Human Disease due to Mycobacterium bovis Linked to Free-Ranging Deer in Michigan.

BACKGROUND: A unique enzootic focus of Mycobacterium bovis in free-ranging deer was identified in northern lower Michigan in 1994, with subsequent evidence of transmission to local cattle herds. Between 2002 and 2017, 3 Michigan deer hunters with M. bovis disease were previously reported. We present 4 additional human cases linked to the zoonotic focus in deer, utilizing genomic epidemiology to confirm close molecular associations among human, deer and cattle M. bovis isolates. METHODS: Identification of human tuberculosis (TB) cases with cultures of M. bovis was provided from the Michigan Department of Health and Human Services (MDHHS) tuberculosis database. Clinical review and interviews focused on risk factors for contact with wildlife and cattle. Whole genome sequences of human isolates were compared with a veterinary library of M. bovis strains to identify those linked to the enzootic focus. RESULTS: Three confirmed and 1 probable human case with M. bovis disease were identified between 2019 and 2022, including cutaneous disease, 2 severe pulmonary disease cases, and human-to-human transmission. The 3 human isolates had 0-3 single-nucleotide polymorphisms (SNPs) with M. bovis strains circulating in wild deer and domestic cattle in Michigan. CONCLUSIONS: Spillover of enzootic M. bovis from deer to humans and cattle continues to occur in Michigan. Future studies should examine the routes of transmission and degree of risk to humans through expanded epidemiological surveys. A One Health approach linking human, veterinary and environmental health should address screening for TB infection, public education, and mitigation of transmission.

Disparities in COVID-19 Hospitalization at the Intersection of Race and Ethnicity and Income.

BACKGROUND: Existing studies have elucidated racial and ethnic disparities in COVID-19 hospitalizations, but few have examined disparities at the intersection of race and ethnicity and income. METHODS: We used a population-based probability survey of non-institutionalized adults in Michigan with a polymerase chain reaction-positive SARS-CoV-2 test before November 16, 2020. We categorized respondents by race and ethnicity and annual household income: low-income (< $50,000) Non-Hispanic (NH) Black, high-income (≥ $50,000) NH Black, low-income Hispanic, high-income Hispanic, low-income NH White, and high-income NH White. We used modified Poisson regression models, adjusting for sex, age group, survey mode, and sample wave, to estimate COVID-19 hospitalization prevalence ratios by race and ethnicity and income. RESULTS: Over half of the analytic sample (n = 1593) was female (54.9%) and age 45 or older (52.5%), with 14.5% hospitalized for COVID-19. Hospitalization was most prevalent among low-income (32.9%) and high-income (31.2%) Non-Hispanic (NH) Black adults, followed by low-income NH White (15.3%), low-income Hispanic (12.9%), high-income NH White (9.6%), and high-income Hispanic adults (8.8%). In adjusted models, NH Black adults, regardless of income (low-income prevalence ratio [PR]: 1.86, 95% CI: 1.36-2.54; high-income PR: 1.57, 95% CI: 1.07-2.31), and low-income NH White adults (PR: 1.52, 95% CI: 1.12-2.07), had higher prevalence of hospitalization compared to high-income NH White adults. We observed no significant difference in the prevalence of hospitalization among Hispanic adults relative to high-income NH White adults. CONCLUSIONS: We observed disparities in COVID-19 hospitalization at the intersection of race and ethnicity and income for NH Black adults and low-income NH White adults relative to high-income NH White adults, but not for Hispanic adults.

The Need for Responsive Workforce Development During the Pandemic and Beyond: A Case Study of the Regional Public Health Training Centers.

