A performance comparison between fluorescent immunoassay and immunochromatography for rapid dengue detection in clinical specimens.

Dengue virus (DENV 1-4) infection has been a global health threat where no specific treatment is currently available. Therefore, a rapid and accurate diagnosis is critical for an appropriate management as it could reduce the burden of severe clinical manifestation. Currently, dengue immunochromatography (IC) is commonly used to primarily differentiate acute febrile illnesses. Fluorescent immunoassay (FIA) utilized a highly sensitive detection system and claimed 70-100% sensitivity and 83.5-91.7% specificity for dengue infection in a preliminary report. This report recruited samples with acute febrile illnesses sent for dengue screening and tested IC and FIA in parallel. The performance of both tests was verified by a definitive diagnosis retrieved from combinatorial reverse transcription-quantitative polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) for IgM and IgG confirmation tests. Results showed that the viral nonstructural protein (NS1) performance of FIA was slightly higher than IC with the sensitivity, specificity, PPV, NPV, agreement, kappa, and its standard error at 79.11, 92.28, 86.81, 87.31, 352 (87.13%), 0.725 ± 0.035, respectively; whereas those of the IC were at 76.58, 92.28, 86.43, 85.98, 348 (86.14%), 0.703 ± 0.037, respectively. Moreover, the IgM and IgG performance of FIA had higher specificity, PPV, and agreement than the IgM IC performance, suggesting that the FIA was more specific but less sensitive for antibody detection. No correlation was observed in IgM and IgG levels of ELISA and FIA assays. In conclusion, the FIA and IC were highly sensitive, specific, and substantially agreed in NS1 detection but moderately agreed in IgM and IgG detection.

Hospital epidemiology and antimicrobial susceptibility of isolated methicillin-resistant Staphylococcus aureus: a one-year retrospective study at a tertiary care center in Thailand.

BACKGROUND: Increased rates of Staphylococcus aureus resistance and its morbidity and mortality have raised concern about the strategy of antibiotic use. OBJECTIVES: This study aimed to determine the prevalence of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) isolates among Thai patients with S. aureus infection and to identify risk factors and appropriate antibiotics for these resistant strains. METHODS: Data of culture-proven S. aureus isolates from clinical specimens during 2017 in King Chulalongkorn Memorial Hospital, Thailand, were retrospectively collected and classified as methicillin-sensitive S. aureus or MRSA by cefoxitin screening and oxacillin minimum inhibitory concentration by the Vitek 2 system. Each isolate was also tested for susceptibility to teicoplanin, erythromycin, clindamycin, linezolid, trimethoprim/sulfamethoxazole, ciprofloxacin, moxifloxacin, tetracycline, doxycycline, and vancomycin by Vitek 2. Demographic information and comorbidities from medical records were reviewed to identify risk factors for S. aureus infection. RESULTS: MRSA isolates were identified in 147 (17%) of 890 patients with no different ratio in adults or children. A higher proportion of MRSA in hospital-acquired settings was observed (27% vs. 12%; p < 0.001). Comorbidities significantly associated with MRSA were chronic lung, cardiovascular, and neurological diseases. Atrial fibrillation, dementia, and benign prostatic hyperplasia were independently associated with MRSA isolation. Vancomycin was still susceptible to all kinds of infection. One VRSA isolate was from colonization. CONCLUSION: The prevalence of MRSA in our facility seemed to be comparatively low. Vancomycin is still an appropriate option for MRSA coverage since all S. aureus isolates in our center were sensitive to vancomycin. However, careful attention is warranted since one colonization isolate was VRSA.