Lyme disease is caused by a bacterium borrelia burgdorferi and is transmitted by ticks. A screening test with high sensitivity is used as the first step in the CDC recommended algorithm. Immunoblot testing qualitatively examines, with high specificity, antibodies in a patient's specimen. Immunoblot testing is appropriate for confirming a detected screening result.

Ehrlichia chaffeensis DNA PCR is a highly sensitive method to detect the presence of ehrlichia chaffeensis DNA in clinical specimens.
The diagnosis of ehrlichia chaffeensis infection should not rely solely upon the result of PCR assay. A positive result should be considered in conjunction with clinical presentation and additional established clinical tests. Moreover, this assay cannot differentiate between viable and nonviable organisms. A negative PCR result indicates the absence of ehrlichia chaffeensis DNA at detectable levels in the sample tested and does not exclude the diagnosis of disease.

This test is intended for the qualitative detection of Babesia microti DNA in whole blood or ticks. Babesia microti is a protozoan parasite that infects red blood cells and causes Babesiosis. Transmission to humans occurs primarily through the bite of an infected Ixodes scapularis or Ixodes pacificus tick, occasionally through transfusion of contaminated blood products, and rarely through organ transplantation or from an infected mother to her baby during pregnancy or delivery.

Clinical diagnosis of human babesiosis can be difficult, especially in the early stages. Symptoms are nonspecific and typically include fever, chills, headache, myalgia, and anorexia. Hepatomegaly and splenomegaly may also be present. Severe disease most commonly occurs in elderly and/or immunocompromised patients and is associated with higher levels of parasitemia (≥4 percent), nausea, vomiting, and diarrhea.

Symptoms typically appear one to four weeks after infection via tick bite but may appear after a longer incubation period for infections from a contaminated blood product. Babesia parasitemia may persist in asymptomatic hosts for months or years, leading to concerns about the safety of blood products since there are currently no licensed tests for donor screening.

Laboratory evaluation for Babesia microti infection includes examination of thin blood smears for the presence of parasites within red blood cells, serological assays for antibody detection in serum, and molecular identification of Babesia microti DNA in whole blood or ticks. The Babesia microti DNA, Real-Time PCR assay is rapid, sensitive and does not detect DNA sequences from the closely related canine pathogen Babesia gibsoni.

A Babesia microti PCR result should be considered in the context of clinical observations, patient history, and epidemiological data when making a final diagnosis and patient management decisions. A negative result means that Babesia microti DNA was not present in the specimen above the limit of detection but does not exclude the possibility of infection.

This test is for the qualitative detection of antibodies against Borrelia burgdorferi, the causative agent of Lyme disease, using the modified two-tier testing (MTTT) algorithm. Initial testing is performed using a Lyme total (IgG and IgM) antibody assay and if positive or equivocal, the sample is then tested using separate IgG and IgM immunoassays. This algorithm differs from the STTT algorithm in that the second-tier assays are chemiluminescent immunoassays, not immunoblots. MTTT may be able to assist in the identification of Lyme disease with improved sensitivity earlier in infection compared to STTT.

Diagnostic testing for Lyme disease relies on a two-step algorithm to increase sensitivity and specificity. Testing is performed in patients presenting with signs and symptoms consistent with Lyme disease and with potential tick exposure in endemic regions. Most infections are transmitted by blacklegged ticks in the upper midwestern, northeastern, and mid-Atlantic states.

Negative results can occur in patient with recent infection (≤14 days). In persons with recent or past infection, both IgG and IgM can be detectable months to years after the infection has resolved. Therefore, it is recommended to interpret results in the context of the clinical picture, history, including exposure risk, and symptom onset.

References:
1. Mead, P. et al. Updated CDC Recommendation for Serologic Diagnosis of Lyme Disease. Wkly Rep. 2019 Aug 16;68(32):703. doi: 10.15585/mmwr.mm6832a4.
2. Suggested Reporting Language, Interpretation and Guidance For Lyme Disease Serologic Test Results. Association of Public Health Laboratories. April 2024.
3. Sfeir MM, Meece JK, Theel ES, et al. Multicenter clinical evaluation of modified two-tiered testing algorithms for Lyme disease using zeus scientific commercial assays. J Clin Microbiol 2022; 60:e0252821.
4. Tickborne Diseases of the United States. A Reference Manual for Healthcare Providers, Sixth Edition, 2022. Centers for Disease Control and Prevention.

This test is for the detection of IgG and IgM antibodies against Babesia microti to aid in the diagnosis of Babesiosis. Babesiosis is a tickborne disease caused by transmission of the protozoa via the bite of an infected tick. B. microti is most common in the northern and upper Midwestern United States.

Testing for B. microti is based on a clinical evaluation and risk of tick exposure with consideration to the geographic region. Symptoms may be nonspecific, including headache, fever/chills, malaise, myalgia, and gastrointestinal symptoms. Infection can have similarities with other tickborne illnesses with overlapping vectors, geographic endemicity, and similar clinical signs and symptoms, including Anaplasma spp, Ehrlichia spp, and Borrelia burgdorferi (Lyme disease).

