1
RRAABBIIEESS CCOONNTTRROOLL && PPRREEVVEENNTTIIOONN
EEPPIIDDEEMMIIOOLLOOGGYY RREEPPOORRTT
RRII 22000088--22000099
AAUUGGUUSSTT 22001100
RRII DDEEPPAARRTTMMEENNTT OOFF HHEEAALLTTHH
DDIIVVIISSIIOONN OOFF IINNFFEECCTTIIOOUUSS DDIISSEEAASSEE && EEPPIIDDEEMMIIOOLLOOGGYY
BACKGROUND
Since its arrival in 1994, the mid-Atlantic raccoon-adapted strain of the rabies virus has become enzootic
(endemic) among the wild animal population throughout Rhode Island. Animals with the greatest
susceptibility to this strain are raccoons, with spill over into the skunk, fox, woodchuck and other
terrestrial mammal populations (also called high-risk, target or vector species). Unimmunized
(therefore susceptible) pets such as cats, dogs and ferrets (medium-risk or suspicious species) and strays
can acquire rabies through exposure to wildlife. Cattle, sheep, pigs, horses and other farm animals can
also develop rabies. Animals such as rodents, rabbits, squirrels and opossums rarely acquire rabies and
are considered (low-risk species). Bats in RI are also endemic for the bat strain of rabies virus.
Humans may be exposed to the rabies virus through a bite, scratch or direct contact, where there is
contamination of a scratch, abrasion, mucous membrane, or fresh open wound with potentially infectious
material such as saliva or central nervous system tissue from an animal. The majority of such exposures
are from dog bites or cat bites/scratches. Often indirect exposures occur, such as when fresh saliva from a
target species is carried passively in a wound or on the muzzle or fur of a pet animal. Exposure by
inoculation of a mucous membrane (nose, eyes) or into an open skin lesion or wound of the human
caretaker is, theoretically possible in such a situation. Of note, bat rabies strains are highly transmissible
to humans, and prophylaxis is often recommended for exposure by proximity even without a visible
wound, if the bat is not available for testing.
The clinical and public health management of a person who may have been exposed to rabies requires first
the assessment of whether a significant bite or non-bite exposure has occurred, and then an assessment of
the likelihood that the animal involved was rabid. To this end, it is extremely important to capture the
exposing animal for quarantine, or euthanasia and testing. 10-day quarantine is the recommended option
only in the case of a captive dog or cat or ferret, which appears healthy. This action is based on the
biologic fact that cats, dogs and ferrets shed rabies virus in the saliva only for the 10-day period
immediately prior to death. A dog, cat or ferret that is alive and well at the end of a 10-day period of
observation counting from the date of exposure could not have transmitted rabies to the patient. The
authority and operational enforcement of all animal control procedures occurs under regulations and
guidelines from the RI State Veterinarian and the Governor’s Rabies Control Board. The RI State
Epidemiologist represents the Department of Health at this Board along with representatives from the RI
Veterinary Medical Society, Association of Animal Control Officers, RI SPCA, RI Division of Fish and
Wildlife, and Association of Livestock Farmers.
Target species (or pets with clinical rabies symptoms) should be euthanized and tested as soon as
possible, with vaccination decisions based on results. Exposures by animals that escape capture, as
well as all low-risk species, livestock and exotic animals should be assessed on a case-by-case basis in
consultation with public health experts. The Division of Infectious Disease epidemiology maintains a
24/7 on call system to accept and case-manage animal exposure reports from health care providers and
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other community sources, and provides expert consultation including pre-authorization for vaccine on
a case-by-case basis. Post-exposure vaccination is recommended in accordance with national
guidelines from the Advisory Council for Immunization Practice
(http://cdc.gov/mmwr/preview/mmwrhtml/rr5902a1.htm). Also see the algorithm for management of a
suspected rabid animal on last page of this document (Appendix A).
ANIMAL RABIES TESTING:
The RI Department of Health’s Division of Laboratories (Molecular Biology Lab) is the only lab in the
state that performs animal rabies testing. Currently rabies testing is performed in response to animal-
to-human exposure situations or animal-to-animal exposure such as pets and farm animals.
Surveillance testing without human or pet exposure may be performed in special situations.
A total of 872 specimens were tested for rabies in 2008 and 2009 (460 in 2008 and 412 in 2009).
There were 79 rabid animals (34 in 2008 and 45 in 2009) identified, with 9.0% of all animals examined
were positive for rabies. Wild species (including bats) that tested positive for rabies accounted for
97.5% of the total while only 2.5% of domestic animals (1 cat and 1 horse) tested positive (Table 1
and Figure 1).
