Georgia epidemiology report, Vol. 23, no. 9 (Sept. 2007)

September 2007

volume 23 number 09

Rabies: The Epidemic Continues in Georgia

Rabies is perhaps the oldest known infectious disease (Rupprecht, of positive animal rabies tests (Table 1). Bats are also a common rabies

2002); its ancient history is evidenced by Greek and Chinese writings reservoir and associated with most human cases of rabies in the U.S.

(Woldehiwet, 2002). Significant scientific progress, including

(CDC, 2003).

the identification of virus strains in bats and the development

of effective vaccines, has led to its current status as a completely Several factors may explain the association of bats with human cases

preventable disease. Nonetheless, 55,000 people die of rabies each of rabies. It is often difficult to confirm a bat bite. The mouth of a

year across the world.

bat may be less than 5mm across, and many people may not be aware

that they have been bitten (Rupprecht, 2002). A person may wake up

Although human rabies is extremely rare in Georgia, rabies risk

from sleep to find a bat in the room with them, or they may feel they

assessments and the administration of post-exposure prophylaxis were simply "brushed" by a bat. In addition, there is a lack of public

(PEP) are an everyday occurrence. Since 1991 there have only been awareness that bats are reservoirs of rabies virus.

two confirmed cases of human rabies infection in Georgia; both

were fatal. There are many reasons for the high frequency of risk Livestock (including horses) are considered a low risk of rabies

assessments and PEP in Georgia, including the increasing contact transmission to humans because of low infection rates and the reduced

between human populations and wildlife in expanding suburban probability of an aggressive manifestation of rabies infection in these

areas, hyper-endemic raccoon rabies, and the high number of animal species. Small rodents (squirrels, hamsters, chipmunks, rats, and mice)

bites reported.

and lagomorphs (rabbits and hares) represent a very low risk of rabies

transmission to humans, as they are rarely infected with rabies and

The Virus

have never been reported to transmit rabies to humans (CDC, 2003;

Rabies is caused by an RNA virus of the family Rhabdovirus, genus Rupprecht, 2002). In 2006, at least 25 non-carnivorous species (i.e.

Lyssavirus. Typically, within a geographic area rabies viruses are squirrels, opossums, mice, moles, groundhogs, or otters) were submitted

maintained in a single wildlife reservoir species and spread primarily for rabies testing in Georgia; none were found to have rabies.

in intraspecies transmission cycles with occasional interspecies

spillover. In Georgia, for example, the primary wildlife reservoir Common Misperceptions about Rabies Exposures

for rabies is the raccoon, with spillover of the raccoon rabies

The highest risk of rabies transmission is associated with a bite

virus variant to other wildlife species (e.g. foxes, skunks, etc.) and exposure from an infected animal, in particular terrestrial carnivores

domestic animals. Bat rabies virus variants are found all across the and bats (Table 1). In addition, direct contact of an open cut with

contiguous United States.

saliva or central nervous tissue from a rabid animal may result in rabies

transmission. However, there are several misperceptions about rabies

Since rabies is an enveloped RNA virus, it does not survive in the exposures.

environment (CDC, 2003; Johnson, 2006). Once outside the host, the virus is rapidly deactivated by drying and ultraviolet radiation, making fomites and bodies of water (e.g. water bowls used by infected animals) ineffective for disease transmission (Rupprecht, 2002).

Table 1: Animal Species that tested positive for rabies in Georgia during 2002-2006

Species

Year (% of total animals)

2002 (%)

2003 (%)

2004 (%) 2005 (%)

2006(%)

Total (%)

Bat

26 (6.33%) 16 (4.0%) 18 (5.2%) 23 (9%)

28 (10.5%) 111 (6.6%)

Animal Reservoirs Globally, dogs are the major reservoir and vector of rabies (Rupprecht, 2002). In North America, however, rabies control programs have nearly eliminated this reservoir. Consequently, skunks and raccoons serve as the primary reservoirs in North America, with raccoons being the dominant reservoir in the Eastern U.S. (Kahn, 2006). Figures 1-4 illustrate the distributions of the four animal species most commonly diagnosed with laboratoryconfirmed rabies in Georgia during 2006. However, keep in mind that laboratory submissions for rabies testing in Georgia result only from either human or domestic animal contact (e.g. bite or deep scratch) with a potentially rabid animal. Consequently, these data cannot be used to estimate the prevalence of rabies in each of the reported species. Each year in Georgia raccoons represent 55-60%

Beaver Bobcat Cat Cow Coyote Dog Fox Horse Llama Mule Pig Raccoon Skunk Total

1 (.24%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

1 (0.1%)

3 (.73%)

