Exam 1: Tick Transmitted Zoonotic Diseases

How can Tularemia be transmitted to humans?

1. Integumental invasion by bite or open wound 2. Exposure to eye 3. Ingestion 4. Inhalation 5. Water borne 6. Lab accidents 7. Bioterrorism

What are 4 main ways to prevent getting tick borne diseases?

1. Long pants and long sleeves should be worn when hiking or in tick infested areas 2. Insect repellent spray such as DEET 3. Pant legs tucked into socks 4. Tick checks every 3 hours in tick infested areas

What are 6 main ways to prevent Tularemia transmission to humans?

1. Report animal die offs 2. Ectoparasite control of domestic animals 3. Avoid ticks 4. Education of hunters like using gloves for cleaning game and cooking wild game well before eating 5. Vaccine for persons at high risk 6. Avoid drinking water directly from clean mountain streams

Why are veterinarians involved with helping to prevent tick borne diseases?

1. Ticks are animals 2. Wild animals are typically the natural reservoirs 3. Pets can bring infected ticks into the homes of humans where they can bite people

What is the incubation period of Rocky Mountain Spotted Fever in humans?

2-12 days

What does the fatality rate of cases of Rocky Mountain Spotted Fever go down to when treated?

5%

What is the "reaction time" for the etiologic agent of Rocky Mountain Spotted Fever, Rickettsia rickettsii, to enter the new host?

5-20 hours

What has caused transmission of Tularemia by direct contact with infected game to decrease?

A decrease in hunting of rabbits and other game

Describe the typical ulceroglandular case of Tularemia:

A small wound develops at the site of tick attachment. Later, the regional lymph nodes enlarge and become tender. Fever and chills are common, like the flu

These are the two "headquarter" states of Tularemia where it is extremely common:

Arkansas and Missouri

Why are the number of cases of Rocky Mountain Spotted Fever increasing despite case fatalities decreasing?

Because more mild cases are being reported

Why are reported cases of Rocky Mountain Spotted Fever often unrepresentative of all the cases?

Because shotgun antibiotics may treat many undiagnosed cases due to fever of unknown origin and mild cases probably recover spontaneously

Why are large mammals often dead end hosts for Rocky Mountain Spotted Fever?

Because they have lower levels of the agent in their blood and can't infect ticks that bite them

What months do most infections with Rocky Mountain Spotted Fever occur?

Between April and September

What is the distribution of age and sex of reported Tularemia in people?

Bimodal, with increased cases in the young and middle aged and increased cases in males

What is the tick vector of human granulocytic ehrlichiosis?

Black legged tick (Ixodes scapularis or Ixodes pacificus)

The ulcerogalndular case of Tularemia is similar to the symptoms of these two other diseases:

Bubonic plague and cat scratch disease

This can be serious when it comes to tick borne diseases:

Co-infections

What is the etiologic agent causing Q fever?

Coxiella burneti

What has happened to the overall reported cases of tularemia in the United States since 1950?

Decreased

What is the tick vector of Colorado Tick Fever?

Dermacentor andersoni

This animal is a good serological sentinel for Rocky Mountain Spotted Fever

Dogs

These usually serve as the "vector of the vector" for human tick transmitted disease:

Domestic animals

What are the best antibiotics to sue to treat Rocky Mountain Spotted Fever?

Doxycycline and Chloramphenicol

At what time of year are Rocky Mountain Spotted Fever cases most prevalent?

Early summer (May, June and July)

What is the etiologic agent causing Human Monocytic Ehrlichiosis?

Ehrlichia chaffeensis

What are the symptoms of Colorado Tick Fever?

Fever, chills, headache, and muscle pain (flu like symptoms)

What are the symptoms of human erlichiolses?

Fever, renal failure, respiratory insufficiency, CNS problems, headache, myalgia, nausea, vomiting and rarely a rash

Rocky Mountain Spotted Fever often presents as these sorts of symptoms:

Flu like symptoms

What are the symptoms of Rocky Mountain Spotted Fever in humans?

Flu like symptoms such as high fever, nausea, vomiting, headache, chills, muscle pain and possibly a maculopapular rash

What is the etiologic agent of Tularemia?

Francisella tularensis

This form of Ehrlichiolses is more severe and acute and sometimes causes a fatal febrile syndrome, HME or HGE?

HGE

This is reported in about 60% of all cases of Rocky Mountain Spotted Fever:

History of tick bite or exposure to tick infested habitats

This tick borne disease can look a lot like rocky mountain spotted fever but without the rash

Human erlichiolses

This is very important for preventing transmission of Rocky Mountain Spotted Fever after the tick is already attached:

Immediate removal of the tick

What can cause the fatality rate of Rocky Mountain Spotted Fever to increase?

Increased length of time between onset of symptoms and antibiotic treatment

This is the most common route of transmission of Tularemia:

Integumental invasion by arthropod bite via ticks

What is happening to the case fatality rate of Rocky Mountain Spotted Fever throughout the years?

It is decreasing

What is happening to the number of cases of Rocky Mountain Spotted Fever throughout the years?

It is increasing

These are dead end hosts of Rocky Mountain Spotted Fever

Large mammals

What do the adult ticks feed on?

Larger mammals including humans and dogs

What is the tick vector of human monocytic ehrlichiosis?

Lone star tick (Amblyomma americanuum)

This is diagnostic for Rocky Mountain Spotted Fever

Maculopapular rash

This symptom of Rocky Mountain Spotted Fever can be seen in 50% of patients

Maculopapular rash

Tularemia is more common in this sex of humans:

Males

What type of vector are ticks for Tularemia?

