Acute Encephalitis Syndrome Due to Scrub Typhus: A Missed Diagnosis

Abstract

Introduction- Clinically, a case of Acute Encephalitis Syndrome (AES) is defined as a person of any age, at any time of year with the Acute onset of fever and a change in mental status (including symptoms such as confusion, disorientation, come, or inability to talk) and/or new onset of seizures (excluding simple febrile seizures). Acute encephalitis syndrome (AES) is a major public health problem worldwide because of its high morbidity and mortality. Although incidence of AES varies according to different studies, it is generally between 3·5 and 7·4/1,00,000 patient-years, and is higher in children aged <1 year and adults aged > 65 years.(3). Material and methods- This study was Open Labeled, Prospective study and was performed over a period of 1 year and 6 months from January 2018 to June 2019 at Department of Microbiology, TNMC and BYL Nair Ch. Hospital, Mumbai and Molecular Diagnostic Reference Laboratory, Kasturba Hospital, Mumbai only after taking Approval from Institutional Ethics Committee and Informed consent of every patient enrolled in the study. Results- This study was done on adult population and the mean age was 42.5 years. The minimum age was 14 years and the maximum age was 78 years. Almost half of the patients were between 15 and 45 years of age, which suggest the disease has a higher incidence in the younger adults. A maximum number of patients came during the month of July -October, suggesting the seasonal occurrence of the disease. The most common clinical features of AES patients were fever and altered sensorium followed by behavioral changes, headache, and seizures. The most common finding of general examination of AES patients was pallor followed by tachycardia and tachypnea. Most of the patients had low GCS (<=7), hypotonia and abnormal movements during their CNS examination. In this study, 17(28.3%) the CSF R/M finding were suggestive of bacterial infection (white cell counts high with neutrophilic predominance, accompanied by elevated proteins and hypoglycorrachia) and in 5(8.4%) the CSF R/M findings were suggestive of viral infection (mild pleocytosis and lymphocytic predominance, slightly elevated protein, and normal glucose), however in 38(63.33%) patients CSF R/M findings were normal. Conclusion- To conclude, the etiology panorama of acute encephalitis syndrome including Scrub Typhus and viral agents (excluding JE) is not well documented especially in western India. The lack of published data from western India leads to lack of understanding of disease. Conventional methods like culture and routine CSF studies lead to identification of only few etiologic agents causing AES, Diagnosis of AES should be done by new molecular diagnostic technologies including PCR, nucleic acid sequence-based amplification, and branched-DNA assay. Multiplex PCR is a boon for CNS infections where “TIME IS PRECIOUS” and help in early diagnosis of infectious agents and thereby providing specific treatment. A surveillance system for undiagnosed infections should be developed which helps to monitor the trends of emerging infection and aid in their early diagnosis.