METHODS: This prospective cross-sectional study consecutively recruited 494 patients with suspected dengue from a health clinic in Malaysia. Both RDTs were performed onsite. The evaluated ELISA and reference tests were performed in a virology laboratory. The reference tests comprised of a reverse transcription-polymerase chain reaction and three ELISAs for the detection of dengue NS1 antigen, IgM and IgG antibodies, respectively. The diagnostic performance of evaluated tests was computed using STATA version 12.
RESULTS: The sensitivity and specificity of ViroTrack were 62.3% (95%CI 55.6-68.7) and 95.0% (95%CI 91.7-97.3), versus 66.5% (95%CI 60.0-72.6) and 95.4% (95%CI 92.1-97.6) for SD NS1 ELISA, and 52.4% (95%CI 45.7-59.1) and 97.7% (95%CI 95.1-99.2) for NS1 component of SD Bioline, respectively. The combination of the latter with its IgM and IgG components were able to increase test sensitivity to 82.4% (95%CI 76.8-87.1) with corresponding decrease in specificity to 87.4% (95%CI 82.8-91.2). Although a positive test on any of the NS1 assays would increase the probability of dengue to above 90% in a patient, a negative result would only reduce this probability to 23.0-29.3%. In contrast, this probability of false negative diagnosis would be further reduced to 14.7% (95%CI 11.4-18.6) if SD Bioline NS1/IgM/IgG combo was negative.
CONCLUSIONS: The performance of ViroTrack Dengue Acute was comparable to SD Dengue NS1 Ag ELISA. Addition of serology components to SD Bioline Dengue Duo significantly improved its sensitivity and reduced its false negative rate such that it missed the fewest dengue patients, making it a better point-of-care diagnostic tool. New RDT like ViroTrack Dengue Acute may be a potential alternative to existing RDT if its combination with serology components is proven better in future studies.
METHODS: We established a multi-country cross-sectional dataset of first available quantitative HCV RNA linked to demographic and clinical data. We excluded individuals on HCV treatment. We analyzed the distribution of HCV RNA and determined critical thresholds for detection of HCV viraemia. We then performed logistic regression to evaluate factors associated with LLV, and derived relative sensitivities for significant covariates.
RESULTS: The dataset included 66,640 individuals with HCV viraemia from Georgia (44.4%), Canada (40.9%), India (8.1%), Cambodia (2.6%), Egypt (1.6%), Pakistan (1.3%), Cameroon (0.4%), Indonesia (0.2%), Thailand (0.2%), Vietnam (0.1%), Malaysia (0.05%), and Mozambique (0.02%). The 97% LOD was 1,318 IU/mL (95% CI 1298.4, 1322.3). Factors associated with LLV were younger age 18-30 vs. 51-64 years (OR 2.56 95% CI 2.19, 2.99), female vs. male sex (OR 1.32, 95% CI 1.18, 1.49), and advanced fibrosis stage F4 vs. F0-1 (OR 1.44, 95%CI 1.21, 1.69). Only the younger age group had a decreased relative sensitivity below 95% at 93.3%.
CONCLUSIONS: In this global dataset, a test with an LOD of 1,318 IU/mL would identify 97% of viraemic HCV infections among almost all populations. This LOD will help guide manufacturers in the development of affordable POC diagnostics to expand HCV testing and linkage to care in LMICs.
LAY SUMMARY: We created and analyzed a dataset from 12 countries with 66,640 participants with chronic hepatitis C virus infection. We determined that about 97% of those with viraemic infection had 1300 International Units/mL or more of circulating virus at the time of diagnosis. While current diagnostic tests can detect as little as 12 International Units/mL of virus, our findings suggest that increasing the level of detection closer to 1300 would maintain good test accuracy and will likely allow for more affordable portable tests to be developed for use in low and middle income countries.
CASE PRESENTATION: A 23-year-old trauma patient with closed fracture of left femoral shaft and left humerus presented to our emergency department (ED). 11 h after admission to ED, patient became confused, hypoxic and hypotensive. He was then intubated for respiratory failure and mechanically ventilated. Transesophageal ultrasound revealed hyperdynamic heart, dilated right ventricle with no regional wall abnormalities and no major aorta injuries. Whole-body computed tomography was normal. During central venous cannulation of right internal jugular vein (IJV), we found free floating mobile hyperechoic spots, located at the anterior part of the vein. A diagnosis of fat embolism syndrome later was made based on the clinical presentation of long bone fractures and fat globulin in the blood. Despite aggressive fluid resuscitation, patient was a non-responder and needed vasopressor infusion for persistent shock. Blood aspirated during cannulation from the IJV revealed a fat globule. Patient underwent uneventful orthopedic procedures and was discharged well on day 5 of admission.
CONCLUSIONS: Point-of-care ultrasound findings of fat embolism in central vein can facilitate and increase the suspicion of fat embolism syndrome.
OBJECTIVE: Our aim was to create and describe a homemade, high-fidelity ultrasound phantom model for demonstrating pneumonia with pleural effusions for teaching purposes.
DISCUSSION: An ultrasound phantom was constructed using a water-filled latex glove with a sliver of meat in it, covered over by a palm-sized piece of meat (skin and ribs are optional to increase ultrasonographic details and realism). This would appear like parapneumonic effusions with organized pneumonia under ultrasound examination. Creamer (or talc) can be added to the water in the glove to simulate empyema. The model can also be used to teach simple effusions and for ultrasound-guided thoracentesis and in clinical decision making.
CONCLUSIONS: Easily prepared, homemade high-fidelity ultrasound phantom models for instructions on identification of pleural effusions and ultrasound-guided pleural tap of parapneumonic effusion were made.
METHODS: The POCT was used to test 170 serum specimens collected through measles surveillance or vaccination programmes in Ethiopia, Malaysia and the Russian Federation: 69 were positive for measles immunoglobulin M (IgM) antibodies, 74 were positive for rubella IgM antibodies and 7 were positive for both. Also tested were 282 oral fluid specimens from the measles, mumps and rubella (MMR) surveillance programme of the United Kingdom of Great Britain and Northern Ireland. The Microimmune measles IgM capture enzyme immunoassay was the gold standard for comparison. A panel of 24 oral fluids was used to investigate if measles virus haemagglutinin (H) and nucleocapsid (N) genes could be amplified by polymerase chain reaction directly from used POCT strips.
FINDINGS: With serum POCT showed a sensitivity and specificity of 90.8% (69/76) and 93.6% (88/94), respectively; with oral fluids, sensitivity and specificity were 90.0% (63/70) and 96.2% (200/208), respectively. Both H and N genes were reliably detected in POCT strips and the N genes could be sequenced for genotyping. Measles virus genes could be recovered from POCT strips after storage for 5 weeks at 20-25 °C.
CONCLUSION: The POCT has the sensitivity and specificity required of a field-based test for measles diagnosis. However, its role in global measles control programmes requires further evaluation.