Clinical and paraclinical profile, and predictors of outcome in 90 cases of scrub typhus, Meghalaya, India

Abstract

BackgroundIndia is an integral component of “tsutsugamushi triangle” which depicts a part of the globe endemic to scrub typhus. Owing to frequent outbreaks witnessed in different parts of the country in the recent past, scrub typhus is described as a re-emerging infectious disease in India. The present study aimed to study the clinical and paraclinical profile, complications and predictors of outcome among 90 cases of scrub typhus diagnosed in a hospital of north-eastern India from Sept 2011 to Aug 2012.MethodsA longitudinal study was conducted in a hospital of Meghalaya, India between Sept 2011 and Aug 2012. Diagnosis of scrub typhus was arrived by SD BIOLINE tsutsugamushi (solid phase immunochromatographic assay) rapid diagnostic test for antibodies (IgM, IgG or IgA). Descriptive analyses of age, gender, geographic area, symptoms and signs, treatment, laboratory findings, complications, and outcome were conducted. Relative risk (RR) with 95 % confidence interval (CI) was computed for Multiple Organ Dysfunction Syndrome (MODS) and mortality. Binary logistic regression was applied to the significant correlates (P < 0.05) on univariate analysis to identify the predictors of MODS and mortality in scrub typhus.ResultsAs many as 662 clinically suspected scrub typhus patients were tested and 90 (13.6 %) were diagnosed to have scrub typhus. Out of 90 patients, 52.2 % (n = 47) were males and their mean (SD) age was 36.29 (13.38) years. Fever of <7 days (n = 75, 83.3 %), myalgia (n = 56, 62.2 %), pain abdomen (n = 24, 26.7 %), headache (n = 24, 26.7 %), nausea/vomiting (n = 21, 23.3 %), dry cough (n = 21, 23.3 %), hepatomegaly (n = 24, 26.7 %), splenomegaly (n = 22, 24.4 %), and lymphadenopathy (n = 20, 22.2 %) were the predominant clinical features. Eschar was seen in 10 patients (11.1 %). One third (n = 30) of the patients developed at least one systemic complication. Acute hepatitis (n = 15, 16.7 %), pneumonitis (n = 14, 15.6 %), and acute kidney injury (n = 11, 12.2 %) were the common complications. MODS was seen in 14.4 % (n = 13) and 38.5 % (n = 5) of the patients with MODS died. Overall, case fatality rate was 5.15 % (n = 5). On univariate analysis, platelets <100 000/mm3, serum creatinine >1.5 mg/dl, and transaminase (AST, ALT or both) >500 U/L were associated with MODS (P < 0.001) and mortality (P < 0.05). In addition, serum bilirubin >3 mg/dl was also associated with MODS (P < 0.001). On applying binary logistic regression, serum creatinine >1.5 mg/dl was a predictor of MODS (OR: 76.1, 95 % CI: 4.9–1175.6) and mortality (OR: 18.03, 95 % CI: 1.38–235.1).ConclusionIn this study setting, approximately one-seventh (13.6 %) of the acute undifferentiated febrile illness were due to scrub typhus. Systemic complications were common (33.3 %). Serum creatinine >1.5 mg/dl was a predictor of MODS and mortality.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-016-0186-x) contains supplementary material, which is available to authorized users.

A Review of Scrub Typhus (Orientia tsutsugamushi and Related Organisms): Then, Now, and Tomorrow

“…Additionally, the widespread use of Orientia- resistant beta-lactam antimicrobials coincided with the increased incidences of scrub typhus [ 101 ]. In this review, we have documented human outbreaks of scrub typhus from 2007 to the present, 2017 ( Table 1 ) [ 19 , 95 , 99 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 ].…”

“…The baseline level of scrub typhus in the endemic regions may not be known, and therefore, some of the scrub typhus outbreaks described herein may be sporadic, unrelated cases of the same disease, particularly for the hospital-based studies conducted prospectively [ 121 ] or retrospectively [ 114 , 116 ]. In these outbreaks, the patients presented with an undifferentiated febrile illness of varying severity with symptoms ranging from fever, headache, cough, rash and/or eschar, myalgia, lymphadenopathy [ 19 , 108 ], to more dramatic ones such as multiple organ failure [ 95 , 109 ], and death in some of the outbreaks [ 95 , 104 , 105 , 114 , 115 , 116 ]. In a review by Taylor et al, it was observed that the case fatality rate can be as high as 30–70% in untreated cases [ 96 ].…”

“…For some of the outbreak investigations, other causes of undifferentiated febrile illness, such as dengue, malaria, leptospirosis, and typhoid fevers [ 104 ], were ruled out. During some of the outbreaks, diagnosis was based on detection of antibodies (IgM) using commercial ELISA assay(s) coupled with presence of eschar [ 107 ], or exclusion of other causes of fever [ 115 ], or response to treatment [ 109 ]. The outbreaks affected people of all ages, but some were reported exclusively among pediatric patients [ 19 , 95 , 104 , 108 ].…”

“…In complicated scrub typhus cases, such as those with meningoencephalitis, septic shock, myocarditis, and/or multi-organ system involvement, broad spectrum antibiotics were indicated [ 95 , 108 ]. Case fatalities were most likely due to delayed diagnosis and treatment resulting in multi-organ system failure, as observed in some of the studies [ 104 , 109 , 112 , 115 ], or may be as a result of complications due to mixed infections (co-morbidities) observed in some of the outbreaks [ 109 ].…”

Targeting metabolic pathways proteins of Orientia tsutsugamushi using combined hierarchical approach to combat scrub typhus

“…Scrub typhus in India is considered as the emerging and re‐emerging infectious disease . Outbreaks of this disease were also reported in various Indian provinces . The previous report showed that the infection can lead to acute encephalitis syndrome, Parkinson's disease, and various neurological complications …”