Negative results can occur early in infection. Nucleic acid amplification tests are the preferred method for diagnosis during acute infection. Seroconversion or a four-fold increase between acute and convalescent sera can be used to support a diagnosis. The presence of IgG alone may indicate past infection, and IgM may persist for many months after infection has resolved. Antibody levels may remain elevated for several years after acute illness. Other less common Babesia species in different geographic regions have been identified to infect humans, such as B. duncani and B. divergens. The extent of cross-reactivity between Babesia species is variable and may not be detected by this assay. Therefore, interpretation of serologic results is done in the context of pertinent clinical picture, including timing from symptom onset.

References:
1. Tickborne Diseases of the United States. A Reference Manual for Healthcare Providers, Sixth Edition, 2022. Centers for Disease Control and Prevention.
2. Clinical Testing and Diagnosis for Ehrlichiosis. Centers for Disease Control and Prevention. Last updated May 15, 2024. https://www.cdc.gov/ehrlichiosis/hcp/diagnosis-testing/index.html⁠⁠⁠⁠⁠⁠⁠
3. Krause, PJ. et al. Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA): 2020 Guideline on Diagnosis and Management of Babesiosis. Clin Infect Dis. 2021 Jan 27;72(2):e49-e64. doi: 10.1093/cid/ ciaa1216.

This panel contains components for the detection of antibodies against Borrelia burgdorferi (Lyme disease) using the modified two-tier algorithm, Anaplasma phagocytophilum, Ehrlichia chaffeensis, and Babesia microti. Infection with these organisms can occur from the bite of a tick found in endemic regions, including the upper Northeast and Midwestern United States. Appropriate reflex testing of individual components is performed for initial screen results.

The tests included in the panel are serologic assays used to aid in the diagnosis of select tickborne related illnesses. Testing for tickborne diseases is based on a clinical evaluation and risk of tick exposure with consideration to the geographic region of potential exposure. Symptoms may be nonspecific, including fever/chills, muscle aches, fatigue, and rash. Although infections may have a distinctive rash, some may be undifferentiated or atypical. These infections often have overlapping vectors, geographic endemicity, and similar clinical signs and symptoms. In some cases, co-infection can occur. Therefore, it is suggested that testing for multiple pathogens in the same endemic region be considered.

Testing of IgG and IgM are included for individual components. Negative results can occur early in infection. Seroconversion or a four-fold increase between acute and convalescent sera can be used to support a diagnosis. The presence of IgG alone may indicate past infection and IgM in some cases may persist for many months after infection has resolved. Cross-reactivity between related organisms, such as Anaplasma and Ehrlichia, can occur. Therefore, interpretation of serologic results is done in the context of pertinent clinical picture, including timing from symptom onset.

This assay allows for the detection of Rickettsia species DNA in whole blood from symptomatic patients, facilitating the diagnosis during the acute phase of the disease especially in severe cases. It can be used to aid in the diagnosis of Rocky Mountain spotted fever, epidemic and murine typhus and other tick bite fevers. This testing methodology may in some cases provide earlier diagnostic information when compared to serological methods. The collection of specimens should be done before implementation of antibiotic therapy; this test does not detect past or resolved infections. A not detected result does not rule out infection, especially if the sample is collected after the acute phase or after the use of antimicrobials. The results of this test should be interpreted in the context of pertinent clinical presentation and history.

Borrelia miyamotoi is a tick-borne bacterial organism that causes a nonspecific febrile illness that may be misdiagnosed as Lyme disease or other tick-borne infections. Positive antibody results suggest B. miyamotoi infection; however, other tick-borne organisms may induce cross-reactive antibodies. Negative IgG and IgM results do not exclude the possibility of B. miyamotoi infection.

Persons infected with Borrelia miyamotoi most likely have fever, joint pains, fatigue, and headache, though unlike Lyme disease, rash is uncommon.
The diagnosis of Borrelia miyamotoi is most often made by history and clinical examination combined with exposure in endemic areas. Amplification of B. miyamotoi genomic DNA from blood, fluids or tissues confirms the diagnosis.

The Ehrlichia ewingii DNA PCR test is highly sensitive and specific, and can be used to confirm the diagnosis of human ehrlichiosis especially during the acute phase of the disease.

This test is for the detection of IgG and IgM antibodies against Ehrlichia chaffeensis to aid in the diagnosis of Ehrlichiosis (human monocytic ehrlichiosis). Ehrlichiosis is a tickborne disease caused by transmission of the bacteria via the bite of an infected tick. It is most common in the eastern to southeastern and south-central United States.

Testing for E. chaffeensis is based on a clinical evaluation and risk of tick exposure with consideration to the geographic region. Symptoms may be nonspecific, including headache, fever/chills, malaise, myalgia, gastrointestinal symptoms, and rash. Infection can have similarities with other tickborne illnesses with overlapping vectors, geographic endemicity, and similar clinical signs and symptoms, including Anaplasma spp, Borrelia burgdorferi (Lyme disease) and Babesia microti.

