Outbreak of Influenza A Infection Among Travelers— Alaska and the Yukon Territory, May-June 1999 FREE

MMWR. 1999;48:545-555

On June 18, 1999, CDC and Health Canada received reports from public health authorities in Alaska and the Yukon Territory about clusters of febrile respiratory illness and associated pneumonia among travelers and tourism workers. This report presents information about the outbreak. Laboratory evidence, including rapid influenza A antigen–detection tests and viral cultures from respiratory specimens, has implicated influenza A virus as the cause of illness.

As of June 29, CDC has received reports of 428 cases of acute respiratory infection (ARI) among tourists who traveled to Alaska and the Yukon Territory from May 22 through June 28 on seven separate week-long cruises. For 187 (48%) of the 386 ill persons whose dates of illness onset were known, illness occurred before or within 48 hours after boarding a cruise ship, suggesting that transmission occurred during a preceding land-based tour. The ARI incidence for the 386 cases was 3.8% among 10,110 passengers for a 7-day travel itinerary; the ARI attack rate was 5.5 per 1000 passenger-days. One hundred thirty-two (34%) cases met criteria for influenza-like illness (ILI) (i.e., fever or feverishness with cough or sore throat); four persons were hospitalized for pneumonia. No deaths have been reported. Among tourism workers, 104 cases of ARI have been reported.

Div of Public Health, Section of Epidemiology, and Section of Laboratories, Alaska Dept of Health and Social Svcs. Travel Medicine, Laboratory Center for Disease Control, Health Canada. Arctic Investigations Program, Influenza Br, Div of Viral and Rickettsial Diseases, and Surveillance and Epidemiology Br, Div of Quarantine, National Center for Infectious Diseases, CDC.

Summer outbreaks of influenza A have been reported previously among tourists in the United States and Canada.^1-3 In 1998, approximately 40,000 tourists and tourism workers were affected by an influenza outbreak in Alaska and the Yukon Territory.⁴ As with the 1998 summer outbreak of influenza A in this region, the findings in this report suggest that influenza appears to be initially transmitted during land-based travel among tourists on combination land and sea tours and among tourism workers.

In anticipation of possible persistent influenza activity, some cruise lines initiated policies to vaccinate crew members during the fall of 1998 to decrease the risk for influenza transmission by crew members to travelers. In addition, health departments in Alaska, the Yukon Territory, and British Columbia and collaborating cruise lines have implemented summertime respiratory illness surveillance.

In response to this outbreak, CDC and Health Canada developed recommendations for travelers to the region and for regional tourism workers. These recommendations are based on the following assumptions and considerations: (1) persons who travel with large organized groups are at risk for exposure to influenza, (2) new cases of influenza A infection probably will continue to occur among tourists to the region, (3) persons aged ≥65 years and persons with underlying health conditions are at increased risk for influenza-related complications, (4) tourism workers have frequent contact with persons at risk for influenza-related complications, (5) influenza vaccine availability during the summer is limited, and (6) when the supply of influenza vaccine is inadequate, influenza A–specific antiviral medications (i.e., amantadine or rimantadine) have a primary role in influenza A prevention and treatment.

On the basis of these considerations, CDC and Health Canada recommend that persons aged ≥65 years or who have certain underlying chronic medical conditions (e.g., pulmonary or cardiac disease) should consult their health-care providers before traveling to Alaska and the Yukon Territory this summer, regardless of their vaccination status, about their risk for influenza, the symptoms of influenza, and the advisability of carrying antiviral medications for either prophylaxis or treatment for influenza A infections. These groups are at increased risk for serious complications from influenza, including pneumonia, hospitalization, and death.⁵ Both amantadine and rimantadine can reduce the duration of influenza A illness and viral shedding if administered within 48 hours of symptom onset; however, these drugs also may cause side effects (particularly central nervous system or gastrointestinal effects) and may require dosage adjustment in elderly patients and those with underlying renal or hepatic disease. Health-care providers in Alaska, the Yukon Territory, and British Columbia and on cruise ships in regional waters who may be providing care for persons with ILI should consider prescribing antiviral agents for patients with febrile respiratory illness. Rapid antigen-detection tests for influenza, if available, will be useful for early diagnosis. CDC, in collaboration with state and provincial health authorities and the tourism industry, is working to implement surveillance for ILI among travelers and tourism workers for the remainder of the Alaska/Yukon Territory tourist season.

