Ciphi Rabies

Rabies Investigations

By: Todd Veres

Submitted to the Board of Certification of the Canadian Institute of Public Health Inspectors

February 2005

2

TABLE OF CONTENTS

Introduction 3

Prophylaxis: An Overview 4

Legislative Authority / Guidelines 5

Public Health Significance 6

Inspection Background 7

Inspection 9

Discussion / Rationale 10

Inspection Results 11

Conclusion 12

References 13

Appendices 15

Rabies InvestigationsBy: Todd Veres

3

INTRODUCTION

Rabies is a preventable infectious viral disease that causes acute encephalopathy in mammals.

The rabies virus is found in wild and domestic animal reservoirs, and is typically transmitted via

saliva from the bite or scratch of an infected animal. The rabies virus can also be transmitted via

viral contact with an intact mucous membrane (i.e., eyes, nose, mouth), by corneal transplant, or

by aerosol transmission. These means of transmission, however, are much more rare (Chin,

2000).

Rabies has extreme human health significance due to the fatal nature of this disease. The

Haldimand-Norfolk Health Unit acts to prevent any cases of human rabies, and works with

neighboring health units when investigations cross county lines. All cases of suspected human

exposure to the virus are investigated, and the health unit controls the vaccines required for

treatment.

Rabies is fatal to both humans and other mammals once symptoms appear. From the point of

introduction in the body, the virus travels retrograde in the peripheral nerves, on its way to the

central nervous system. The incubation period, which is the time from which the animal is

infected, to when it becomes symptomatic, may be as short as 3 to 7 days, but is typically 1 to 3

months (Hemachudha, Laothamatas, & Rupprecht, 2002).

Once the virus reaches the brain, it replicates much more quickly, and begins to spread to the

remainder of the body via the nerves, including into the salivary glands. At this point, the animal

is capable of transmitting the virus via bite. Behavioral changes begin to develop due to brain

damage caused by the virus. The animal remains infective until death (Rabies, 2003).


4

In humans, early symptoms of rabies are nonspecific, consisting of fever, headache, and malaise.

As the disease progresses, neurological symptoms appear and may include insomnia, anxiety,

confusion, paralysis, excitation, hallucinations, hypersalivation, fear of water, and difficulty

swallowing. Death usually occurs within 7 days of the onset of symptoms (Rabies, 2003).

PROPHYLAXIS: AN OVERVIEW

A prophylaxis (vaccine) exists to protect humans and animals against the virus. For humans,

treatment takes 2 forms. The rabies immunoglobulin (RIG) provides rapid protection against

rabies for only 1 to 2 weeks after exposure. It is only issued after exposure to the virus (post-

exposure). The quantity given depends on the body mass of the victim (“Rabies prevention,”

2001).

The second vaccine in use is the human diploid cell vaccine (HDCV). This vaccine requires

approximately 7 to 10 days to develop and provides protection for greater than or equal to 2

years. It can be administered before or after viral exposure. For those exposed, it is

administered in a series of 5 shots over the course of 28 days. When issued before exposure,

HDCV is administered in 3 shots in as little as 21 days. Pre-exposure vaccination does not

eliminate the need for post-exposure treatment. It does, however, eliminate the need for the RIG,

and reduces the total number of doses of HDCV needed. It also offers a measure of protection

when post-exposure therapy is delayed or unavailable (“Rabies prevention,” 2001).


5

LEGISLATIVE AUTHORITY / GUIDELINES

The requirement to conduct rabies investigations begins with the Health Promotion and

Protection Act (HPPA). Section 5 of the act states that every board of health shall provide health

programs regarding the control of infectious diseases. Section 7 of the act authorizes the Minister

of Health to publish guidelines for these programs to which the boards of health shall adhere.

The Mandatory Health Programs and Services Guidelines, 1997, in the section on Rabies Control

states a board of health must act to maintain the incidence of rabies at 0 in the human population.

This is done through promoting vaccination, offering information and education, investigating

possible human exposure, and providing access to the vaccines in the event it is required.

Also under the HPPA are two regulations that pertain to rabies control. Regulation 557:

Communicable Diseases – General, and Regulation 567: Rabies Immunization. Regulation 557

deals with the requirements for a physician, police officer, veterinarian, or any other person to

notify the health unit in the event of possible human rabies exposure, the need for the health unit

to investigate all cases received, the procedure for observation or quarantine of animals, and the

destruction of animals when required and permissible.

