Results from a Ukrainian-US collaborative study: prevalence and predictors of respiratory symptoms among Ukrainian coal miners.

BACKGROUND: Underground coal mining is an expanding industry in Ukraine, yet little is known about the burden of respiratory disease among Ukrainian miners. METHODS: A Fogarty International Center-supported collaboration between researchers at the University of Illinois and the Institute of Occupational Health in Kyiv, Ukraine formed to improve capacity for conducting and monitoring medical surveillance among Ukrainian coal miners. A cross-sectional survey among a random sample of working and former miners was conducted; demographic, work, and health information were collected using a standardized questionnaire. Weighted prevalence rates were calculated and predictors of respiratory symptoms explored. RESULTS: Improvements in infrastructure, including spirometry and chest radiography testing, transformed medical surveillance among these miners. Results from the health study included that the prevalence of respiratory symptoms was higher among former compared to current miners (shortness of breath 35.6% vs. 5.1%; chronic bronchitis 18.1% vs. 13.9%, respectively). A statistically significant exposure-response relationship was observed between years mining and respiratory symptoms in former miners and between years mining at the coal face and respiratory symptoms among current miners. Evidence of downward bias from the healthy worker survivor effect was observed. CONCLUSIONS: This successful international collaboration built a sustainable infrastructure for conducting workplace medical surveillance and research. The resulting study was the first in the western literature to report on respiratory symptoms in this population; likely underestimation of disease rates due to selection and measurement biases was demonstrated. Efforts should continue to build this collaboration and to characterize and reduce respiratory illness among Ukrainian coal miners.

Epidemiology of recurrent genital herpes simplex virus types 1 and 2.

OBJECTIVES: To describe the epidemiology of type specific recurrent genital herpes, and to compare the duration of recurrent genital lesions caused by herpes simplex virus (HSV) types 1 and 2. METHODS: Participants were enrolled at clinics across the United States. Adults suspected of having active genital herpes were eligible. Lesions were cultured for HSV and typed. Data from 940 participants with recurrent culture positive HSV lesions were analysed. Pearson's chi(2) and Fisher's exact tests, multivariate logistic regression models, and a stratified Cox proportional hazards model were used to compare epidemiological characteristics and lesion duration of HSV-1 and HSV-2. RESULTS: HSV-1 was present in 4.2% of the recurrent HSV culture positive lesions. HSV-1 was most prevalent among whites (6.5%) and individuals with 0-2 recurrences in the previous year (9.1%) and, among men, in those with rectal/perirectal lesions (13.2%). Longer lesion duration was not significantly associated with virus type (hazard ratio (HR) 0.95, 95% confidence interval (CI) 0.65 to 1.38, p = 0.79), but was associated with male sex (HR 0.85, 95% CI 0.74 to 0.99, p = 0.04), and HIV seropositivity (HR 0.62, 95% CI 0.48 to 0.81, p<0.01). CONCLUSIONS: The authors found that, in the United States, recurrent genital HSV-1 is relatively rare in the STD and HIV clinic setting, especially among black people. Among men, rectal/perirectal recurrent lesions are more likely to be caused by HSV-1 than are penile lesions. In addition, lesion duration depends on sex and HIV status but not virus type. These findings shed new light on the type specific epidemiology of recurrent genital HSV, and suggest that type specific testing can inform the prognosis and management of genital herpes.

Assessment of occupational risk for hantavirus infection in Arizona and New Mexico.

Differentiating occupational exposure from other potential domestic or recreational exposure(s) for Sin Nombre virus (SNV) infection is an epidemiologic challenge. Interviews on work-related activities were conducted, and serum specimens were obtained from 494 workers in Arizona and New Mexico. These workers may have been exposed to rodents and rodent excreta at work, but their primary occupation did not require rodent contact (National Park Service [n = 193]; Navajo Agricultural Product Industry [n = 65], utility companies [n = 169] and plumbing and heating contractors [n = 67]. Within each occupational group (farm workers [n = 57], laborers [n = 20], professionals [n = 70], repairers [n = 211], service industry workers [n = 83], and technicians [n = 53], the majority of workers reported working in areas that had rodent droppings (range, 75 to 95%); 70% of laborers and 64% of service industry workers reported handling rodents. More than 60% of workers in each group, except technicians, reported reopening and cleaning or working in closed spaces. Approximately 90% of laborers, repairers, and farm workers reported hand-plowing. Although the risk for occupationally related SNV infection appears to be low, workers frequently performed risk activities associated with hantavirus pulmonary syndrome (HPS). All workers were seronegative for SNV by enzyme-linked immunoassay or Western blot testing. These findings, the known occupational exposure of some HPS cases, and the high HPS case-fatality rate (52%) support the need for recommendations to reduce human contact with rodents in the workplace. Increased understanding of hantavirus transmission to humans will help focus future recommendations to minimize human exposures effectively.

