[Effectiveness of the vagino-rectal exudate self-sampling for prenatal screening of Streptococcus agalactiae infection. GALL study]. / Efectividad de la autotoma del exudado vaginorrectal para el cribado prenatal de la infección por Streptococcus agalactiae. Estudio GALL.

OBJETIVE: To evaluate the effectiveness of vagino-rectal swab autotomy for prenatal screening for GBS infection and to identify the barriers and facilitators encountered by the pregnant woman for this intervention. DESIGN: Cross-sectional study of diagnostic tests. PARTICIPANTS AND SITE: A total of 213 pregnant women who attended the primary care midwife's office in 6 health centers of the Basque Health Service/Osakidetza in Bizkaia, who met the inclusion criteria and agreed to participate in the study, participated in the study. MAIN MEASUREMENTS: The result of the vagino-rectal culture obtained by the pregnant woman was compared with the result of the vagino-rectal culture taken by the midwife in consultation on the same day, and the barriers and facilitators encountered by the women in the self-test were collected. RESULTS: Self-testing as a test for GBS was found to have a sensitivity of 93.3% (95% CI 78.7-98.2), a specificity of 99.4% (95% CI 96.5-99.9), a positive predictive value of 96% (95% CI 82.8-99.4) and a negative predictive value of 98.8% (95% CI 95.6-99.7). 27.3% of respondents encountered some difficulty in the collection, only 4.8% did not feel qualified, 84.2% felt comfortable, 99.5% considered the information provided to be adequate and complete, 94.7% did not find the steps to follow complicated, and 96% were satisfied with the study. CONCLUSIONS: Self-collection of vagino-rectal exudate for GBS detection has proved to be valid and reliable, which would make it possible to offer this option to pregnant women in the systematic screening for GBS infection.

High-resolution temporal wastewater treatment plant investigation to understand influent mass flux of per- and polyfluoroalkyl substances (PFAS).

This study aims to identify sources of per- and polyfluoroalkyl substances (PFAS) to wastewater treatment plants (WWTPs) and reveals previously undescribed variability in daily PFAS concentrations by measuring their occurrence in WWTP influent each hour over the course of a week. ∑50PFAS concentrations ranged between 89 ± 38 on Monday and 173 ± 110 ng L-1 on Friday, where perfluoroalkyl carboxylic acids (PFCAs), disubstituted phosphate esters (diPAPs), and perfluoroalkyl sulfonic acids (PFSAs) contributed the largest proportion to overall weekly concentrations 37%, 30%, and 17% respectively. Simultaneous pulse events of perfluorooctanesulfonic acid (PFOS; 400 ng L-1) and perfluoroheptanesulfonic acid (PFHpS; 18 ng L-1) indicate significant industrial or commercial waste discharge that persists for up to 3 h. The minimum number of hourly grab samples required to detect variation of PFOS and PFHpS concentrations are 7 and 9 samples respectively, indicating a high degree of variability in PFAS concentrations between days. Overall, the risk of sampling bias from grab samples is high given the variability in PFAS concentrations and more frequent sampling campaigns must be balanced against the cost of analysis carefully to avoid the mischaracterisation of mass flux to receiving surface waters.

BoSL FAL pump: A small, low-cost, easily constructed, 3D-printed peristaltic pump for sampling of waters.

Water sampling is an essential undertaking for water utilities and agencies to protect and enhance our natural resources. The high variability in water quality, however, often necessitates a spatially distributed sampling program which is impeded by high-cost and large sampling devices. This paper presents the BoSL FAL Pump - a low-cost, easily constructed, 3D-printed peristaltic pump which can be made from commonly available components and is sized to suit even the most space constrained installations. The pump is 38 mm in height and 28 mm in diameter, its components cost $19 AUD and the construction time is just 12 min (excluding 3D printing times). The pump is driven by a direct current motor which is commonly available, cheap and allows for flexibility in the energy supply (5-12 V). Optionally, the pump has a Hall effect sensor and magnet to detect rotation rates and pumping volumes to improve the accuracy of pumping rates/volumes. The pump can be easily controlled by commonly available microcontrollers, as demonstrated by this paper which implements the ATmega328P on the Arduino Uno R3. This paper validates the pump for long-term deployments at flow rates of up to 13 mL per minute in 0.14 mL volume increments at accuracy levels of greater than 99%. The pump itself is scalable, allowing for a wider range of pumping rates when, for example, large volume samples are required for pathogen and micropollutant detection.