Tickborne Diseases

The bacteria that causes Lyme disease is only transmitted through the bites of infected blacklegged ticks (also called deer ticks). The tiny blacklegged tick nymphs cause most cases of infection. The black legged nymph season takes place in early summer, coinciding with peak outdoor human activities (sports, hiking, etc.). Since blacklegged nymphs are very small, move slowly, and tend to cause little itch or irritation compared to other Virginia ticks, most people never realize they have been bitten unless the tick attaches to a part of the body that is in plain sight. Lyme disease is not transmitted person-to-person.

Most patients (about 75%) will see the development of a red rash called an erythema migrans (“EM” or “bull’s-eye” rash) around a tick bite site within days or weeks of the tick bite. This rash expands (up to 12 inches in diameter) and often clears around the center. The rash does not itch or hurt, so it may not be noticed if it is on a person’s back-side or scalp. The initial illness may cause fatigue, fever, headache, muscle and joint pains, and swollen lymph nodes.

If untreated or improperly treated in the early stage of illness, some patients may develop one or several of the following symptoms: multiple EM rashes on their body, intermittent arthritis (pain and swelling) in their large joints (e.g., knees), facial palsy, heart palpitations, severe headaches/neck stiffness (due to inflammation of spinal cord), or neurological problems (shooting pains or numbness and tingling in hands and feet, or memory problems) months to years after the initial illness. Pain and swelling in large joints will occur in about 60% of untreated patients and neurological symptoms occur in about 5% of untreated patients. Arthritis and neurological problems may last for years after the infection.

The diagnosis of Lyme disease is based primarily on signs and symptoms of illness. Laboratory tests for Lyme disease antibody may be done on a patient’s blood to confirm the diagnosis, but if blood is collected too early in the course of illness, an infected person may not yield an antibody response. If laboratory confirmation is desired, re-testing may be necessary.

When Lyme disease is detected early and treated with an appropriate antibiotic (e.g., doxycycline), treatment is typically effective.

The number of reported Lyme disease cases have been dramatically on the rise in recent years.  2017 had the highest ever number of Lyme disease cases in VA with 1,652 reported cases. On average, 1,215 cases have been reported per year in VA during the last decade. Lyme disease may also be heavily under-reported with a CDC study estimating that only 30,000 cases are reported from 300,000 cases annually.

SFR is spread by the bite of an infected tick, or by contamination of the skin with tick blood or feces.  It cannot be spread from one person to another.  Typically, ticks must be attached to the person for a period of between ten and twenty hours in order for transmission to occur, but there have been instances of SFR transmission where ticks were attached for less than an hour.

Rocky Mountain spotted fever(RMSF) is characterized by a sudden onset of moderate to high fever, severe headache, fatigue, deep muscle pain, chills and rash. The rash typically begins on the legs or arms, may include the soles of the feet or palms of the hands, and may spread rapidly to the trunk or rest of the body.  If left untreated Rocky Mountain spotted fever can be fatal.

SFR can be diagnosed through laboratory tests of blood or skin.  Antibodies to the infectious agent typically do not become detectable until seven to ten days after onset of illness, therefore testing for the agent’s DNA via PCR is the best diagnostic laboratory test in the early stages of illness. If PCR is not preformed, the pairing of an acute and convalescent serum sample taken seven or so days apart can be an effective means of diagnosing RMSF.

Rickettsial infections can be treated with certain antibiotics in both children and adults.  Prompt treatment may decrease the chance of developing serious illness.

RMSF cases are reported within the Spotted Fever Rickettsial group which also includes R. parkerii. In the last decade, there have been an average of 255 SFR cases in Virginia per year.

The bacteria are transmitted to humans by the bite of an infected lone star ticks. Ehrlichiosis cannot be transmitted from person-to-person, except by blood transfusion. Lone star ticks are the most common tick to bite people in Virginia, and as many as 1 in 20 lone star ticks (5%) may be infected with an Ehrlichial agent.

Ehrlichiosis cases range from mild to moderately severe, with a few cases causing life-threatening or fatal illness. Infected individuals that experience symptoms may expect a fever and one or more of the following; headache, chills, discomfort, muscle pain, nausea, vomiting, diarrhea, confusion, and a rash or red eyes that begin about one to two weeks after the bite of an infected tick. Ehrlichiosis causes rash in about 30% of infected adults and 60% of infected children. Severe cases may cause difficult breathing, neurologic problems, and bleeding disorders. Symptoms and biological markers of Ehrlichiosis may be similar to those of Anaplasmosis and RMSF,  causing those illnesses to also be considered as well in the diagnosis.

