The Diagnosis of Severe Fever with Thrombocytopenia Syndrome Using Metagenomic Next-Generation Sequencing: Case Report and Literature Review

The first diagnosis of Severe Fever with Thrombocytopenia Syndrome caused by tick-borne Severe Fever with Thrombocytopenia Syndrome virus in Chongqing, China: A case report and literature review

BACKGROUND

Severe Fever with Thrombocytopenia Syndrome (SFTS) is a tick-borne disease caused by the SFTS virus (SFTSV) which has the potential to become a pandemic and is currently a major public health concern.

CASE PRESENTATION

We present the case of a 74-year-old female from an urban area of Chongqing, with leukocytopenia, thrombocytopenia, organ function, inflammatory, blood coagulation, and immune abnormalities. SFTSV infection was confirmed through molecular detection and metagenomic next-generation sequencing (mNGS) analysis, indicating a diagnosis of SFTS due to the patient's history of tick bites. The patient received symptomatic and supportive therapy, including antibiotics, antiviral treatment, and antifungal therapy, and finally discharged from the hospital on day 18.

CONCLUSIONS

This study highlights the need for increased awareness, early diagnosis, and prompt treatment for tick-borne SFTS. It also provides a comprehensive understanding of the disease's characteristics, pathogenesis, detection methods, and available treatments.

Application of metagenomic next-generation sequencing technology in the etiological diagnosis of peritoneal dialysis-associated peritonitis

Pathogens detected by metagenomic next-generation sequencing (mNGS) and the laboratory blood culture flask method were compared to understand the advantages and clinical significance of mNGS assays in the etiological diagnosis of peritoneal dialysis-associated peritonitis (PDAP). The study involved a total of 37 patients from the hospital's peritoneal dialysis centre, six of whom were patients with non-peritoneal dialysis-associated peritonitis. Peritoneal dialysis samples were collected from the 37 patients, who were divided into two groups. One group's samples were cultured using conventional blood culture flasks, and the other samples underwent pathogen testing using mNGS. The results showed that the positive rate of mNGS was 96.77%, while that of the blood culture flask method was 70.97% (p < 0.05). A total of 29 pathogens were detected by mNGS, namely 24 bacteria, one fungus, and four viruses. A total of 10 pathogens were detected using the bacterial blood culture method, namely nine bacteria and one fungus. The final judgment of the PDAP's causative pathogenic microorganism was made by combining the clinical condition, response to therapy, and the whole-genome sequencing findings. For mNGS, the sensitivity was 96.77%, the specificity was 83.33%, the positive predictive value was 96.77%, and the negative predictive value was 83.33%. For the blood culture flask method, the sensitivity was 70.97%, the specificity was 100%, the positive predictive value was 100%, and the negative predictive value was 0%. In conclusion, mNGS had a shorter detection time for diagnosing peritoneal dialysis-related peritonitis pathogens, with a higher positive rate than traditional bacterial cultures, providing significant advantages in diagnosing rare pathogens.

Diagnostic value of metagenomic next-generation sequencing in sepsis and bloodstream infection

Objective

To evaluate the diagnostic value of metagenomic next-generation sequencing (mNGS) in sepsis and bloodstream infection (BSI).

Methods

A retrospective analysis of patients diagnosed with sepsis and BSI at the First Affiliated Hospital of Zhengzhou University from January 2020 to February 2022 was conducted. All the patients underwent blood culture and were divided into mNGS group and non-mNGS group according to whether mNGS was performed or not. The mNGS group was further divided into early group (< 1 day), intermediate group (1-3 days), and late group (> 3 days) according to the time of mNGS inspection.

