Tackling the Lead Gremlins: A Response to Take-Home Lead Exposure in a Minnesota Industrial Facility, 2019.

Lead exposure that occurs from contamination inadvertently brought home from a workplace is known as take-home exposure. Take-home exposures are a public health hazard that adversely affects health equity for families and communities. This article describes coordinated action by agencies in Minnesota to curb lead exposure among children of workers at a facility that produces fishing sinkers and battery terminals. (Am J Public Health. 2022;112(S7):S655-S657. https://doi.org/10.2105/AJPH.2022.306982).

Screening for Elevated Blood Lead Levels: False-Positive Rates of Tests on Capillary Samples, Minnesota, 2011-2017.

CONTEXT: A typical strategy for identifying children with elevated blood lead levels (BLL) is to use a test on a capillary sample as a screening tool and then perform a confirmatory test on a venous sample following an elevated capillary screen. However, tests on capillary samples are prone to false-positive results, which affect surveillance estimates of the prevalence of elevated BLL. OBJECTIVE: We sought to measure the prevalence and risk of false-positive results in elevated tests on capillary samples based on various potential predictors. DESIGN, SETTING, PARTICIPANTS, AND MAIN OUTCOME MEASURES: We analyzed blood lead results for children aged 0 to 6 years tested during 2011 to 2017 in Minnesota. A false positive was defined as a test on a capillary sample of at least 5 µg/dL, followed by a test result on a venous sample less than 5 µg/dL within 90 days. Binomial regression was used to estimate the probability of false-positive results dependent on the initial test result and the time between initial and confirmatory tests. RESULTS: Results from 3898 children were included in analyses. Of these, 2330 (60%) had confirmatory results below 5 µg/dL and were classified as false positives. The proportion of false positives varied with time between tests, dependent on the initial result. Extrapolating the model to zero days between tests, without time for any change in the child's true BLL, we predicted 55% false positives in this study group (95% confidence interval: 53%-57%). CONCLUSION: Caution is warranted when interpreting elevated tests on capillary samples without confirmatory tests on venous samples. Providers should be encouraged to follow up all elevated capillary screens with confirmatory tests on venous samples.

Lead Exposure Among Workers at a Shipyard-Wisconsin, 2015 to 2016.

OBJECTIVE: In March 2016, the state health departments of Wisconsin and Minnesota learned of three shipyard workers with blood lead levels (BLLs) more than 40 µg/dL. An investigation was conducted to determine the extent of and risk factors for the exposure. METHODS: We defined a case as an elevated BLL more than or equal to 5 µg/dL in a shipyard worker. Workers were interviewed regarding their symptoms and personal protective equipment (PPE) use. RESULTS: Of 357 workers, 65.0% had received more than or equal to 1 BLL test. Among tested workers, 171 (73.7%) had BLLmax more than or equal to 5 µg/dL. Workers who received respirator training or fit testing had a median BLLmax of 18.0 µg/dL, similar to the median BLLmax of workers who did not receive such training (22.6 µg/dL, P = 0.20). CONCLUSIONS: Our findings emphasize the importance of adequate provision and use of PPE to prevent occupational lead exposure.

Colorado tick fever in the United States, 2002-2012.

BACKGROUND: Colorado tick fever (CTF) is an acute systemic febrile illness caused by the CTF virus (CTFV). The last national summary of CTF cases in the United States included cases reported through 2001. This study summarizes national surveillance data for CTF from 2002 through 2012 and examines trends in the epidemiology and testing of identified CTF cases. METHODS: Because CTF is not nationally notifiable, we identified CTF cases through solicited reports from state health departments and diagnostic laboratory records. For all cases, we collected data on age, sex, county of residence, travel history, symptom onset date, laboratory testing, and clinical outcome. Poisson regression was used to examine trends over time in case counts, and simple linear regression and logistic regression were used to examine trends in case characteristics. RESULTS: From 2002 through 2012, 75 CTF cases were identified with a median of five cases per year (range 3-14). Forty-seven (63%) cases occurred in males and 49 (65%) occurred in people aged ≥40 years. The majority (80%) of cases had onset of illness during May through July. Cases occurred in residents of 14 states but the infections were acquired in six western states. Wyoming had the highest annual incidence of CTF among residents (3.4 cases per million population), followed by Montana (1.5 per million), and Utah (0.5 per million). Over the 11 years, there was an increase in the proportion of cases diagnosed by RT-PCR testing and in the proportion of cases among travelers to another state. CONCLUSIONS: CTF cases continue to occur annually among residents and visitors to the western United States. Public health prevention messages about decreasing tick exposure should be targeted to residents and travelers who will spend time outdoors in an endemic region during the spring and summer months.