1336. Six-Year Clinical Experience of Pediatric Murine Typhus in Houston, TX

Abstract

Abstract Background Murine typhus is a flea-borne rickettsial disease endemic to gulf states. It shares clinical features of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C). We sought to explore the six-year experience with murine typhus among children living in Houston, TX. Methods We conducted a retrospective chart review to identify clinical and laboratory features of children with murine typhus from January 2015 to July 2021. Cases were identified by positive Rickettsia typhi serology with single IgG >=1:256, single IgM >=1:128, or increase in IgG from 1:64 to 1:28 in convalescent sera. Results 162 cases of pediatric murine typhus were identified. Most cases (85, 52.5%) occurred in the summer. There was a bimodal distribution of age, with peaks at 4 and 17 years (Figure 1). Most children (96, 59.3%) required hospitalization; 11 were admitted to intensive care, and 3 required intubation. All children had fever; the mean duration of fever at presentation was 8.9 days (+/-2.9). Only 67 (41.4%) had a combination of fever, headache, and rash (Table 1). 64 (39.5%) had documented flea or opossum exposure. The most common laboratory abnormalities were elevated serum liver transaminases, hypoalbuminemia, thrombocytopenia, and hyponatremia (Table 1). Cardiac abnormalities were not uncommon: 20/59 (33.9%) had an abnormal electrocardiogram, 5/50 (10.0%) had troponin >0.04 ng/mL, and 4/50 (8.0%) had b-type natriuretic protein >100 pg/mL (Table 1). Most children (149, 92.0%) were diagnosed based on positive initial serological testing. Nine (5.6%) received intravenous immunoglobulin for a diagnosis of KD before typhus was diagnosed. The median duration of hospitalization was 3 days (IQR 2,5), and most children were treated with doxycycline (146, 90.1%). Figure 1.Histogram of age at time of murine typhus diagnosis.Table 1.Clinical and Laboratory Features of Children Diagnosed with Murine Typhus. Conclusion Murine typhus is a common cause of prolonged unexplained fever in children living in endemic areas and shares clinical features of KD and MIS-C. Cardiac abnormalities are not uncommon, and severity of illness can range from outpatient to intensive care. Lack of flea or opossum exposure or lack of headache or rash does not rule out infection. Therefore, a high index of suspicion is warranted, and initial serology testing may accelerate diagnosis in children with prolonged fever. Disclosures All Authors: No reported disclosures.