The Best Test for Detecting Tick-Borne Relapsing Fever (TBRF)?

The diagnosis of Tick-Borne Relapsing Fever (TBRF) typically relies on a combination of factors, including clinical symptoms, medical history, and laboratory tests. There isn't a single definitive test for TBRF, but several tests can aid in its diagnosis. The choice of test depends on the stage of the disease and other factors. The AcuDart TBRF test, which is powered by the ImmunoBlot technology from IGeneX Laboratory, is considered the best test for TBRF because of its superior sensitivity and specificity. The AcuDart TBRF test tests for the Relapsing Fever Borrelia genus and speciates to multiple species of Relapsing Fever that infect humans, including B. hermsii, B. miyamotoi, B. parkeri, and B. turicatae.

It looks like Lyme, behaves like Lyme, but it’s not Lyme. Is it TBRF? Some of the Borrelia that causes TBRF are transmitted by the same ticks that transmit B. burgdorferi, the causative agent of Lyme disease. Moreover, both TBRF and Lyme sufferers display many similar symptoms, often leading to misdiagnosis if only relying on clinical presentation. Therefore, it is crucial to test for both TBRF and Lyme.

TBRF is a bacterial infection caused by spirochetes of the genus Borrelia. As the name suggests, it is transmitted to humans through the bite of infected ticks. The primary vector for transmitting the bacteria varies depending on the geographical region. In North America, the soft tick of the genus Ornithodoros is the main vector, while in other parts of the world, it can be transmitted by hard ticks.

The characteristic feature of TBRF is recurrent episodes of fever, which occur as a result of the spirochetes periodically invading the bloodstream. Symptoms typically include fever, chills, headache, muscle and joint aches, and fatigue. The fever may last for several days to a week, followed by a period of remission where the symptoms improve. However, without treatment, the fever will usually recur.

Diagnosis of TBRF often involves identifying the spirochetes in blood smears during febrile episodes or through serological tests. Treatment usually involves antibiotics such as doxycycline or tetracycline.

Symptoms of TBRF typically include:

Fever: The hallmark symptom is recurrent episodes of fever, which can spike suddenly and reach high temperatures.

Chills: Patients often experience chills along with fever during episodes of illness.

Headache: Headaches are common and can range from mild to severe.

Muscle and joint aches: Patients may experience muscle and joint pain, which can be generalized or localized.

Fatigue: TBRF can cause significant fatigue and weakness, especially during episodes of fever.

Nausea and vomiting: Some individuals may experience gastrointestinal symptoms such as nausea and vomiting.

Abdominal pain: Pain in the abdomen may occur, often accompanied by other gastrointestinal symptoms.

Photophobia: Sensitivity to light can be present during episodes of illness.

Rash: In some cases, a rash may develop, but it's less common compared to other tick-borne illnesses like Lyme disease.

It's important to note that symptoms can vary in severity and duration, and not all individuals infected with the bacteria may experience all of these symptoms. Additionally, symptoms may overlap with other tick-borne illnesses, so a thorough evaluation by a healthcare professional is necessary for accurate diagnosis and treatment.

Laboratory testing plays a crucial role in diagnosing TBRF, especially considering its nonspecific symptoms, which can mimic other febrile illnesses. Here are some of the common tests used for diagnosing TBRF:

Blood Smear Examination: The most common method for diagnosing TBRF is examining a stained blood smear under a microscope. During febrile episodes, Borrelia spirochetes can be visualized directly in the blood. However, spirochetes may not always be present in the blood smear, especially during the non-febrile periods or if the patient has received antibiotic treatment.

PCR (Polymerase Chain Reaction): PCR assays can detect Borrelia DNA in blood samples with high sensitivity and specificity. This method is particularly useful when spirochetes are not detectable by microscopy. PCR can also help differentiate between various Borrelia species.

Serologic Tests: Serologic tests, such as enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence assay (IFA), detect antibodies produced by the patient's immune system in response to Borrelia infection. However, it's essential to note that antibody production may take a few weeks after infection, so these tests may not be useful during the acute phase of the illness.

Culture: Culturing Borrelia from blood samples is possible but challenging due to the fastidious nature of the organism. Culture-based methods are less commonly used for diagnosis due to the time-consuming process and lower sensitivity compared to PCR.

Western Blot: Western blot assays can be used to confirm the presence of specific antibodies against Borrelia antigens. However, similar to serologic tests, this method may not be useful during the acute phase of infection.

The choice of test depends on factors such as the stage of the illness, availability of laboratory facilities, and the expertise of healthcare providers. Additionally, clinical correlation with the patient's symptoms and epidemiological factors (such as recent exposure to tick bites) is essential for accurate diagnosis and management.

The AcuDart TBRF Test is not based on any of the above mentioned technologies, but rather the ImmunoBlot technology developed by IGeneX Laboratory. An ImmunoBlot has two key differentiators. First, it looks for multiple pathogens, instead of one with a test such as IFA. And second, it uses recombinant proteins instead of proteins from natural sources. The recombinant DNA technology provides a more efficient method to obtain large amounts of proteins (i.e. billions of copies). Additionally, by using recombinant technology, scientists are able to create DNA sequences that would not naturally exist under normal circumstances and environmental conditions, leading to more sensitive and specific tests.

The ImmunoBlot technology has many advantages over other TBRF testing methods, including:

• Uses specifically created recombinant proteins and not proteins from cultures

• Unlike IFA, can detect multiple species in one test

• Detects the full spectrum of disease: early, active and late-stage

• Detects Relapsing Fever Borrelia genus and speciates to B. hermsii, B. miyamotoi, B. parkeri, and B. turicatae

• Replaces the IFA

• Avoids the error prone process of visualizing slides through a microscope