Characteristics and Outcomes of Patients with Pulmonary Acute Respiratory Distress Syndrome Infected with Influenza versus Other Respiratory Viruses / 결핵

BACKGROUND: Although the frequency of respiratory viral infection in patients with pulmonary acute respiratory distress syndrome (ARDS) is not uncommon, clinical significance of the condition remains to be further elucidated. The purpose of this study was to compare characteristics and outcomes of patients with pulmonary ARDS infected with influenza and other respiratory viruses. METHODS: Clinical data of patients with pulmonary ARDS infected with respiratory viruses January 2014–June 2018 were reviewed. Respiratory viral infection was identified by multiplex reverse transcription–polymerase chain reaction (RT-PCR). RESULTS: Among 126 patients who underwent multiplex RT-PCR, respiratory viral infection was identified in 46% (58/126): 28 patients with influenza and 30 patients with other respiratory viruses. There was no significant difference in baseline and clinical characteristics between patients with influenza and those with other respiratory viruses. The use of extracorporeal membrane oxygenation (ECMO) was more frequent in patients with influenza than in those with other respiratory viruses (32.1% vs 3.3%, p=0.006). Co-bacterial pathogens were more frequently isolated from respiratory samples of patients with pulmonary ARDS infected with influenza virus than those with other respiratory viruses. (53.6% vs 26.7%, p=0.036). There were no significant differences regarding clinical outcomes. In multivariate analysis, acute physiology and chronic health evaluation II was associated with 30-mortality (odds ratio, 1.158; 95% confidence interval, 1.022–1.312; p=0.022). CONCLUSION: Respiratory viral infection was not uncommon in patients with pulmonary ARDS. Influenza virus was most commonly identified and was associated with more co-bacterial infection and ECMO therapy.

Comparison of multiplex RT‑PCR and real‑time HybProbe assay for serotyping of dengue virus using reference strains and clinical samples from India.

Background: Dengue virus serotyping is crucial from clinical management and epidemiological point of view. Aims: To compare efficacy of two molecular detection and typing methods, namely, multiplex reverse transcription polymerase chain reaction (RT‑PCR) and real‑time Hybprobe assay using a panel of known dilution of four reference Dengue virus strains and a panel of sera collected from clinically suspected dengue patients. Settings: This study was conducted at a tertiary‑care teaching hospital in Delhi, India. Materials and Methods: Dengue serotype specific virus strains were used as prototypes for serotyping assays. Viral load was quantified by quantitative real time reverse transcription polymerase chain reaction (qRT‑PCR). Acute phase serum samples were collected from 79 patients with clinically suspected Dengue fever on their first day of presentation during September‑October 2012. Viral RNA from serum and cell culture supernatant was extracted. Reverse transcription was carried out. Quantitative detection of DENV RNA from reference strain culture supernatants and each of the 79 patient samples by real‑time PCR was performed using light cycler Taqman master mix kit. Serotyping was done by multiplex RT‑PCR assay and Hybprobe assay. Results: The multiplex RT‑PCR assay, though found to be 100% specific, couldn’t serotype either patient or reference strains with viral load less than 1000 RNA copies/ml. The Hybprobe assay was found to have 100% specificity and had a lower limit of serotype detection of merely 3.54 RNA copies/ml. Conclusions: HybProbe assay has an important role especially in situations where serotyping is to be performed in clinical samples with low viral load.

Studies on simultaneous detection of four foodborneviruses by multiplex reverse transcription-polymerase chain reaction / 中华流行病学杂志

Objective To establish a method for simultaneous detection of norovirus (NV),rotavirus (RV), astrovirus (AV) and hepatitis A virus (HAV) by multiplex reverse transcriptionpolymerase chain reaction (RT-PCR). Methods Specific primers of the four viruses were designed based on the high conserved sequences, the reaction system and conditions optimized and the specificity and sensitivity confirmed. The method was then applied to detect the four viruses in clinical samples. Results The steady detection limits were 100 pg/ml for hepatitis A virus, 50 pg/ml for rotavirus, norovirus and astrovirus respectively. When the developed method was used to detect clinical fecal samples, 62(48.44%)were iden tified as rotavirus, 8 (6.25%) as norovirus, 11 (8.59%) as astrovirus and 4 (3.12%) as hepatitis A virus in a total of 128 samples. Conclusion Data from our study showed that multiplex RTPCR system could be used to simultaneously detect the four viruses in routine monitoring and risk assessment in disease outbreaks with high specificity and sensitivity.