Evaluation of Convalescent Plasma for Ebola Virus Disease in Guinea

: In the wake of the recent outbreak of Ebola virus disease (EVD) in several African countries, the World Health Organization prioritized the evaluation of treatment with convalescent plasma derived from patients who have recovered from the disease. We evaluated the safety and efficacy of convalescent plasma for the treatment of EVD in Guinea. : In this nonrandomized, comparative study, 99 patients of various ages (including pregnant women) with confirmed EVD received two consecutive transfusions of 200 to 250 ml of ABO-compatible convalescent plasma, with each unit of plasma obtained from a separate convalescent donor. The transfusions were initiated on the day of diagnosis or up to 2 days later. The level of neutralizing antibodies against Ebola virus in the plasma was unknown at the time of administration. The control group was 418 patients who had been treated at the same center during the previous 5 months. The primary outcome was the risk of death during the period from 3 to 16 days after diagnosis with adjustments for age and the baseline cycle-threshold value on polymerase-chain-reaction assay; patients who had died before day 3 were excluded. The clinically important difference was defined as an absolute reduction in mortality of 20 percentage points in the convalescent-plasma group as compared with the control group. : A total of 84 patients who were treated with plasma were included in the primary analysis. At baseline, the convalescent-plasma group had slightly higher cycle-threshold values and a shorter duration of symptoms than did the control group, along with a higher frequency of eye redness and difficulty in swallowing. From day 3 to day 16 after diagnosis, the risk of death was 31% in the convalescent-plasma group and 38% in the control group (risk difference, -7 percentage points; 95% confidence interval [CI], -18 to 4). The difference was reduced after adjustment for age and cycle-threshold value (adjusted risk difference, -3 percentage points; 95% CI, -13 to 8). No serious adverse reactions associated with the use of convalescent plasma were observed. : The transfusion of up to 500 ml of convalescent plasma with unknown levels of neutralizing antibodies in 84 patients with confirmed EVD was not associated with a significant improvement in survival. (Funded by the European Union's Horizon 2020 Research and Innovation Program and others; ClinicalTrials.gov number, NCT02342171.).<br/

Evaluation of an enzymatic Chlamydia trachomatis point-of-care rapid assay in Rwanda: the BioChekSwab Rapid Test

Objectives: We evaluated the performance of an enzymatic point-of-care rapid test for Chlamydia trachomatis (CT) (the BioChekSwab CT Rapid Test, EnZtek Diagnostics, Rio Vista, California, USA), which detects CT's Peptidase 123CBV enzyme and provides a result 15 min after specimen collection. Methods: Two endocervical swabs, including one BioChekSwab, per person were obtained from 137 women who participated in a reproductive health study in Rwanda. The BioChekSwab was processed according to the manufacturer's instructions. A substrate was squirted over the swab by the study physician immediately after collection, and another reagent was released over the swab tip at arrival in the laboratory. The test was considered positive if a blue colour developed within 2 min. The other regular flocked endocervical swab was processed at the Institute of Tropical Medicine (ITM), Belgium, using a testing algorithm: Abbott RealTime CT/Neisseria gonorrhoeae (NG) assay with the confirmation of positive results by an in-house real-time PCR assay. Results: Of the 137 women, nine were CT positive by the testing algorithm. All nine positive results were missed by the BioChekSwab assay and four false-positive results were obtained. The sensitivity was therefore 0% (95% CI 0% to 33.6%) and the specificity was 96.9% (95% CI 92.2% to 99.1%). Conclusions: The BioChekSwab Rapid Test, although ISO13485 certified and Conformitée Européenne (CE) labelled, lacked any sensitivity in our setting.</p

Evaluation of an enzymatic Chlamydia trachomatis point-of-care rapid assay in Rwanda: the BioChekSwab Rapid Test

Objectives: We evaluated the performance of an enzymatic point-of-care rapid test for Chlamydia trachomatis (CT) (the BioChekSwab CT Rapid Test, EnZtek Diagnostics, Rio Vista, California, USA), which detects CT's Peptidase 123CBV enzyme and provides a result 15 min after specimen collection. Methods: Two endocervical swabs, including one BioChekSwab, per person were obtained from 137 women who participated in a reproductive health study in Rwanda. The BioChekSwab was processed according to the manufacturer's instructions. A substrate was squirted over the swab by the study physician immediately after collection, and another reagent was released over the swab tip at arrival in the laboratory. The test was considered positive if a blue colour developed within 2 min. The other regular flocked endocervical swab was processed at the Institute of Tropical Medicine (ITM), Belgium, using a testing algorithm: Abbott RealTime CT/Neisseria gonorrhoeae (NG) assay with the confirmation of positive results by an in-house real-time PCR assay. Results: Of the 137 women, nine were CT positive by the testing algorithm. All nine positive results were missed by the BioChekSwab assay and four false-positive results were obtained. The sensitivity was therefore 0% (95% CI 0% to 33.6%) and the specificity was 96.9% (95% CI 92.2% to 99.1%). Conclusions: The BioChekSwab Rapid Test, although ISO13485 certified and Conformitée Européenne (CE) labelled, lacked any sensitivity in our setting.</p

Distribution and morphology of mud volcanoes and other fluid flow-related lake-bed structures in Lake Baikal, Russia

New high-resolution multibeam bathymetry data recorded in 2009 in the deepest lake in the World, Lake Baikal, Siberia, enabled a better understanding of the morphology of ten known lake-bed structures-the Bolshoy, Malenki, Malyutka and Stari mud volcanoes in the South Baikal Basin, the K1-4 structures in the Selenga delta, and the Novosibirsk and St. Petersburg structures in the Central Baikal Basin-and also the discovery of 29 new lake-bed structures. These new structures are the S1, Tolstiy, mTSG and S2 in the South Baikal Basin, the P1-P4, P6-P19 and K5-K8 in the Selenga delta accommodation zone, and the C1, C3 and C4 edifices in the Central Baikal Basin. In all, 39 positive relief structures were identified and their large-scale distribution mapped. Based on their typical shape, the observation of high-reflectivity areas on side-scan sonar data records, and evidence of feeder channels on subsurface data, these structures can be classified as mud volcanoes. This has already been confirmed in other publications for the Bolshoy, Malenki and K2 structures, by the recovery of mud breccias in sediment cores. Most structures occur on or near faults and have orientations parallel with the major faults and main stress orientations in the basins, suggesting a strong structural control on the formation of the mud volcanoes. Their slopes are generally steeper than 5A degrees, consistent with interpretation as mud cones formed by high-viscosity, stiff mud plugs. Only few structures appear to be characterised by a crater, in which case this apparent crater seems to be formed by the coalescence of several single cones, leaving a depression in the centre. Some structures have a moat, which has probably an erosional origin. Furthermore, three depressions have been found, named P5, P20 and C2, which are suggested to be pockmarks