CONTEXT: The COVID-19 pandemic underscored the importance of a strong public health infrastructure for protecting and supporting the health of communities. This includes ensuring an adaptive workforce capable of leading through rapidly changing circumstances, communicating effectively, and applying systems thinking to leverage cross-sector partnerships that help promote health equity. The 10 Regional Public Health Training Centers (PHTCs) advance the capacity of the current and future public health workforce through skill development and technical assistance in these and other strategic areas. PROGRAM: This study examines activities through which the Regional PHTCs and their partners supported the public health workforce during the pandemic. Representatives of the 10 Regional PHTCs completed a survey in the spring of 2022. The survey included (1) pulling trends in training usage from 2018-2021 annual performance reports and (2) questions assessing the type, content, and reach of training needs assessments, training and technical assistance, student placements, and PHTC Network collaborative activities that occurred from January 1, 2020, to December 31, 2021. Respondents also reflected on trends in use, challenges, lessons learned, stories of impact, and future PHTC practice. EVALUATION: During the pandemic, the Regional PHTCs engaged in numerous efforts to assess needs, provide training and technical assistance to the practice community, facilitate projects that built student competency to support public health agency efforts, and collaborate as the PHTC Network on national-level initiatives. Across these activities, the Regional PHTCs adjusted their approaches and learned from each other in order to meet regional needs. DISCUSSION: The Regional PHTCs provided student and professional development in foundational public health knowledge and skills within their regions and nationally while being flexible and responsive to the changing needs of the field during the pandemic. Our study highlights opportunities for collaboration and adaptive approaches to public health workforce development in a postpandemic environment.

A statewide population-based approach to examining Long COVID symptom prevalence and predictors in Michigan.

OBJECTIVE: The current broad definition of Long COVID, and an overreliance on clinical and convenience samples, is leading to a wide array of Long COVID estimates with limited generalizability. Our objective was to examine Long COVID symptoms using a statewide population-based probability sample. METHODS: Among 8000 sampled adults with polymerase-chain-reaction-confirmed SARS-CoV-2 between June 2020 and July 2021 in the Michigan Disease Surveillance System, 2533 completed our survey (response rate 32.2%). Using modified Poisson regression, we examined sociodemographic, behavioral, and clinical predictors of eight Long COVID symptom clusters, defined as at least one applicable symptom lasting 90 or more days post COVID-19 onset. RESULTS: Neuropsychiatric Long COVID symptoms, including brain fog, were most prevalent (23.7%), followed by systemic symptoms (17.1%), including fatigue, musculoskeletal (11.4%), pulmonary (10.4%), dermatologic (6.7%), cardiovascular (6.1%), gastrointestinal (5.4%), and ear, nose, and throat symptoms (5.3%). In adjusted analyses, female sex, a pre-existing psychological condition, and intensive care unit admission were strong predictors of most Long COVID symptom clusters. Older age was not associated with a higher prevalence of all symptoms - cardiovascular and dermatologic symptoms were most prevalent among middle-aged adults and age was not associated with neuropsychiatric or gastrointestinal symptoms. Additionally, there were fewer associations between pre-existing conditions and cardiovascular, neuropsychiatric, and dermatologic symptoms compared to other symptom clusters. CONCLUSIONS: While many predictors of Long COVID symptom clusters were similar, the relationship with age and pre-existing conditions varied across clusters. Cardiovascular, neuropsychiatric, and dermatologic symptoms require further study as potentially distinct from other Long COVID symptoms.

Differential care-seeking behaviors during the beginning of the COVID-19 pandemic in Michigan: a population-based cross-sectional study.

BACKGROUND: At the beginning of the COVID-19 pandemic in the United States in the spring of 2020, many Americans avoided the healthcare system, while those with COVID-19 symptoms were faced with decisions about seeking healthcare services for this novel virus. METHODS: Using a probability sample (n = 1088) from the Michigan adult population of PCR-confirmed COVID-19 cases who were diagnosed prior to July 31, 2020, we used logistic regression to examine sociodemographic and symptom severity predictors of care-seeking behaviors. The analyses examined three different outcomes: (1) whether respondents sought care and, among those who sought care, whether they sought care from (2) a primary care provider or (3) an emergency room. Final models were adjusted for sex, age, race and ethnicity, income, education, marital status, living arrangement, health insurance, and self-reported symptom severity. RESULTS: We found that participants ages 65 and older had 4.00 times higher odds of seeking care than 18-34-year-olds (95% CI: 2.21, 7.24), while adults reporting very severe symptoms had roughly 15 times higher odds of seeking care than those with mild symptoms (95% CI: 7.73, 27.01). Adults who were non-Hispanic Black or were uninsured had lower odds of seeking care from a primary care physician versus seeking care from other locations in comparison to adults who were non-Hispanic White or were privately insured, respectively (non-Hispanic Black: aOR = 0.27, 95% CI: 0.16, 0.44; Uninsured: aOR = 0.19, 95% CI: 0.09, 0.42). Conversely, adults who were older or reported more severe symptoms had higher odds of seeking care from an emergency room versus other locations in comparison to adults who were younger or reported less severe symptoms (Age 65+: aOR = 2.96, 95% CI: 1.40, 6.28; Very Severe Symptoms: aOR = 6.63, 95% CI: 3.33, 13.20). CONCLUSIONS: Our results suggest differential utilization of healthcare services early in the COVID-19 pandemic. Further analyses are needed to examine the reasons for these differences.

