Jason Goldstick

Heavy Rainfall Events and Diarrhea Incidence: The Role of Social and Environmental Factors

The impact of heavy rainfall events on waterborne diarrheal diseases is uncertain. We conducted weekly, active surveillance for diarrhea in 19 villages in Ecuador from February 2004 to April 2007 in order to evaluate whether biophysical and social factors modify vulnerability to heavy rainfall events. A heavy rainfall event was defined as 24-hour rainfall exceeding the 90th percentile value (56 mm) in a given 7-day period within the study period. Mixed-effects Poisson regression was used to test the hypothesis that rainfall in the prior 8 weeks, water and sanitation conditions, and social cohesion modified the relationship between heavy rainfall events and diarrhea incidence. Heavy rainfall events were associated with increased diarrhea incidence following dry periods (incidence rate ratio = 1.39, 95% confidence interval: 1.03, 1.87) and decreased diarrhea incidence following wet periods (incidence rate ratio = 0.74, 95% confidence interval: 0.59, 0.92). Drinking water treatment reduced the deleterious impacts of heavy rainfall events following dry periods. Sanitation, hygiene, and social cohesion did not modify the relationship between heavy rainfall events and diarrhea. Heavy rainfall events appear to affect diarrhea incidence through contamination of drinking water, and they present the greatest health risks following periods of low rainfall. Interventions designed to increase drinking water treatment may reduce climate vulnerability.

Synergistic Effects Between Rotavirus and Coinfecting Pathogens on Diarrheal Disease: Evidence from a Community-based Study in Northwestern Ecuador

In developing countries where diarrheal disease is a leading cause of morbidity and mortality in children under 5 years of age, enteric coinfection is common. There is little understanding, however, of the biologic interaction between coinfecting pathogens. The authors investigated the potential for synergistic interaction between coinfecting pathogens on diarrhea pathogenesis using an epidemiologic framework. They conducted community-based, case-control studies in 22 communities in northwestern Ecuador between 2003 and 2008. Risk ratios of diarrhea associated with single infections and coinfections were estimated. Interaction between coinfecting pathogens was assessed through departure from risk ratio additivity and multiplicativity after adjustment for age. On the additive scale, the authors found departure from the null value of 0 for rotavirus-Giardia coinfections (interaction contrast ratio = 8.0, 95% confidence interval: 3.1, 18.9) and for rotavirus-Escherichia coli coinfections (interaction contrast ratio = 9.9, 95% confidence interval: 2.6, 28.4). On the multiplicative scale, they found departure from the value of 1 for rotavirus-Giardia coinfections (multiplicative interaction = 3.6, 95% confidence interval: 1.3, 8.7). This research provides epidemiologic evidence for synergism between rotavirus and other enteric pathogens. During coinfection, the pathogenic potential of each organism appears to be enhanced. The potential for pathogenesis to be more severe in the presence of a rotavirus coinfection amplifies the need for rotavirus vaccination.

Violent Reinjury and Mortality Among Youth Seeking Emergency Department Care for Assault-Related Injury: A 2-Year Prospective Cohort Study

IMPORTANCE Violence is a leading cause of morbidity and mortality among youth, with more than 700000 emergency department (ED) visits annually for assault-related injuries. The risk for violent reinjury among high-risk, assault-injured youth is poorly understood. OBJECTIVE To compare recidivism for violent injury and mortality outcomes among drug-using, assault-injured youth (AI group) and drug-using, non-assault-injured control participants (non-AI group) presenting to an urban ED for care. DESIGN, SETTING, AND PARTICIPANTS Participants were enrolled in a prospective cohort study from December 2, 2009, through September 30, 2011, at an urban level I ED and followed up for 24 months. We administered validated measures of violence and substance use and mental health diagnostic interviews and reviewed medical records at baseline and at each point of follow-up (6, 12, 18, and 24 months). EXPOSURE Follow-up over 24 months. MAIN OUTCOMES AND MEASURES Use of ED services for assault or mortality measured from medical record abstraction supplemented with self-report. RESULTS We followed 349 AI and 250 non-AI youth for 24 months. Youth in the AI group had almost twice the risk for a violent injury requiring ED care within 2 years compared with the non-AI group (36.7% vs 22.4%; relative risk [RR], 1.65 [95% CI, 1.25-2.14]; P<.001). Two-year mortality was 0.8%. Poisson regression modeling identified female sex (RR, 1.30 [95% CI, 1.02-1.65]), assault-related injury (RR, 1.57 [95% CI, 1.19-2.04), diagnosis of a drug use disorder (RR, 1.29 [95% CI, 1.01-1.65]), and posttraumatic stress disorder (RR, 1.47 [95% CI, 1.09-1.97]) at the index visit as predictive of ED recidivism or death within 24 months. Parametric survival models demonstrated that assault-related injury (P<.001), diagnosis of posttraumatic stress disorder (P=.008), and diagnosis of a drug use disorder (P= .03) significantly shortened the expected waiting time until the first ED return visit for violence or death. CONCLUSIONS AND RELEVANCE Violent injury is a reoccurring disease, with one-third of our AI group experiencing another violent injury requiring ED care within 2 years of the index visit, almost twice the rate of a non-AI comparison group. Secondary violence prevention measures addressing substance use and mental health needs are needed to decrease subsequent morbidity and mortality due to violence in the first 6 months after an assault injury.