Results

In 194 patients with sepsis and BSI, the positive rate of mNGS for identifying pathogens was significantly higher than that of blood culture (77.7% vs. 47.9%), and the detection period was shorter (1.41 ± 1.01 days vs. 4.82 ± 0.73 days); the difference was statistically significant (p < 0.05). The 28-day mortality rate of the mNGS group (n = 112) was significantly lower than that of the non-mNGS group (n = 82) (47.32% vs. 62.20%, p = 0.043). The total hospitalization time for the mNGS group was longer than that for the non-mNGS group (18 (9, 33) days vs. 13 (6, 23) days, p = 0.005). There was no significant difference in the ICU hospitalization time, mechanical ventilation time, vasoactive drug use time, and 90-day mortality between the two groups (p > 0.05). Sub-group analysis of patients in the mNGS group showed that the total hospitalization time and the ICU hospitalization time in the late group were longer than those in the early group (30 (18, 43) days vs. 10 (6, 26) days, 17 (6, 31) days vs. 6 (2, 10) days), and the ICU hospitalization time in the intermediate group was longer than that in the early group (6 (3, 15) days vs. 6 (2, 10) days); the differences were statistically significant (p < 0.05). The 28-day mortality rate of the early group was higher than that of the late group (70.21% vs. 30.00%), and the difference was statistically significant (p = 0.001).

Conclusions

mNGS has the advantages of a short detection period and a high positive rate in the diagnosis of pathogens causing BSI and, eventually, sepsis. Routine blood culture combined with mNGS can significantly reduce the mortality of septic patients with BSI. Early detection using mNGS can shorten the total hospitalization time and the ICU hospitalization time of patients with sepsis and BSI.

Early detection of gram‑negative bacteria using metagenomic next‑generation sequencing in acute respiratory distress syndrome: A case report

Metagenomic next-generation sequencing (mNGS) is an effective method that can be used for the identification of early pathogens in patients with suspected severe pneumonia. However, the potential of mNGS for evaluating the prognosis of acute respiratory distress syndrome (ARDS) in patients with severe pneumonia remains unclear. In the present report, hospital-acquired gram-negative bacteria infections were detected in a case using metagenomic next-generation sequencing (mNGS) in a sample of bronchoalveolar fluid. This was obtained from a 58-year-old male patient with traumatic wet lung after a neurosurgery. According to the results, of which the profiles of the resistance genes were detected by mNGS, drugs designed to control infection were adjusted, namely to polymyxin B (500,000 U/12 h), azithromycin (0.5 g/24 h) and ganciclovir (0.25 g/12 h). Following adjusting treatment for 8 days, the symptoms of lung infection and hypoxemia were markedly improved, resulting in the patient being transferred out of the intensive care unit 15 days after treatment. To conclude, observations from the present report suggest that mNGS is a useful method for the early identification of pathogens in patients with pneumonia caused by ARDS. However, further studies are required to identify the complementary role of mNGS in supporting conventional microbiological methods in routine clinical practice.

Clinical Application and Influencing Factor Analysis of Metagenomic Next-Generation Sequencing (mNGS) in ICU Patients With Sepsis

Objective

To analyze the clinical application and related influencing factors of metagenomic next-generation sequencing (mNGS) in patients with sepsis in intensive care unit (ICU).

Methods

The study included 124 patients with severe sepsis admitted to the ICU in the First Affiliated Hospital of Zhengzhou University from June 2020 to September 2021. Two experienced clinicians took blood mNGS and routine blood cultures of patients meeting the sepsis diagnostic criteria within 24 hours after sepsis was considered, and collection the general clinical data.

Results

mNGS positive rate was higher than traditional blood culture (67.74% vs. 19.35%). APACHE II score [odds ratio (OR)=1.096], immune-related diseases (OR=6.544), and hypertension (OR=2.819) were considered as positive independent factors for mNGS or culture-positive. The sequence number of microorganisms and pathogen detection (mNGS) type had no effect on prognosis. Age (OR=1.016), female (OR=5.963), myoglobin (OR=1.005), and positive virus result (OR=8.531) were independent risk factors of sepsis mortality. Adjusting antibiotics according to mNGS results, there was no statistical difference in the prognosis of patients with sepsis.

Conclusion

mNGS has the advantages of rapid and high positive rate in the detection of pathogens in patients with severe sepsis. Patients with high APACHE II score, immune-related diseases, and hypertension are more likely to obtain positive mNGS results. The effect of adjusting antibiotics according to mNGS results on the prognosis of sepsis needs to be further evaluated.