We report the detection of a Shigella sonnei outbreak from a small investigation in the San Francisco Bay area, California, USA, in 2024. By combining outbreak investigation with genomic sequencing, we show the utility of phylodynamics to aid outbreak investigations of bacterial pathogens by state or local public health departments.

BACKGROUND: In 2020, there were 36.7 million reported falls among older adults (65+) in the United States. Ethanol and other sedating substances may increase fall risk among older adults due to their effect on cognitive and physical function. We estimate the prevalence of these substances in blood specimens of older adults presenting with a fall injury at selected trauma centers. METHODS: The initial study collected blood specimens from May 2020 through July 2021 from adults undergoing a trauma team evaluation at selected United States Level 1 trauma centers. We limited our study to older adults evaluated after a fall (n = 1,365) and selected a random sample (n = 300) based on age, sex, and trauma-center quotas. Medical health records and blood specimens obtained at trauma center presentation were analyzed. We estimated the prevalence of ethanol, benzodiazepines, cannabinoids, and opioids in the blood specimens. Two-sample tests of binomial proportions and Chi-square two-tailed tests were used to compare prevalence estimates of substances by demographic characteristics. RESULTS: At least one substance was detected among 31.3% of samples analyzed. Prevalences of specific substances detected were 9.3% (95% CI: 6.0-12.6%) for benzodiazepines, 4.3% (95% CI: 2.0-6.7%) for cannabinoids, 8.0% (95% CI: 5.2-11.7%) for ethanol, and 15.0% (95% CI: 10.9-19.1%) for opioids. There were 18 deaths (6%; 95% CI: 3.6-9.3%). One-third of decedents had at least one substance detected in their blood. DISCUSSION: Opioids were the most frequently detected substance, followed by benzodiazepines, ethanol, and cannabinoids. Substance use prevalence was not uniform across demographics, with differences observed by sex and age. CONCLUSIONS: This study provides insight into the frequency of the presence of substances that may contribute to fall risk and serious injury among older adults. Screening older adults for substances that impair cognitive and physical function can enhance clinical fall prevention efforts.

Error rates that have been published in recent open black box studies of forensic firearms examiner performance have been very low, typically below one percent. These low error rates have been challenged, however, as not properly taking into account one of the categories, "Inconclusive", that examiners can reach in comparing a pair of bullets or cartridges. These challenges have themselves been challenged; how to consider the inconclusives and their effect on error rates is currently a matter of sharp debate. We review several viewpoints that have been put forth, and then examine the impact of inconclusives on error rates from three fresh statistical perspectives: (a) an ideal perspective using objective measurements combined with statistical algorithms, (b) basic sampling theory and practice, and (c) standards of experimental design in human studies. Our conclusions vary with the perspective: (a) inconclusives can be simple errors (or, on the other hand, simply correct or at least well justified); (b) inconclusives need not be counted as errors to bring into doubt assessments of error rates; (c) inconclusives are potential errors, more explicitly, inconclusives in studies are not necessarily the equivalent of inconclusives in casework and can mask potential errors in casework. From all these perspectives, it is impossible to simply read out trustworthy estimates of error rates from those studies which have been carried out to date. At most, one can put reasonable bounds on the potential error rates. These are much larger than the nominal rates reported in the studies. To get straightforward, sound estimates of error rates requires a challenging but critical improvement to the design of firearms studies. A proper study-one in which inconclusives are not potential errors, and which yields direct, sound estimates of error rates-will require new objective measures or blind proficiency testing embedded in ordinary casework.