The Geography of Violence, Alcohol Outlets, and Drug Arrests in Boston

OBJECTIVES We examined the relationship between alcohol outlets, drug markets (approximated by arrests for possession and trafficking), and violence in Boston, Massachusetts, in 2006. We analyzed geographic and environmental versus individual factors related to violence and identified areas high in violent crime. METHODS We used data from the Boston Police Department, US Census, and Massachusetts State Alcohol Beverage Control Commission. Spatial modeling was employed at the block group level, and violent crime, alcohol outlets, and drug markets were mapped. RESULTS Relative to other block groups, block groups in the highest decile of violent crime (n = 55) were found to be poorer (e.g., lower incomes, higher percentages of vacant homes), and they had greater numbers of alcohol outlets and higher drug arrest rates. Alcohol outlets and drug possession and trafficking arrests were predictive of violent crime. Also, spatial effects resulting from neighboring block groups were related to violent crime. Both alcohol outlet density and type were associated with violent crime in a differentiated and complex way. CONCLUSIONS With drug possession and trafficking arrests as a proxy for drug markets, spatial relationships between alcohol outlets and violence were found in addition to typical sociodemographic predictors.

Impact of rainfall on diarrheal disease risk associated with unimproved water and sanitation.

Diarrheal disease remains a leading cause of morbidity in areas with limited access to safe water and sanitation. As water and sanitation interventions continue to be implemented, it will be important to understand the ecological context in which they can prevent diarrhea. We conducted six serial case control studies in Ecuador to estimate the risk of diarrhea from unimproved water and sanitation and the potential for effect modification by rainfall. Unimproved water source and unimproved sanitation increased the adjusted odds of diarrhea (odds ratio [OR] = 3.6, 95% confidence interval [95% CI] = 1.7-7.8 and OR = 1.7, 95% CI = 1.2-2.5, respectively). The OR associated with an unimproved water source was highest after maximum rainfall (OR = 6.8, 95% CI = 1.9-24.5), whereas the OR associated with unimproved sanitation was highest after minimal rainfall (OR = 2.9, 95% CI = 1.3-6.6). Our finding that use of safe water sources and improved sanitation facilities are most protective under opposing rainfall conditions highlights the need for integrated interventions to reduce the burden of diarrheal disease.

In-roads to the spread of antibiotic resistance: regional patterns of microbial transmission in northern coastal Ecuador

The evolution of antibiotic resistance (AR) increases treatment cost and probability of failure, threatening human health worldwide. The relative importance of individual antibiotic use, environmental transmission and rates of introduction of resistant bacteria in explaining community AR patterns is poorly understood. Evaluating their relative importance requires studying a region where they vary. The construction of a new road in a previously roadless area of northern coastal Ecuador provides a valuable natural experiment to study how changes in the social and natural environment affect the epidemiology of resistant Escherichia coli. We conducted seven bi-annual 15 day surveys of AR between 2003 and 2008 in 21 villages. Resistance to both ampicillin and sulphamethoxazole was the most frequently observed profile, based on antibiogram tests of seven antibiotics from 2210 samples. The prevalence of enteric bacteria with this resistance pair in the less remote communities was 80 per cent higher than in more remote communities (OR = 1.8 [1.3, 2.3]). This pattern could not be explained with data on individual antibiotic use. We used a transmission model to help explain this observed discrepancy. The model analysis suggests that both transmission and the rate of introduction of resistant bacteria into communities may contribute to the observed regional scale AR patterns, and that village-level antibiotic use rate determines which of these two factors predominate. While usually conceived as a main effect on individual risk, antibiotic use rate is revealed in this analysis as an effect modifier with regard to community-level risk of resistance.