In the United States and Canada, health-care providers evaluating patients with febrile respiratory illnesses or pneumonia should obtain a travel history and consider influenza A in their differential diagnosis. Additional information about this outbreak is available on the CDC World-Wide Web sites, http://www.cdc.gov/travel/index.htm and http://www.cdc.gov/ncidod/diseases/flu/fluvirus.htm.

References: 5 available

MMWR. 1999;48:525

The CDC/University of California Public Health Leadership Institute (PHLI) is a 1-year scholars' program that includes an intensive on-site week, scheduled for March 11-17, 2000. The PHLI is conducted under a cooperative agreement between CDC's Public Health Practice Program Office and the University of California at Los Angeles. The purpose of the PHLI is to strengthen the nation's public health system by enhancing the leadership capacities of senior city, county, state, federal, and international public health officials.

The ninth year of the PHLI will begin on November 6, 1999, with an orientation for scholars at the American Public Health Association Annual Meeting in Washington, D.C. Approximately 35 senior public health officials from city, county, state, federal, or international health agencies will be selected to participate in the institute.

Senior state and local health officials, including "deputy" level staff nominated by state health directors or local health directors with a service population of greater than 200,000, are eligible to apply. Applications must be submitted by August 10, 1999. Selections will be made and the scholars notified during the week of September 27, 1999. Additional information and applications are available from the Director, PHLI, telephone (510) 986-0140.

MMWR. 1999;48:461-469

5 figures, 1 box omitted

At the beginning of this century, workers in the United States faced remarkably high health and safety risks on the job. Through efforts by individual workers, unions, employers, government agencies, scientists such as Alice Hamilton, MD (1869-1970)—the first US physician to devote herself to research in industrial medicine—and others, considerable progress has been made in improving these conditions. Despite these successes, much work remains, with the goal for all workers being a productive and safe working life and a retirement free from long-term consequences of occupational disease and injury. Using the limited data available, this report documents large declines in fatal occupational injuries during the 1900s, highlights the mining industry as an example of improvements in worker safety, and discusses new challenges in occupational safety and health.

Data from multiple sources reflect the large decreases in work-related deaths from the high rates and numbers of deaths among workers during the early 20th century. The earliest systematic survey of workplace fatalities in the United States in this century covered Allegheny County, Pennsylvania, from July 1906 through June 1907;¹ that year in the one county, 526 workers died in "work accidents";* 195 of these were steelworkers. In contrast, in 1997, 17 steelworker fatalities occurred nationwide.² The National Safety Council estimated that in 1912, 18,000-21,000 workers died from work-related injuries.³ In 1913, the Bureau of Labor Statistics documented approximately 23,000 industrial deaths among a workforce of 38 million, equivalent to a rate of 61 deaths per 100,000 workers.⁴ Under a different reporting system, data from the National Safety Council from 1933 through 1997 indicate that deaths from unintentional work-related injuries declined 90%, from 37 per 100,000 workers to 4 per 100,000.³ The corresponding annual number of deaths decreased from 14,500 to 5100; during this same period, the workforce more than tripled, from 39 million to approximately 130 million.³

More recent and probably more complete data from death certificates were compiled from CDC's National Institute for Occupational Safety and Health (NIOSH) National Traumatic Occupational Fatalities (NTOF) surveillance system⁵ (CDC, unpublished data, 1999). These data indicate that the annual number of deaths declined 28%, from 7405 in 1980 to 5314 in 1995 (the most recent year for which complete NTOF data are available). The average rate of deaths from occupational injuries decreased 43% during the same time, from 7.5 to 4.3 per 100,000 workers. Industries with the highest average rates for fatal occupational injury during 1980-1995 included mining (30.3 deaths per 100,000 workers), agriculture/forestry/fishing (20.1), construction (15.2), and transportation/communications/public utilities (13.4).† Leading causes of fatal occupational injury during the period include motor vehicle-related injuries, workplace homicides, and machine-related injuries.

On December 6, 1907, a coal mine explosion in Monongah, West Virginia, killed a reported 362 men and boys (unofficial estimates exceeded 500 deaths), marking the largest coal mining disaster in U.S. history. Of the 2534 mining-related fatalities that occurred in bituminous coal mines that year, 911 (36%) resulted from explosions of gas, coal dust, or a combination; 869 deaths occurred in only 11 incidents. The Monongah catastrophe catalyzed public awareness and led to passage of the Organic Act of 1910, which established the U.S. Bureau of Mines (USBM).

