1369. Ten Year Trends of Typhus Fever in North Texas: Epidemiologic Characteristics and Clinical Manifestations

Abstract

Abstract Background Murine Typhus remains endemic in southern California and in southern Texas where it is transmitted by fleas, with opossums serving as the amplifying host. In Texas, the disease is increasingly recognized in municipalities outside its historic rural range and is spreading in a northward distribution. Since its expansion, we have observed increased cases in the Dallas-Fort Worth (DFW) area and aim to describe murine typhus in North Texas from 2011-2021. Methods Leveraging the electronic health record, we retrospectively identified 482 individuals tested for murine typhus by Rickettsia typhi (R. typhi) serology in 2 Dallas hospitals. We subsequently collected epidemiologic characteristics, clinical features, and outcomes of 58 patients with positive R. typhi serologies ( >1:64). Results Of the 58 patients with positive R. typhi serology, 39 (67%) were male, 45 (78%) were White, and 23 (40%) were Hispanic. Seventy-nine percent had symptom onset between May and November, and 36/58 (62%) were diagnosed in 2020 and 2021. Twenty-six (45%) had exposure to dogs, 18 (31%) to cats, and 13 (22%) to opossums. Twelve (21%) patients were immunocompromised. Fifty-two (90%) had fever, 35 (60%) headache, 26 (45%) nausea and vomiting, 26 (45%) rash, 25 (43%) myalgia, 20 (34%) cough, and 17 (29%) abdominal pain. In 2020 and 2021, 35/36 (97%) patients were additionally tested for COVID-19, and 29/35 (83%) patients had more than one negative SARS-CoV-2 test prior to R. typhi serologies being sent. Twenty-one out of fifty (42%) had an abnormal chest x-ray (CXR) and 28/30 (93%) had an abnormal chest computed tomography (CT). Nine (16%) had hypoxia, 9 (16%) required an intensive care unit, and 3 (5%) required mechanical ventilation. No patients died within 30 days of diagnosis. Conclusion Our study highlights the expansion of murine typhus in North Texas (Figure 1) and demonstrates the heightened need for clinicians to be aware of this disease in the appropriate epidemiologic and clinical settings. We also describe increasing rates of respiratory findings, demonstrated through over half of patients having at least one respiratory symptom, and 93% having an abnormal chest CT (findings traditionally associated with severe disease). Figure 1:Heatmap Distribution of Murine Typhus Cases in the Dallas-Fort Worth Metroplex (2011-2021) Disclosures Christoph U. Lehmann, MD, FAAP, FACMI, FIAHSI, Celanese: Stocks/Bonds|Markel: Stocks/Bonds|Springer: Honoraria Helen L. King, MD, Gilead Sciences: Grant/Research Support.