Acute undifferentiated fever presenting as multi-organ dysfunction: Narrowing the differential diagnosis

Introduction: Acute undifferentiated fever (AUF) in India is highly prevalent in the monsoon and postmonsoon periods. AUF may trigger potentially fatal illnesses with acute-onset complications; therefore, this study was carried out to recognize the common forms of organ dysfunction in tropical vector-borne diseases which present as AUF. Materials and Methods: A 20-month prospective study was conducted to estimate the incidence of multi-organ dysfunction syndrome (MODS) among the common causes of AUF. The association of mortality with MODS patterns was also determined. All nonparametric variables were compared using Chi-square and Kruskal–Wallis. Bivariate as well as multivariate logistic regression analyses were performed to find the predictors of mortality/poor outcome. Results: Scrub typhus had the highest incidence of MODS and highest mortality with simultaneous hepatic and renal involvement in 35.8%, followed by hepatic involvement with acute respiratory distress syndrome (ARDS) in 33.9% and hepatic involvement with shock in 32%. Patients of MODS with acute kidney injury (AKI), shock, or sepsis had higher mortality rates. Conclusion: AUF presents with multiple overlapping manifestations which are difficult to discern clinically into specific etiologies, especially once MODS sets in. However, we observed statistically higher odds of the patient having scrub typhus as the cause of AUF when simultaneous hepatitis, AKI, ARDS, and shock were present.