Utility of emergency, telephone-based national surveillance for Hantavirus pulmonary syndrome. Hantavirus Task Force.

On May 27, 1993, in response to the outbreak investigation of newly recognized Hantavirus pulmonary syndrome (HPS) in the Four Corners states (New Mexico, Arizona, Utah, and Colorado), the Centers for Disease Control and Prevention established a national surveillance case definition for severe, unexplained respiratory disease to determine the extent of HPS throughout the United States. A toll-free telephone hotline number was instituted to provide updated information about unexplained respiratory illness and to serve as a passive mechanism for reporting suspected cases. Clinical information was obtained from callers reporting suspected cases, and diagnostic specimens and medical record reviews were requested from health care providers. From June 3 through December 31, 1993, the hotline received 21,443 telephone inquiries; callers identified 280 suspected cases living outside the Four Corners states with at least one specimen available for diagnostic testing. By December 31, 1993, 21 confirmed cases (age range, 14 to 58 years) residing in 11 states outside the Four Corners region had been identified. This passive surveillance system was successful in rapidly identifying the widespread sporadic geographic distribution for HPS cases throughout the United States and could serve as a model for similar emergencies. Expanding and coordinating surveillance systems for the early detection, tracking, and evaluation of emerging infections is a critical component of disease prevention.

Trends in infectious diseases mortality in the United States.

OBJECTIVE: To evaluate recent trends in infectious diseases mortality in the United States. DESIGN: Descriptive study of infectious disease mortality, classifying International Classification of Diseases, Ninth Revision codes as infectious diseases, consequence of infectious diseases, or not infectious diseases. Multiple cause-of-death tapes from the National Center for Health Statistics for the years 1980 through 1992 were used, with a focus on underlying cause-of-death data and on codes that exclusively represent infectious diseases. SETTING: United States. SUBJECTS: All persons who died between 1980 and 1992. MAIN OUTCOME MEASURE: Death. RESULTS: Between 1980 and 1992, the death rate due to infectious diseases as the underlying cause of death increased 58%, from 41 to 65 deaths per 100,000 population in the United States. Age-adjusted mortality from infectious diseases increased 39% during the same period. Infectious diseases mortality increased 25% among those aged 65 years and older (from 271 to 338 per 100,000), and 6.3 times among 25- to 44-year-olds (from six to 38 deaths per 100,000). Mortality due to respiratory tract infections increased 20%, from 25 to 30 deaths per 100,000, deaths attributed to human immunodeficiency virus increased from virtually none to 13 per 100,000 in 1992, and the rate of death due to septicemia increased 83% from 4.2 to 7.7 per 100,000. CONCLUSIONS: Despite historical predictions that infectious diseases would wane in the United States, these data show that infectious diseases mortality in the United States has been increasing in recent years.

Investigation of proviral load in individuals infected with human T-lymphotropic virus type II.

Human T-lymphotrophic virus type II (HTLV-II) has not yet been associated with any disease. Little is known about the proviral loads of HTLV-II in vivo and its relationship, if any, to lack of pathogenicity. We determined the HTLV-II proviral copy number in peripheral blood lymphocyte (PBL) samples from 49 HTLV-II-infected individuals, of whom 25 were coinfected with human immunodeficiency virus type 1 (HIV-1). The HTLV-II copy numbers were determined by polymerase chain reaction (PCR) amplification of end-point dilutions of PBL lysates, followed by hybridization to a 32P-labeled HTLV-II-specific probe. The proviral copy number for the 49 samples ranged from < 0.02 to 200 per 1000 PBLs; 6% had < 0.02, 16% had 0.02, 20% had 0.2, 18% had 2, 31% had 20, and 8% had 200 copies per 1000 PBLs. The distributions of HTLV-II copy numbers in the coinfected and singly infected subgroups were not significantly different (Wilcoxon rank sum, p = 0.24). In the coinfected subgroup, there was no significant correlation between the HTLV-II proviral load and the counts of CD4-positive lymphocytes or CD8-positive lymphocytes (Spearman Coefficient = 0.26, p = 0.20; = 0.091, p = 0.67, respectively). Our data demonstrate the presence of a wide range of viral loads in HTLV-II-infected individuals. The high viral loads (> or = 20 copies/1000 lymphocytes) detected in 39% of our samples suggest that the low pathogenicity of HTLV-II is not related to the presence of low viral loads in the infected subjects. Our data from the HIV-1 coinfected individuals show no apparent effect of HIV-1 on HTLV-II proviral loads.