There are multiple ways to test for Ehrlichiosis, one of which is a method called indirect immunofluorescence IgG assay that detects Ehrlichiosis specific markers. This test involves a blood sample taken as early as possible and a second blood sample taken 2 to 4 weeks later to compare immunological response. The best laboratory method to assist in diagnosis of Ehrlichiosis is the Multiplex PCR which can detect the DNA of multiple pathogens at one time.

Prompt treatment (in the first five days of illness) with an appropriate antibiotic (doxycycline) will minimize the chances of a severe illness development, and usually results in a rapidly effective cure. Ehrlichiosis can be a severe or fatal illness, so treatment should be given based on suspicion of illness, and not be delayed until laboratory results are complete.

On average, there have been 95 cases of ehrlichiosis or undistinguished ehrlichiosis/anaplasmosis cases per year in Virginia within the last decade.

The most likely method of transmission is through the bite of an infected black-legged tick, but in rare cases, Anaplasma phagocytophilum has been spread by blood transfusion. Otherwise, it cannot be transmitted directly from person-to-person.

Symptoms will typically begin within 1-2 weeks after the bite of an infected tick. Early signs usually present as an acute onset of fever, headaches, body aches, nausea, vomiting, and in rare cases, a rash. Also characteristic of the illness are signs such as leukopenia (low white blood cell count), thrombocytopenia (low platelet levels), elevated liver enzymes, and anemia.

Testing for Anaplasmosis usually consists of serological testing for antibodies present in the blood. Anaplasmosis is serologically cross-reactive with Ehrlichiosis, which causes added laboratory challenges. To determine a current, ongoing infection, it may be necessary to provide an acute serum sample paired with a second sample taken about a week or so after the first. This paired sample method allows us to observe a change in the amount of antibody present in the blood when comparing the first and second serum samples. However, the preferred method of testing is PCR of whole blood (usually Multiplex PCR, which is able to detect multiple challenges at once), to confirm the presence of Anaplasma phagocytophilum in an individual’s blood.

Treatment with the antibiotic (doxycycline) is the only effective treatment for Anaplasmosis.

The incidence of Anaplasmosis in Virginia has been increasing in recent years. There have been an average of 13 cases of reported Anaplasma phagocytophilum per year,  and 18 cases on average if you include those that go undetermined as either anaplasmosis or ehrliciosis due to serological cross-reactivity among testing mechanisms.

Humans become infected with the Babesia microbe via the bite of an infected Blacklegged tick. Human-to-human transmission does not occur except in the case of blood transfusions which have been documented in the past.

Most individuals who become infected with Babesia do not exhibit symptoms of disease. Others will develop flu-like, non-specific symptoms such as fever, chills, sweats, headache, body aches, nausea, loss of appetite, and fatigue. Babesia is well known for infecting red blood cells and can cause a specific form of anemia called hemolytic anemia that can result in jaundice (yellowing of the skin) and dark urine. Other characteristic signs of babesiosis include a low and unstable blood pressure, low platelet count, disseminated intravascular coagulopathy (DIC – which can lead to blood clots and bleeding), malfunction of vital organs, and in severe cases death may result.

Lab testing for babesiosis involves the identification of the Babesia parasite in a blood smear under the microscope or detection of the organism’s DNA in whole blood using PCR methods.

Treatment of babesiosis usually involves the combination of two prescription medications: an antibiotic and an antiparasitic, taken together over a 7-10 day period. In more severe cases, additional supportive care may be necessary.

There have been 10 total cases of Babesiosis reported within the last decade in Virginia.

SFR is spread by the bite of an infected tick, or by contamination of the skin with tick blood or feces.  It cannot be spread from one person to another.  Usually, ticks must be attached to the person for a period of between ten and twenty hours in order for transmission to occur, but there have been instances of SFR transmission in which ticks were attached for less than an hour.

Symptoms usually appear within two weeks of the bite of an infected tick. R. parkeri disease is typically less severe than the other major disease of the SFR group with symptoms including fever, headache, muscle aches, and rash.  People diagnosed with this illness typically have an eschar (dark scab) at the tick bite location.

SFR can be diagnosed through laboratory tests of blood or skin.  If an eschar is present, it can be used to accurately diagnose R. parkeri disease. Antibodies to the infectious agent typically do not become detectable until seven to ten days after onset of illness, therefore testing for the agent’s DNA via PCR is the best diagnostic laboratory test in the early stages of illness.

SFR can be diagnosed through laboratory tests of blood or skin.  If an eschar is present, it can be used to accurately diagnose R. parkeri disease. Antibodies to the infectious agent typically do not become detectable until seven to ten days after onset of illness, therefore testing for the agent’s DNA via PCR is the best diagnostic laboratory test in the early stages of illness.

R. parkeri is reported within the Spotted Fever Rickettsial group which includes RMSF. In the last decade, there have been an average of 255 SFR cases in Virginia per year.

