Evaluation of Luminex xTAG Gastrointestinal Pathogen Panel Assay for Detection of Multiple Diarrheal Pathogens in Fecal Samples in Vietnam.

Diarrheal disease is a complex syndrome that remains a leading cause of global childhood morbidity and mortality. The diagnosis of enteric pathogens in a timely and precise manner is important for making treatment decisions and informing public health policy, but accurate diagnosis is a major challenge in industrializing countries. Multiplex molecular diagnostic techniques may represent a significant improvement over classical approaches. We evaluated the Luminex xTAG gastrointestinal pathogen panel (GPP) assay for the detection of common enteric bacterial and viral pathogens in Vietnam. Microbiological culture and real-time PCR were used as gold standards. The tests were performed on 479 stool samples collected from people admitted to the hospital for diarrheal disease throughout Vietnam. Sensitivity and specificity were calculated for the xTAG GPP for the seven principal diarrheal etiologies. The sensitivity and specificity for the xTAG GPP were >88% for Shigellaspp.,Campylobacterspp., rotavirus, norovirus genotype 1/2 (GI/GII), and adenovirus compared to those of microbiological culture and/or real-time PCR. However, the specificity was low (∼60%) for Salmonella species. Additionally, a number of important pathogens that are not identified in routine hospital procedures in this setting, such as Cryptosporidiumspp. and Clostridium difficile, were detected with the GPP. The use of the Luminex xTAG GPP for the detection of enteric pathogens in settings, like Vietnam, would dramatically improve the diagnostic accuracy and capacity of hospital laboratories, allowing for timely and appropriate therapy decisions and a wider understanding of the epidemiology of pathogens associated with severe diarrheal disease in low-resource settings.

Tracking the establishment of local endemic populations of an emergent enteric pathogen.

Shigella sonnei is a human-adapted pathogen that is emerging globally as the dominant agent of bacterial dysentery. To investigate local establishment, we sequenced the genomes of 263 Vietnamese S. sonnei isolated over 15 y. Our data show that S. sonnei was introduced into Vietnam in the 1980s and has undergone localized clonal expansion, punctuated by genomic fixation events through periodic selective sweeps. We uncover geographical spread, spatially restricted frontier populations, and convergent evolution through local gene pool sampling. This work provides a unique, high-resolution insight into the microevolution of a pioneering human pathogen during its establishment in a new host population.

Is a cell saver necessary in off-pump coronary artery bypass surgery?

BACKGROUND: Off-pump coronary artery bypass surgery should have a significantly lower risk of postoperated bleeding than on-pump surgery. However, the use of a cell saver has been considered necessary, with significant additional cost incurred. Can we consider performing off-pump coronary artery bypass surgery without a cell saver? PATIENTS AND METHODS: A prospective observational study was performed in 68 consecutive patients operated on for 2- or 3-vessel coronary lesions by the off-pump technique. RESULTS: The mean number of distal anastomoses was 2.7 ± 0.7. Both internal thoracic arteries were used in 45 patients, and sequential revascularization was performed in 27, with 140 (77.8%) arterial grafts. Cell savers were used in 21 (30.9%) patients. In these 21 patients, the mean volume retransfused after treatment was 315 ± 177 mL. Postoperatively, 11 (16.2%) patients were transfused with packed red blood cells, with a mean volume of 636 ± 234 mL per patient. The 2 factors identified as associated with a higher risk of autotransfusion were female sex and a lower preoperative hemoglobin. CONCLUSIONS: The use of a cell saver in off-pump surgery is useless in most cases. Careful surgical hemostasis is essential to limit hypovolemia.