Firearm Violence Among High-Risk Emergency Department Youth After an Assault Injury

BACKGROUND: The risk for firearm violence among high-risk youth after treatment for an assault is unknown. METHODS: In this 2-year prospective cohort study, data were analyzed from a consecutive sample of 14- to 24-year-olds with drug use in the past 6 months seeking assault-injury care (AIG) at an urban level 1 emergency department (ED) compared with a proportionally sampled comparison group (CG) of drug-using nonassaulted youth. Validated measures were administered at baseline and follow-up (6, 12, 18, 24 months). RESULTS: A total of 349 AIG and 250 CG youth were followed for 24 months. During the follow-up period, 59% of the AIG reported firearm violence, a 40% higher risk than was observed among the CG (59.0% vs. 42.5%; relative risk [RR] = 1.39). Among those reporting firearm violence, 31.7% reported aggression, and 96.4% reported victimization, including 19 firearm injuries requiring medical care and 2 homicides. The majority with firearm violence (63.5%) reported at least 1 event within the first 6 months. Poisson regression identified baseline predictors of firearm violence, including male gender (RR = 1.51), African American race (RR = 1.26), assault-injury (RR = 1.35), firearm possession (RR = 1.23), attitudes favoring retaliation (RR = 1.03), posttraumatic stress disorder (RR = 1.39), and a drug use disorder (RR = 1.22). CONCLUSIONS: High-risk youth presenting to urban EDs for assault have elevated rates of subsequent firearm violence. Interventions at an index visit addressing substance use, mental health needs, retaliatory attitudes, and firearm possession may help decrease firearm violence among urban youth.

The effect of neighborhood context on the relationship between substance misuse and weapons aggression in urban adolescents seeking ED care

Background: Frameworks for studying the ecology of human behavior suggest that multiple levels of the environment influence behavior and that these levels interact. Applied to studies of weapons aggression, this suggests proximal risk factor (e.g., substance use) effects may differ across neighborhoods. Objectives: To estimate how the association between weapons aggression and substance use varies as a function of several community-level variables. Methods: Individual-level measures (demographics, behavioral measures) were obtained from a survey of youth aged 14–24 years old seeking care at a Level-1 ED in Flint, Michigan. Community-level variables were obtained from public sources. Logistic generalized additive models were used to test whether community-level variables (crime rates, alcohol outlets, demographics) modify the link between individual-level substance use variables and the primary outcome measure: self-reported past 6-month weapon (firearm/knife) related aggression. Results: The effect of marijuana misuse on weapons aggression varied significantly as a function of five community-level variables: racial composition, vacant housing rates, female headed household rates, density of package alcohol outlets, and nearby drug crime rates. The effect of high-risk alcohol use did not depend on any of the eight community variables tested. Conclusions: The relationship between marijuana misuse and weapons aggression differed across neighborhoods with generally less association in more disadvantaged neighborhoods, while high-risk alcohol use showed a consistently high association with weapons aggression that did not vary across neighborhoods. The results aid in understanding the contributions of alcohol and marijuana use to the etiology of weapon-related aggression among urban youth, but further study in the general population is required.

Football players' head-impact exposure after limiting of full-contact practices

CONTEXT Sporting organizations limit full-contact football practices to reduce concussion risk and based on speculation that repeated head impacts may result in long-term neurodegeneration. OBJECTIVE To directly compare head-impact exposure in high school football players before and after a statewide restriction on full-contact practices. DESIGN Cross-sectional study. SETTING High school football field. PATIENTS OR OTHER PARTICIPANTS Participants were varsity football athletes from a single high school. Before the rule change, 26 athletes (age = 16.2 ± 0.8 years, height = 179.6 ± 6.4 cm, weight = 81.9 ± 13.1 kg) participated. After the rule change, 24 athletes (age = 15.9 ± 0.8 years, height = 178.3 ± 6.5 cm, weight = 76.2 ± 11.6 kg) participated. Nine athletes participated in both years of the investigation. MAIN OUTCOME MEASURE(S) Head-impact exposure was monitored using the Head Impact Telemetry System while the athletes participated in football games and practices in the seasons before and after the rule change. Head-impact frequency, location, and magnitude (ie, linear acceleration, rotational acceleration, and Head Impact Telemetry severity profile [HITsp], respectively) were measured. RESULTS A total of 15 398 impacts (592 impacts per player per season) were captured before the rule change and 8269 impacts (345 impacts per player per season) after the change. An average 42% decline in impact exposure occurred across all players, with practice-exposure declines occurring among linemen (46% decline); receivers, cornerbacks, and safeties (41% decline); and tight ends, running backs (including fullbacks), and linebackers (39% decline). Impact magnitudes remained largely unchanged between the years. CONCLUSIONS A rule change limiting full-contact high school football practices appears to have been effective in reducing head-impact exposure across all players, with the largest reduction occurring among linemen. This finding is likely associated with the rule modification, particularly because the coaching staff and offensive scheme remained consistent, yet how this reduction influences concussion risk and long-term cognitive health remains unknown.

Development of the SaFETy Score: A Clinical Screening Tool for Predicting Future Firearm Violence Risk

Firearm violence has been identified by health and legal professionals as a critical public health problem (1). Homicide is the third leading cause of death in the United States among youth aged 15 to 24 years, with more than 86% of these deaths due to firearms (2). Furthermore, firearm violence results in substantial monetary cost; for example, medical and work-loss costs of nonfatal firearm injuries treated in U.S. emergency departments were estimated to exceed