Regulation 567 deals with the requirement of owners to vaccinate their domestic animals, and

allows a public health inspector (PHI) to issue a fine against a person who does not have their

animal vaccinated when required. A fine would be issued by the PHI under the Provincial

Offenses Act (POA). The particulars of the POA will not be discussed in this report.


6

PUBLIC HEALTH SIGNIFICANCE

In order to prevent rabies in the human population, prevention efforts are necessary to keep

people from becoming exposed in the first place, and to prevent the disease from developing in

those people who have been exposed. This is done by:

1. Reducing contact between humans and potentially rabid animals.

2. Immunizing domestic animals.

3. Providing post-exposure prophylaxis to people who may have been exposed.

To achieve the first two goals, the Haldimand-Norfolk Health Unit offers education to the general

public regarding the risks of rabies, and the need to avoid wild animals. This is typically done

via media. However, because much of the population of these two counties is outside urban

centers, the potential for a rabid animal to come in contact with a domestic (companion) animal is

high. This newly infected domestic animal would then have the ability to transmit the virus

within the home environment.

To combat this, the health unit has been offering “rabies clinics,” where anyone can bring a dog

or cat to receive a rabies vaccine for $10. The rationale is by maintaining a well-established level

of animal vaccinations; the pathway for transmission between humans and wild reservoirs is

reduced (Robertson, Irwin, Lymbery, & Thompson, 2000)

Pre-exposure prophylaxis should be offered to all persons whose activities place them at high risk

for exposure to either the rabies virus or to rabid animals. However, this service is not offered

through the Haldimand-Norfolk Health Unit, and will not be discussed further.


7

Post-exposure prophylaxis must be given to all persons exposed to the rabies virus, or to those

where exposure to the virus is suspected, but the animal isn’t available for confirmation. The

vaccines must be administered before any symptoms appear for it to be effective in preventing

death. With the recent exception of a 15-year-old girl in Fond du Lac County, Wisconsin, who

survived without any form of vaccine (“Recovery,” 2004), only 5 people have been recorded to

survived rabies without post-exposure prophylaxis. Of these 5, all were either previously

vaccinated or received some form of prophylaxis before the onset of illness.

INSPECTION BACKGROUND

Human rabies investigations are typically initiated by either a report being faxed from a local

hospital or police department in accordance with Regulation 557, or when the victim notifies the

health unit. The health unit must begin an investigation within 24 hours.

The PHI first contacts the victim, and all pertinent information is included on the form “Report of

Bite / Contact with Animal Suspected of Rabies.” This information includes the person’s

demographic information, the date and nature of the wound, the animal description, the treatment

received, their local healthcare provider, if the attack was provoked or not, and any other

information that would be useful to locating the animal.

The PHI uses the information provided to find the animal. In some cases, the animal is known, in

other cases, the animal is unfamiliar to the victim. If the PHI can find and positively identify the

animal, an assessment of the animal begins. This includes the general state of health and

behavior of the animal. The PHI would then order the animal to be placed under observation, or

in confinement / quarantine. The differences between these orders are:


8

1. Observation orders are only available if the attack was provoked and the animals’

vaccination status is currently up-to-date. The owner would be required to monitor the

animal for changes in health status for 10 days following the bite. He would also have to

notify the health unit in the event of abnormal behavior, death, or escape.

2. Confinement / Quarantine orders apply if either the attack was unprovoked or if the

animals’ vaccination status is out-of-date. These orders include the same requirements as

Observation orders, but the animal must be confined to the home during this period, and

cannot come in contact with any people / wildlife other than the primary caregiver.

The owner would have to sign one of the orders, if he or she wanted to take personal

responsibility for the animal. The owner would need to provide government ID, and proof of the

animals’ up-to-date vaccination status, if applicable. The PHI would explain the owners’

responsibilities and requirements under the law. If the owner did not wish to sign an order, the

health unit would take possession of the animal and send it to a kennel. The animal would also

be sent to a kennel if ownerless.

If, however, the animal were showing signs of rabies at the time of the assessment, or during the

10 days, the PHI would contact animal control to deliver the animal into quarantine. There, a

veterinarian would confirm that assessment. The animal would be destroyed humanely, and the

brain would be released to the Canadian Food Inspection Agency (CFIA) for analysis. Post-

exposure treatment would begin for the victim immediately.

