The risk of pulmonary NTM infections and water-quality constituents among persons with cystic fibrosis in the United States, 2010-2019

Rationale

The prevalence of nontuberculous mycobacterial (NTM) pulmonary disease varies geographically in the United States. Previous studies indicate that the presence of certain water-quality constituents in source water increases NTM infection risk.

Objective

To identify water-quality constituents that influence the risk of NTM pulmonary infection in persons with cystic fibrosis in the United States.

Methods

We conducted a population-based case-control study using NTM incidence data collected from the Cystic Fibrosis Foundation Patient Registry during 2010-2019. We linked patient zip code to the county and associated patient county of residence with surface water data extracted from the Water Quality Portal. We used logistic regression models to estimate the odds of NTM infection as a function of water-quality constituents. We modeled two outcomes: pulmonary infection due to Mycobacterium avium complex (MAC) and Mycobacterium abscessus species.

Results

We identified 484 MAC cases, 222 M. abscessus cases and 2816 NTM-negative cystic fibrosis controls resident in 11 states. In multivariable models, we found that for every 1-standardized unit increase in the log concentration of sulfate and vanadium in surface water at the county level, the odds of infection increased by 39% and 21%, respectively, among persons with cystic fibrosis with MAC compared with cystic fibrosis-NTM-negative controls. When modeling M. abscessus as the dependent variable, every 1-standardized unit increase in the log concentration of molybdenum increased the odds of infection by 36%.

Conclusions

These findings suggest that naturally occurring and anthropogenic water-quality constituents may influence the NTM abundance in water sources that supply municipal water systems, thereby increasing MAC and M. abscessus infection risk.

Environmental risk of nontuberculous mycobacterial infection: Strategies for advancing methodology

The National Institute of Allergy and Infectious Diseases organized a symposium in June 2022, to facilitate discussion of the environmental risks for nontuberculous mycobacteria exposure and disease. The expert researchers presented recent studies and identified numerous research gaps. This report summarizes the discussion and identifies six major areas of future research related to culture-based and culture independent laboratory methods, alternate culture media and culturing conditions, frameworks for standardized laboratory methods, improved environmental sampling strategies, validation of exposure measures, and availability of high-quality spatiotemporal data.

Detecting clusters of high nontuberculous mycobacteria infection risk for persons with cystic fibrosis - An analysis of U.S. counties

Nontuberculous mycobacteria are ubiquitous environmental bacteria that frequently cause disease in persons with cystic fibrosis (pwCF). The risks for NTM infection vary geographically. Detection of high-risk areas is important for focusing prevention efforts. In this study, we apply five cluster detection methods to identify counties with high NTM infection risk. Four clusters were detected by at least three of the five methods, including twenty-five counties in five states. The geographic area and number of counties in each cluster depended upon the detection method used. Identifying these clusters supports future studies of environmental predictors of infection and will inform control and prevention efforts.

Estimating the optimal population upper bound for scan methods in retrospective disease surveillance

Correctly and quickly identifying disease patterns and clusters is a vital aspect of public health and epidemiology so that disease outbreaks can be mitigated as effectively as possible. The circular scan method is one of the most commonly used methods for detecting disease outbreaks and clusters in retrospective and prospective disease surveillance. The circular scan method requires a population upper bound in order to construct the set of candidate zones to be scanned, which is usually set to 50% of the total population. The performance of the circular scan method is affected by the choice of the population upper bound, and choosing an upper bound different from the default value can improve the method's performance. Recently, the Gini coefficient based on the Lorenz curve, which was originally used in economics, was proposed to determine a better population upper bound. We present the elbow method, a new method for choosing the population upper bound, which seeks to address some of the limitations of the Gini-based method while improving the performance of the circular scan method over the default value. To evaluate the performance of the proposed approach, we evaluate the sensitivity and positive predictive value of the circular scan method for publicly-available benchmark data for the default value, the Gini coefficient method, and the elbow method.

A modified CUSUM test to control postoutbreak false alarms

The cumulative sum (CUSUM) control chart is a method for detecting whether the mean of a time series process has shifted beyond some tolerance (ie, is out of control). Originally developed in an industrial process control setting, the CUSUM statistic is typically reset to zero once a process is discovered to be out of control since the industrial process is then recalibrated to be in control. The CUSUM method is also used to detect disease outbreaks in prospective disease surveillance, with a disease outbreak coinciding with an out-of-control process. In a disease surveillance setting, resetting the CUSUM statistic is unrealistic, and a nonrestarting CUSUM chart is used instead. In practice, the nonrestarting CUSUM provides more information but suffers from a high false alarm rate following the end of an outbreak. In this paper, we propose a modified hypothesis test for use with the nonrestarting CUSUM when testing whether a process is out of control. By simulating statistics conditional on the presence of an out-of-control process in recent time periods, we are able to retain the CUSUM's power to detect an out-of-control process while controlling the post-out-of-control false alarm rate at the desired level. We demonstrate this method using data on a Salmonella Newport outbreak that occurred in Germany in 2011. We find that in 7 out of 8 states where the outbreak was detected, the outbreak was detected at the same speed as an unmodified nonrestarting CUSUM while controlling the postoutbreak rate of false alarms at the desired level.

Microsite and elevation zone effects on seed pilferage, germination, and seedling survival during early whitebark pine recruitment

Tree recruitment is a spatially structured process that may undergo change over time because of variation in postdispersal processes. We examined seed pilferage, seed germination, and seedling survival in whitebark pine to determine whether 1) microsite type alters the initial spatial pattern of seed caches, 2) higher abiotic stress (i.e. higher elevations) exacerbates spatial distribution changes, and 3) these postdispersal processes are spatially clustered. At two study areas, we created a seed distribution pattern by burying seed caches in microsite types frequently used by whitebark pine's avian seed disperser (Clark's nutcracker) in upper subalpine forest and at treeline, the latter characterized by high abiotic environmental stress. We monitored caches for two years for pilferage, germination, and seedling survival. Odds of pilferage (both study areas), germination (northern study area), and survival (southern study area) were higher at treeline relative to subalpine forest. At the southern study area, we found higher odds of 1) pilferage near rocks and trees relative to no object in subalpine forest, 2) germination near rocks relative to trees within both elevation zones, and 3) seedling survival near rocks and trees relative to no object at treeline. No microsite effects were detected at the northern study area. Findings indicated that the microsite distribution of seed caches changes with seed/seedling stage. Higher odds of seedling survival near rocks and trees were observed at treeline, suggesting abiotic stress may limit safe site availability, thereby shifting the spatial distribution toward protective microsites. Higher odds of pilferage at treeline, however, suggest rodents may limit treeline recruitment. Further, odds of pilferage were higher near rocks and trees relative to no object in subalpine forest but did not differ among microsites at treeline, suggesting pilferage can modulate the spatial structure of regeneration, a finding supported by limited clustering of postdispersal processes.

Assessing NARCCAP climate model effects using spatial confidence regions

We assess similarities and differences between model effects for the North American Regional Climate Change Assessment Program (NARCCAP) climate models using varying classes of linear regression models. Specifically, we consider how the average temperature effect differs for the various global and regional climate model combinations, including assessment of possible interaction between the effects of global and regional climate models. We use both pointwise and simultaneous inference procedures to identify regions where global and regional climate model effects differ. We also show conclusively that results from pointwise inference are misleading, and that accounting for multiple comparisons is important for making proper inference.

autoimage: Multiple Heat Maps for Projected Coordinates

Heat maps are commonly used to display the spatial distribution of a response observed on a two-dimensional grid. The autoimage package provides convenient functions for constructing multiple heat maps in unified, seamless way, particularly when working with projected coordinates. The autoimage package natively supports: 1. automatic inclusion of a color scale with the plotted image, 2. construction of heat maps for responses observed on regular or irregular grids, as well as non-gridded data, 3. construction of a matrix of heat maps with a common color scale, 4. construction of a matrix of heat maps with individual color scales, 5. projecting coordinates before plotting, 6. easily adding geographic borders, points, and other features to the heat maps. After comparing the autoimage package's capabilities for constructing heat maps to those of existing tools, a carefully selected set of examples is used to highlight the capabilities of the autoimage package.

An improved cumulative sum-based procedure for prospective disease surveillance for count data in multiple regions

We present an improved procedure for detecting outbreaks in multiple spatial regions using count data. We combine well-known methods for disease surveillance with recent developments from other areas to provide a more powerful procedure that is still relatively simple and fast to implement. Disease counts from neighboring regions are aggregated to compute a Poisson cumulative sum statistic for each region of interest. Instead of controlling the average run length criterion in the monitoring process, we instead utilize the FDR, which is more appropriate in a public health context. Additionally, p-values are used to make decisions instead of traditional critical values. The use of the FDR and p-values in testing allows us to utilize recently developed multiple testing methodologies, greatly increasing the power of this procedure. This is verified using a simulation experiment. The simplicity and rapid detection ability of this procedure make it useful in disease surveillance settings. The procedure is successfully applied in detecting the 2011 Salmonella Newport outbreak in 16 German federal states. Copyright © 2016 John Wiley & Sons, Ltd.

Exercise and myocardial tolerance to ischaemia-reperfusion

It is well established that both short-term (1-5 days) and long-term (weeks to months) high intensity exercise (i.e. 70-75%VO2max) provides cardioprotection against ischaemia-reperfusion injury. However, it is unclear if moderate intensity exercise will also provide cardioprotection.

AIM

Therefore, these experiments compared the protective effects of moderate vs. high intensity exercise in providing defense against ischaemia-reperfusion injury.

METHODS

Male Sprague-Dawley rats were randomly assigned to one of three-experimental groups: (1) sedentary (control); (2) moderate intensity treadmill exercise (60 min day(-1) at approximately 55%VO2max); or (3) high intensity treadmill exercise (60 min day(-1) at approximately 75%VO2max). Hearts were exposed to 20 min of global ischaemia followed by 30 min reperfusion in an isolated working heart preparation.

RESULTS

Compared with sedentary rats, both moderate and high intensity exercised rats maintained a higher (P < 0.05) percentage of pre-ischaemia cardiac output and cardiac work (cardiac output x systolic blood pressure) during reperfusion. No differences in the percent recovery of cardiac output and heart work existed (P > 0.05) between the two exercise groups.

CONCLUSIONS

These data reveal that both moderate and high intensity exercise training provide equivalent protection against ischaemia-reperfusion injury.

Drug withdrawal symptoms in children after continuous infusions of fentanyl

The purpose of this research was to determine the extent to which critically ill infants exhibited signs and symptoms of narcotic withdrawal after receiving continuous infusions of fentanyl. The convenience sample consisted of 12 pediatric intensive care unit (PICU) patients under 25 months of age who received fentanyl infusions for at least 24 hours. Drug withdrawal symptoms were monitored using the Neonatal Abstinence Score Tool (NAST), which assigns a score to each behavior indicative of withdrawal. A score of 8 or greater indicates Neonatal Abstinence Syndrome (NAS). Scoring began 4 hours after discontinuation of fentanyl and was conducted once per hour for 8 hours. Six subjects had a NAST score exceeding 8; these infants frequently exhibited tremors with or without stimulation, increased muscle tone, insomnia, and increased respiratory rate and effort. There were significant correlations between fentanyl dosage and NAST score (r = .76, p < 0.01), between length of infusion of fentanyl and NAST score (r = .70, p < 0.05), and between chloral hydrate dosage and NAST score (r = .62, p < 0.05). These findings suggest the need for an observation protocol and a possible weaning regimen after fentanyl is discontinued.

A statewide evaluation of pediatric prehospital and hospital emergency services

OBJECTIVE

To evaluate the extent of pediatric emergency training and the availability of pediatric equipment and patient care protocols in the prehospital and hospital settings.

DESIGN

Statewide surveys developed by the North Carolina Provisional Committee on Pediatric Emergency Medical Services and by the Office of Emergency Medical Services.

SETTING AND PARTICIPANTS

Surveys were mailed to all 572 prehospital Emergency Medical Service (EMS) agencies and separately to all 125 acute-care hospitals in North Carolina.

INTERVENTIONS

None.

MEASUREMENTS/MAIN RESULTS

Surveys were returned by 335 (58.6%) of the prehospital providers, including all 45 paramedic and 14 advanced-intermediate provider agencies. One hundred (80%) of the acute-care hospitals returned surveys. Only 10.8% of the prehospital EMS agencies provided more than 10 hours of basic training in pediatric emergency care; 18% provided more than 5 hours of continuing education in pediatric emergencies over a 3-year period. Pediatric-specific equipment was available in many prehospital vehicles, although some deficiencies were noted. Written pediatric management, bypass, and helicopter transport protocols were absent in most prehospital programs. Paramedic programs generally were much better in all areas, although deficiencies were present. Only 14% of the responding hospitals had more than 20 pediatric beds; 13% reported seeing more than 100 patients per day in the emergency department. Deficiencies were identified in pediatric patient care protocols, triage and transport agreements, pediatric training of nurses and physicians, and equipment. Equipment deficiencies were more marked in the intensive care units than in the emergency departments.

CONCLUSIONS

These survey data are inexpensive to obtain and demonstrate EMS system deficiencies. The survey information provides a baseline measurement that can lead to measurable, targeted changes in the state's EMS system for children.