Negative results can occur early in infection. Nucleic acid amplification tests are the preferred method for diagnosis during acute infection. Seroconversion or a four-fold increase between acute and convalescent sera can be used to support a diagnosis. The presence of IgG alone may indicate past infection, and IgM may persist for many months after infection has resolved. Antibody levels may remain elevated for several years after acute illness. Cross-reactivity between related organisms Anaplasma and Ehrlichia spp, can occur. Therefore, interpretation of serologic results is done in the context of pertinent clinical picture, including timing from symptom onset.

References:
1. Tickborne Diseases of the United States. A Reference Manual for Healthcare Providers, Sixth Edition, 2022. Centers for Disease Control and Prevention.
2. Clinical Testing and Diagnosis for Ehrlichiosis Centers for Disease Control and Prevention. Last updated May 15, 2024. https://www.cdc.gov/ehrlichiosis/hcp/diagnosis-testing/index.html.
3. Miller, MJ. Et al. Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2024 Update by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM). Clin Infect Dis. 2024 Mar 5: ciae104.doi: 10.1093/cid/ciae104.
4. Biggs, HM, et al. Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis - United States. MMWR Recomm Rep. 2016 May 13;65(2):1-44.

Recent or current Colorado Tick Fever is indicated by a four-fold or greater rise in IgG titer between acute and convalescent sera and/or an IgM level of 1:20 or greater.

Aiding in the diagnosis of tularemia caused by Francisella tularensis.

This test should not be used as a test of cure as it is not quantitative. Patients may remain seropositive for months to years following resolution of disease.

This test is for the detection of IgG and IgM antibodies against Anaplasma phagocytophilum to aid in the diagnosis of Anaplasmosis (human granulocytic anaplasmosis). Anaplasmosis is a tickborne disease caused by transmission of the bacteria via the bite of an infected tick. It is most common in the Northeastern and upper Midwestern United States during warmer months.

Testing for Anaplasmosis is based on a clinical evaluation and risk of tick exposure with consideration to the geographic region. Symptoms may be nonspecific, including headache, fever/chills, malaise, myalgia, gastrointestinal symptoms, and rash (less common). Infection can have similarities with other tickborne illnesses with overlapping vectors, geographic endemicity, and similar clinical signs and symptoms, including Ehrlichia spp, Borrelia burgdorferi (Lyme disease) and Babesia microti.

Negative results can occur early in infection. Nucleic acid amplification tests are the preferred method for diagnosis during acute infection. Seroconversion or a four-fold increase between acute and convalescent sera can be used to support a diagnosis. The presence of IgG alone may indicate past infection, and IgM may persist for many months after infection has resolved. Antibody levels may remain elevated for several years after acute illness. Cross-reactivity between related organisms Anaplasma and Ehrlichia spp, can occur. Therefore, interpretation of serologic results is done in the context of pertinent clinical picture, including timing from symptom onset.

References:
1. Tickborne Diseases of the United States. A Reference Manual for Healthcare Providers, Sixth Edition, 2022. Centers for Disease Control and Prevention.
2. Clinical Testing and Diagnosis for Anaplasmosis. Centers for Disease Control and Prevention. Last updated May 15, 2024. https://www.cdc.gov/anaplasmosis/hcp/diagnosis-testing/index.html
3. Miller, MJ, et al. Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2024 Update by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM). Clin Infect Dis. 2024 Mar 5: ciae104.doi: 10.1093/cid/ciae104.
4. Biggs, HM, et al. Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis - United States. MMWR Recomm Rep. 2016 May 13;65(2):1-44.

The diagnosis of Borreliosis is most often made by clinical examination combined with exposure in endemic areas. Amplification of Borrelia genomic DNA from blood can support the diagnosis. This test detects Borrelia species which are associated with either Lyme disease (Borrelia burgdorferi), or relapsing fever (Borrelia miyamotoi). A positive result for Borrelia species but negative result for Borrelia burgdorferi and Borrelia miyamotoi, may indicate that infection is caused by other Borrelia species. A negative result for Borrelia species does not rule out Borrelia infection and appropriate serology testing may be clinically warranted.

Antigen specific IgG and IgM titers allow rapid diagnosis of infection by any of the spotted fever group of rickettsial agents. This group of agents include R. rickettsii (Rocky Mountain Spotted Fever) and R. akari (rickettsial pox), both seen in the continental United States.

Persons infected with Borrelia miyamotoi most likely have fever, joint pains, fatigue, and headache, though unlike Lyme disease, rash is uncommon.
The diagnosis of Borrelia miyamotoi is most often made by history and clinical examination combined with exposure in endemic areas. Amplification of B. miyamotoi genomic DNA from blood, fluids or tissues confirms the diagnosis.

Human granulocytic ehrlichiosis (HGE) DNA PCR is a highly sensitive and specific method to detect the agent responsible for HGE, Ehrlichia equi and Ehrlichia phagocytophilia. This assay does not recognize sequences for the human ehrlichial pathogen Ehrlichia chaffeensis. The diagnosis of HGE infection should be considered in conjunction with clinical presentation and additional established clinical tests. A negative PCR result indicates the absence of HGE at detectable levels in the sample tested and does not exclude the diagnosis of disease.