The end of the period of observation, or confinement / quarantine, occurs 10 days from the date

of the bite. The PHI or a veterinarian then observes the animal to ensure it’s asymptomatic. The


9

rationale behind this is that if the animal was infective at the time of the bite, it will become

symptomatic or die within 10 days. If the animal remains in apparent good health on day 10, it

does not mean that it isn’t incubating rabies; it means at worst, it was not infective at the time of

bite. Therefore, the victim would not need vaccines.

If the PHI cannot locate the animal within 10 days of the bite, post-exposure prophylaxis must be

administered to the victim as a precaution. Should the animal be located and in good health

before the treatment is finished, the vaccinations can be stopped.

At the end of the 10 days, the PHI would ensure that the owner vaccinated the animal in

accordance with Regulation 567: Rabies Immunization, if applicable. The POA can be used by

the PHI to force compliance. It can also be used if an Order was signed, and not adhered to.

INSPECTION

The investigation started on October 18 2004, when the student PHI was contacted by a man

whose wife was attacked by a raccoon while walking the dog. The woman was on the sidewalk

with her dog, when she heard a rustling and growing in the bushes. The raccoon then rushed out,

wrapped itself around her leg, and bit her. She was able to shake it off, at which point the

raccoon turned around and growled at her. The raccoon “turned back to attack again,” but the

victim threw a stone at it, and it ran off into the woods beside the road.

Upon hearing this, the student PHI determined that post-exposure prophylaxis would most likely

be the proper course of action. The student PHI first recommended washing the wound with soap

and water, allowing it to bleed to flush the virus out. Then, she would be required to seek


10

medical attention. The name of the victim’s family doctor was obtained, and that doctor was

contacted to inform her that a patient would be coming in who would be requiring rabies

vaccinations.

The student PHI gathered the required vaccines and a copy of the “Ministry of Health Post-

Exposure Rabies Prophylaxis Guide” and delivered it to the victim’s family doctor to administer

treatment. The course of treatment was expected to begin on October 18, and run until

November 15, in accordance with the Guide.

DISCUSSION / RATIONALE

The rationale for the difference in the 2 orders is based on the risk of an animal being infectious

with rabies. Animals involved in provoked attacks with up-to-date vaccines do not typify

“abnormal” behavior. The definition of provocation depends on the animal, and can simply

involve feeding it. In these cases, it is sufficient for the owner to observe the animals’ health

status, and notify the health unit of any changes. This 10-day observation is required because

Haldimand-Norfolk is endemic for rabies, and the vaccines do not provide 100% protection.

For animals with out-of-date vaccines, or involved in unprovoked attacks, the risk of rabies is

much higher. Unprovoked attacks are one of the neurological symptoms in animals. The

potential exists for that animal to be infective. In this case, the animal must be isolated from

contact with other animals and humans for 10 days. If this is done at home, the animal must be

housed in a separate room. The only person allowed to be in contact with that animal is its

primary caregiver.


11

With regard to the inspection, immediate washing of all bite wounds or scratches, for 10 minutes

with soap and water is one of the most important measures for preventing rabies following

exposure. Elimination of the rabies virus via chemical or physical means is the goal.

Experiments in animals show that thorough and vigorous cleansing to the depth of the wound

with soap significantly reduces the risk of developing rabies, even without further treatment

(“Human rabies prevention,” 1999).

The reason for immediately deciding to start vaccinations is based on animal behavior. It is

extremely unusual for a raccoon to attack a human. In addition, this attack was unprovoked, the

possibility of locating and positively identifying the raccoon would be slim to non-existent, and

raccoons have been common carriers of the rabies virus.

INSPECTION RESULTS

On the afternoon of October 18, the husband was walking in the woods near where the attack

occurred and found a dead raccoon. The victim believed that this was the same raccoon, so she

contacted the student PHI. The student PHI instructed the husband to use a shovel and place the

raccoon inside a double garbage bag, and freeze it. The student PHI then arranged for CFIA to

collect the corpse and analyze the brain.

On October 21, the results of the test were returned and the raccoon was negative for rabies. The

victim was adamant that this was the same animal and expressed a desire to end treatment. It was

the opinion of the student PHI that it would be impossible to know for sure if this was the same

animal that was involved in the attack. For this reason, treatment was continued, and concluded

on November 15 as expected. The student PHI obtained confirmation of completed treatment


12

from the family doctor on November 16. The paperwork was sent to the support staff for

processing, with no further action required.

