Other Tick-borne diseases

Of all the tick-borne bacterial infections, Rocky Mountain spotted fever causes the most severe disease and has the highest mortality rate. Rocky Mountain spotted fever is transmitted by the American Dog tick, Brown Dog tick, and Rocky Mountain Wood tick. It is important to note that 5 non-Rocky Mountain states (North Carolina, Oklahoma, Arkansas, Tennessee, and Missouri) account for over 60% of RMSF cases.

Incubation lasts for 1-2 weeks and symptoms include:

• Sudden onset of fever
• Nausea
• Vomiting
• Muscle pain
• Lack of appetite

In adults, symptoms also include a severe headache and photophobia.

In children, symptoms include abdominal pain, altered mental status, injected conjunctiva (red eye)

A characteristic spotted rash may begin 5-6 days after fever onset on wrists, ankles, palms, and soles through the rash may be absent early in the disease and 10% of all patients never exhibit the rash.

Lab testing:
Acute = no readily available tests, culture by specialized labs, PCR or immunohistochemical (IHC) staining of rash biopsy
Confirmatory = acute and convalescent IgG IFA titers

Treatment: doxycycline – should begin when the illness is first suspected.

Long-term complications are possible if vasculitis occurred: expect end-organ damage, tissue necrosis, profound neurologic deficits, diminished renal function, amputations.

Transmitted by Gulf Coast ticks, spotted fevers are caused by the bacterium Rickettsia parkeri. Though related to the agent that causes RMSF, this illness is less severe.

Incubation lasts from 1-2 weeks and symptoms include:

• Fevers
• Muscle aches
• Headache
• Rash
• Eschars at bite site

Lab testing: Tests in acute state = PCR of skin biopsy

Please be aware that cross-reacting antibodies may cause false positive results for RMSF.

Treatment: doxycycline – should begin as soon as illness is suspected

Caused by an RNA virus which is transmitted by the Rocky Mountain Wood tick.

Symptoms begin 3-5 days after the bite and include:

• Abrupt onset of fever
• Headaches
• Chills
• Malaise
• Photophobia
• Myalgias
• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Rash – occurs in 5 to 15%

Lab testing: IFA titers

Treatment: consists of supportive care

Caused by Coxiella burnetti, disease can be tick-borne, but most cases result from inhaling dust containing the bacterium.

When tick-borne, symptoms include:

• High fevers up to 105 degrees Fahrenheit
• Severe headache
• Malaise
• Myalgia
• Chills and/or sweats
• Cough
• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Chest pain

Lab testing: Diagnosis made based on IFA titers.

Treatment: doxycycline

HME is a potentially serious infection caused by Ehrlichia chaffeensis, which may be transmitted by Lone Star and Western blacklegged ticks. HME has a 2-3% mortality rate. Most cases are located in SE and south-central states.

Incubation lasts from 1-2 weeks and symptoms include:

• Chills
• Fever
• Headache
• Muscle aches
• Nausea

66% of kids and 30% of adults develop a fine petechial rash

Lab testing: blood smears to look for bacteria, serology and PCR

Treatment: doxycycline – should begin when the illness is first suspected.

Transmitted via a Lone Star tick bite; not known whether infectious agent is bacterial, viral or parasitic.

Symptoms are very similar to Lyme disease and include:

• EM-like rash
• Fatigue
• Headache
• Fever
• Muscle pains

Lab testing: No tests are currently available.

Treatment: doxycycline

There are multiple transmission routes which include contaminated water, skin contact with infected animals, inhalation or deer fly and tick bites.  The tick-borne form can be transmitted by multiple vectors which include the Lone Star tick, American Dog tick, and Rocky Mountain Wood tick.

Symptoms include:

• Headache
• Chilliness
• Vomiting
• Aching pains
• Fever
• Swollen glands
• Weight loss
• Debility
• Ulcer formation at bite site

Lab testing: culture, immunohistochemical staining, PCR, direct fluorescent antibody, acute and convalescent titers

Treatment: streptomycin or gentamicin.