RISK ASSESSMENTS AND PRECAUTIONS OF DISEASES SHARED BY PEOPLE AND ANIMALS James Wright, DVM, MPVM Zoonosis Control Division Texas Department of State Health Services Tyler, Texas Buddy Faries, DVM, MS Texas Cooperative Extension Texas A&M University College Station, Texas

Buddy – James, you are a public health veterinarian. What occupies most of your time? James – Zoonotic diseases (rabies, WNV, anthrax, plague), also anmal control officer rtraining and consultation.

Buddy – Do a lot of people get rabies? James – No. Very few. However, because transmission is via animal bites, every bite must be followed up. In the mind of most physicians, every biting animal is rabid until proven otherwise. Buddy – So how does someone prove an animal was not rabid when it inflicted a bite?

How to prove an animal does NOT have rabies….. Quarantine (dog, cat, or ferret)

Transmission of the rabies virus is via the saliva Important fact in dogs, cats, and ferrets— Animal will not have virus in its salivary glands for more than 5-6 days before showing some other sign of being ill. Therefore……quarantine for 10 days

Buddy – What is the other way to prove the animal was not rabid when it bit?

How to prove an animal does NOT have rabies….. Quarantine (dog, cat, or ferret) Lab testing

So when a mother whose child has been bitten by an animal calls, what our audience tell her?

Bite victim should…… Find the animal Animal control can help Do NOT shoot in the head

Buddy – That makes sense. I am sure some of our audience might get confused on quarantine period vs incubation period. The incubation period for rabies is 2 weeks to several months. Therefore, the quarantine just looks at the very last part of the incubation period and the very earliest time of clinical signs. That is to evaluate whether a dog or cat might be shedding the virus in its saliva.

Incubation Period Variable –2 weeks to several months Quarantine period (dog or cat) –10 days

Buddy – Rabies is a universally fatal disease. There is no cure. If a person cannot quarantine or laboratory test an animal that inflicted a bite, what does a person do to prevent rabies?

Treatment –Wash wound immediately –Consider post-exposure prophylaxis Not a foregone conclusion Rarely an emergency

James – Determine the species of the biting animal. Buddy – Yes certain species are considered to be very high risk of being a rabies reservoir. For example……

Post-exposure Prophylaxis Decision Species of biting animal

Skunk High Risk

Coyote High Risk

Fox High Risk

Raccoon High Risk

James will talk about bats after Buddy mentions the species

BAT High Risk Since 1980 in the US, over 90% of the domestically acquired human rabies cases were from bats.

James – We have talked about high risk animal species, would you list some low risk animals, too?

Low Risk Animals opossums armadillos rabbits rats, mice, squirrels, beavers

Buddy – Besides the availability for quarantine or testing and the animal’s species, what else helps a doctor in deciding whether to administer the rabies post-exposure treatment?

Post-exposure Prophylaxis Decision Species of biting animal Prevalence of rabies in the area Vaccination status of animal Provoked vs not provoked

Buddy – There are thousands of animal bites every year in Texas. Why do you think there are so few cases of human rabies?

Few Cases of Human Rabies in US Vaccination of pets Public health education Bite follow-up

Local Rabies Control Authority (LRCA) Health and Safety Code Commissioners Court of each county and local governing body of each municipality shall designate.…..local rabies control authority. Can be health officer, animal control officer, peace officer, or any other entity.

James – What are protective measures that people can follow to protect themselves against exposure to rabies?

CREATE RABIES IMMUNED BARRIERS BETWEEN PEOPLE AND WILDLIFE

MAINTAIN IMMUNITY IN DOMESTIC ANIMALS –CONFINED HORSES, SHOW LIVESTOCK –DOGS, CATS

ADOPT VACCINATION PROGRAMS RECOMMENDED BY VETERINARIANS

DISCOURAGE POTENTIAL RABIES RESERVOIRS FROM INHABITING PREMISES AROUND HOME SKUNKS, BATS, RACCOONS, FOXES, COYOTES

ELIMINATE BRUSHY, GRASSY AREAS FOR WILDLIFE NESTING

PREVENT PET AND LIVESTOCK FOODS FOR WILDLIFE FEEDING ELIMINATE WILD PERSIMMON TREES AND BERRY VINES THAT ATTRACT WILDLIFE

AVOID WILDLIFE PETS SKUNKS, RACCOONS

Buddy– Is there anywhere in Texas that rabies is not something to be considered?

James – Afraid not, Buddy. Let’s look at the distribution of rabies in Texas.