PH WINS for All: The Critical Role of Partnerships for Engaging All Local Health Departments in the Public Health Workforce Interests and Needs Survey.

The 2021 "PH WINS for All" pilot sought to address a rural research gap by including small local health departments in the Public Health Workforce Interests and Needs Survey (PH WINS) for the first time. To do so, the de Beaumont Foundation partnered with the Public Health Training Centers in Health and Human Services Regions V and X. This article describes the collaborative efforts that made the PH WINS for All pilot successful, presents respondent demographics by agency size, and discusses the importance of gathering such data to address the unique needs of the workforce in small local health departments.

Public Health Workforce Development During and Beyond the COVID-19 Pandemic: Findings From a Qualitative Training Needs Assessment.

CONTEXT: The Region V Public Health Training Center (RVPHTC) serves the public health workforce in Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin. An important tool in priority-setting workforce development is the training needs assessment (TNA), which is vital to identifying and addressing the capacity-building needs of the public health workforce. PROGRAM: In 2021, we conducted semistructured qualitative interviews with key partners in the local, state, and tribal health workforce. IMPLEMENTATION: Findings reflect the results of 23 interviews administered from March to May 2021. Questions solicited in-depth input related to key training gaps identified in our 2020 quantitative TNA; the impact of COVID-19 on the public health workforce; general needs, including preferred training modalities; needs by audience type; and the current capacity for public health agencies to support student development. EVALUATION: Key training needs of the public health workforce identified by the 2021 TNA include the strategic skills domains of (1) resource management; (2) change management; (3) justice, equity, diversity, and inclusion; and (4) effective communication. The first 3 domains were also noted as having the greatest training need in our 2020 quantitative TNA of local health department leadership. DISCUSSION: The COVID-19 pandemic highlighted the need for training in effective communication in new ways and the continued need for training support in the skill domains prioritized in the 2020 assessment. Findings demonstrate the need for capacity building around crosscutting skills and the intersection of strategic skill domains if the field is to be prepared for future threats to public health.

Population-Based Estimates of Post-acute Sequelae of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection (PASC) Prevalence and Characteristics.

BACKGROUND: Emerging evidence suggests many people have persistent symptoms after acute coronavirus disease 2019 (COVID-19) illness. Our objective was to estimate the prevalence and correlates of post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC). METHODS: We used a population-based probability survey of adults with COVID-19 in Michigan. Living noninstitutionalized adults aged ≥18 in the Michigan Disease Surveillance System with COVID-19 onset through mid-April 2020 were eligible for selection (N = 28 000). Among 2000 selected, 629 completed the survey between June-December 2020. We estimated PASC prevalence, defined as persistent symptoms ≥30 (30-day COVID-19) or ≥60 (60-day COVID-19) days post-COVID-19 onset, overall and by sociodemographic and clinical factors. We used modified Poisson regression to produce adjusted prevalence ratios (aPRs) for potential risk factors. RESULTS: The analytic sample (n = 593) was predominantly female (56.1%), aged ≥45 years (68.2%), and non-Hispanic White (46.3%) or Black (34.8%). Thirty- and 60-day COVID-19 were highly prevalent (52.5% and 35.0%), even among nonhospitalized respondents (43.7% and 26.9%) and respondents reporting mild symptoms (29.2% and 24.5%). Respondents reporting very severe (vs mild) symptoms had 2.25 times higher prevalence of 30-day COVID-19 (aPR, 2.25; 95% CI, 1.46-3.46) and 1.71 times higher prevalence of 60-day COVID-19 (aPR, 1.71; 95% CI: 1.02-2.88). Hospitalized (vs nonhospitalized) respondents had ~40% higher prevalence of both 30-day (aPR, 1.37; 95% CI: 1.12-1.69) and 60-day (aPR, 1.40; 95% CI: 1.02-1.93) COVID-19. CONCLUSIONS: PASC is highly prevalent among cases reporting severe initial symptoms and, to a lesser extent, cases reporting mild and moderate symptoms.

