Transmission of Mycobacterium tuberculosis from medical waste.

CONTEXT: Washington State has a relatively low incidence rate of tuberculosis (TB) infection. However, from May to September 1997, 3 cases of pulmonary TB were reported among medical waste treatment workers at 1 facility in Washington. There is no previous documentation of Mycobacterium tuberculosis transmission as a result of processing medical waste. OBJECTIVE: To identify the source(s) of these 3 TB infections. DESIGN, SETTING, AND PARTICIPANTS: Interviews of the 3 infected patient-workers and their contacts, review of patient-worker medical records and the state TB registry, and collection of all multidrug-resistant TB (MDR-TB) isolates identified after January 1, 1995, from the facility's catchment area; DNA fingerprinting of all isolates; polymerase chain reaction and automated DNA sequencing to determine genetic mutations associated with drug resistance; and occupational safety and environmental evaluations of the facility. MAIN OUTCOME MEASURES: Previous exposures of patient-workers to TB; verification of patient-worker tuberculin skin test histories; identification of other cases of TB in the community and at the facility; drug susceptibility of patient-worker isolates; and potential for worker exposure to live M tuberculosis cultures. RESULTS: All 3 patient-workers were younger than 55 years, were born in the United States, and reported no known exposures to TB. We did not identify other TB cases. The 3 patient-workers' isolates had different DNA fingerprints. One of 10 MDR-TB catchment-area isolates matched an MDR-TB patient-worker isolate by DNA fingerprint pattern. DNA sequencing demonstrated the same rare mutation in these isolates. There was no evidence of personal contact between these 2 individuals. The laboratory that initially processed the matching isolate sent contaminated waste to the treatment facility. The facility accepted contaminated medical waste where it was shredded, blown, compacted, and finally deactivated. Equipment failures, insufficient employee training, and respiratory protective equipment inadequacies were identified at the facility. CONCLUSION: Processing contaminated medical waste resulted in transmission of M tuberculosis to at least 1 medical waste treatment facility worker. JAMA. 2000;284:1683-1688.

Measles vaccination in pediatric emergency departments during a measles outbreak.

OBJECTIVE: To determine the proportion of preschool-aged patients attending two inner-city hospital pediatric emergency departments (EDs) who were eligible for measles vaccination, to describe their demographic and clinical characteristics, and to assess the performance of the ED immunization programs that were implemented during a measles outbreak in vaccinating eligible children. DESIGN: Cross-sectional study. SETTING: Pediatric EDs of two urban hospitals in Chicago, Ill, in 1989. PARTICIPANTS: Children 6 months to 5 years of age seen in the EDs. INTERVENTION: None. MAIN OUTCOME MEASURES: The proportion of preschool-aged patients attending the two EDs who were eligible for measles vaccination and the proportion of vaccine-eligible children who were given measles vaccine. RESULTS: Of 508 ED patients at hospital A and 255 patients at hospital B, 18% and 29%, respectively, were considered to be vaccine eligible. The most common discharge diagnoses of eligible patients were viral syndrome, otitis media, and minor trauma. Of vaccine-eligible patients, 59% at hospitals A and B were not vaccinated in the ED. At hospital B, patients with an infectious or respiratory disease diagnosis were less likely to be vaccinated than those with other diagnoses (P < .05). CONCLUSIONS: Many children seen in these EDs were eligible for measles vaccination, and many eligible patients were not vaccinated. During community outbreaks of measles, optimal vaccination programs in pediatric EDs could increase vaccination coverage among inner-city preschool-aged children who may have limited access to health care.

Evaluation of telephoned computer-generated reminders to improve immunization coverage at inner-city clinics.

The authors evaluated the effectiveness of computer-generated telephoned reminders used to raise the rates of on-time immunization among preschool-age children in two public clinics in Atlanta, GA. The overall effect of the intervention on immunization levels appeared to be minimal (crude relative risk = 1.07, 95 percent confidence interval = 0.78, 1.46), in part because only about 80 percent of children in both the randomly selected intervention group and in the control group were members of a household with a telephone number listed in clinic records. However, logistic regression analysis indicated that 36 of 68 children (52.9 percent) in the intervention group whose households were reached were vaccinated within 30 days of their due dates, compared to 31 of 75 children (41.3 percent) in the control group whose household telephone numbers were recorded but not called (adjusted odds ratio = 2.12, 95 percent confidence interval = 1.01, 4.46). This analysis indicates that telephoned reminders demonstrated a level of effectiveness in improving immunization levels at inner-city clinics that recommends further trial and study.

The aetiology and risk factors for warts among poultry processing workers.