From 1911 through 1997, approximately 103,000 miners died at work. During 1911-1915, an average of 3329 mining-related deaths occurred per year among approximately 1 million miners employed annually, with an average annual fatality rate of 329 per 100,000 miners. During the century, the average annual number of workers (operators and contractors combined) in the mining industry has declined to approximately 356,000, and deaths have dropped approximately 37-fold, from 3329 to 89; injury fatality rates have decreased approximately 13-fold, to 25 per 100,000 during 1996-1997.

Historically, the largest number of miners have been killed by collapsing mine roofs and vertical walls, followed by haulage-related incidents. However, methane gas and coal dust explosions have caused the largest number of deaths from "disasters" (i.e., incidents in which five or more deaths occurred); airborne suspension of dry coal dust and natural liberation of methane (present in all coal beds) create an environment susceptible to explosions. From 1911 through 1920, explosions accounted for approximately 84% of all disaster-related deaths. Workplace interventions (e.g., safer equipment and improved ventilation) during the first half of the century led to a dramatic decline in explosion-related fatalities, from an average of 477 per year in 1906-1910 to <3 per year in 1991-1995. All other causes of death associated with underground coal mines (except machinery) declined similarly from the first to the last 20-year interval of this period.

The decline in occupational fatalities in mining and other industries reflects the progress made in all workplaces since the beginning of the century in identifying and correcting the etiologic factors that contribute to occupational health risks. If today's workforce of approximately 130 million had the same risk as workers in 1933 for dying from injuries, then an additional 40,000 workers would have died in 1997 from preventable events (CDC, unpublished data, 1999). The declines can be attributed to multiple, interrelated factors, including efforts by labor and management to improve worker safety and by academic researchers such as Dr. Alice Hamilton. Other efforts to improve safety were developed by state labor and health authorities and through the research, education, and regulatory activities undertaken by government agencies (e.g., USBM, the Mine Safety and Health Administration [established as the Mining Enforcement and Safety Administration in 1973], the Occupational Safety and Health Administration [OSHA] [established in 1970], and NIOSH). Efforts by these groups led to physical changes in the workplace, such as improved ventilation and dust suppression in mines; safer equipment; development and introduction of safer work practices; and improved training of health and safety professionals and of workers. The reduction in workplace deaths has occurred in the context of extensive changes in U.S. economic activity, the U.S. industrial mix, and workforce demographics.⁶ Societywide progress in injury control also contributes to safer workplaces—for example, use of safety belts and other safety features in motor vehicles⁶ and improvements in medical care for trauma victims.

Only in some instances do data permit association of declines in fatalities with specific interventions. Before 1920, using permissible explosives and electrical equipment (which can be operated in an explosive methane-rich environment without igniting the methane), applying a layer of rock dust over the coal dust (which creates an inert mixture and prevents ignition of coal dust), and improved ventilation, such as reversible fans, led to dramatic reductions in fatalities from explosions.⁷ New technologies in roof support and improved mine design reduced the number of deaths from roof falls. However, technology also introduced new hazards, such as fatalities associated with machinery. An approximately 50% decrease in coal mining fatality rates occurred from 1966-1970 to 1971-1975; 1971-1975 is the period immediately following passage of the 1969 Federal Coal Mine Health and Safety Act, which greatly expanded enforcement powers of federal inspectors and established mandatory health and safety standards for all mines. The act also served as the model for the 1970 Occupational Safety and Health Act. Following the 1977 Federal Mine Safety and Health Act, a 33% decrease in fatalities occurred in metal and nonmetallic minerals mining (1976-1980 compared with 1981-1985).

