Nontuberculous mycobacterial disease following hot tub exposure.

Nontuberculous mycobacteria (NTM) have been recognized as an important cause of disease in immunocompromised hosts. Pulmonary disease caused by NTM is increasingly recognized in previously healthy persons. Investigation of pulmonary disease affecting a family of five identified an indoor hot tub as the source of NTM-related disease.

Maternal exposure to prescription and non-prescription pharmaceuticals or drugs of abuse and risk of craniosynostosis.

BACKGROUND: The pre- and peri-natal drug exposures reported by women participating in a case-control study of children in Colorado were examined for association with infant craniosynostosis. METHODS: Mothers of case and control children underwent a standardized telephone interview and obstetric and newborn medical record review. The interview included questions on the use of prescription and non-prescription drugs, nutritional supplements, recreational and drugs of abuse. The mother's obstetric record was abstracted for information about pharmacologic agents taken before and during the antepartum period. RESULTS: There were no statistically significant risk ratios associating craniosynostosis with prenatal exposure to hydantoin, valproic acid, or cocaine. Mothers of four case children and one control child reported specific exposure to retinoic acid. There were no statistically significant increases in the odds ratio (OR) for any suture type among children exposed to hypoxigenic agents, sympathomimetic or parasympatholytic agents, or metal-containing agents. The OR was 1.87 (lower bound of the two-sided 95% test-based confidence interval (CI): 1.08) among children with sagittal/lambdoid suture synostosis who were exposed to nitrosatable drugs chlorpheniramine, chlordiazepoxide, and nitrofurantoin compared to controls. CONCLUSIONS: Certain nitrosatable drugs may be associated with increased risk of infant sagittal/lambdoid craniosynostosis. A possible mechanism related to ischaemia/reperfusion injury is suggested.

Diagnostic practice and the estimated prevalence of craniosynostosis in Colorado.

BACKGROUND: In the late 1980s, evidence of an epidemic of craniosynostosis in Colorado included reports of clusters from selected high-altitude communities and an investigation showing the high and rapidly rising rates of surgically corrected synostosis. Some evidence suggested that local diagnostic practice could account for the epidemic. OBJECTIVE: To determine the contributions of any excess rates of disease occurrence, surgery-based ascertainment, and diagnosis to the reported epidemic. DESIGN: Population-based birth prevalence study with diagnostic evaluation. SETTING: The Colorado Department of Health, April 15, 1986, to July 14, 1989. PATIENTS OR OTHER PARTICIPANTS: Children in the Craniosynostosis Registry or state birth record files. MAIN OUTCOME MEASURES: Birth prevalence was estimated from registry and birth record data; case classification by suture type and malformation patterns were determined by review of radiographs and medical records. RESULTS: The period birth prevalence of radiographically confirmed nonsyndromic synostosis was 14.1 per 10,000 live births. Of a total of 605 children, 307 (51%) had definite radiographic evidence of synostosis, for which the intrarater reliability was good (except for the coronal suture on plain films) and the interrater reliability was fair or good (except for the metopic suture on plain films). Between the first and third years, case reports fell from 347 to 103. CONCLUSIONS: Diagnostic criteria strongly influenced the rate of synostosis. The rate of radiographically confirmed synostosis was within the range of published estimates. Low diagnostic thresholds, which changed over time, created the semblance of a severe statewide epidemic and may have obscured excess rates of disease at high altitude.

Increased risk of craniosynostosis with higher antenatal maternal altitude.

BACKGROUND: During the 1980s, the Colorado Department of Health received reports from several high-altitude communities of clusters of the malformation craniosynostosis. In a population-based, case-control study, we examined the association between overall and trimester-specific maternal antenatal altitude exposure and the occurrence of infant craniosynostosis. METHODS: We identified case children through a statewide registry and randomly sampled control children from birth records. By telephone interview, each mother provided data on the locations of all antenatal residences and places of employment as well as other factors. Staff mapped all locations and abstracted the corresponding altitudes. RESULTS: The odds ratio (OR) of any synostosis for a time-weighted mean antenatal altitude of > or = 2000 metres (high altitude) versus < 2000 metres (low altitude) was 1.4 (lower bound of the one-sided 95% test-based confidence interval (CI): 0.9). The OR was elevated in smokers but not in non-smokers. As compared to non-smokers, the OR of any synostosis for high-altitude smokers was 4.6 (lower bound of the 95% one-sided exact CI: 1.7). Particularly elevated were the corresponding OR of coronal (18.1, 4.4) and metopic synostosis (16.3, 2.8), and OR for high-altitude exposure during the second trimester (any synostosis: 6.4, 1.99; coronal: 28.6, 6.1; metopic: 26.7, 4.1). CONCLUSIONS: Antenatal maternal high-altitude exposure and smoking are associated with increased risk of infant craniosynostosis, perhaps through generation of intermittent hypoxaemia.