Vaccination Inequality in India, 2002-2013.

INTRODUCTION: India's childhood vaccination coverage has increased amid the implementation of national health policies intended to improve immunization levels. However, there is a dearth of contemporary studies comparing state-level childhood vaccination rates across India's highly diverse states and territories. This study assesses SES-based inequalities in childhood vaccination by state for 2002-2013. METHODS: National surveys from 2002 to 2004, 2007 to 2008, and 2012 to 2013 were used for analyses. Household SES was assessed using an asset index created through principal component analysis. Full vaccination comprised 1 dose bacille Calmette-Guerin, 3 doses diphtheria-pertussis-tetanus vaccine, 3 doses oral polio vaccine, and 1 dose measles-containing vaccine at age 12-60 months. Inequality analyses were stratified by 3 time periods and by government-designated high focus group versus non-high focus group states. RESULTS: Childhood vaccination steadily increased between 2002 and 2013 in high focus group states but fell in some non-high focus group states, whereas SES-based vaccination inequalities generally decreased in both. In 2012-2013, rural areas had lower vaccination rates than urban areas in high focus group states but similar vaccination rates as urban areas in non-high focus group states. Increases in vaccination rates were not consistently accompanied by improvements in SES-based inequalities in vaccination. CONCLUSIONS: Childhood vaccination in India has improved overall, although increases are more pronounced in high focus group states than in non-high focus group states over the study period. The gap in coverage between these states decreased over time owing in part to the latter experiencing reductions in full vaccination rates during 2007-2013. SES-based vaccination disparities persist in India, highlighting the need to improve vaccination rates for all children, especially those from disadvantaged and underserved groups. SUPPLEMENT INFORMATION: This article is part of a supplement entitled Global Vaccination Equity, which is sponsored by the Global Institute for Vaccine Equity at the University of Michigan School of Public Health.

Are community health workers cost-effective for childhood vaccination in India?

INTRODUCTION: Accredited Social Health Activists (ASHAs) are female community health workers whose primary role is to promote utilization of primary healthcare services and improve sanitation in rural areas and are financially incentivized for services provided. Prior studies evaluating ASHAs have been largely qualitative, and assess their knowledge, skills, and practice. Globally, there have been very few studies that have quantitatively assessed community health workers. We analyzed the cost effectiveness of ASHAs in facilitating measles vaccination among children under 5 years during 2012-2013. METHODS: We utilized Markov modeling simulating a cohort of children in villages with and without ASHAs. We extrapolated the health states to a lifetime of 68 years to estimate the effects of ASHA intervention. Measles vaccination rates were obtained from 2013 District Level Household and Facilities Survey 4. Other parameter estimates were obtained from a review of relevant literature. RESULTS: ASHA intervention was highly cost effective at $162 per DALY averted compared to no ASHA and remained cost effective with the ASHA incentive increased from $2 to $15, across the range of probabilities and cost parameters. Analyses were sensitive to probability of death due to childhood pneumonia, susceptibility to measles after one dose measles vaccine, and probability of pneumonia after measles infection. CONCLUSION: ASHAs were cost-effective under a wide range of scenarios even when a single health outcome such as measles vaccination was considered. The Government of India and individual state governments of India should consider increasing the incentives provided to ASHAs.

Childhood full and under-vaccination in Nigeria, 2013.