Texas rabies map

Buddy - We have covered rabies. Now let’s move on and talk about some disease vectors common all over the state. James – You must mean ticks. Buddy – Yes. Ticks are an irritant themselves, but they can carry some diseases also. Since most of our audience are not physicians or direct patient care providers, let’s take only a brief look at the clinical symptoms of these illnesses. We can then discuss what our public health staffs can tell folks to help them keep from acquiring the illnesses. James, give us a brief overview of the tickborne diseases.

Ticks and Disease Rocky Mountain Spotted Fever Erhlichia Lyme Disease STARI

Rocky Mountain Spotted Fever Transmit –Infected tick bite –Contamination of broken skin or mucous membranes with infected tick feces. Symptoms are severe Treat -- antibiotics

Erhlichia Symptoms – Fever, headache, muscle aches, vomiting, nausea – Mild to fatal Treat -- antibiotics

Flu-like symptoms (fever, malaise, fatigue, muscle aches) Erythema Migrans (60%) Chronic Neurological abnormalities Cardiac abnormalities Arthritis (swelling & pain) Treat – antibiotics Lyme Disease

James – That is a quick look at the illnesses transmitted by ticks. Buddy, how about discussing ways a person avoids getting these diseases? Buddy – There are a few strategies for avoiding disease transmission from ticks. First, don’t get bit by ticks. That is, of course, easier said than done.

Preventing Tick-borne Disease Clothes to exclude or see the ticks

Preventing Tick-borne Disease

Preventing Tick-borne Disease Clothes to exclude or see the ticks Repellants –DEET is the gold standard

James – Even if a tick attaches to a person, that doesn’t mean disease transmission is for sure.

Preventing Tick-borne Disease Clothes to exclude or see the ticks Repellants Tick Checks –Ticks must be attached several hours before transmit the organism

Preventing Tick-borne Disease Clothes to exclude or see the ticks Repellants Tick Checks –Ticks must be attached several hours before transmit the organism Proper tick removal

Not Recommended

Tick Removal

Preventing Tick-borne Disease Clothes to exclude or see the ticks Repellants Tick checks Proper tick removal Don’t crush ticks

James – Buddy, how can people control ticks in their environment? That would go a long way in helping them avoid a tick bite. (Buddy, talk as much as you want to on keeping ticks off pets and livestock and controlling them in the yard

Preventing Tick-borne Disease Clothes to exclude or see the ticks Repellants Tick checks Proper tick removal Don’t crush ticks Keep pets and yard free of ticks

APPLY CHEMICALS ON ANIMALS –SPRAYS, DIPS, COLLARS, SPOT-ONS, BACKRUBBERS

 BURN NON-FLAMMABLE HOUSING AREAS

SURVEY OUTDOOR AREAS –DRAG WHITE FLANNEL SHEET

APPLY ENVIRONMENTAL CHEMICALS ON PREMISES –SPRAYS, BAITS

DISCOURAGE ENVIRONMENTAL HOSTS ON PREMISES –DEER, RABBITS, RODENTS, FERAL SWINE

CONTROL BRUSH AND WEEDS –CHEMICAL APPLICATION –MECHANICAL REMOVAL –BURN PASTURE

James – The zoonotic diseases, that we have discussed this afternoon, are transmitted by animal bites or tick bites. A food-borne, zoonotic disease, that is not known to be in the US, is BSE. What is BSE? What are the safeguards or firewalls enforced by USDA to prevent this disease from entering the US and from being transmitted to cattle and people?

BOVINE SPONGIFORM ENCEPHALOPATHY (BSE) MAD COW DISEASE

SPECIFIED RISK MATERIALS (SRMs) BRAIN, SPINAL CORD, SKULL, VERTEBRAE, ILEUM OF CATTLE

TRANSMISSION CATTLE EAT CONTAMINATED MEAT, BONE, BLOOD MEALS PEOPLE EAT CONTAMINATED GROUND MEAT

SAFEGUARDS – FIREWALLS USDA IMPORT BANS –RUMINANTS AND RUMINANT PRODUCTS –COUNTRIES KNOWN TO HAVE BSE

USDA CATTLE FEED BANS –RUMINANT MEAT, BONE AND BLOOD MEALS –POULTRY LITTER

USDA CATTLE SLAUGHTER BANS –DOWNERS –BRAIN, SPINAL CORD –SMALL INTESTINE –SKULL, VERTEBRAE >30 MOS AGE

James – Enforcement of the safeguards by USDA, as you have discussed; the slaughter surveillance in testing of cattle brains by USDA; and no evidence of BSE in the US, reduce consumers’ concern of exposure to BSE by consumption of beef in the US.

Buddy – Closing remarks James – Closing remarks