Comparison of initial presentations of murine typhus and Multisystem-Inflammatory Syndrome in children in a typhus-endemic area

ABSTRACT

Purpose of Study In areas endemic for murine typhus, it can be difficult to distinguish from other febrile syndromes. During COVID-19 surges, we identified several cases of typhus. Presenting symptoms and quantitative lab values at and during admission were compared between patients who were diagnosed with murine typhus or multisystem-inflammatory syndrome in children (MIS-C). Methods Used Retrospective data was collected at a tertiary care center from July 2020 to March 2022. Inclusion criteria were patients under 21 years of age diagnosed at discharge with murine typhus or MIS-C based on clinical and laboratory evidence, serologic data, and expert consultation. Patients found to have an alternate diagnosis, and those without serologic testing were excluded. Subjects were grouped as either MIS-C or typhus based final diagnosis. Categorical data included headache, fatigue, mucocutaneous changes, rash, con-junctival injection, sore throat, rhinorrhea, palpitations, shortness of breath, chest pain, abdominal pain, nausea/vomiting, diarrhea, myalgia, and appetite change at initial presentation. The categorical data were compared using chi-square test. Quantitative data included age, maximum temperature in first 24 hours of hospitalization, duration of symptoms prior to admission, C-reactive protein, erythrocyte sedimentation rate, platelet count, white blood cell count (WBC), absolute neutrophil count (ANC), absolute lymphocyte count, serum sodium, alanine aminotransferase, hemoglobin (Hgb), and albumin (Alb). Means of the quantitative data were compared with a one-tailed 2- Sample T-Test. The maximum and minimum laboratory values during admission were also compared. Additional demographic data including gender and date of initial presentation was also collected. Summary of Results: There were 7 patients in the MIS-C group and 19 in the typhus group. The average age of MIS-C patients, 6.5 years of age vs. 11.5,was significantly lower (p < 0.5) than the typhus group. Initial mean WBC (cells x 103/mm3) was higher in MIS-C than typhus (12.21, SD = 3.52, vs. 7.85, SD = 3.52, p < 0.05), as was ANC (8.9, SD = 3.7vs. 5.12, SD = 2.05, p < 0.05). During hospitalization, minimum Hgb (g/dL) was 9.3, SD = 2.07, and11.49, SD = 1.67, in MIS-C and typhus respectively (p < 0.05). Minimum albumin (g/dL) was also lower in MIS-C than typhus (2.32, SD = 0.86 vs. 2.8, SD = 0.45, p < 0.05). There were no other statistically significant differences in categorical or quantitative data. Typhus cases typically occurred in the summer and fall months. There was no clear seasonality of MIS-C, but occurred during local COVID-19 surges. Conclusion(s) The initial presenting symptoms of typhus and MIS-C were similar. WBC and ANC were higher in MIS-C, while age, Hgb and Alb were lower. These parameters may aid in distinguishing the diseases. A high clinical suspicion for both typhus and MIS-C in endemic areas for typhus is crucial. A rapid detection for typhus would aid in distinguishing these diseases and allow prompt treatment interventions. Copyright © 2023 Southern Society for Clinical Investigation.