Zoonotic Disease Prevention

References

• McCurnin’s Clinical Textbook for Veterinary Technicians 9th Edition

  • CH. 4 & 9

• AR 40-5: Preventive Medicine

  • CH. 3

• DA PAM 40-11: Preventive Medicine

  • CH. 9

• AR 40-3: Medical, Dental, and Veterinary Care

  • CH.15

• AR 40-905: Veterinary Health Services

  • CH. 4

• TB MED 298: Veterinary Care and Management of the Military Working Dog

  • CH. 5

• Merck Veterinary Manual

  • Zoonoses CH.

• National Association of State Public Health (NASPHV) Rabies Compendium

Zoonotic Diseases

• Zoonosis: An infection or infectious disease transmitted under natural conditions from vertebrate animals to humans.

• Zoonotic Diseases: Infectious diseases that can be passed from animals to humans.

  • One Health Concept: Term that emphasizes the interconnectedness of human, animal, and environmental health and need for collaborative approaches to achieve optimal health outcomes.

Zoonotic Diseases in Veterinary Medicine

1. Borreliosis (Lyme disease):

   • Description: Tickborne/bacterial disease in animals and humans

     • Most common vector-borne disease in U.S.

       • Vector: Carrier of disease

   • Pathogen: Caused by bacterium Borrelia burgdorferi.

   • Transmission: Spread through bite of infected tick (blacklegged tick or deer tick)

     • Attach to hard to see areas for 36-46 HRS.

   • Symptoms in Humans: Fever/headache/fatigue/bulls-eye skin rash.

   • Prevention Strategies:

     • Use insect repellent

     • Wear protective clothing treated with permethrin

     • Daily tick checks and prompt removal

     • Shower after outdoor exposure

     • Tumble-dry clothing on high heat to remove ticks (10 minutes)

     • Use pesticides to reduce tick populations

     • Flea/tick products on pets.

2. Leptospirosis:

   • Description: Disease that causes multi-organ damage

     • Clinical Signs:

       • Kidney damage

       • Meningitis (inflammation of brain and spinal cord

       • Liver failure

       • Respiratory Distress

       • Death

     • Pathogen: Caused by bacteria Leptospira.

     • Symptoms: Fever, muscle aches, vomiting, diarrhea, abdominal pain, jaundice, gastrointestinal signs

     • Transmission: From urine of infected animals that can survive in water/soil.

     • Prevention Strategies:

       • Pest control

       • Avoidance of high-risk areas

       • Pet vaccinations

       • Good hand hygiene.

3. Giardia

   • Pathogen: A small parasite found in contaminated soil, food, or water.

   • Symptoms: GI signs such as diarrhea, vomiting, nausea, and abdominal discomfort.

   • Transmission: Drinking water/food contaminated with feces or direct contact with infected animals.

   • Prevention Strategies:

     • Cleaning/disinfecting surfaces

     • Good hand hygiene

     • Prevent pets from drinking from unknown sources (ponds/creeks/puddles)

     • Use protective equipment when gardening/outdoor activities

4. Chagas Disease

• Pathogen: American trypanosomiasis caused by parasite Trypanosoma cruzi.

• Transmission: By triatomine bugs (kissing bugs) through infected feces

  • Bites people’s faces and defecates

  • Can be congenital

  • Blood transfusions/organ transplants

• Symptoms in Humans:

  • Acute Phase: Swollen eyes (particularly in children)

  • Chronic Phase: Heart issues (arrhythmias, enlarged heart) and/or GI Signs (megacolon [enlarged colon]/megaesophagus [enlarged esophagus]

• Symptoms in MWDs:

  • Severe structural changes in heart

  • Sever tachycardia arrythmias (can lead to sudden death)

• Prevention Strategies:

  • Pest control around kennels

  • Appropriate insect repellant use

5. Leishmaniasis

• Pathogen: Caused by Leishmania parasite in tropical regions/parts of Europe

• Transmission: Bite of infected sand flies.

• Symptoms: Skin (cutaneous) lesions causing sores

• Clinical Signs: Spread to internal organs (spleen/liver/bone marrow)

• Prevention Strategies:

  • Pest control

  • Use of flea/tick products effective against sand flies.

6. Sarcoptic Mange

• Pathogen: Caused by infestation with skin mite Sarcoptes scabiei var hominis

  • Mite burrows under top layer of skin and lays eggs

• Symptoms: Intense itching, pimple-like rash, potential for significant outbreaks.

• Transmission: Prolonged/direct skin-to-skin contact with infected person/animal (very contagious)

• Prevention Strategies:

  • Good hygiene

  • Use of personal protective equipment (PPE) when handling affected animals.

7. Toxoplasmosis

• Pathogen: Caused by parasite Toxoplasma gondii.

• Symptoms: Flu-like symptoms, swollen lymph nodes, muscle aches, severe signs in brain/other organs.

• Transmission:

  • Ingestion of undercooked meat.

  • Contamination from cat feces/litter box handling.

• Prevention Strategies:

  • Good hand hygiene

  • Proper cooking methods

  • Use of PPE during food preparation.