3 (.75%)

5 (1.5%) 4 (1.6%)

1 (.37%)

16 (1%)

14 (3.4%) 20 (5.0%) 10 (2.9%) 9 (3.5%)

17 (6.4%) 70 (4.2%)

6 (1.5%)

1 (.25%)

3 (.87%) 0 (0%)

0 (0%)

10 (0.6%)

0 (0%)

1 (.25%)

1 (.29%) 2 (.78%)

1 (.37%)

5 (0.3%)

5 (1.2%)

3 (.75%)

4 (1.2%) 4 (1.6%)

7 (2.6%)

23 (1.4%)

59 (14.4%) 43 (10.7%) 35 (10.2%) 16 (6.3%) 16 (6%)

169 (10.1%)

0 (0%)

4 (1.0%)

2 (.58%) 2 (.78%)

0 (0%)

8 (0.5%)

0 (0%)

0 (0%)

1 (.29%) 0 (0%)

0 (0%)

1 (0.1%)

0 (0%)

0 (0%)

0 (0%)

0 (0%)

1 (.37%)

1 (0.1%)

0 (0%)

1 (.25%)

0 (0%)

0 (0%)

0 (0%)

1 (0.1%)

247 (60.1%) 242 (60.2%) 227 (66%) 156 (60.9%) 154 (57.7%) 1026 (61.1%)

50 (12.2%) 68 (16.9%) 38 (11%) 40 (15.6%) 42 (15.7%) 238 (14.2%)

411

402

344

256

267

1680

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A few of these are addressed below: Misperception 1: A person or animal that was exposed to blood, urine, or
feces of a rabid animal is at risk for the disease. Correction: No exposure to rabies occurs upon contact with blood, urine or feces of a rabid animal. Rabies can only be transmitted via direct contact with saliva or central nervous tissue. Misperception 2: A person who pets their dog after it was attacked by a rabid animal is at risk for rabies infection. Correction: Rabies virus is not able to penetrate unbroken skin. In addition, the virus does not survive on the coat of an animal, so there is no risk to a person who has not had direct contact with the rabid animal. Misperception 3: A pet was attacked by a rabid animal a couple of days ago. The pet is unvaccinated, and now it licked the cut hand of its owner. The pet needs to be tested to see if it exposed its owner to rabies. Correction: The incubation period of rabies is weeks to months. Consequently, a pet will be not be capable of exposing other pets or humans or test positive for rabies until it becomes sick with rabies--weeks to months after the attack. Misperception 4: A person found a bat in their child's room and it tested positive for rabies. However, post exposure prophylaxis (PEP) is not needed because no bite can be found on the child. Correction: Assessing the risk for rabies transmission from bats can be difficult, because bat bites are very small. Consequently, if a person has spent the night in a room with a bat, or a bat is found in a room with an unattended child, rabies post-exposure prophylaxis should be initiated. Please see the Georgia Rabies Manual (available at http://health.state.ga.us/epi/zvbd/zoonotic/index.asp) for specific details on assessing rabies transmission risk.

Fig. 1: Number of Bats Submitted for Testing and Proportion Confirmed Rabid in 2006
Fig. 2: Number of Cats Submitted for Testing and Proportion Confirmed Rabid in 2006

Clinical Course and Diagnostic Testing for Human Rabies The incubation period of the rabies virus in humans is variable and often lengthy, ranging from 2 weeks to years with an average of 2-3 months. The long incubation period contributes to the effectiveness of PEP for individuals exposed to rabies by allowing ample time to stimulate immunity (Kahn, 2006).

A person infected with rabies may initially present with nonspecific symptoms such as malaise, fever, or headache, which may last for days. Discomfort or paresthesias (pain or itching) may be experienced at the site of viral entry. As the disease progresses, signs of encephalopathy will be observed, commonly manifested by anxiety, confusion, and agitation (CDC, 2003). The symptoms most consistent with rabies are acute behavioral changes and unexplained progressive paralysis (Kahn, 2006). The acute clinical phase of rabies lasts 2 to 10 days. With rare exceptions, once clinical signs are observed, the disease is fatal. Treatment given at this point is typically supportive (CDC, 2003).

Prior to the onset of clinical signs, there are no tests to determine whether humans have been infected with the rabies virus. Serological testing (RFFIT) measuring the presence of antibodies in humans cannot be used to determine infection status prior to symptom onset. Diagnostic testing for suspected rabies infection requires several tests; no single test is sufficient for confirmation. Samples used for testing include saliva, nuchal skin biopsies, serum, and cerebrospinal fluid. All testing must be coordinated by the Georgia Division of Public Health, Notifiable Disease Epidemiology Section (404-657-2588).

