islands. Rabies is not a notifiable disease and the 30,000 deaths reported by national authorities may not be complete picture since these represent only the deaths reported from hospitals. It is estimated that the number of deaths due to rabies may be 1.1 to 1.5 million people receive post-exposure treatment with either nerve tissue or cell culture rabies vaccine. More than 95 percent of these cases are bitten by dogs. In the world rabies continue to exist in 87 countries or territories of the world and this accounts for 99 percent of all human rabies. The human death toll worldwide is about 60,000. Two countries India and Bangladesh belong to high incidence category. Most deaths from rabies occur in countries with inadequate public health resources and limited access to preventive treatment.

STRUCTURE : 

STRUCTURE Rhabdoviruses are approximately 180 nm long and 75 nm wide.  The rabies genome encodes five proteins:  nucleoprotein (N),  phosphoprotein (P), matrix protein (M), glycoprotein (G) and polymerase (L).  All rhabdoviruses are have two major structural components: a helical ribonucleoprotein core (RNP) and a surrounding envelope.   In the RNP, genomic RNA is tightly encased by the nucleoprotein.  Two other viral proteins, the phospoprotein and the large protein (L-protein or polymerase) are associated with the RNP. The glycoprotein forms approximately 400 trimeric spikes which are tightly arranged on the surface of the virus.  The M protein is associated both with the envelope and the RNP and may be the central protein of rhabdovirus assembly.

STRUCTURE : 

STRUCTURE The basic structure and composition of rabies virus is depicted in the longitudinal diagram below.

Rabies : 

Rabies Viral illness of mammals, e.g. bats. Close to 100% fatal in humans; 35,000-40,000 deaths annually worldwide. Duration: 2-6 days No treatment

Background Rabies Virus : 

Background Rabies Virus Single-stranded RNA virus Non-segmented genome Prototype virus for genus Lyssavirus Neurotropic, causes fatal encephalitis Historically, dogs were the most common source Currently, most cases occur in wildlife species 2003 first report of human case due to raccoon variant Most common sources of human rabies cases in the US Bat rabies virus variants

Rabies Pathogenesis : 

Rabies Pathogenesis Bite Incubation - non-infectious10 days – 6 months or possibly more Viral sheddingand illnesson the order of days Death Bite – virus may replicate locally. Virus goes up the nerves into the spinal cord and brain. Slide courtesy CDC

Common MisconceptionRabies is rabies is rabies…. : 

Common MisconceptionRabies is rabies is rabies…. There are many different rabies viruses. These are termed rabies virus variants or strains of rabies. They can be differentiated by monoclonal antibody reaction patterns (antigenic differences) and by differences in genetic sequences. Rabies virus variants are usually maintained in a single host reservoir species, although they may be transmitted to any susceptible mammal (i.e., spillover).

Signs of Rabies in Animals : 

Signs of Rabies in Animals Phase I: Prodromal (change in disposition, etc.). Phase II: Furious or “mad” rabies. Phase III: “Dumb” rabies (paralysis). Average incubation period in dogs and cats is 3 – 6 weeks.

Rabies Vaccinations & Wild Animals : 

Rabies Vaccinations & Wild Animals No approved vaccine; should not be vaccinated (zoos are exception). Most wild animals very susceptible. Other diseases may mimic rabies.

Transmission : 

Transmission Transmission of rabies virus usually begins when infected saliva of a host is passed to an uninfected animal. Various routes of transmission have been documented and include contamination of mucous membranes (i.e., eyes, nose, mouth), aerosol transmission, and corneal transplantations. The most common mode of rabies virus transmission is through the bite and virus-containing saliva of an infected host.

Transmission is Most Often by Saliva : 

Transmission is Most Often by Saliva Bites most common by far. Minor wound may be big enough to transmit virus (Bats).

Transmission (continued) : 

Transmission (continued) Nonbite exposure: --Rare! --Contamination of wounds or mucous membranes with saliva or neural tissue possible. --Should be evaluated for postexposure prophylaxis (PEP).

Transmission (continued) : 

Transmission (continued) The following are usually NOT considered exposure: -Petting a rabid animal. -Contact with blood, urine, or feces (e.g., guano) of a rabid animal. -If the material containing the virus is dry (the virus is fragile; it is inactivated by desiccation and ultraviolet irradiation).

Low Risk Species : 

Low Risk Species There has never been a documented case of rabies transmission from a rodent or lagomorph to a human. Case-by-case basis.

Large rodent species…. : 

Large rodent species…. Consider PEP following a bite if not available for testing …. ….since they are more likely (than a small rodent) to survive an attack by a rabid animal.