Other Zoonotic Diseases

• Ringworm: Fungal infection causing skin lesions.

• Bacterial Pathogens: Bacteria that cause diarrhea.

  • Such as Salmonella or Campylobacter

• Plague: Characterized by swollen lymph nodes.

• Cat Scratch Fever: Caused by Bartonella henselae.

General Zoonotic Disease Prevention Guidelines

• Safe handling of animals to avoid bites/scratches.

• Wash wounds thoroughly and report injuries immediately.

• Avoid eating/drinking/smoking/applying cosmetics while handling animals or in animal housing areas.

• Wear gloves when handling animals/animal tissues/waste/body fluids and wash hands after contact.

• Use dedicated protective clothing and launder soiled garments separately.

• Use respiratory protection when necessary.

• Maintain cleanliness in animal areas and disinfect equipment.

• Clean/disinfect produce before consumption and ensure thorough cooking of meat.

• Familiarize oneself with animals handled and species associated zoonotic diseases.

• Report any suspected zoonotic disease to supervisor and seek medical assistance.

Rabies

Rabies Overview

• Rabies: An infectious disease of warm-blooded animals caused by a Rhabdoviridae lyssavirus (virus)

  • Fatal acute viral encephalomyelitis

  • Only area rabies free is Hawaii

• Transmission:

  • Two Types of Exposure:

    • Bite: Penetration of skin by teeth pf infected animal

      • Face/hands carry highest risk (but shouldn’t base bite severity from location)

    • Non-bite: Contamination by scratches/abrasions/open wounds/mucous membranes through saliva/neural tissue from infected animals

      • Both bites/non-bites (scratches) should be treatyed seriously and immediately acted upon

    • Virus doesn’t linger in environment/susceptible to chemicals, soap, or drying.

• Clinical Signs (vary and sometimes not present):

  • Hallmark Signs:

    • Wild animals showing abnormal behavior (lack of fear)

    • Nocturnal animals out during daytime

    • Fatal if untreated and vigilance required post-exposure.

  • Other Symptoms:

    • Lack of appetite (inappetence)

    • Difficulty swallowing (dysphagia)

    • Cranial nerve deficits

    • Abnormal behavioral changes

    • Ataxia

    • Paralysis

    • Seizures

  • Obvious Neurological Clinical Signs (Reached brain) = Death

    • If left untreated upon immediate exposure

      • 14 days after exposure (post exposure prohylaxis)

Carriers vs Non-carriers

• Common reservoirs (carriers) are only mammals:

  • Raccoons/Skunks/Dogs/Cats/Foxes/Otters/Bats (Most commonly infect large population of humans)

    • Rabies threat is slim as most animals have short life expectancy after infection (infected/dead animals are still infectious)

• Animals who pose little threat of rabies:

  • Possums/Rabbits/Mice

• Animals who pose no threat:

  • Chickens/Reptiles/Snakes

    • Birds/reptiles/fish can’t spread rabies

Exposure

• Initial Incubation Period: Incubates in Peripheral Nervous System (PNS) for 9 -365 days (1 year)

  • Can possibly exceed 7 years or more

• After incubation period:

  • Travels from PNS to Central Nervous System (CNS)

  • Moves from brain to salivary glands

    • Can stay for several days before animal shows symptoms (Up to 12 days for bats)

Prevention/Control of Rabies

• Prevention Strategies:

  • Avoid potentially rabid animals

    • Follow General Order 1

    • Don’t assume animal is not infected by how they look (passive/aggressive)

  • Use PPE when handling feral/stray animals

  • Test all bats found in house/room

  • Vaccinate animals/humans (high risk personnel)

    • Mandatory by law for POAs (dogs/cats) in U.S. at 3 months with boosters every 3 years

• Post-Exposure Prophylaxis (PEP): Involves human rabies immune globulin (HRIG) and rabies vaccinations

  • Critical care measure as rabies is fatal without prevention

Military Stray Animal Programs

Roles of 68T in Military Stray Animal Programs (Depend on SOP):

• Identify stray species and where they gather on post

  • Determine disposition of animals

    • If animal has owner

    • If animal is candidate to be rehomed

    • If animal is sick/feral and may require euthanasia

• Assist in stray/feral animal euthanasia when authorized

• Record controlled drugs used on stray/feral animals

• Use of appropriate measures when handling stray/feral animals

• Complete animal bite reports

Installation Zoonosis Prevention

• Ways installations/veterinary staff (VCO/68T) have responsibility to prevent zoonosis for personnel living/working/training on post

  • Stray/feral animal programs

  • Childcare facilities that contain animal quarterly inspections

    • Includes health completed forms for POAs in home-based childcares on base

    • VCO will perform Physical Exam (PE) of animals

    • Can require fecals/urinalyssi/bloodwork

  • Report public health diseases as required by state/federal entities

  • Ensure MWR events with animal exhibitions comply with local/state guidlelines

  • Track disease trends in patients

• “One Health”: Collaborative approach to healthcare (local/regional/national/global levels) to achieve optimal health outcomes that recognizes connection between people/animals/plants/shared environments