Tularemia cannot be spread from one person to another, but can be spread in a variety of other ways. The skin, eyes, mouth and throat of hunters may be exposed to the bacteria while skinning or dressing wild animals, especially rabbits or hares. Handling or eating uncooked meat from infected animals, handling pelts and paws of animals, drinking contaminated water, or getting bitten by certain arthropods may also transmit the bacterial disease. Another possible, but rare, route of exposure is by inhaling infected aerosols, such as dust from contaminated soil, hay or grain.

Symptoms typically appear 3 to 5 days after exposure to the bacteria, but can take anywhere between 1 to 14 days to develop. Tularemia causes different symptoms depending on where and how the bacteria has entered the body. Tularemia can cause swollen and painful lymph glands, inflamed eyes, sore throat, ulcers in the mouth or on the skin, and pneumonia-like illness. Early symptoms almost always include the abrupt onset of fever, chills, headache, muscle aches, joint pain, dry cough and progressive weakness. Pneumonia may be a complication of infection and requires prompt diagnosis and specific treatment to prevent death.

Tularemia can be difficult to diagnose. It is a rare disease, and the symptoms can be mistaken for other more common illnesses. For this reason, it is important to share with your health care provider any likely exposures, such as tick and deer fly bites, or contact with sick or dead animals. Laboratory tests of specimens taken from the affected part(s) of the body can help confirm the diagnosis.

Early treatment with an antibiotic is recommended.

Tularemia occurs very infrequently in Virginia where there has been an average of 2 cases per year in the last decade.

It is currently believed that people acquire Heartland virus through the bite of an infected Lone Star tick.

People infected with Heartland virus may experience symptoms such as fever, fatigue, headache, nausea, joint aches, and diarrhea. Incubation time, or time from tick exposure to illness onset, is estimated to be about 14 days.

No commercially availble testing currently exists for Heartland virus. However, patients with symptoms and exposure consistent with Heartland virus may be tested for evidence of viral antibodies at CDC arboviral rickettsial diseases branch upon clinician request.

Many patients infected with Heartland require hospitalization, with most patients having full recovery after supportive care and intravenous fluids.

Heartland virus is not currently a notifiable disease so statistics for case numbers in Virginia are unknown. Since its identification in 2009, about 30 cases have been reported from the Midwest and Southeast US.

People acquire POW virus through the bite of an infected Blacklegged tick. The virus can be transmitted in as little as 15 minutes, much faster than most other tick-borne illnesses found in Virginia. Powassan virus is typically maintained in a cycle amongst ticks and small-to-medium-sized rodents that they feed on, such as woodchucks, squirrels, and white-footed mice to name a few. There are two separate types of POW virus in the U.S. (POW1 and POW2). POW1 virus is transmitted by the ticks that feed on woodchucks and squirrels. POW2 virus is transmitted by the black-legged tick, the same tick responsible for Lyme disease transmission in Virginia.

Most individuals do not experience symptoms. However, those that do may notice symptoms such as fever, headaches, vomiting, general weakness, confusion, loss of coordination, speech difficulties, or seizures appearing within 1 week to 1 month of suspected tick bite. About half of the survivors of POW experience permanent neurological symptoms.

Laboratory diagnosis generally involves testing of serum or Cerebrospinal fluid (CSF) to detect virus specific IgM and neutralizing antibodies. Initial serological testing will be performed using IgM capture ELISA, MIA (Microsphere-Based Immunoassay) and IgG ELISA. If the initial results are positive, further confirmatory testing may delay the reporting of final results.

Currently there are no vaccines or medications developed to treat or prevent POW virus infection. Persons with severe POW illnesses often need to be hospitalized, where they can receive respiratory support, intravenous fluids, and medications that decrease swelling in the brain. After illness, recovery may require long-term therapy to regain speech and/or movement of limbs.

There has been only one reported case of Powassan virus infection in the state of Virginia (in 2009).

It is currently hypothesized that people acquire Bourbon virus through the bite of an infected Lone Star tick.

Due to a limited number of identified cases, little is known about the typical presentation of Bourbon virus. People with confirmed cases of Bourbon virus have had fever, fatigue, headache, joint aches, nausea, vomiting, and rash. People have also reported leukopenia (low white blood cell count) and thrombocytopenia (low platelet count).

No commercially available testing currently exists for Bourbon virus and laboratories are currently developing specific testing mechanisms to indicate Bourbon virus infection. The CDC has the capacity to test specimen if a case of Bourbon virus is suspected.

Antibiotics are not an effective treatment as this condition is a virus. While no specific treatment exists, patients with Bourbon virus may require hospitalization and supportive care to manage symptoms.

Bourbon virus is not currently a notifiable disease so statistics for case numbers in Virginia are unknown. Since its identification in Bourbon County, Kansas in 2014, a limited number of cases have been identified in Missouri, Oklahoma, and other neighboring states.