Testing efforts for SARS-CoV-2 have been burdened by the scarcity of testing materials and personal protective equipment for health care workers. The simple and painless process of saliva collection allows for widespread testing, but enthusiasm is hampered by variable performance compared to nasopharyngeal swab (NPS) samples. We prospectively collected paired NPS and saliva samples from a total of 300 unique adult and pediatric patients. SARS-CoV-2 RNA was detected in 32.2% (97/300) of the individuals using the TaqPath COVID-19 Combo Kit (Thermo Fisher). Performance of saliva and NPS were compared against the total number of positives regardless of specimen type. The overall concordance for saliva and NPS was 91.0% (273/300) and 94.7% (284/300), respectively. The positive percent agreement (PPA) for saliva and NPS was 81.4% (79/97) and 89.7% (87/97), respectively. Saliva detected 10 positive cases that were negative by NPS. In symptomatic and asymptomatic pediatric patients not previously diagnosed with COVID-19, the performances of saliva and NPS were comparable (PPA: 82.4% vs 85.3%). The overall PPA for adults were 83.3% and 90.7% for saliva and NPS, respectively, with saliva detecting 4 cases less than NPS. However, saliva performance in symptomatic adults was identical to NPS (PPA of 93.8%). With lower cost and self-collection capabilities, saliva can be an appropriate alternative sample choice to NPS for detection of SARS-CoV-2 in children and adults.

Testing efforts for SARS-CoV-2 have been burdened by the scarcity of testing materials and personal protective equipment for healthcare workers. The simple and painless process of saliva collection allows for widespread testing, but enthusiasm is hampered by variable performance compared to nasopharyngeal swab (NPS) samples. We prospectively collected paired NPS and saliva samples from a total of 300 unique adult and pediatric patients. SARS-CoV-2 RNA was detected in 32.2% (97/300) of the individuals using the TaqPath COVID-19 Combo Kit (Thermo Fisher). Performance of saliva and NPS were compared against the total number of positives regardless of specimen type. The overall concordance for saliva and NPS was 91.0% (273/300) and 94.7% (284/300), respectively. The positive percent agreement (PPA) for saliva and NPS was 81.4% (79/97) and 89.7% (87/97), respectively. Saliva detected 10 positive cases that were negative by NPS. In symptomatic and asymptomatic pediatric patients not previously diagnosed with COVID-19, the performances of saliva and NPS were comparable (PPA: 82.4% vs 85.3%). The overall PPA for adults were 83.3% and 90.7% for saliva and NPS, respectively, with saliva detecting 4 cases less than NPS. However, saliva performance in symptomatic adults was identical to NPS (PPA of 93.8%). With lower cost and self-collection capabilities, saliva can be an appropriate alternative sample choice to NPS for detection of SARS-CoV-2 in children and adults.

While real-time reverse transcriptase-polymerase chain reaction (RT-PCR) on nasopharyngeal swabs is the current standard for SARS-CoV-2 detection, saliva is an attractive alternative for diagnosis and screening due to ease of collection and minimal supply requirements. 1,2 Studies on the sensitivity of saliva-based SARS-CoV-2 molecular testing have shown considerable variability. 3 We conducted a prospective, longitudinal study to investigate the testing timeframe that optimizes saliva sensitivity for SARS-CoV-2 detection.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–specific antibodies have been detected in human milk up to 6 weeks post–coronavirus disease 2019 (COVID-19) vaccination. We evaluated SARS-CoV-2-specific antibodies, neutralization activity, effect of pasteurization, and persistence through 6 months after vaccination. METHODS: This prospective longitudinal study enrolled 30 pregnant or lactating women. SARS-CoV-2 antibodies and neutralization capacity were analyzed using an enzyme-linked immunosorbent assay compared at prevaccination and 1, 3, and 6 months postvaccination, and through Holder pasteurization. RESULTS: Human milk SARS-CoV-2-specific IgG levels peaked at 1 month postvaccination and persisted above prevaccination levels for at least 6 months (P = .005). SARS-CoV-2-specific IgA was detected at 1 and 3 months (both P < .001) but waned by 6 months compared with baseline (P = .07). Milk SARS-CoV-2-specific IgG and IgA correlated with serum IgG at the same time point (R2 = 0.37, P < .001 and R2 = 0.19, P < .001). Neutralization activity was seen in 83.3%, 70.4%, and 25.0% of milk samples at 1, 3, and 6 months postvaccination. Neutralization most strongly correlated with SARS-CoV-2-specific IgG (R2 = 0.57, P < .001). Pre- and postpasteurization samples showed similar IgG (0.84 vs 1.07, P = .36) and neutralizing activity (57.7% vs 58.7% inhibition, P = .27), but lower IgM and IgA levels postpasteurization (0.09 vs 0.06, P = .004 and 0.21 vs 0.18, P = .043). CONCLUSIONS: The data suggest that human milk SARS-CoV-2-specific antibodies may be available to milk-fed infants for up to 6 months. In addition, donor milk from vaccinated mothers retain IgG and neutralizing activity.

A soil washing process was applied to remediate arsenic (As)-contaminated stream sediments around an abandoned mine in Goro, Korea. Laboratory scale soil washing experiments for As-contaminated stream sediments were performed under various washing conditions in order to maximize As removal efficiency. Stream sediments were taken from two sites (S1 and S5) along the main stream connected to an abandoned mine. Stream sediments at the two sites were divided into two groups (>or=0.35 and <0.35 mm in diameter), giving four types of sediments, which were thereupon used for soil washing experiments. The results of soil washing experiments involving various pH conditions suggested that As removal efficiency is very high in both strongly acidic and basic solutions (pH 1 and 13), regardless of sediment type. Removal efficiencies for fine sediments from S1 and S5 were >95% after 1 h of washing with 0.2 M citric acid (C(6)H(8)O(7)). When using 0.2 M citric acid mixed with 0.1 M potassium phosphate (KH(2)PO(4)), the As removal efficiency increased to 100%. When recycled washing solution was applied, As removal efficiency was maintained at a level greater than 70%, even after eight recycling events. This suggests that the recycling of washing solution could be successfully applied as a means of decreasing the cost of the washing process. Results from the experiments suggest that soil washing is a potentially useful process for the remediation of As-contaminated stream sediments around abandoned mines.