We conducted an investigation at a poultry processing plant in New Zealand to estimate the prevalence of warts among workers and the risk of developing warts associated with specific work areas or individual work practices. We obtained information on demographic characteristics and self-reported medical and occupational histories from 88 (83%) of 106 permanent employees at the plant; almost half (39 people or 44%) had developed wart-like lesions on their arms or hands after they began working at this plant. We also conducted clinical evaluations of 28 of the 32 (88%) people with wart-like lesions at the time of the investigation; in all but one case, a diagnosis of warts was confirmed. We collected scrapings of warts from 22 (79%) people and identified human papillomavirus (HPV) type 7, which is reportedly uncommon in the general public, in 12 of these specimens. People working at the time of their interview in areas where they often handled dead, raw, unfrozen chickens were three times more likely to have developed warts (Odds ratio [OR] = 3.0, 95% confidence interval [CI]: 1.2-8.0); for those who had ever worked in these 'high-risk' areas, this excess risk almost doubled (OR = 5.6, 95% CI: 2.1-14.7). Nine of the 12 (75%) people with HPV type 7 had worked in these areas at some time. In contrast to previous reports, we found no increased risk of having warts associated with environmental factors or the frequency of cuts and abrasions.(ABSTRACT TRUNCATED AT 250 WORDS)

Vaccination levels and missed opportunities for measles vaccination: a record audit in a public pediatric clinic.

A record audit of 254 children attending a public clinic in Los Angeles was conducted to assess immunization levels prior to a measles outbreak in the community. Coverage with all vaccines appropriate for age decreased from 67% at 3 months to 25% at 19 months. Delay in initiating vaccination was associated with increasing risk for delayed measles-mumps-rubella vaccine beyond age 2 years (P less than .05). In one third of children, health care providers missed an opportunity to administer measles-mumps-rubella vaccine. Recall systems and elimination of missed opportunities may increase vaccination levels in clinic populations. Record audits should be considered for use in guiding the management of immunization programs.

Pediatric emergency room visits: a risk factor for acquiring measles.

In recent years, measles outbreaks have occurred among unimmunized children in inner cities in the United States. From May 1988 through June 1989, 1214 measles cases were reported in Los Angeles, and from October 1988 through June 1989, 1730 cases were reported in Houston. More than half of cases were in children younger than 5 years of age, most of whom were unvaccinated. Of cases of measles in preschool-aged children, nearly one fourth in Los Angeles and more than one third in Houston were reported by one inner-city emergency room. To evaluate whether emergency room visits were a risk factor for acquiring measles, in Los Angeles, 35 measles patients and 109 control patients with illnesses other than measles, and in Houston, 49 measles patients and 128 control patients, who visited these emergency rooms, were enrolled in case-control studies. Control patients were matched to case patients for ethnicity, age, and week of visit. Records were reviewed to determine whether case patients had visited the emergency room during the period of potential measles exposure, which was defined as 10 to 18 days before rash onset, and whether control patients had visited 10 to 18 days before their enrollment visit. In Los Angeles, 23% of case patients and 5% of control patients (odds ratio = 5.2, 95% confidence interval = 1.7, 15.9; P less than .01), and in Houston, 41% of case patients and 6% of control patients (odds ratio = 8.4, 95% confidence interval = 3.3, 21.2; P less than .01), visited the emergency room during these periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Predictors of vaccination behavior among persons ages 65 years and older.

We estimated influenza vaccination coverage of 32 percent among persons 65 years of age and older from the 1987 Behavioral Risk Factor Surveillance System survey. Race other than White, obesity, lack of seatbelt use, and current smoking were associated with decreased likelihood of having been vaccinated. Controlling for these factors, the best predictor of having received influenza vaccination was having had a medical checkup within the last year (Odds Ratio = 2.40, 95% confidence interval = 1.84, 3.14).

Exposure to toxic waste sites: an investigative approach.

Improper dumping and storage of hazardous substances and whether these practices produce significant human exposure and health effects are growing concerns. A sequential approach has been used by the Centers for Disease Control and the Agency for Toxic Substances and Disease Registry in investigating potential exposure to and health effects resulting from environmental contamination with materials such as heavy metals, volatile organic compounds, and pesticide residues at sites throughout the United States. The strategy consists of four phases: site evaluation, pilot studies of exposure or health effects, analytic epidemiology studies, and public health surveillance. This approach offers a logical, phased strategy to use limited personnel and financial resources of local, State, national, or global health agency jurisdictions optimally in evaluating populations potentially exposed to hazardous materials in waste sites. Primarily, this approach is most helpful in identifying sites for etiologic studies and providing investigative leads to direct and focus these studies. The results of such studies provide information needed for making risk-management decisions to mitigate or eliminate human exposures and for developing interventions to prevent or minimize health problems resulting from exposures that already have occurred.