BACKGROUND: Nigeria's government is challenged with vaccinating the world's third largest birth cohort within a culturally and socioeconomically diverse country. This study estimated full childhood immunization coverage in Nigeria and characterizes the association between vaccination status and urbanicity, region of residence, ethnicity, and other factors. METHODS: In 2013, households throughout Nigeria were enrolled in the Demographic and Health Survey which included questions about vaccination. We defined full vaccination of a child as having received a single dose of bacillus Calmete-Guerin (BCG), one dose of measles-containing vaccine (MCV), three doses of diphtheria, pertussis, tetanus (DPT), and four doses of oral polio vaccine (OPV). Using a multinomial logistic regression model, full vaccination and under-vaccination versus non-vaccination was regressed onto various demographic and socioeconomic characteristics. RESULTS: Among 5759 children 1 year of age, 25.5% were fully vaccinated, 47.9% were under-vaccinated, and 26.6% had not received any vaccinations. Children were more likely to be fully vaccinated if they belonged to wealthier families, resided in southern regions of the country, were Christian, belonged to the Igbo or Yoruba ethnic group, had mothers who made ≥5 antenatal care visits, delivered at an institution, or were more highly educated. CONCLUSIONS: Full vaccination among children in Nigeria is exceptionally low by global standards and certain groups, such as Muslims and individuals in northern regions who are higher risk of non- or under-vaccination should be targeted by vaccination programs. Providing a wide range of health care services for mothers and pregnant women could improve full vaccination of children.

Severe Acute Respiratory Infection (SARI) sentinel surveillance in the country of Georgia, 2015-2017.

BACKGROUND: Severe Acute Respiratory Infection (SARI) causes substantial mortality and morbidity worldwide. The country of Georgia conducts sentinel surveillance to monitor SARI activity and changes in its infectious etiology. This study characterizes the epidemiology of SARI in Georgia over the 2015/16 and 2016/17 influenza seasons, compares clinical presentations by etiology, and estimates influenza vaccine effectiveness using a test-negative design. METHODS: SARI cases were selected through alternate day systematic sampling between September 2015 and March 2017 at five sentinel surveillance inpatient sites. Nasopharyngeal swabs were tested for respiratory viruses and Mycoplasma pneumoniae using a multiplex diagnostic system. We present SARI case frequencies by demographic characteristics, co-morbidities, and clinical presentation, and used logistic regression to estimate influenza A vaccine effectiveness. RESULTS: 1,624 patients with SARI were identified. More cases occurred in February (28.7%; 466/1624) than other months. Influenza was the dominant pathogen in December-February, respiratory syncytial virus in March-May, and rhinovirus in June-November. Serious clinical symptoms including breathing difficulties, ICU hospitalization, and artificial ventilation were common among influenza A and human metapneumovirus cases. For influenza A/H3, a protective association between vaccination and disease status was observed when cases with unknown vaccination status were combined with those who were unvaccinated (OR: 0.53, 95% CI: 0.30, 0.97). CONCLUSIONS: Multi-pathogen diagnostic testing through Georgia's sentinel surveillance provides useful information on etiology, seasonality, and demographic associations. Influenza A and B were associated with more severe outcomes, although the majority of the population studied was unvaccinated. Findings from sentinel surveillance can assist in prevention planning.

Socioeconomic factors associated with full childhood vaccination in Bangladesh, 2014.

OBJECTIVES: Childhood vaccination in Bangladesh has improved, but there is room for improvement. This study estimated full immunization coverage in Bangladeshi children and characterized risk factors for incomplete immunization. METHODS: Using the 2014 Bangladesh Demographic and Health Survey (DHS), full vaccination of children aged 12 to 24 months was examined; this was defined as the receipt of one dose of bacillus Calmette-Guérin (BCG), three doses of pentavalent vaccine, three doses of oral polio vaccine (OPV), and one dose of measles-containing vaccine (MCV). Associations between full vaccination and selected risk factors were assessed by logistic regression. RESULTS: Overall, 83% of children were fully vaccinated. BCG had the highest completion (97%), followed by OPV (92%), pentavalent vaccine (91%), and MCV (85%). Full vaccination coverage ranged from 64.4% in Sylhet to 90.0% in Rangpur and was lowest among non-locals of all regions (78.4%). Children who were in the lowest wealth quintile, who had mothers without antenatal care visits, or who had mothers without autonomy in healthcare decision-making were less likely to be fully vaccinated. CONCLUSIONS: Overall, full vaccination of children is high, but varies by vaccine type. Disparities still exist by wealth and by region. Maternal access to care and autonomy in healthcare decision-making are associated with higher vaccination coverage.

