New-onset atrial fibrillation predicting for complicating cardiac adverse outcome in scrub typhus infection

Cardio-cerebrovascular adverse outcomes in patients with influenza with and without preexisting cardiovascular disease: Oral antiviral agents impact

This study aimed to compare the 2-year cardio-cerebrovascular adverse outcomes of patients with influenza with and without preexisting cardiovascular disease (preCVD) treated with oral antiviral agents in the outpatient clinic. Oral antiviral agents are routinely prescribed to treat influenza infection with a positive rapid-antigen test in the outpatient clinic; however, influenza-associated cardio-cerebrovascular outcomes have not yet been characterized in patients with preCVD treated with oral antiviral agents. Data between 2006 and 2016 were extracted from the National Health Database of South Korea. A total of 865,522 patients with influenza treated with oral antiviral agents were selected in South Korea and classified as preexisting ischemic heart disease (IHD), heart failure (HF), or atrial fibrillation (AF), and 2-year cardio-cerebrovascular outcomes were analyzed using a Cox proportional hazard regression model. Among the participants, 96,433 had preCVD (11.1%; mean age, 46 years) including IHD (86.4%), HF (23.1%), and AF (12.5%). The incidence of new-onset IHD, AF, HF, and death was similar between patients with influenza with and without preCVD. The incidences of IHD and stroke were 0.489 and 0.047 per 100-person year in the preCVD group, respectively. The incidence of cardiovascular mortality was 0.489 per 100-person year in the preCVD group, and the hazard ratio for cardiovascular mortality in the preCVD group was not significantly different from that in patients without preCVD. Based on the national health data, 2-year cardio-cerebrovascular adverse outcomes were not significantly different between patients with and without preCVD treated with oral antiviral agents.

Identification of novel variants for complicating cardiac disease in the scrub typhus infection using whole genome sequencing

BACKGROUND/AIMS

Scrub typhus infection has been known to complicate cardiovascular diseases mainly attributing to high mortality. Genetic susceptibility loci for complicating cardiac diseases such as atrial fibrillation, heart failure, and ischemic heart disease identified by genomic study have been limited in scrub typhus infection. Therefore, we investigated the genetic novel variants predicting complicating cardiac diseases in patients with confirmed scrub typhus infection using whole genome sequencing.

METHODS

We performed a prospective study for eight consecutive patients with scrub typhus infection. During follow-up, six cases were clinically diagnosed with complicating cardiac diseases and two controls without complicating cardiac diseases. The whole genomes of the all patients were sequenced, and the individual sequence variants were compared between accordcase and control patients. Variant genotypes were compared and identified as a single nucleotide polymorphism (SNP) of the different genotype distributions between six cases and two controls.

RESULTS

The GG genotype in SNP (rs4977397) of solute carrier 24 family member 2 (SLC24A2) gene and non-TT genotype in SNP (rs2676750) of adenosine deaminase, RNA specific, B2 (ADARB2) gene were distinctively found in the case patients with complicated cardiac disease, compared with control patents in the scrub typhus infection.

CONCLUSION

We suggest that the SNPs of SLC24A2 and ADARB2 might be genetic surrogate markers for complicating cardiac diseases in the scrub typhus infection. Our study show that early detection based on individual sequence variants might be feasible to predict complicating cardiac diseases in patients with scrub typhus infection, if further studies with more participants confirm these findings.

Multifaceted realities of scrub typhus: a case series from southern India

Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi, a Gram-negative bacillus, commonly occurring in the Asia-Pacific region. It is transmitted to humans by the bite of an infected Leptotrombidium mite and the bacterium causes endothelial dysfunction resulting in widespread vasculitis and the possible development of thrombocytopenia, meningitis, acute respiratory distress syndrome, and infrequently, myocarditis. Early diagnosis and prompt treatment are crucial in managing scrub typhus. Here, we present four cases of scrub typhus with a comprehensive literature review. This study highlights the significance of considering scrub typhus as a possible diagnosis in patients of all ages from endemic regions who exhibit symptoms such as fever, thrombocytopenia, or transaminitis, even in the absence of typical clinical features. Two cases exhibited the characteristic lesion of eschar at the site of mite feeding. One case involved a middle-aged woman who was diagnosed with typhus-induced myocarditis with left ventricular dysfunction. Another case involved a 23-day-old neonate with poor feeding and seizures, who was diagnosed with late-onset sepsis with meningitis. Scrub typhus was confirmed in all cases using a positive qualitative IgM ELISA. However, it is preferred to use paired (ELISA before and after antibiotic therapy) or quantitative titers for confirmation. Healthcare providers must consider the patient's exposure history and clinical presentation to diagnose and treat scrub typhus promptly.

Treatment outcomes of oral doxycycline versus intravenous azithromycin in adults hospitalized with scrub typhus: A retrospective study using inverse probability treatment weighting (IPTW) propensity analysis

OBJECTIVE

Only a few well-designed studies that have investigated the effectiveness of azithromycin in treating adult patients hospitalized with scrub typhus are currently available. The purpose of our study was to compare the effects of intravenous azithromycin administration with those of oral doxycycline, and to evaluate cardiovascular death associated with intravenous azithromycin in adult patients hospitalized with scrub typhus.