Mechanical

These are the two kinds of human erlichiolses:

Monocytic and granulocytic

Are ticks the only vector for Tularemia?

No

What is the clinical syndrome of Tularemia associated with exposure to eye transmission?

Oculoglandular, with cephalic and cervical nodes involved

What is a possible reason for the increased cases of Tularemia in the very young?

Possible pet exposure

What is a possible reason for the increased cases of Tularemia in middle aged?

Possible wilderness exposure

This tick borne disease is extremely infectious!

Q fever

This tick borne disease/agent is very resistant to desiccation and disintegration, and therefore has very good viability in the free state

Q fever caused by Coxiella burneti

Tularemia is also called what?

Rabbit fever

Reported cases of Tularemia are really not caused by this anymore:

Rabbit hunting

What is the etiologic agent of Rocky Mountain Spotted Fever?

Rickettsia rickettsii

What are 5 examples of diseases that ticks can transmit in the US?

Rocky mountain spotted fever Tularemia Colorado tick fever Lyme disease Q fever

Where do most cases of Rocky Mountain Spotted Fever occur?

South Atlantic States

The large majority of cases of Rocky Mountain Spotted Fever are reported in this geographical location:

Southeastern United States

All forms of Tularemia may disseminate to where in the body?

Spleen, liver, lungs and pleura

What is a common sign that a rabbit is infected with Tularemia?

Spots on liver

As of 2010, cases of Rocky Mountain Spotted Fever are reported under a new category called what?

Spotted Fever Rickettsiosis

During what time of year is Tularemia most common?

Spring and early summer

This tick borne disease has a wide range of hosts, methods of transmission, portals of entry and clinical syndromes

Tularemia

This tick borne disease has an incredibly wide host range including many mammals, birds and aquatic animals

Tularemia

This tick borne disease is unique in that its route of exposure determines the clinical syndromes:

Tularemia

These tick borne diseases have been used as biological warfare weapons

Tularemia and Q fever

You can't distinguish between these two diseases when a rabbit has spots on its liver:

Tularemia or Eimeria

90% of cases in North America of Tularemia are of this type

Type A

This type of Tularemia appears to be more virulent in animals and man

Type A

Tickborne Tularemia is usually type ____ and has this presentation:

Type A with an ulceroglandular presentation

This type of Tularemia is less severe and may therefore be less likely reported

Type B

This type of Tularemia is more rare in the United States

Type B

What type of Tularemia can be transmitted via water?

Type B

What are the two main types of Tularemia?

Types A and B

What is the clinical syndrome of Tularemia associated with ingestion transmission?

Typhoidal forms, causing oral and GI symptoms, stomatitis, and pharyngitis

What is the clinical syndrome of Tularemia associated with integumental invasion transmission?

Ulceroglandular, adenopathy proximal to the point of entry

This is the most common clinical presentation of Tularemia for rabbit hunters and for this reason:

Ulceroglandular; because exposure usually through direct exposure through wounds, knife cuts, scratches or conjunctiva while cleaning and dressing wild game

What is the etiologic agent causing Human Granulocytic Ehrlichiosis?

Unknown but probably Ehrlichia equi

What are the symptoms of Rocky Mountain Spotted Fever in dogs?

Usually sub-clinical, but can also get flu like symptoms, conjunctivitis, mucopurulent oculonasal discharge, cough, and petechial or ecchymotic hemorrhages on the ocular, oral and genital mucous membranes

Tularemia is more common in this age of humans:

Very young and middle aged

What is a way Tularemia can be transmitted to campers and hikers?

Via drinking water from mountain streams

Transmission of tick borne diseases can be prevented by prompt removal of the tick except in these circumstances:

Where the tick is strictly a mechanical vector

These animals are rarely clinically infected with Rocky Mountain Spotted Fever

Wild animals

What do the larva and nymphal ticks feed on?

Wild rodents

These are common reservoirs for Rocky Mountain Spotted Fever

Wild rodents, rabbits and other small mammals

This is the main tick vector of Rocky Mountain Spotted Fever in WESTERN parts of the US

Wood tick

What is the tick vector of Rocky Mountain Spotted Fever?

Wood tick and American dog tick

Where are the most common places on the body to get a maculopapular rash from Rocky Mountain Spotted Fever?

Wrist and ankles

What is the demographic of the most common victim of Rocky Mountain Spotted Fever?

Young males

This is the main tick vector of Rocky Mountain Spotted Fever in SOUTHEASTERN parts of the US

American dog tick

What is Rocky Mountain Spotted Fever named after?

The laboratory that discovered it

What is unique about the epidemiology of Tularemia?

The route of exposure determines the clinical syndromes

What is the significance of the fact that ticks are only a mechanical vector for Tularemia?

There is no reactivation period

What is the danger with ticks being mechanical vectors for disease rather than biological vectors?

There is no reactivation period so transmission of the disease is immediate upon the bite

How can ticks themselves be considered reservoirs for Rocky Mountain Spotted Fever?

They can transmit the agent through transoverian or transtadial transmission

This will not help prevent Tularemia infection:

Tick checks

This is an important public health role of veterinary practitioners in preventing tick borne diseases:

Tick control for domestic animals

It used to be about half of US cases of Tularemia were from ticks and half from hunting, mostly rabbit. Today, it is mostly from what?

Ticks

What is the objective of removing an attached tick?

To avoid crushing the tick to prevent its body fluids from contacting the open wound