781. Scrub Typhus: Clinical and Laboratory Manifestations, Genetic Variability and Outcome
Session: Oral Abstract Session: Travel/Tropical Medicine and Parasitology
Friday, October 21, 2011: 3:15 PM
Room: 204AB
Background: This study was done to evaluate the clinical and laboratory manifestations, genetic variability of causative strains and assess the outcome of scrub typhus caused by Orientia tsutsugamushi in India.

Methods: Patients admitted with scrub typhus confirmed by IgM ELISA and / or pathognomonic eschar, to a university teaching hospital in India between August 2009 and March 2010, were evaluated. Detailed clinical examination including a careful search for eschar and laboratory parameters were documented in all patients. The sequences of a 483-base pair region of the 56-kD type-specific antigen gene from 10 Orientia tsutsugamushi eschar samples were compared with isolates from other regions in Asia.

Results: One hundred and thirty eight cases (Males 76 and females 62) of scrub typhus were seen during this 6 months period. The mean age of patients was 46 years and agricultural workers and housewives formed majority of cases (75%). Common symptoms were fever (mean duration 9 days), breathlessness, cough, nausea, vomiting, headache and myalgia. Eschar was present in 51% of cases and the common sites were groin, axilla, neck and breast fold. Liver enzymes were elevated in majority (72.5%). On phylogenetic analysis, 4 strains clustered with Karp while the remaining six clustered with the Kato group.  Multiple Organ Dysfunction Syndrome was present in more than one third of patients (40.6%). ARDS (44.9%), hypotension requiring ionotropic support (26.8%), hepatitis with total bilirubin >2.5 gm/dl (24.6%), meningitis or meningoencephalitis (21%) and renal impairment with creatinine >2.5 gm/dl (13%) were the important complications. Case fatality rate was 7.9%. There was a dramatic response to doxycycline in nearly all the patients who survived with mean fever defervesence duration of 2 days.

Conclusion: Scrub typhus is a multi-system infection causing significant morbidity and mortality in South India. The 10 Indian strains sequenced in this study are grouped in two distinct clusters. Strategies for early diagnosis and control of this infection are warranted.

Subject Category: T. Travel/tropical medicine and parasitology

George Varghese, MD, DNB, DTMH1, John Prakash, MD2, O Abraham, MD1, Prasad Mathews, MD, FRACP1, Kurien Thomas, MD, MSc3 and Dilip Mathai, MD, PhD, FIDSA4, (1)Christian Medical College, Vellore, India, (2)Microbiology, Christian Medical College, Vellore, India, (3)Christian Medical College Hospital, Vellore, India, (4)Christian Medical College and Hospital, Vellore, India


G. Varghese, None

J. Prakash, None

O. Abraham, None

P. Mathews, None

K. Thomas, None

D. Mathai, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.