METHODS

This retrospective study investigated Korean National Infectious Disease Cohort Collaborative-registered scrub typhus-infected patients who were hospitalized between January 1, 2013, and December 31, 2021, and who were ≥18 years old. The primary outcome was time to fever clearance and the secondary outcomes were treatment failure, relapse, scrub typhus-related death, or azithromycin-related cardiovascular death. To address any indication bias, inverse probability of treatment weighting (IPTW) analysis was performed. Times to fever clearance between the doxycycline and azithromycin groups were compared using log-rank tests and Kaplan-Meier curves.

RESULTS

A total of 326 consecutive patients with laboratory-confirmed scrub typhus were included in this study of whom 109 were treated with azithromycin and 217 with doxycycline. Using IPTW, there were no statistically significant differences in the following end points between the azithromycin and doxycycline groups: median time to fever clearance (3 days vs. 3 days, P = 0.649), treatment failure (0.71% vs. 0.42%, P = 0.702), relapse (0.0% vs. 0.0%), and scrub typhus-related death (5.12% vs. 0.0%, P = 0.155). No azithromycin-related cardiovascular deaths occurred. In the sensitivity analyses, there were no significant changes in effect size.

CONCLUSIONS

Our study showed that the therapeutic effects and safety of intravenous azithromycin are comparable to those of oral doxycycline administration in patients hospitalized with scrub typhus. A well-designed randomized controlled trial may help further evaluate the most adequate route of administration, dose and duration of treatment with azithromycin.

Atrial Fibrillation in Scrub Typhus: A Series of Four Cases

Scrub typhus, also known as bush typhus, is an acute febrile zoonosis caused by Orientia tsutsugamushi, transmitted by the bite of chigger mite. Patients with scrub typhus can have many different presentations such as acute hearing loss, interstitial pneumonitis, acute respiratory distress syndrome, myocarditis, pericarditis, meningoencephalitis, acute renal failure, acute hepatic failure, and septic shock. The occurrence of multi-organ dysfunction is responsible for high mortality seen in scrub typhus patients. Cardiovascular involvement can also occur in the form of arrhythmia, which leads to an increase in mortality in these patients, and if associated with ischemic heart disease and acute heart failure, it leads to higher mortality. The early use of antibiotics and telemetry monitoring along with aggressive management of patients can decrease the complications and mortality seen in these patients. This study describes a series of four scrub typhus patients with new-onset atrial fibrillation who were managed with either direct current (DC) cardioversion, amiodarone, or diltiazem.

Scrub typhus manifesting as electrocardiographic disturbance: A case report and review of literature

Scrub typhus (ST) has wide organ system involvement, but cardiac involvement is paramount in this spectrum due to early hemodynamic compromise. Various forms of cardiac involvement have been described in the literature, but we are describing rare electrocardiographic changes in the ST infection. A young male presented in our emergency department with complaints of restlessness and vomiting of 2 days’ duration. The patient was having stable vitals on presentation, but his electrocardiogram (ECG) demonstrated second-degree atrioventricular block type 1 (also known Mobitz 1) and Osborn wave in the precordial leads. Further, he was having thrombocytopenia and eventually diagnosed with ST. For this, appropriate antibiotic treatment was given, which led to considerable symptomatic improvement and reversal of the ECG changes.

New-onset atrial fibrillation predicting for complicating cardiac adverse outcome in scrub typhus infection

BACKGROUND

Scrub typhus is a well-known infectious disorder of the Asia-Pacific region. However, adverse cardiac outcomes are an under-recognized complication of scrub typhus infection, and new-onset AF has been reported to be a prognostic factor in other, more common infectious diseases. The present study investigated whether new-onset atrial fibrillation (AF) is significantly associated with 3-month mortality and adverse cardiac complications in scrub typhus infection.

METHODS

We examined data from the National Health Information Database (NHID) which covers nearly the entire population of South Korea, from 2006 to 2016. In total, 233 473 patients diagnosed with scrub typhus infection were selected as study participants. New-onset AF, acute heart failure (AHF), ischemic heart disease (IHD), and 3-month mortality were analyzed using a generalized estimating equation model with a Poisson distribution.

RESULTS

Of these, 2402 patients (1%) were diagnosed with new-onset AF (87.2% were over 60 years of age, 43.3% were male). Those with new-onset AF were more likely to have underlying cardiovascular disease compared to those without new-onset AF. After being adjusted for demographic factors and comorbidities, those with new-onset AF had a higher incidence risk of concurrent AHF (4.1-fold) and IHD (1.9-fold) compared with those without new-onset AF. In particular, the 3-month mortality was also significantly associated with new-onset AF (1.3-fold), concurrent AHF (2.4-fold), and IHD (13.7-fold).

CONCLUSIONS

New-onset AF was significantly associated with 3-month mortality and concurrent AHF and IHD. Therefore, new-onset AF could be a poor prognostic factor for 3-month mortality and cardiac complications in scrub typhus infection.