Lyme disease is often called “The Great Imitator” as its presentation can mimic several medical conditions. It is rarely reported as a cause of lone‐persistent fever especially in adults. We report a unique case of viral co‐infection with Lyme.

Case Presentation:

A 57‐year‐old healthy female pediatrician was admitted for persistent fever for 2 weeks in late summer. She frequently sees children with viral illnesses and MRSA abscesses. She lives in an area with many deer and her husband recently had Lyme disease. She never noticed any attached tick, or rash. She is originally from Russia, had a positive PPD in 1996 that was treated with isoniazid. She stated multiple recent mosquito bites. Outside tests showed Enzyme Immunoassay (EIA) IgM positivity for Lyme. She received oral doxycycline. However, she had no improvement with continued fevers, lethargy and weakness. She was tachycardic, with episodes of hypotension. Examination was unremarkable. She had mild leukopenia with relative lymphocytosis (53%), thrombocytopenia (82 K) and normocytic anemia (Hemoglobin 9.5 gm/dL). ESR and CRP were elevated. She had abnormal liver enzymes, prolonged PTT and normal bilirubin.

Tests for tropical zoonoses, Erlichia, Babesiosis, blood/CSF cultures and PCR for common bacterial, viral or fungal infections were negative. “Two‐tiered testing” for Lyme was strongly positive for EIA screen followed by 2/3 positive IgM and one positive IgG on Western‐blot. Parvovirus‐B19 serology was strongly positive for IgM with mildly positive IgG. She was continued on oral doxycycline. She continued having fevers for 5 more days, and then gradually stopped. She was discharged in a week. Follow up serology for both Lyme and parvovirus‐B19 after 3 weeks were positive for IgG but negative for IgM. She continued to feel weak for several weeks and was able to return to work after a month.


Lyme disease is reported as a cause of fever of unknown origin in children but rarely in adults. Lone persistent fever could be a result of co‐infection as parvovirus can change the presentation of several illnesses including Lyme. Acute parvovirus‐B19 infection causes non‐specificity frequently in Borrelia burgdorferi. EIA IgM for Lyme is highly positive (79%) in acute parvovirus‐B19 infection. Therefore, it’s crucial to follow up for IgG serology after several weeks. Parvovirus can cause severe myalgia, abnormal liver enzymes or bone marrow suppression. Slow clearance of B19 viral infection is reported in adults with Lyme disease. Therefore, it is important to continue treatment for Lyme as it may take longer for symptoms to resolve. Oral doxycycline and intravenous ceftriaxone are equally effective in the treatment of acute Lyme as well as in preventing late manifestations. Doxycycline is usually preferred for ease of treatment.


Parvovirus‐B19 co‐infection can alter the natural clinical or serologic course of Lyme disease. This adds to the diagnostic challenge as Lyme’s symptoms can imitate many other diseases. It may be reasonable to continue to treat for Lyme disease for longer than recommended until complete IgG conversion in such situations.