Regional variation in the severity of pesticide exposure outcomes: applications of geographic information systems and spatial scan statistics.

INTRODUCTION: Geographic information systems and spatial scan statistics have been utilized to assess regional clustering of symptomatic pesticide exposures reported to a state Poison Control Center (PCC) during a single year. In the present study, we analyzed five subsequent years of PCC data to test whether there are significant geographic differences in pesticide exposure incidents resulting in serious (moderate, major, and fatal) medical outcomes. METHODS: A PCC provided the data on unintentional pesticide exposures for the time period 2001-2005. The geographic location of the caller, the location where the exposure occurred, the exposure route, and the medical outcome were abstracted. RESULTS: There were 273 incidents resulting in moderate effects (n = 261), major effects (n = 10), or fatalities (n = 2). Spatial scan statistics identified a geographic area consisting of two adjacent counties (one urban, one rural), where statistically significant clustering of serious outcomes was observed. The relative risk of moderate, major, and fatal outcomes was 2.0 in this spatial cluster (p = 0.0005). CONCLUSIONS: PCC data, geographic information systems, and spatial scan statistics can identify clustering of serious outcomes from human exposure to pesticides. These analyses may be useful for public health officials to target preventive interventions. Further investigation is warranted to understand better the potential explanations for geographical clustering, and to assess whether preventive interventions have an impact on reducing pesticide exposure incidents resulting in serious medical outcomes.

Regional and temporal variation in methamphetamine-related incidents: applications of spatial and temporal scan statistics.

INTRODUCTION: This investigation utilized spatial scan statistics, geographic information systems, and multiple data sources to assess spatial clustering of statewide methamphetamine-related incidents. Temporal and spatial associations with regulatory interventions to reduce access to precursor chemicals (pseudoephedrine) were also explored. METHODS: Four statewide data sources were utilized including regional poison control center statistics, fatality incidents, methamphetamine laboratory seizures, and hazardous substance releases involving methamphetamine laboratories. Spatial clustering of methamphetamine incidents was assessed using SaTScan. SaTScan was also utilized to assess space-time clustering of methamphetamine laboratory incidents, in relation to the enactment of regulations to reduce access to pseudoephedrine. RESULTS: Five counties with a significantly higher relative risk of methamphetamine-related incidents were identified. The county identified as the most likely cluster had a significantly elevated relative risk of methamphetamine laboratories (RR = 11.5), hazardous substance releases (RR = 8.3), and fatalities relating to methamphetamine (RR = 1.4). A significant increase in relative risk of methamphetamine laboratory incidents was apparent in this same geographic area (RR = 20.7) during the time period when regulations were enacted in 2004 and 2005, restricting access to pseudoephedrine. Subsequent to the enactment of these regulations, a significantly lower rate of incidents (RR = 0.111, p = 0.0001) was observed over a large geographic area of the state, including regions that previously had significantly higher rates. CONCLUSIONS: Spatial and temporal scan statistics can be effectively applied to multiple data sources to assess regional variation in methamphetamine-related incidents, and explore the impact of preventive regulatory interventions.

Pyrethrin and pyrethroid exposures in the United States: a longitudinal analysis of incidents reported to poison centers.

