rabies & snake bite

8/7/2019 RABIES & SNAKE BITE

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REMELYN JOY E. BOGADOR, MDResident Physician

St. Elizabeth Hospital

RABIES & SNAKE BITE

MANAGEMENT



RABIES:A Preventable Disease



RATIONALEy Rabies is present in all continents, endemic in most African

&Asian countriesy E stimated to cause at least 55,000 deaths/year worldwide

y

56% in Asiay 43.6 % in Africay In the PHILIPPINES , it is considered a significant health

problemIt is one of the most acutely fatal infectionsIt is responsible for the death of 200 ² 300 Filipinos annually

Anti ²Rabies Act of 2007 ² post & pre exposure prophylaxis

Rabies free country in 2020



The ANTI ± RABIES ACTRepublic Act 9482

´ An act providing for the control and eradication of HUMAN & ANIMAL RABIES, prescribing penalties for

violation thereof and appropriating funds thereforeµ

y Provide a system for the control, prevention of the spread ,and eventual eradication of human and animal rabies

y E stablish the advocacy on responsible pet ownershipy Mandatory registration & vaccination of dogsy Leashing of dogsy Shoulder medical expenses relative

to the victim·s injury



P ENALTIES

y Failure or refusal to have their dog registered and immunizedagainst rabies (P2,000)

y Refusal to have his dog put under observation after said dog hasbitten an individual (P10,000)

y Refusal to have their dog put under observation and do notshoulder the medical expenses of the person bitten by their dog(P25,000)

y Refusal to put leash on their dogs when they are brought outsidethe house (P500)

y Impounded dog shall be released to its owner upon payment of afine not less thanP500 but not more than P1,000

y Person found guilty of trading dogs meat shall be fined not lessthan P5,000 per dog & subject to imprisonment for 1 to 4 years



W hat is RABIES?- Rabies is am acute viral encephalitis caused by rabies virus after being

bitten or exposed to infected animals.

THE VIRUS IS SENSITIVE TO:Heating/BoilingDryingUV and X-raySunlightTrypsinB-propiolactone

EtherDetergents

W HAT IS THE MOST COMMON RESERVOIR OF RABIES VIRUS?- In the Philippines, the most common reservoir of rabies virus are the dogs

which accounts for more than 98% and cats at 1.3%.**



How is the rabies virus transmitted?y It can be transmitted through a bite, an abrasion, lick on mucous

membrane or damaged skin and eating of raw or partially cookedinfected meat of animals.

IN ALMOSTALL CASES

Is due to a bite, scratch or even lick on mucous

membrane by animals (Dogs/Cats) whose salivacontains the virus.

IN VERY

EXCEPTIONALCASES

By inhaling virulent aerosol (laboratoryexperiment, exploration of enclosed cavesinhabited by infected bats*)

By transmission: from man to manIndirectly: transplantation of infected

cornea*Directly: from a bite or through saliva of aninfected person***



How long is the incubation period of Rabies?

Average incubation period is 20-90 days.

INCUBATIONPERIOD MAYBE MUCHSHORTER

A few days to several weeks especially inchildren with severe exposures in wellinnervated areas (face, head, neck««.)

IN VERYEXCEPTIONAL

CASES MUCHLONGER

Incubation of up to 6 years has beenrecently reported in the United States

INCUB AT ION PER IOD

is the only time when vaccination is effective



How long is the prodromal period of Rabies?

y Duration: 2-10 days

Earliest rabies specific symptoms:

Pain / paresthesia / itching at the bite site

There will be non-specific symptoms such as:

FeverMalaise

FatigueHeadacheAnorexia

Post-exposure treatment is no longer useful in this stage.



W hat is the course of the virus in the body?

1 . Clinic Symptom:Virus spread within the brain

2. Incubation:Multiplication, penetration in the localnerve endings and spread by the axonalroute towards central nervous system .

3. Contamination:Inoculation of the virus mainly through abite from infected animal

4. Possible contamination:Migration through peripheral nerve in thesecretory and excretory glands (at this stagethe virus is found in the saliva)

� The animal vector is

noninfectious during themajority of the incubationperiod**

When infectious rabies virus issecreted in the saliva of rabiesvectors, the host becomesinfectious



P OST EX P OSURE P ROPHY LAXIS ( P EP)

y Refers to anti- rabies treatment administered after anexposure (bite, scratch, lick, etc) to potentially rabid animals

y Includes local wound care, administration of rabies vaccine

+ RIG



C ATE GORIES of RABIES EX POSU RE

Category of Exposure Management

CATEGORY 1

a.) Feeding/touching an animal

b.) Licking of intact skin (with reliablehistory & thorough physical examination)

c.) E xposure to patient with signs andsymptoms of rabies by sharing of eating ordrinking utensils

d.) C asual contact (talking to, visiting andfeeding suspected rabies cases) and routinedelivery of health care to patient with signsand symptoms of rabies

1.) W ASH exposed skin immediatelywith soap & water.