Diminished thymosin alpha-1 levels in persons exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

There is evidence from animal studies that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) impairs immune responses, with the thymus being a principal target organ. The purpose of this study was to evaluate thymic function, through measurement of thymic hormone levels, in persons exposed to TCDD. We examined thymosin alpha-1 (Thya-1) levels in sera from a group of 94 persons who were presumed to be exposed to TCDD from living, working, or recreating in a contaminated residential area. We compared these results, along with results from in vitro and in vivo tests of immune function, with those from a group of 105 unexposed persons who were similar with regard to age, sex, and race. The exposed group had a significantly lower mean Thya-1 serum level (977.3 +/- 304.1 pg/ml vs. 1148.7 +/- 482.1 pg/ml, p less than .01 by t-test). We also found a statistically significant trend of decreasing Thya-1 levels with increasing number of years of residence in the TCDD-contaminated area. However, Thya-1 levels were not associated with other measures of immune function in the TCDD-exposed group. Thus, while the principal findings suggest that long-term TCDD exposure may be associated with diminished secretion of Thya-1, the lack of an association with an increased prevalence of clinically diagnosed immune suppression in these TCDD-exposed persons makes the biologic significance of the findings unclear. Further studies are needed to more fully evaluate possible long-term TCDD-induced effects on the thymus and human immune function.

Demographic and seasonal influences on human serum pesticide residue levels.

This study was intended to characterize more fully the distribution of serum concentrations of 16 pesticide residues with regard to key demographic and seasonal variables in a subsample of persons from the Second National Health and Nutrition Examination Survey between the ages of 12 and 74 yr old. Blood sera in 2-ml aliquots were analyzed, and the results were confirmed for 5994 persons. Almost all participants (99.5%) had p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) concentrations greater than or equal to 1 ppb, ranging as high as 378.6 ppb. For the other pesticide residues, only beta-benzene hexachloride (beta-BHC) (quantified in 17.2% of the sera), dieldrin (10.6%), and another DDT-related residue, p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) (35.7%) were found at quantifiable levels in more than 10% of the serum specimens. Of the remaining analytes, hexachlorobenzene (HCB), trans-nonachlor (TNC), and heptachlor epoxide (HE) were found at quantifiable concentrations in 1-10% of the specimens, whereas o,p'-DDT, o,p'-DDE, p,p'-DDD, mirex, alpha-BHC, gamma-BHC, heptachlor, delta-BHC, and aldrin were found in less than 1% of the serum specimens. Results showed that increasing age, residing on a farm, or being a male conferred increased risks of exposure to most of the pesticide residues, independent of all other demographic and seasonal factors. In a pattern less consistent across the different pesticide residues and for fewer of the pesticides, persons who lived below the national poverty level, were nonwhite, resided in the South or West, or were examined in the spring or winter also seemed to have an increased likelihood of having quantifiable serum levels.

Human exposure to polychlorinated biphenyls at toxic waste sites: investigations in the United States.

Beginning in 1982, environmental and population data were evaluated from waste sites contaminated with polychlorinated biphenyls (PCBs). Pilot exposure assessment studies were conducted at 12 sites where risks of human exposure were thought to be greatest. Serum PCB levels in persons at highest risk of nonoccupationally related exposures (because of their self-reported frequencies and types of activities in contaminated areas) at 10 sites were within background ranges, even though environmental contamination levels as high as 2.5 parts per billion (ppb) in monitoring well water samples and 330,000 ppb in soil samples were measured. At the 2 remaining sites, elevated serum levels were found in these high-risk persons, which require further evaluation by community surveys. These results illustrate that, despite elevated environmental contaminant levels, unless uptake of chemicals above background exposure levels can be demonstrated, adverse health effects cannot be attributed to waste site chemicals. However, health risks due to background exposure levels, as well as in populations with elevated PCB body burdens need further study.

A survey of measured levels and dietary sources of selected organochlorine pesticide residues and metabolites in human sera from a rural population.

We measured serum levels of 11 pesticide residues and metabolites in 85 rural-dwelling persons. In general, the serum levels increased with age, with males having slightly higher levels than females. Consumption of eggs from home-raised hens contributed substantially to increased serum concentrations of trans-nonachlor, heptachlor epoxide, and oxychlordane; consumption of home-grown root vegetables likewise contributed to increased serum concentrations of trans-nonachlor and oxychlordane. Health risks, if any, that may be attributable to these "background" levels of exposure remain to be fully characterized in this, and all other, affected populations.

