Clinical significance of abnormal chest radiographic findings for acute kidney injury in patients with scrub typhus

Rickettsiosis with Pleural Effusion: A Systematic Review with a Focus on Rickettsiosis in Italy

BACKGROUND

Motivated by a case finding of Mediterranean spotted fever (MSF) associated with atypical pneumonia and pleural effusion in which Rickettsia conorii subsp. israelensis was identified by molecular methods in the pleural fluid, we wanted to summarize the clinical presentations of rickettsiosis in Italy by systematic research and to make a systematic review of all the global cases of rickettsiosis associated with pleural effusion.

METHODS

For the literature search, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was followed. We chose to select only the studies published in last 25 years and confirmed both with serological and molecular assays.

RESULTS

Human cases of rickettsiosis in Italy were reported in 48 papers describing 2831 patients with very different clinical presentations; the majority was MSF accounted to R. conorii and was reported in Sicily. Pleural effusion associated with infection with microorganisms belonging to Rickettsiales was described in 487 patients. It was rarely associated with microorganisms different from O. tsutsugamushi; also rarely, cases of scrub typhus were reported outside Southeast Asia and in the largest majority, the diagnosis was achieved with serology.

CONCLUSIONS

MSF, especially when caused by R. conorii subsp. israelensis, may be a severe disease. A high index of suspicion is required to promptly start life-saving therapy. Pleural effusion and interstitial pneumonia may be part of the clinical picture of severe rickettsial disease and should not lead the physician away from this diagnosis.

Urinary Exosomal microRNA-21 as a Marker for Scrub Typhus-Associated Acute Kidney Injury

Background: Urinary microRNA (miRNA)-21 is a biomarker for acute kidney injury (AKI). We conducted this study to determine if a urinary exosomal analysis for this biomarker could serve as a novel diagnostic approach for detecting kidney disease. Materials and Methods: We investigated the clinical significance of urinary exosomal miRNA-21 levels for AKI in scrub typhus patients. We collected 138 urine samples from scrub typhus patients at the time of admission. Urinary exosomal miRNA-21 was assessed in 25 age- and sex-matched scrub typhus patients with and without AKI. Results: The total leukocyte count was higher in AKI patients than in non-AKI patients (10.40 × 10³/mL vs. 6.40 × 10³/mL, p < 0.01). Urinary exosomal miRNA-21 levels were higher in the AKI group than in the non-AKI group (20.1 ± 1.2 vs. 17.8 ± 1.8 ΔCt value of miRNA-21, p < 0.01). Additionally, the miRNA-21 levels correlated directly with the total leukocyte counts and inversely with the estimated glomerular filtration rate. A receiver operating characteristic curve analysis demonstrated good discriminative power for the diagnosis of scrub typhus-associated AKI, with an area under the curve value of 0.907. Conclusion: Urinary exosomal miRNA-21 could be a surrogate marker for scrub typhus-associated AKI diagnosis.

Clinical and biochemical profile of scrub typhus patients at a tertiary care hospital in Northern India

Background

Scrub typhus is a neglected rickettsial disease in India. Every year, we are facing outbreaks of Scrub typhus after Monsoon season. Patients present with a wide clinical spectrum ranging from pyrexia of unknown origin to multiple organ dysfunction. Some of these clinical features overlap with presentation of other tropical infections prevalent in Indian subcontinent, which leads to diagnostic dilemma and delay in diagnosis. Hence, we planned this study to know the demographic, clinical and biochemical profile of scrub typhus patients.

Methods

This was an observational study conducted in department of Medicine, King George's Medical University Lucknow, India a leading tertiary care hospital of Northern India. All scrub typhus patients were evaluated by detailed history, examination and laboratory tests.

Results

We enrolled 52 patients in our study. The mean age of the patients was 35.17 ± 16.90 years with majority (82.7%) of patients from rural background. All the patients had fever with an average duration of 9.6 ± 2 days. Most of the patients developed hepatitis (69.2%) followed by acute encephalitis syndrome (47%), acute kidney injury (23.1%) and acute respiratory failure (19.2%). Eschar was found in 11 patients (21.2%).

Conclusion

Scrub typhus is often misdiagnosed or diagnosed late due to its wide clinical spectrum overlapping with clinical presentation of other commonly prevalent tropical diseases. One should always consider the differential diagnosis of scrub typhus while evaluating a young febrile patient of rural background, with features of single or multiple organ dysfunction and laboratory findings of leucocytosis, thrombocytopenia and elevation of transaminases.

Clinical significance of hypoalbuminemia in patients with scrub typhus complicated by acute kidney injury

Background

This study aimed to investigate the clinical significance of hypoalbuminemia (HA) in patients with scrub typhus complicated by acute kidney injury (AKI).

Methods

From 2009 to 2018, 611 patients were diagnosed with scrub typhus. We divided the patients into two groups [normoalbuminemia (NA) vs. HA] based on the serum albumin level of 3.0 g/dL and compared the incidence, clinical characteristics, and severity of AKI based on the RIFLE classification between the two groups.

Results

Of the total 611 patients, 78 (12.8%) were categorized into the HA group. Compared to patients in the NA group, patients in the HA group were older (73 ± 9 vs. 62 ± 14 years, P<0.001). The HA group had a significantly longer hospital stay (9.6 ± 6.2 vs 6.2 ± 3.1 days, p<0.001) and a higher incidence of complications in respiratory and cardiovascular systems. Furthermore, AKI developed significantly more in patients in the HA group (58% vs. 18%, p<0.001) as compared to the NA group. The overall incidence of AKI was 23.1%; of which, 14.9%, 7.0%, and 1.2% of cases were classified as Risk, Injury, and Failure, respectively. The serum albumin level correlated with AKI severity (3.4 ± 0.5 vs 3.0 ± 0.5 vs 2.6 ± 0.3, p<0.05). In a multivariate logistic regression analysis for predicting AKI, age, presence of co-morbidities such as chronic kidney disease, total bilirubin, leukocytosis, and hypoalbuminemia were significant predictors for AKI.

Conclusion

Serum albumin level is helpful to predict the development and severity of scrub typhus-associated AKI.