2.) NO vaccine or RIG needed

3.) Pre-exposure prophylaxis may beconsidered for high risk person





CATEGORY II

a.) Nibbling of uncovered skin with or withoutbruising/hematoma

b.)Minor scratches/abrasions without bleeding

c.)Minor scratches/abrasions which are induced tobleed

d.) All C ategory 2 exposures on the head and neck areaare consideredC ategory 3 and should be managed as

such

1. W ash wound with soap and water

2. Start vaccine immediately:

a.) C omplete vaccination regimen until Day 28/30:

i. Biting animal is laboratory proven to be rabidii. Biting animal is killed/died without laboratory testingOR

iii. Biting animal has signs & symptoms of rabies ORiv. Biting animal is not available for observation for 14

daysb.)May omit day 28/30 dose if i. Biting animal is alive AND remains healthy after the

14-day observation period, ORii. Biting animal died within the 14 days observation

period, confirmed by veterinarian to have FAT ² negative

3. RIG is not indicated





CATEGORY III

a.) transdermal bites (puncture wounds, lacerations,avulsions) or scratches/abrasions with spontaneousbleeding

b.) licks on broken skin

c.) exposure to rabies patient through bites,contamination of mucous membranes (eyes, oral/nasalmucosa, genital/anal mucous membranes)or open skin

lesions with body fluids through splattering and mouth-

to- mouth resuscitation.

d.) handling of infected carcass or ingested of rawinfected meat

e.) all category II exposures on head and neck area

1. W ash wound with soap and water

2. Start vaccine and RIG immediately

a. C omplete vaccination regimen until day 28/30i. Biting animal is laboratory proven to be rabid ORii. Biting animal is killed/died without laboratory

testing ORiii. Biting animal has signs and symptoms ORiv. Biting animal is not available for observation for 14

days

b. May omit day 28/30 dosei. Biting animal is alive AND remains healthy after the

14 day observation period ORii. Biting animal dead within the 14 days observation

period, confirmed by veterinatian to have no signsand symtoms of rabies and was FAT negative



PRE EX POSU RE PROPHYLAX IS

y Refers to rabies vaccination administered before an exposureto potentially rabid animals

y U sually given to those who are at high risk of getting rabiessuch as veterinarians, animal handlers, staff in the rabieslaboratory, hospitals handling rabies patients and schoolchildren from high risk areas, etc.

y DAY 0, 7, 21/28



Are there any contraindications to anti-rabies vaccination?

y There is no contraindication to anti- rabies vaccination

Yes, rabies vaccine and RIG can be given safely during pregnancyThe risk of teratogenicity is less than the risk of rabies

Interchanging of vaccine brands is NOT RE C OMME NDE D byWHOOnly if it cannot be avoided, one may interchange brands as longas it is one of the WHO recommended modern vaccines

Is it safe to give anti-rabies vaccination duringpregnancy?

Can we interchange vaccine brands?



Can we interchange vaccine regimens?

Interchanging of vaccine regimens is NOT RECOMMENDED by W HO

Practice should be the exception since no immunegenicity studiesavailable

Antibody monitoring highly recommended for these case

Vaccine should always be given on the deltoid muscle in adultsand on anterolateral thigh in young infants, never on teal regionsince it results in lower neutralizing antibody titers

Can the vaccine be given on the buttocks?



W hy is it necessary to vaccinate the patient if the dog is vaccinated?

Reasons:At least 80% of dog population need to be vaccinated tocut the transmission of rabies among dogsAs in humans, not all dogs will respond to vaccinationSome dog owners may claim their dog is vaccinated evenif they are not

Open reconstituted vials that have been kept in therefrigerator may still be used up to 8 hours

How long can you keep an open reconstituted vial of vaccine?



SNAKE BITES

World Health Organization



Venomous snakes of South-East AsiaC LASS IFIC ATIONS :

1. ELAPIDAEhave short permanently erect fangsthis family includes the cobras, king cobra, kraits, coral

snakes and the sea snakes

Short, permanently erect, fangs of atypical elapid (Thai monocellate cobra± Naja kaouthia)

North Indian or Oxus cobra ( Najaoxiana) (Copyright DA Warrell) Viperdae

have long fangs

Indo-Chinese spittingcobra (Naja Saimensis)



2. VIPERIDAEhave long fangs which are normally folded up against the upper jawbut, when the snake strikes, are erectedThere are two subgroups, the typical vipers (Viperinae) and the pitvipers (C rotalinae)

Head of a typical pit viper ± white-lipped green pit viper (Trimeresurus albolabris) s howing the pit organ situatedbetween the nostril and the eye (arrow head)

Russell¶s vipers(Copyright DA Warrell) detailsof fangs

White-lipped green pit viper (Trimeresurus albolabris) (Copyright DAWarrell)



How to Identify Venomous Snakes?y Some of the most notorious

venomous snakes can be recognizedby their SIZE, SHAPE, COLOR,PATTERN of MARKINGS, their

BEHAVIOUR, SOUND theymake when they feelthreatened

y C OBRAS ² rear up, spread a hood,

hiss and make repeated strikestowards the aggressory Blowing hiss of Russells viper &

grating rasp of saw scaled viper



How Common are Snake Bites?

PHILIPPINESy there are no reliable estimates of mortalityy Figures of 200- 300 deaths each year have been suggestedy Only cobras cause fatal envenoming, their usual victims being rice

farmers.INDIAy It is estimated that between 35,000 and 50,000 people die of

snake bite each year among India·s population of 980 million.



How can snake bites be avoided?y Snake bite is an occupational hazard that is very difficult to avoid

completelyy Education! K now your local snakes, know the sort of places where they

like to live and hide, know at what times of year, at what times of day/night or in what kinds of weather they are most likely to be active

y Be specially vigilant about snake bites after rains, during flooding, atharvest time and at night.

y Try to wear proper shoes or boots and long trousers, especially when

walking in the dark or in undergrowthy Avoid or take great care handling dead snakes, or snakes that appear to be

dead



SIGNS & SYMPTOMS (venom injected)Local symptoms and signs in the

bitten party fang marksy local painy

local bleedingy bruisingy lymphangitisy lymph node enlargementy Inflammation (swelling, redness,

heat)y blisteringy local infection, abscess formationy necrosis



Systemic Signs & Symptomsy G eneral - n ausea, vomiting, malaise, abdominal pain, weakness, drowsiness, prostrationy C ardiovascular (Viperidae) -v isual disturbances, dizziness, faintness, collapse, shock,

hypotension, cardiac arrhythmias, pulmonary oedema, conjunctival oedemay Bleeding and clotting disorders (Viperidae)- epistaxis, bleeding into the tears,

haemoptysis, haematemesis, rectal bleeding or melaena,haematuria, vaginal bleeding,bleeding into the skin (petechiae, purpura,ecchymoses) and mucosae, intracranialhaemorrhage

y Neurological (Elapidae, Russell·s viper) -d rowsiness, paraesthesiae, abnormalities of taste and smell, ´heavyµ eyelids, ptosis, external ophthalmoplegia , paralysis of facialmuscles and other muscles innervated by the cranial nerves, aphonia, difficulty inswallowing secretions, respiratory and generalised flaccid paralysis

y Skeletal muscle breakdown (sea snakes, Russell·s viper)- g eneralised pain, stiffnessand tenderness of muscles, trismus, myoglobinuria, hyperkalaemia, cardiac arrest, acuterenal failure



y Renal (Viperidae, sea snakes)- lower back pain, haematuria, haemoglobinuria,myoglobinuria, oliguria/anuria,symptoms and signs of uraemia (acidotic breathing,hiccups, nausea, pleuritic chestpain....)

y Endocrine (acute pituitary/adrenal insufficiency) (Russell·s viper)y Acute phase: shock, hypoglycaemiay C hronic phase (months to years after the bite): weakness, loss of secondary sexual hair,

amenorrhoea, testicular atrophy, hypothyroidism etc



MANAGE ME NT OF SNAK E BITE

Recommended first aid methodsy Reassure the victim who may be very anxiousy Immobilise the bitten limb with a splint or sling (any movement or

muscular contraction increases absorption of venom into thebloodstream and lymphatics)

y C onsider pressure- immobilisation for some elapid bitesy Avoid any interference with the bite wound as this may introduce

infection, increase absorption of the venom and increase localbleeding

Most traditional first aid methods should be discouraged:They do more harm than good !



The special danger of rapidly developing paralytic envenoming after bites by some elapid snakes: use of pressure-immobilisation

P ressure bandaging is not recommended for bites by vipers and cobras whose

venoms cause local necrosis.



Early clues that a patient has severe envenoming:� Snake identified as a very dangerous one

� Rapid early extension of local swelling from the site of the bite� Early tender enlargement of local lymph nodes, indicating spread of venom in

the lymphatic system� Early systemic symptoms: collapse (hypotension, shock), nausea, vomiting,

diarrhoea, severe headache, ³heaviness´ of the eyelids, inappropriate(pathological) drowsiness or early ptosis/ophthalmoplegia

� Early spontaneous systemic bleedingP assage of dark brown urine



Antivenom is the only specific antidote to snake

venom. A most important decision in themanagement of a snake bite victim is whether or

not to give antivenom .

Antivenom treatment carries a risk of severereactions and in most countries it is costly and

limited supply. It should therefore be used onlyin whom the benefits of antivenom treatment arexceed the risks .

rabies & snake bite

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