Slide 19: 

Eastern pipistrelle and Silver-haired bat Bats and The Trivial Bite Story Most human rabies cases acquired in the USA are due to rabies virus variants associated with insectivorous bats and, in particular, a specific variant associated with Eastern pipistrelle and Silver-haired bats. Insectivorous bats are small – less than 20 grams with tiny, needle-like teeth. Trauma alone, from a bat bite, is unlikely to send anyone to an emergency room. For example, an adult male dismissed a bite from a bat and decided that the risk of rabies in bats was small enough to not seek post-exposure prophylaxis. He died of rabies several weeks later. Rabies-positive red bat (Lasuirus borealis)

Signs of Rabies in People : 

Signs of Rabies in People Apprehension, headache, fever, malaise, indefinite sensory changes at site of bite (itching, numbness, tingling, etc.). Excitability, aerophobia, paralysis, spasms of swallowing muscles (hydrophobia). Delirium, convulsions, death (often due to respiratory paralysis) in 2 – 6 days. IP: Days to years (average 3 – 8 weeks).

Preexposure Vaccination(Unknown Exposure?!) : 

Preexposure Vaccination(Unknown Exposure?!) Two vaccines available: --Pasteur-Merieux --Chiron Corporation Regimen the same for both: --Three 1.0 ml injections on days 0, 7, and 21 or 28.

Preexposure Vaccination, continued : 

Preexposure Vaccination, continued Given intramuscularly. Intradermal no longer available.

Preexposure Vaccination, continued : 

Preexposure Vaccination, continued CDC recommends serum titer test every two years. If titer insufficient, receive single booster dose of vaccine. Names of laboratories that test serum titer are available.

Preexposure Vaccination, continued : 

Preexposure Vaccination, continued Vaccine not available Dept. of Health and Senior Services. Sources of vaccine: (1) Private medical providers – regional associations may get “group rate.” (2) Travel clinics. (3) City and county health departments – may offer; check with them; will charge for vaccine plus administration.

Actions to Take When Bitten : 

Actions to Take When Bitten Identify and, if possible, confine the biting dog, cat, or ferret for quarantine (do not vaccinate) or submit head of wild animal for examination.

Actions to Take When Bitten (continued) : 

Actions to Take When Bitten (continued) WOUND TREATMENT Wash immediately and thoroughly! Use soap, water, and virucidal agent (e.g., povidone-iodine solution).

Actions to Take When Bitten (continued) : 

SEE A DOCTOR Check tetanus status. Control bacterial infection. Suture? Depends on cosmetics and infection. Postexposure therapy? Actions to Take When Bitten (continued)

Post-exposure Prophylaxis (PEP) : 

Post-exposure Prophylaxis (PEP) A medical urgency (not an emergency) Complex decision Animal species Type of exposure Bite versus nonbite Availability of animal for rabies testing or observation

Animal Control: Quarantine or Test? : 

Animal Control: Quarantine or Test? Ten-day quarantine applies only to dogs, cats, ferrets (not to their crosses). Ten-day quarantine begins at the time of exposure.

Considering the Need for PEP : 

Considering the Need for PEP Dogs, cats, ferrets: -If available, observe for signs of rabies for 10 days. -If remain healthy, cannot have transmitted rabies. -PEP may be needed if not available for observation. -PEP needed if animal tests positive. Wild carnivores (skunks, foxes, raccoons), bats: -High risk, test animal or PEP needed. Livestock, small rodents, rabbits: -Low risk, treat on a case-by-case basis, consult with local and state health officials.

Postexposure Therapy for Previously Vaccinated Persons : 

Postexposure Therapy for Previously Vaccinated Persons BE HAPPY! YOU ONLY NEED TWO SHOTS! 1.0 ml, IM, three days apart. No rabies immune globulin (RIG)!

Postexposure Therapy for Persons Not Previously Vaccinated : 

Postexposure Therapy for Persons Not Previously Vaccinated These people get more shots! RIG given once, IM, at the site of the bite (ouch!); 20 IU/kg. Vaccine – five doses, 1.0 ml, IM, days 0, 3, 7, 14 and 28; never in gluteal region.

Cardinal Rules for Prevention of Rabies in the Community : 

Cardinal Rules for Prevention of Rabies in the Community 1. Ensure dogs, cats, and ferrets are UTD on vaccinations; vaccinations also available for horses, cattle, and sheep. 2. Keep pets under control; don’t run loose. 3. Avoid contact with stray pets/wild animals. 4. Do not keep wild animals or wild animal crosses as pets.

Slide 34: 

World Rabies Day Logo WRD logo currently available in many languages: English French Spanish Portuguese German Dutch Chinese Hausa Hindi Arabic Czech Slovak ~15 more under development

Slide 35: 

LOUIS PASTEUR PIONEER CHEMIST OF THE WORLD WHO INVENTED RABIES VACCINE

THANKS : 

THANKS