CONCLUSION

According to a study based out of the Infectious Diseases Hospital in Delhi (Chhabra, Ichhpujani,

Tewari, & Lal, 2004), most people who die due to rabies either did not receive any treatment or

were inappropriately and inadequately treated. This illustrates the need for a PHI to educate both

individuals and health care professionals about the need for adequate post-exposure treatment.

In addition to the fatal nature of the disease, the cost of treatment is extremely high. A study out

of Massachusetts (Kreindel, 1998) revealed the average cost for post-exposure prophylaxis was

over $US 1,600. For this reason, it is extremely important to ensure that every effort is made to

find and assess any animal involved in an attack.

Rabies surveillance is extremely important, as is collaboration between persons involved in the

animal handling industry, CFIA, veterinarians, and other public health professionals. The rabies

clinics offered in Haldimand-Norfolk have been extremely well received in the community, with

approximately 3,000 vaccinations issued through the program in 2004 alone. However, due to

the success of the Ministry of Natural Resources’ aerial baiting program, the incidence of

recorded rabies in ground mammals has been dropping significantly. Since 1998, only brown

bats have been found rabid within Haldimand-Norfolk. Due to the reduction of rabies in wild

reservoirs, the need for rabies clinics is being assessed for the 2005 season.


13

REFERENCES

Centers for Disease Control and Prevention. (2003). Rabies. Retrieved 09 February 2005 from:

http://www.cdc.gov/ncidod/dvrd/rabies/default.htm.

Centers for Disease Control and Prevention. (1999). Human rabies prevention – United States,

1999 Recommendations of the Advisory Committee on Immunization Practices. MMWR,

48, 1-21. Retrieved 12 February 2005 from:

http://www.cdc.gov/mmwr/preview/mmwrhtml/00056176.htm

Centers for Disease Control and Prevention. (2004). Recovery of a patient from clinical rabies

--- Wisconsin, 2004. MMWR, 53(50), 1171-1173. Retrieved 12 February 2005 from:

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5350a1.htm.

Chhabra, M., Ichhpujani, R.L., Tewari, K.N., Lal, S. (2004). Human rabies in Delhi. Indian

Journal of Pediatrics,71, 217-220

Chin, J. (2000). Control of communicable diseases manual. Washington, DC: American Public

Health Association.

Hemachudha, T., Laothamatas, J., & Rupprecht, C. (2002). Human rabies: A disease of

complex neuropathogenetic mechanisms and diagnostic challenges. The Lancet

Neurology, 2, 101-109. Retrieved 14 March 2004 from Science Direct.


14

Health Protection and Promotion Act, R.S.O., Chapter H.7 (1990). Retrieved February 09, 2005

from: http://www.e-laws.gov.on.ca/DBLaws/Statutes/English/90h07_e.htm

Kreindel, S. (1998). The cost of rabies post-exposure prophylaxis: One state’s experience –

Massachusetts. Public Health Reports, 113, 247-51.

Ontario Ministry of Health and Long-Term Care. (1997). Mandatory Programs and

Services Guidelines. Retrieved on February 09, 2005 from:

http://www.health.gov.on.ca/english/providers/pub/pubhealth/manprog/mhp.pdf

Regulation 557: Communicable Diseases – General, Revised Regulations of Ontario, Amended

to O. Reg. 471/91. (1990). Retrieved on February 09, 2005 from: http://www.e-

laws.gov.on.ca/DBLaws/Regs/English/900557_e.htm

Regulation 567: Rabies Immunization, Revised Regulations of Ontario, Amended to O. Reg.

360/01. (1990). Retrieved on February 09, 2005 from:

http://www.e-laws.gov.on.ca/DBLaws/Regs/English/900567_e.htm

Robertson, I., Irwin, P., Lymbery, A., & Thompson, R. (2000). The role of companion animals

in the emergence of parasitic zoonoses. International Journal for Parasitology, 30, 1369-

1377. Retrieved 18 March 2004 from Science Direct.


http://www.health.gov.on.ca/english/providers/pub/pubhealth/manprog/mhp.pdf



15

University of Washington. (2001). Rabies prevention in Washington State. Retrieved 10

February 2005 from: http://healthlinks.washington.edu/nwcphp/rabies/index.html

LIST OF APPENDICES

Report of Bite / Contact with Animal Appendix A

Suspected of Rabies Form

Order for Observation Appendix B

Order for Confinement / Quarantine Appendix C

Post-Exposure Rabies Prophylaxis Guide Appendix D


Ciphi Rabies

Documents

Transcript of Ciphi Rabies