An overview of the Missouri dioxin studies.

Among the problems inherent in evaluating public health impacts around toxic waste sites are the difficulties in measuring exposure, our incomplete understanding of low-dose effects, the low frequency of disease incidence, the long latency period and silent course of disease development, the nonspecificity of clinical findings, and the probable multifactorial nature of diseases of interest. A multiphase approach for implementing epidemiologic studies in such settings was used in assessing the 2,3,7,8-tetrachlorodibenzodioxin (TCDD, or dioxin) contaminations in Missouri, where waste oil mixtures contaminated with dioxins were sprayed on various sites throughout the state for dust control in 1971. Although the toxic effects of dioxin have been studied extensively in animals and documented in cases of accidental high-level exposure in humans, very little is known of the human health effects, if any, produced by long-term exposure to relatively low levels of dioxin. In addition to medical epidemiologic studies, which were done to evaluate the types of problems present in groups of individuals with high-risk of environmental dioxin exposure, other studies to characterize dioxin levels in adipose tissue and serum are under way in a sample of potentially exposed (as well as in unexposed) Missouri residents. Research in these areas will continue to be pursued to develop a more complete understanding of the risks and appropriate public health interventions in situations of community exposure to environmental dioxins and other environmental contaminants.

Risk factors for infection with Echinococcus multilocularis in Alaska.

We studied 19 Eskimo patients with alveolar hydatid disease from the north-western coast of Alaska for risk factors for infection with Echinococcus multilocularis. Each case-patient was matched by age and sex with 2 unrelated controls who had no clinical or serologic evidence of infection with E. multilocularis and who resided in three villages endemic for alveolar hydatid disease. Behaviors thought to increase exposure to E. multilocularis and the chronologic occurrence of these behaviors in the participant's life were assessed by a standardized questionnaire. Case-patients were more likely than controls to have owned dogs for their entire lives (odds ratio 6.00, P less than 0.05), tethered their dogs near the house (odds ratio 8.50, P less than 0.05), and lived in houses built directly on the tundra rather than on gravel or a permanent foundation (odds ratio 11.00, P less than 0.01). Case-patients were not more likely to have owned sled dogs, trapped or skinned foxes, or engaged in other outdoor activities away from home. These findings suggest that controlling the parasite in the domestic dog population, as well as controlling the dog population itself, are important aspects of preventing alveolar hydatid disease in the northwestern Native Alaskan population.

An evaluation of serum pesticide residue levels and liver function in persons exposed to dairy products contaminated with heptachlor.

We studied a group of 45 dairy farm family members who had consumed undiluted raw milk products known to be contaminated with residues of the pesticide heptachlor at concentrations as high as 89.2 ppm (fat basis). We compared results of serum pesticide assays for these exposed persons with results for an unexposed group of 94 persons from the same geographic area and the results from the Second National Health and Nutrition Examination Survey. The exposed group had significantly higher mean levels of primary heptachlor metabolites--ie, heptachlor epoxide (0.84 +/- 1.0 vs 0.50 +/- 0.9 parts per billion) and oxychlordane (0.71 +/- 0.8 vs 0.49 +/- 1.1 parts per billion)--than the unexposed group. In the exposed group, 21.2% had elevated serum concentrations of these same metabolites; this rate was significantly greater than the rates in both the unexposed farm family members (heptachlor epoxide, 3.8%; oxychlordane, 6.3%) and the Second National Health and Nutrition Examination Survey sample (2.5% for both metabolites). However, we found no evidence of related acute and/or subacute hepatic effects in these exposed persons regardless of their serum concentrations of pesticide residues.

Health effects in family pets and 2,3,7,8-TCDD contamination in Missouri: a look at potential animal sentinels.

In 1971, waste oils containing 2,3,7,8:tetrachlorodibenzodioxin (TCDD) were sprayed in Missouri for dust control. To determine if pets could serve as sentinels of human health risks associated with this contamination, we asked pet owners in a pilot study of exposed human populations about their pets' illnesses. Of 13 pets with owner-reported illnesses, 8 had potential TCDD exposures and 5 did not (p less than .05 by Mantel-Haenzel chi-square analysis stratified by age). Owner-reported illnesses in 2 of 8 illness categories were associated with TCDD contamination after adjusting for age. Although these findings suggest that pets in TCDD-contaminated areas may have greater health risks, the small sample size, unlikely pathologic groupings, and unconfirmed nature of the data fail to support a relationship between pet illnesses and possible TCDD exposure and thus make extrapolation to human populations inappropriate. The limited validity found for owner-reported pet illnesses should caution against using such data in future environmental health studies.