Implementation and Performance of a Point-of-Care COVID-19 Test Program in 4000 California Schools.

OBJECTIVE: To evaluate the feasibility and accuracy of an unprecedented COVID-19 antigen testing program in schools, which required a healthcare provider order, laboratory director, a Clinical Laboratory Improvement Amendments certificate of waiver, as well as training of school personnel. STUDY DESIGN: Descriptive report of a point-of-care, school-based antigen testing program in California from August 1st, 2021 through May 30, 2022, in which participants grades K-12 self-swabbed and school personnel performed testing. Participants included 944 009 students, personnel, and community members from 4022 California kindergarten through high schools. Outcomes measured include sensitivity and specificity (with polymerase chain reaction [PCR] as comparator) of the Abbott BinaxNOW antigen test, number of tests performed, and active infections identified. RESULTS: Of 102 022 paired PCR/antigen tests, the overall sensitivity and specificity for the antigen test was 81.2% (95% CI: 80.5%-81.8%) and 99.6% (95% CI: 99.5%-99.6%), respectively, using cycle threshold values <30. During January through March 2022, the highest prevalence period, the positive predictive value of antigen testing was 94.7% and the negative predictive value was 94.2%. Overall, 4022 school sites were enrolled and 3 987 840 million antigen tests were performed on 944 009 individuals. A total of 162 927 positive antigen tests were reported in 135 163 individuals (14.3% of persons tested). CONCLUSIONS: Rapidly implementing a school-based testing program in thousands of schools is feasible. Self-swabbing and testing by school personnel can yield accurate results. On-site COVID-19 testing is no longer necessary in schools, but this model provides a framework for future infectious disease threats.

Older Mayan residents of the western highlands of Guatemala lack sufficient levels of vitamin D.

Vitamin D (VitD) levels in older Mayans are currently unknown. Geographic factors, for example, residences in areas receiving ample sunlight at high altitudes and latitudes near the equator, would favor optimum VitD levels, whereas demographic factors, for example, darker skin pigmentation, clothing practices, and older age, would favor low 25-hydroxy-vitamin D, or 25(OH)D, levels. Conjecturing that demographic factors affecting VitD status might outweigh geographic factors in this population, we hypothesized that older Mayans have suboptimal values of 25(OH)D. We also hypothesized that older Mayans in rural areas would have higher VitD levels than would their urban counterparts. Blood samples were collected from 108 healthy older Mayans (mean age, 69 years) from urban (n = 84, 50% male) and rural settings (n = 24, 50% male) during the summer of 2008 in the highlands of Quetzaltenango, Guatemala. We assessed 25(OH)D concentrations by radioimmunoassay in a US-based laboratory. Mean (SD) serum 25(OH)D values were 53.3 (15.0) nmol/L, and lower 25(OH)D values were associated with increasing age (r = -0.58, P = .004). Of all subjects, 3.7% (n = 4) maintained an optimal status of 25(OH)D (>80 nmol/L), 50% (n = 54) had values between 50 and 80 nmol/L, and 46.3% (n = 50) had levels less than 50 nmol/L. Urban subjects had nonsignificantly higher 25(OH)D values (55.0 ± 15.3 nmol/L) than did rural subjects (47.4 ± 12.4 nmol/L, P = .228). Men had significantly higher values (58.2 ± 16.5 nmol/L) than did women (48.4 ± 11.6 nmol/L, P = .001). We conclude that despite residing in an optimal geographic location to receive adequate sunlight exposure, most older Guatemalan Mayans in Quetzaltenango have suboptimal levels of VitD.