Posters
Presenting Author Academic/Professional Position
Nida Asif
Academic Level (Author 1)
Resident
Discipline/Specialty (Author 1)
Internal Medicine
Academic Level (Author 2)
Resident
Discipline/Specialty (Author 2)
Internal Medicine
Academic Level (Author 3)
Resident
Discipline/Specialty (Author 3)
Internal Medicine
Academic Level (Author 4)
Faculty
Discipline/Specialty (Author 4)
Internal Medicine
Discipline Track
Patient Care
Abstract Type
Case Report
Abstract
Background: Murine Typhus is a rare flea borne illness caused by Rickettsia typhi, with approximately 100-200 cases reported annually in the United States, primarily in Southern Texas, California and Hawaii, transmitted by fleas from rodents or other animals. It often presents with nonspecific symptoms, making diagnosis challenging. Given its vague clinical presentation and regional endemicity, murine typhus is frequently underrecognized delaying appropriate treatment.
Case presentation:A 77-year-old lady with a known history of HFrEF of 25-30% was presented to the ED due to mild left lower quadrant abdominal pain associated with two episodes of loose bowel movements and decreased appetite over the last three days. She also reported that a few days ago she was treated with antibiotics for a urinary tract infection but continued to have the same symptoms. In the emergency room the patient had a Tmax of 100.1 °F, blood pressure was 148/65, pulse rate of 98, respiratory rate was 18 breaths per minute, SpO2 97 % on room air. On physical examination no pertinent positive findings. Laboratory tests showed that she was hyponatremic with sodium of 128 mmol/L, AST 93 U/L normal range (10-36), ALT 42 U/L, (normal range (6-29), platelets of 68000 per microliter. Urinalysis showed few bacteria, 3 + blood, many RBC’s, negative leukocyte esterase, negative for nitrates, other labs unremarkable. The patient was diagnosed with urinary tract infection and started on ceftriaxone. The following day the patient continued to have fevers, she was tachycardiac, getting short of breath requiring oxygen, worsening thrombocytopenia and transaminitis. She was switched to piperacillin-tazobactam and upon further questioning the patient mentioned that she has a lot of animals at home including cats, dogs and rodents. Further lab testing was ordered including CT abdomen pelvis was ordered, Hepatitis panel, HIV 1-2 antibodies, febrile agglutinins, all testing unremarkable. Murine typhus antibodies IgG were also ordered which were 1:256 (normal range < 1:64). The patient was started on doxycycline after which she had clinical improvement in her symptoms and the thrombocytopenia also resolved.
Conclusion: This case highlights the importance of considering murine typhus in the differential diagnosis of febrile illness with non-specific symptoms, especially in endemic regions like southern Texas. The usual classic triad of fever, headaches and rash only occurs in 33% of the cases making diagnosis difficult. Recognition of epidemiology risk factors such as exposure to rodents, fleas or household pets combined with awareness of characteristic key lab findings including elevated liver enzymes, hyponatremia, thrombocytopenia, elevated lactate dehydrogenase, increased ESR can aid in early identification. Serological testing with IFA IgG/IgM titers > 1:64 supports the diagnosis. Tetracyclines, particularly doxycycline, remains the first-line treatment and are associated with rapid clinical improvement.
Presentation Type
Poster
Recommended Citation
Asif, Nida; Durazo, Yareli; Haines, Corey; and Gutierrez, Cesar, "Murine Typhus masquerading as a urinary tract infection: A Case from endemic South Texas" (2025). Research Colloquium. 78.
https://scholarworks.utrgv.edu/colloquium/2025/posters/78
Included in
Murine Typhus masquerading as a urinary tract infection: A Case from endemic South Texas
Background: Murine Typhus is a rare flea borne illness caused by Rickettsia typhi, with approximately 100-200 cases reported annually in the United States, primarily in Southern Texas, California and Hawaii, transmitted by fleas from rodents or other animals. It often presents with nonspecific symptoms, making diagnosis challenging. Given its vague clinical presentation and regional endemicity, murine typhus is frequently underrecognized delaying appropriate treatment.
Case presentation:A 77-year-old lady with a known history of HFrEF of 25-30% was presented to the ED due to mild left lower quadrant abdominal pain associated with two episodes of loose bowel movements and decreased appetite over the last three days. She also reported that a few days ago she was treated with antibiotics for a urinary tract infection but continued to have the same symptoms. In the emergency room the patient had a Tmax of 100.1 °F, blood pressure was 148/65, pulse rate of 98, respiratory rate was 18 breaths per minute, SpO2 97 % on room air. On physical examination no pertinent positive findings. Laboratory tests showed that she was hyponatremic with sodium of 128 mmol/L, AST 93 U/L normal range (10-36), ALT 42 U/L, (normal range (6-29), platelets of 68000 per microliter. Urinalysis showed few bacteria, 3 + blood, many RBC’s, negative leukocyte esterase, negative for nitrates, other labs unremarkable. The patient was diagnosed with urinary tract infection and started on ceftriaxone. The following day the patient continued to have fevers, she was tachycardiac, getting short of breath requiring oxygen, worsening thrombocytopenia and transaminitis. She was switched to piperacillin-tazobactam and upon further questioning the patient mentioned that she has a lot of animals at home including cats, dogs and rodents. Further lab testing was ordered including CT abdomen pelvis was ordered, Hepatitis panel, HIV 1-2 antibodies, febrile agglutinins, all testing unremarkable. Murine typhus antibodies IgG were also ordered which were 1:256 (normal range < 1:64). The patient was started on doxycycline after which she had clinical improvement in her symptoms and the thrombocytopenia also resolved.
Conclusion: This case highlights the importance of considering murine typhus in the differential diagnosis of febrile illness with non-specific symptoms, especially in endemic regions like southern Texas. The usual classic triad of fever, headaches and rash only occurs in 33% of the cases making diagnosis difficult. Recognition of epidemiology risk factors such as exposure to rodents, fleas or household pets combined with awareness of characteristic key lab findings including elevated liver enzymes, hyponatremia, thrombocytopenia, elevated lactate dehydrogenase, increased ESR can aid in early identification. Serological testing with IFA IgG/IgM titers > 1:64 supports the diagnosis. Tetracyclines, particularly doxycycline, remains the first-line treatment and are associated with rapid clinical improvement.