Similarly, the impact of more recent targeted efforts to reduce workplace fatalities can be illustrated by data on work-related electrocutions. During the 1980s, there were concerted research and dissemination efforts by NIOSH, changes to the National Electrical Code and occupational safety and health regulations, and public awareness campaigns by power companies and others. During this decade, work-related electrocution rates declined 54%, from 0.7 per 100,000 workers per year in 1980 to 0.3 in 1989; the number of electrocutions decreased from 577 to 329.⁶

Although the decline in injuries in general industry since 1970 seems to have resulted from a variety of factors, some sources point to the Occupational Safety and Health Act of 1970,§ which created NIOSH and OSHA.^6,8 Since 1971, NIOSH has investigated hazardous work conditions, conducted research to prevent injury, trained health professionals, and developed educational materials and recommendations for worker protection. OSHA's regulatory authority for worksite inspection and development of safety standards has brought about safety regulations, mandatory workplace safety controls, and worker training. During 1980-1996, research findings indicated that training creates safer workplaces through increased worker knowledge of job hazards and safe work practices in a wide array of worksites.⁹

Despite the accomplishments described in this report, workers continue to die from preventable injuries sustained on the job. Ongoing efforts to address important workplace hazards include conducting field investigations of fatalities in high-risk occupations and industries, such as the Fire Fighter Fatality Investigation and Prevention Program, establishing a research center to facilitate childhood agricultural injury prevention (National Children's Center for Rural and Agricultural Health and Safety), and developing educational materials for worker protection, such as Preventing Homicide in the Workplace.¹⁰ Despite major gains in workplace safety, mining remains the most dangerous industry, and mining safety research remains a national priority.

The National Occupational Research Agenda (NORA), developed by NIOSH and approximately 500 organizations and persons nationwide, identified traumatic injuries as one of its public health priorities. NORA was developed in recognition of the rapidly changing nature of the workplace and workforce and provides the framework for research to improve worker safety in the 21st century. The NORA Traumatic Injuries Team sponsored the first National Occupational Injury Symposium in 1997 and outlined priority needs.¹¹ These include the need to identify new sources of surveillance data, to improve identification of work-related injuries and illnesses in existing databases, to link data from existing sources for improved information about injuries, and to better assess injury exposures and intervention outcomes. Increased attention to other NORA priority areas, such as intervention effectiveness research, surveillance research methods, and organization of work, should guide continued national efforts to reduce both occupational illnesses and injuries in the next century.

References: 11 available

*When a death occurs under "accidental" circumstances, the preferred term within the public health community is "unintentional injury."

† The NTOF surveillance system classifies industries according to the Standard Industry Classification Manual, 1987, which, unlike the definition used by the Mine Safety and Health Administration (MSHA), includes the oil and gas sectors of mineral extraction in the mining industry.

‡ MSHA data are used in this section of the report; these data exclude oil and gas extraction, and data collection for mining according to MSHA includes only deaths that occur on mine property. Deaths likely to occur off mine property, such as during operation of a motor vehicle (the overall leading cause of death during 1980-1994), are excluded.

§ Public Law 91-596.

MMWR. 1999;48:509-513

2 tables omitted

Human immunodeficiency virus (HIV) counseling and voluntary testing (CT) programs have been an important part of national HIV prevention efforts since the first HIV antibody tests became available in 1985.¹ In 1995, these programs accounted for approximately 15% of annual HIV antibody testing in the United States, excluding testing for blood donation.¹ CT opportunities are offered to persons at risk for HIV infection at approximately 11,000 sites, including dedicated HIV CT sites, sexually transmitted disease (STD) clinics, drug-treatment centers, hospitals, and prisons. In 39 states, testing can be obtained anonymously, where persons do not have to give their name to get tested. All states provide confidential testing (by name) and have confidentiality laws and regulations to protect this information. This report compares patterns of anonymous and confidential testing in all federally funded CT programs from 1995 through 1997 and documents the importance of both types of testing opportunities.

In CT programs, demographic and HIV risk information is collected, combined with laboratory test results, and reported to CDC after removal of personal identifying information. Federally funded CT programs provided 2.5 million tests (40,605 HIV-positive) in 1995, 2.6 million (39,119 HIV-positive) in 1996, and 2.3 million (34,875 HIV-positive) in 1997. Of the 7.4 million federally funded HIV tests performed during 1995-1997, client information on 6.3 million tests was available for analysis. Because some persons had more than one HIV test in a year, the proportion of persons tested who had positive results could not be calculated. Thus, the proportion positive reflects the number of positive tests divided by the number of tests provided.

From 1995 to 1997, the number of anonymous tests declined 26.6% (from 636,069 to 466,560), and the number of confidential tests increased 2.9% (from 1,394,921 to 1,434,709). Although more tests were provided to women than men each year, more anonymous tests were provided to men than women. In each year, the highest numbers of positive anonymous tests were among white and black men, and the highest number of positive confidential tests were among blacks.