Data on animal rabies from 1994 to 2009 can be found archived at:
http://www.health.ri.gov/disease/communicable/rabies/surveillance.php
Table 1. R. I. State Health Laboratory, Rabies Testing Results by Species, 2008 - 2009
Animal Species Tested
n (%)
Positive
n (%)
Positivity-
Rate
Tested
n (%)
Positive
n (%)
Positivity-
Rate
Cat 108 (23.5%) 1 (2.9%) 0.9% 91 (22.1%) 0 (0.0%) 0.0%
Dog 34 (7.4%) 0 (0.0%) 0.0% 43 (10.4%) 0 (0.0%) 0.0%
Bat 209 (45.4%) 7 (20.6%) 3.3% 161 (39.1%) 10 (22.2%) 6.2%
Skunk 42 (9.1%) 12 (35.3%) 28.6% 40 (9.7%) 13 (28.9%) 32.5%
Raccoon 27 (5.9%) 9 (26.5%) 33.3% 48 (11.7%) 19 (42.2%) 39.6%
Fox 9 (2.0%) 4 (11.8%) 44.4% 10 (2.4%) 1 (2.2%) 10.0%
Woodchuck 13 (2.8%) 0 (0.0%) 0.0% 6 (1.5%) 1 (2.2%) 16.7%
Other* 18 (3.9%) 1 (2.9%) 5.6% 13 (3.2%) 1 (2.2%) 7.7%
Total 460 (100%) 34 (100%) 7.4% 412 (100%) 45 (100%) 10.9%
2008 2009
• Includes 1 coyote (2008), 1 fisher cat (2009), 7 goats (3 in 2008; 4 in 2009), 3 horses (1 in 2008; 2 in 2009), 1
mink (2009), 4 opossums (all in 2008), 6 rabbits (5 in 2008; 1 in 2009), 1 rat (2009), 2 sheep (1 in 2008; 1 in
2009), 3 squirrels (2 in 2008; 1 in 2009), 1 weasel (2009) and 1 wolf (2008)
• These numbers represent burden of public health laboratory work contributed to by rabies prevention efforts,
and are not meant to represent systematic surveillance.
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Figure 1. State Health Laboratory Positive Rabies Tests by Animal Species,
RI 2008 - 2009
1 1
12
9
1 1 1
10
13
19
7
4
0
4
8
12
16
20
Cat Fisher Horse Woodchuck Fox Bat Skunk Raccoon
Animal Type
N
u
m
b
e
r
o
f
P
o
s
it
iv
e
R
a
b
ie
s
T
e
s
ts
2008 2009
ANIMAL EXPOSURE TO HUMANS:
For the purpose of this report, animal exposures are defined as bites, proximity to bats, scratches or
abrasions, or contact of animal saliva with a wound, lesion or mucous membrane. Animal exposures
to humans are reportable to the Division of Infectious Disease Epidemiology (Rabies Control and
Prevention Program) 24/7. Once an animal bite or suspect exposure is reported, public health staff
provides case-management services until final resolution of the case. These services include exposure
evaluation, confirmation of animal capture and quarantine or confirmation of animal capture and
euthanasia, coordination with the laboratory for follow up on animal testing results, notification to the
patient of the status of the investigation, rabies risk assessment and communication to the patient and
release/referral for vaccine and RIG as indicated. Follow up on completion of treatment with dates is not
monitored. Animal exposure reports and case management notes are collected on a standardized form and
data is maintained in a database (NEDSS). A single animal may result in multiple persons being exposed
(most commonly with household bat exposures). Each person is counted individually as an exposure.
Reported Animal Exposures in Rhode Island
The average age of reported animal exposure cases was 37.4 years (37.9 years in 2008 and 36.9 years
in 2009; Table 2). The majority of the cases (57.9%) were women (58.4% in 2008 and 57.3% in
2009). For both years, low/no risk animal exposures comprised the majority of reports, while 29.1% of
the reports were for high-risk animal exposures (29.1% in 2008 and 29.2% in 2009).
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Table 2. Characteristics of Animal Exposure Reports, R.I. 2008 - 2009
2008
n = 1471
2009
n = 1360
Total
N = 2831
Age*, years
mean (σ) 37.9 (39.0) 36.9 (37.1) 37.4 (38.1)
Gender
†
, n (%)
Female 857 (58.4%) 778 (57.3%) 1635 (57.9%)
Male 611 (41.6%) 580 (42.7%) 1191 (42.1%)
Exposure risk
‡
, n (%)
H