Preventing and Treating Human Rabies To prevent rabies, effective pre- and post-exposure prophylaxis regimens exist. Please see the Georgia Rabies Manual (available at http://health.state. ga.us/epi/zvbd/zoonotic/index.asp) for specific details regarding high risk sub populations and determining the need for PEP. If PEP is necessary, prophylaxis consists of administration of one dose

Division of Public Health http://health.state.ga.us
Stuart T. Brown, M.D. Director
State Health Officer

Epidemiology Branch http://health.state.ga.us/epi
Susan Lance, D.V.M., Ph.D. Director
State Epidemiologist

Georgia Epidemiology Report Editorial Board
Carol A. Hoban, M.S., M.P.H. Editor Kathryn E. Arnold, M.D.
Cherie Drenzek, D.V.M., M.S. Susan Lance, D.V.M., Ph.D.
Stuart T. Brown, M.D. Angela Alexander - Mailing List Jimmy Clanton, Jr. - Graphic Designer
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Two Peachtree St., N.W. Atlanta, GA 30303-3186 Phone: (404) 657-2588
Fax: (404) 657-7517

Georgia Department of Human Resources
Division of Public Health

Please send comments to: gaepinfo@dhr.state.ga.us

Fig. and

33P:roNpuomrtbioenr

of Skunks Submitted for Testing Confirmed Rabid in 2006

References 1. CDC. 2003. Rabies. Retrieved on July 7, 2006 from http://www.cdc.gov/ncidod/dvrd/
rabies/default.htm 2. Johnson, N., Wakeley, P., Brookes, S., Fooks, A. (2006). European Bat Lyssavirus Type 2
RNA in Myotis daubentonii. Retrieved on July 11, 2006 from http://www.cdc.gov/ ncidod/EID/vol12no07/06-0287.htm 3. Kahn, C. (2006). Rabies: Merck Veterinary Manual: 9th ed. Retrieved on July 6, 2006 from http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/102300.htm 4. Rupprecht, C., Hanlon, C., Hemachudha, T. (2002). Rabies re-examined. Lancet, 2, 327343. 5. Woldehiwet, Z. (2002). Rabies: recent developments. Research in Veterinary Science, 73, 17-25. 6. World Health Organization. (2005). WHO Expert Consultation on Rabies. Retrieved on July 10, 2006 from http://www.who.int/rabies/trs931_%2006_05.pdf
This article was written by Dana Cole, D.V.M., Ph.D., DeAnna Howell, B.S., Marianne Vello, B.S., M.P.H., and Chrie Drenzek, D.V.M., M.S.
September 8, 2007 is the Inaugural World Rabies Day. Go to www.worldrabiesday.org to get information about events planned all over the world to raise rabies awareness and promote prevention.

Fig. 4: Number of Raccoons Submitted for Testing and Proportion Confirmed Rabid in 2006

Animal Bite Surveillance
As a component of injury prevention and rabies control, animal bites are reportable in Georgia. Animal bites are reported to the local health department and the Notifiable Disease Epidemiology Section (NDES) of the Georgia Division of Public Health. Many other zoonotic diseases can be spread from animals to humans as a result of an animal bite (e.g. bartonellosis, pasteurellosis, and streptobacillosis). However, rabies is considered the most dangerous of the zoonotic diseases, resulting in an encephalomyelitis that is essentially always fatal.

There are two systems used by NDES for the collection of animal bite surveillance data. Bites are directly reported from local health departments via on-line or mailin submissions, through the state electronic notifiable disease surveillance system (SendSSS) and indirectly reported by phone to the Georgia Poison Center (GPC) (404-616-9000 or 1-800-222-1222). GPC provides advice regarding wound treatment, post exposure prophylaxis (PEP) for rabies, and animal quarantine/testing. Often, emergency room and medical personnel report animal bites to GPC whereas animal control agencies and county environmental health specialists report via SendSS.

When an animal bites a human or domestic animal and is considered likely to be rabid, it is quarantined or submitted to the Georgia Public Health Laboratory for testing. Animals confirmed to be rabid are reported to NDES and entered into SendSS. Of the 867 documented rabid animals in Georgia during 2004-2006, 184 (21% of all submissions) were reportedly associated with a human exposure. The species of rabid animals that bit/exposed a human are shown in the table below.

of human rabies immune globulin--HRIG and 5 doses of rabies vaccine over a 28-day period (except if persons have previously received complete preexposure or post-exposure vaccination regimens). Whenever the animal is available for testing, PEP should not be started before animal rabies test results are available because of the limited availability of HRIG. Likewise, PEP should not be started if an animal is in a 10 day quarantine. Modern rabies vaccines do not require painful intra-abdominal inoculation and are well tolerated with few systemic side effects. Consequently, there should be minimal fear associated with receiving PEP. To date, there have been no cases of human rabies documented in the U.S. after PEP was administered in an appropriate and timely manner after an exposure (CDC, 2003).