In 1997, the most recent year for which complete data were available, STD clinics provided more tests overall (551,838) and more confidential tests (494,414) than other sites, and dedicated HIV CT sites provided the largest number of anonymous tests (302,273). Overall, most HIV-positive tests were reported from specially designated HIV CT sites (10,523 [2.0%] of 538,574), STD clinics (8390 [1.5%] of 551,838), prisons (3120 [3.5%] of 88,183), community health centers (2941 [2.1%] of 139,331), and drug-treatment centers (2574 [2.4%] of 109,037).

In 1997, of tests provided to men who have sex with men (MSM), 55.3% were anonymous. Most anonymous tests were among MSM who were injecting-drug users (IDUs) (37.3%), followed by men whose only risk was heterosexual contact (24.7%) and male IDUs (22.1%).

Among men, the highest proportion of tests that were anonymous were among Asians/Pacific Islander (A/PI) MSM (71.6%) and among white MSM (61.9%). A lower proportion of anonymous tests were for American Indian/Alaskan Native (AI/AN) MSM (55.4%), Hispanic MSM (47.9%), and black MSM (32.5%).

Among women, the highest proportion of anonymous tests was among A/PI IDU (40.0%), A/PI with heterosexual contact (35.9%), whites with heterosexual contact (30.8%), AI/AN with heterosexual contact (29.7%), and AI/AN IDUs (29.2%).

Div of HIV/AIDS Prevention-Surveillance and Epidemiology, National Center for HIV, STD, and TB Prevention, CDC.

The benefits of early HIV CT are greater now than at any time during the epidemic. For HIV-infected persons, highly active antiretroviral therapy (HAART) has improved dramatically the quality and duration of life.² For public health, reduced HIV transmission may occur because many infected persons probably will reduce sexual risk behavior after HIV-infection diagnosis.³ In addition, HAART may reduce the risk for transmission by reducing the amount of infectious virus in body fluids of HIV-infected persons.^4,5 For these reasons, public health programs should work to diagnose HIV infection in each of the approximately 200,000 infected persons⁶ who do not know their HIV status, link them to care and prevention services, and assist them in adhering to treatment regimens and in sustaining risk-reduction behavior.

Both anonymous and confidential testing opportunities help to facilitate test seeking among persons at risk for HIV infection. The findings in this report indicate a decline in anonymous tests from 1995 through 1997. Reasons for this decline are unclear but may reflect changes in the characteristics of persons counseled and tested for HIV, a perception that HIV-infection is a treatable and less stigmatizing disease, and the impact of new laws⁷ and regulations on the risk for confidentiality violations and other factors. However, anonymous testing continues to be of value; anonymous testing has been associated with entry into medical care earlier in disease.⁸ Among groups at risk for HIV infection, MSM—particularly A/PI and white MSM—most frequently choose anonymous testing over confidential in publicly funded facilities. These data are consistent with other studies indicating that MSM have high levels of concern about the confidentiality of their HIV test results.⁹ Because of the potential benefits of anonymous testing, CDC encourages states to include anonymous testing as an integral component of CT programs.

The low proportion of women and black men who choose anonymous testing may reflect a lack of awareness that these services exist, a greater willingness to test confidentially, preferentially receiving care in settings where provider practices favor confidential testing, or being tested because of the presence of HIV-related symptoms. A better understanding of the factors that contribute to differences in testing patterns may improve the effectiveness of voluntary testing programs. On the basis of recent trends, HIV-infection programs should assure the provision of voluntary HIV CT in settings that serve at-risk women and black men.

From 1995 through 1997, the number of federally funded confidential tests increased. Three quarters of publicly funded testing is confidential and accounts for nearly 25,000 positive tests each year. Confidential testing is offered in HIV CT sites, prisons, and medical settings (e.g., clinics, community health centers, and hospitals). More than half of positive confidential tests were in federally funded clinical-care settings (e.g., STD, drug-treatment, and tuberculosis and community health centers). Data from emergency departments in hospitals in areas where the prevalence of HIV infection is high indicate that half of infected persons are unaware of their HIV infection (CDC, unpublished data, 1999). To increase the number of infected persons who are aware of their HIV status, voluntary testing will need to be increased in settings where persons at risk for HIV infection seek care for non-HIV-related conditions.

The findings in this report are subject to at least three limitations. First, the data are not representative of all persons tested for HIV during the observation period; the data include approximately 15% of annual nonblood donation tests in the United States. