Animal Bites and Other Potential Rabies Exposures

2nd Quarter DIDE Training

May 18, 2011

Objectives

• Understand the public health burden of animal bites and the purpose of surveillance

• Describe the epidemiology of animal bites in WV

• Review animal bite case management• Review changes to animal bite form• Review current WVEDSS-related issues

Background – Public Health Burden

• True incidence of animal bites is not known

• Estimated 3–6 million mammalian bites/year1

– 0.2–1.0% of ED visits (200,000–1,000,000 visits)2,3

• 10% result in sutures, follow-up visits

• 1–2% result in hospitalization

• Small number of deaths (dogs bites result in 10–20 deaths per year in U.S.)

1Gilchrist J, Sacks JJ, White D, Kresnow MJ. Dog bites: still a problem?. Inj Prev. Oct 2008;14(5):296-301.2Garcia, VF. Animal bites and pasturella infections. Pediatrics in Review. 1997;18:127-130. 3http://www.cdc.gov/nchs/fastats/ervisits.htm

Biting Species

• Multiple animal species account for bites to humans– Dogs (80–90%) – Cats (5–15%) – Rodents (2–5%) – Others

Background – Dog Bites

• Most bites are caused by dogs – Most opportunities for exposure

• 75 million dogs in U.S.• 37% of households own >1

– Jaw pressure (200+ Psi)

• $100 million in hospital expenses4

• $1 billion in homeowner’s claims per year4

4Weiss HB, Friedman DI, Coben JH. Incidence of dog bite injuries treated in emergency departments. JAMA 1998;2711:51–53.

Potential Health Outcomes

• Psychological impact– Lifetime fear of animals– Nightmares/difficulty sleeping– Speech defects– Depression

• Physical damage/disfigurement– Avulsions– Lacerations– Punctures– Crushing

Potential Health Outcomes

• Risk of infection due to microorganisms– In the biter’s saliva (rabies virus, Pasteurella multocida, P.

canis, etc.)– On the victim’s skin (Staphylococcus, Streptococcus spp., etc.)– In the environment (Clostridium tetani)

• Infection risk increases with– Species of animal (cat vs. dog, others)– Type of wound (puncture bites)– Delayed treatment (>24–48 hours)– Patient age >50 years

Animal Bite Surveillance in WV

• Reportable event per §64-7-3 and §64-7-5– Animal bites and other potential

rabies exposures– Rabies post-exposure prophylaxis

(PEP)

• Local health dept – Follow-up of exposures– Case management– Report to DIDE via WVEDSS

Animal Bite Case Definition

• “A bite or scratch from a vector species or the introduction of saliva or central nervous system (CNS) tissue from a vector species into an open, fresh wound or mucous membrane (eye, mouth, or nose) of a human being.”

• Note: this includes bat exposures where a bite or scratch cannot be ruled out

Non-Exposures

• The following are examples of non-exposures– Petting an animal– Animal licking intact skin– Bite from an animal that had contact with a rabid animal– Contact with blood, urine and/or feces of an animal– Looking at a rabid animal…

Purpose of Animal Bite Surveillance

• Mitigate human risk of rabies

• Monitor epidemiology of animal bites

• Monitor PEP use/misuse

Epidemiology of Animal Bites Reported in WV, 2007–2009

RR*=0.1 (0.1–0.2)

RR*=10.9 (8.2–14.5)

RR*=9.4 (6.8–13.0)

*compared to having exposure to any other animal

Rabies PEP

• Approximately 40,000 rabies PEP / yr in U.S.

• Cost is approximately $2,500

• Risk of rabies is often uncertain but very low– High case-fatality of rabies with this

uncertainty influences inappropriate administration of PEP

PEP Recommendations

• Zero risk (for true exposures) does not exist

– Patient with healthcare provider make ultimate decision

• PEP recommendations should take into account:

– Availability of animal for confinement or testing (and outcomes)

– Circumstances of exposure

– Type of exposure

– Type of animal

– Behavior of animal

– Vaccination status of biting animal

– Local rabies epidemiology

Case Management

Case Management

• Each case is a potential legal record• The following should be documented– Patient demographics– Exposure information– Outcome of animal– Outcome of patient

Case Management

• Each case is a potential legal record• The following should be documented– Patient demographics– Exposure information– Outcome of animal– Outcome of patient

Public Health Actions

Report received

Report received

Verify victim info

Report received

Verify victim info

Ensure minimal patient info present: •Name•Address•Age/DOB •Sex •Contact info•Rabies vaccination status (previous to exposure)

Report received

Verify victim info

Verify exposure info

Report received

Verify victim info

Verify exposure info

Ensure critical info present: •Exposure date •Exposure type•Exposing species

Report received

Verify victim info

Verify exposure info

Ensure critical info present: •Exposure date •Exposure type•Exposing species

Determine other details: •Owned vs. non-owned animal•Vaccinated vs. unvaccinated•Provoked or unprovoked•Normal or abnormal behavior•County of exposure

Report received

Verify victim info

Verify exposure info

Management of animal

Report received

Verify victim info

Verify exposure info

Management of animal

Confine / Observe

Animal Dead

Lost to Follow-

up

Report received

Verify victim info

Verify exposure info

Management of animal

Confine / Observe

Cat/dog/ferret: 10 days from exposure date

Livestock: 14 days from exposure date

Others: confine/observe not appropriate

Animal Dead

Lost to Follow-

up

Report received

Verify victim info

Verify exposure info

Management of animal

Confine / Observe

Document Outcome:•Verified healthy•Died•Lost to follow-up

Animal Dead

Lost to Follow-

up

Report received

Verify victim info

Verify exposure info

Management of animal

Confine / Observe

Animal Dead

Tested for rabiesNot tested

Lost to Follow-

up

Report received

Verify victim info

Verify exposure info

Management of animal

Confine / Observe

Animal Dead

Document Test Result:•Positive•Negative•Indeterminate

Lost to Follow-

up

Report received

Verify victim info

Verify exposure info

Management of animal

Confine / Observe

Animal Dead

Lost to Follow-

up

(Document)

Report received

Verify victim info

Verify exposure info

Management of animal

Status of victim

Report received

Verify victim info

Verify exposure info

Management of animal

Status of victim

Document Outcome:•Hospitalization•Death•Rabies PEP

Report received

Verify victim info

Verify exposure info

Management of animal

Status of victim

Document Outcome:•Hospitalization•Death•Rabies PEP

RIG dateVaccine dates

Report received

Verify victim info

Verify exposure info

Management of animal

Status of victim

Document recommendations,attempts to contact

Data Quality (2009)

• Completeness

• Timeliness

• Accuracy

Completeness of Demographic Fields (2009)

Variable Percent Complete

Patient name 100%Date of birth 100%County of residence 99.8%Gender 97.9%Race 56.0%Ethnicity 42.4%

Completeness of Exposure Fields (2009)

Variable Percent Complete

Exposure type 99.8%Exposure date 100.0%Exposure time of day 62.7%Body location 98.2%Exposure provoked 85.9%

Completeness of Species Fields (2009)

Variable Percent CompleteSpecies involved 99.9%Ownership (pet, stray or wild) 97.4%Animal final outcome/status 91.7%Breed (canine only) 74.4%Vaccination history (pet only) 50.7%Specimen submitted 89.1%Specimen result (if submitted) 95.5%

Completeness of Outcome Fields (2009)

Variable Percent CompletePatient death 100.0%Patient hospitalization 96.2%PEP initiated 85.8%PEP status 46.2%

Transition to NBS

• As we move from WVEDSS to NBS we are making changes to forms – Shorter (most are one page front/back)– Disease-specific (no more “general”

forms)• Animal bite form revised early 2011, reviewed

by NBS task team

Structure of New Forms

• Patient demographics

• Investigation summary

• Report Source/ Healthcare provider

• Clinical• Vaccination

• Treatment• Laboratory results• Infection timeline• Epidemiologic

exposures• Public health issues• Public health actions

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