Animal Raccoons Bats Cats Foxes Dogs Skunks Livestock Coyotes Bobcats

Number of Confirmed Human Exposures 63 (34.2%) 35 (19%) 31 (16.8%) 25 (13.6%) 10 (5.4%) 9 (4.9%) 5 (2.7%) 3 (1.6%) 3 (1.6%)

Please look for our upcoming detailed report on animal bite surveillance in Georgia in the November 2007 issue of the GER.
This article was written by Dana Cole, D.V.M., Ph.D., and Laura Atkins, M.S.

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The Georgia Epidemiology Report Epidemiology Branch Two Peachtree St., NW Atlanta, GA 30303-3186

PRESORTED STANDARD U.S. POSTAGE
PAID ATLANTA, GA PERMIT NO. 4528

September 2007

Volume 23 Number 09

Reported Cases of Selected Notifiable Diseases in Georgia, Profile* for June 2007

Selected Notifiable Diseases
Campylobacteriosis Chlamydia trachomatis Cryptosporidiosis E. coli O157:H7 Giardiasis Gonorrhea Haemophilus influenzae (invasive) Hepatitis A (acute) Hepatitis B (acute) Legionellosis Lyme Disease Meningococcal Disease (invasive) Mumps Pertussis Rubella Salmonellosis Shigellosis Syphilis - Primary Syphilis - Secondary Syphilis - Early Latent Syphilis - Other** Syphilis - Congenital Tuberculosis

Total Reported for June 2007
2007 77 21 16 2 59 4 10 8 11 1 1 2 0 2 0 149 196 4 14 5 36 0 38

Previous 3 Months Total

Ending in June

2005

2006 2007

187

139

189

8120

10121

3447

26

54

35

6

12

4

168

140

148

3666

4994

1301

26

27

32

37

15

20

44

65

25

9

9

8

1

3

3

5

6

4

0

4

0

15

5

4

0

0

0

408

360

362

128

259

631

25

42

10

141

104

56

108

98

31

264

260

150

1

3

1

122

124

125

Previous 12 Months Total

Ending in June

2005 2006

2007

607

576

617

33484

37451

34318

167

201

253

20

38

33

850

685

692

15837

18268

16163

114

111

125

189

87

70

334

186

164

32

36

44

5

8

7

18

17

19

3

5

0

41

34

27

0

0

0

1936

1902

1931

555

888

1802

103

147

78

487

486

433

350

401

311

957

992

863

4

7

4

491

501

500

* The cumulative numbers in the above table reflect the date the disease was first diagnosed rather than the date the report was received at the state office, and therefore are subject to change over time due to late reporting. The 3 month delay in the disease profile for a given month is designed to minimize any changes that may occur. This method of summarizing data is expected to provide a better overall measure of disease trends and patterns in Georgia.
** Other syphilis includes latent (unknown duration), late latent, late with symptomatic manifestations, and neurosyphilis.
AIDS Profile Update

Report Period

Disease

Total Cases Reported*

Classification <13yrs

>=13yrs Total

Percent Risk Group Distribution (%)

Female MSM

IDU

MSM&IDU HS

Unknown

Perinatal

Race Distribution (%)

White Black

Hispanic

Other

Latest 12 Months**:

HIV, non-AIDS

34

3,454

3,488

28

28

4

2

10

55

0.9

24

70

6

<1

8/06-7/07 AIDS

12

1,988

2,000

26

29

6

1

10

53

0.5

25

68

6

<1

Five Years Ago:***

HIV, non-AIDS

-

-

-

-

-

-

-

-

-

-

-

-

-

-

8/02-7/03 AIDS

1

1,677

1,678

25

37

9

3

15

36

-

19

74

6

1

Cumulative:

HIV, non-AIDS

265

11,586

11,851

32

28

7

2

11

50

2

23

73

4

<1

07/81-7/07 AIDS

279

37,067

37,346

20

43

15

5

13

23

0.7

31

66

3

<1

Yrs - Age at diagnosis in years

MSM - Men having sex with men

IDU - Injection drug users

HS - Heterosexual

* Case totals are accumulated by date of report to the Epidemiology Section ** Due to a change in the surveillance system, case counts may be artificially low during this time period

***HIV, non-AIDS was not collected until 12/31/2003

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