Case-control study of bladder cancer and water disinfection methods in Colorado.

A population-based case-control study of bladder cancer and drinking water disinfection methods was conducted during 1990-1991 in Colorado. Surface water in Colorado has historically been disinfected with chlorine (chlorination) or with a combination of chlorine and ammonia (chloramination). A total of 327 histologically verified bladder cancer cases were frequency matched by age and sex to 261 other-cancer controls. Subjects were interviewed by telephone about residential and water source histories. This information was linked to data from water utility and Colorado Department of Health records to create a drinking water exposure profile. After adjustment for cigarette smoking, tap water and coffee consumption, and medical history factors by logistic regression, years of exposure to chlorinated surface water were significantly associated with risk for bladder cancer (p = 0.0007). The odds ratio for bladder cancer increased for longer durations of exposure to a level of 1.8 (95% confidence interval 1.1-2.9) for more than 30 years of exposure to chlorinated surface water compared with no exposure. The increased bladder cancer risk was similar for males and females and for nonsmokers and smokers. Levels of total trihalomethanes, nitrates, and residual chlorine were not associated with bladder cancer risk after controlling for years of exposure to chlorinated water.

Assessment of blood lead levels in children living in a historic mining and smelting community.

Lead poisoning in childhood is an important public health problem, and thus, it is important to determine how children are exposed to lead. In 1987, the authors conducted an exposure assessment and blood lead screening for children aged 6-71 months living in Leadville, Colorado. High levels of lead had been found in the soil as a result of both past mining and smelting activities and natural mineralization. Blood was collected from each child for lead analysis, and behavioral characteristics were identified through an interview with a parent or guardian. Three sources of exposure to lead were associated with blood lead levels: lead in a core sample taken from the backyard of the family's home, lead brought home on the clothes of a miner, and lead from soldering in the home. Two pathways of exposure were associated with blood lead levels: the child swallowing things other than food, and taking food or a bottle outside to play. Multivariate regression using these variables found effect modification by age. For children aged 6-36 months, only sources of exposure were independent predictors of blood lead levels, while in children aged 37-71 months, a pathway of exposure in addition to sources of exposure independently predicted blood lead levels.

Lead absorption in indoor firing range users.

To determine if users of indoor firing ranges may be at risk from lead exposure, we studied a law enforcement trainee class during three months of firearms instruction. Blood lead levels were obtained before training and at four-week intervals during training. Air lead levels were measured three times during instruction. Blood lead levels rose from a pre-training mean of 0.31 mumol/L to 2.47 mumol/L. Mean air lead levels were above 2,000 micrograms/m3, more than 40 times the Occupational Safety and Health Administration's standard of 50 micrograms/m3. Cumulative exposure to lead and the change in blood lead were positively correlated. Control measures need to be studied to determine their efficacy in decreasing or eliminating this health risk.

An outbreak of Pontiac fever related to whirlpool use, Michigan 1982.

Fourteen of 23 female members of a church group experienced an acute self-limited illness characterized by chills, fever, chest pain, cough, and nausea, consistent with the diagnosis of Pontiac fever. All 14 affected women had used a whirlpool located in the women's locker room during a racquetball party. Legionella pneumophila serogroup 6 was isolated from the women's whirlpool. Nine of 14 cases showed a seroconversion to heat-fixed antigen prepared from the L pneumophila serogroup 6 isolate. Aerosol size studies show that the whirlpool aerator produced water droplets small enough to travel deep into the tracheobronchial tree but large enough to transport L pneumophila. This outbreak demonstrated that Pontiac fever may be associated with L pneumophila serogroup 6, that whirlpools can serve as a reservoir for these organisms, and that seroconversion can occur in the absence of illness.