INTRODUCTION: Citing the Food Quality Protection Act, the US Environmental Protection Agency (EPA) decided to phase out and eliminate organophosphate insecticide use in residential environments. The phase out process spanned from 2000 to 2005, and it may have resulted in increased consumer use of insecticides containing other active ingredients. This study utilized data from the national Poison Control Center to assess possible changes in exposure incidents involving pyrethrin and pyrethroid insecticides during the phase out of organophosphates from residential uses. METHODS: We extracted pyrethrin and pyrethroid insecticide exposure data from the American Association of Poison Control Centers Toxic Exposure Surveillance System (TESS) annual reports from 2000 to 2005. We examined pyrethrin and pyrethroid incidents by total exposures for each year, and we stratified exposures by age range, reason, number of cases treated in a health care facility, and medical outcome. Cases were examined as a proportion of all insecticide exposures. We calculated the annual incidence rates for exposures involving pyrethrin and pyrethroid insecticides of the population served. RESULTS: Pyrethrin and pyrethroid exposures increased annually in number and as a percentage of all insecticide exposure incidents. The increase in cases was observed for all age categories and exposure reasons. A statistically significant correlation was observed between advancing years (2000-2005) and the number of pyrethrin and pyrethroid incidents (p<.01). While the number of incidents treated in a health care facility increased annually during the study period, the proportion was constant (0.185 +/- 0.012) over the six year period. During the study period, the incidence rate for pyrethrin and pyrethroid exposures increased each year. 44% of all medical outcomes data was recorded, and the majority of outcomes resulted in no symptoms (37%) or minor symptoms (53%). CONCLUSION: TESS data showed a clear increase in cases involving pyrethrins and pyrethroids. The increase was temporally associated with the phase out of organophosphates from residential uses. In the future, medical toxicologists and poison control center personnel should be prepared to respond to an increasing number of pyrethrin and pyrethroid insecticide exposures.

Organophosphate exposures in the United States: a longitudinal analysis of incidents reported to poison centers.

The implementation of the Food Quality Protection Act of 1996 resulted in a decision by the U.S. Environmental Protection Agency to phase out and eliminate the use of organophosphate insecticides in residential environments. The phase-out and cancellation process began in the year 2000 and was complete in 2005. The purpose of this investigation was to utilize national Poison Control Center data to assess whether the risk mitigation decision had an impact on the number of incident cases involving organophosphates in the United States. Organophosphate exposure incident data were extracted from Annual Reports of the American Association of Poison Control Centers Toxic Exposure Surveillance System (TESS) for the years 1995 to 2004. The number of organophosphate exposure incidents peaked at 20,135 in 1997, and declined in each subsequent year. A statistically significant decrease was observed in the average annual number of organophosphate exposure incidents when comparing data from the time periods before (1995-1999) and after (2000-2004) the commencement of the phase-out process. The decrease in organophosphate incident cases was observed for all age categories, as well as for the circumstances surrounding the exposure (unintentional and intentional exposure incidents). TESS data showed a significant decrease in incident cases involving organophosphates in association with the phase-out from residential uses. The results of this investigation are consistent with other studies that have reported that regulatory restriction of access to pesticide formulations may have a significant impact on the number of human exposure incidents.

Zinc adsorption effects on arsenite oxidation kinetics at the birnessite-water interface.

Arsenite is more toxic and mobile than As(V) in soil and sediment environments, and thus it is advantageous to explore factors that enhance oxidation of As(III) to As(V). Previous studies showed that manganese oxides, such as birnessite (delta-MnO2), directly oxidized As(III). However, these studies did not explore the role that cation adsorption has on As(III) oxidation. Accordingly, the effects of adsorbed and nonadsorbed Zn on arsenite (As(III)) oxidation kinetics at the birnessite-water interface were investigated using batch adsorption experiments (0.1 g L(-1); pH 4.5 and 6.0; I= 0.01 M NaCl). Divalent Zn adsorption on synthetic delta-MnO2 in the absence of As(II) increased with increasing pH and caused positive shifts in electrophoretic mobility values at pH 4-6, indirectly suggesting inner-sphere Zn adsorption mechanisms. Arsenite was readily oxidized on birnessite in the absence of Zn. The initial As(III) oxidation rate constant decreased with increasing pH from 4.5 to 6.0 and initial As(III) concentrations from 100 to 300 microM. Similar pH and initial As(III) concentration effects were observed in systems when Zn was present (i.e., presorbed Zn prior to As(III) addition and simultaneously added Zn-As(III) systems), but As(III) oxidation reactions were suppressed compared to the respective control systems. The suppression was more pronounced when Zn was presorbed on the delta-MnO2 surfaces as opposed to added simultaneously with As(III). This study provides further understanding of As(III) oxidation reactions on manganese oxide surfaces under environmentally applicable conditions where metals compete for reactive sites.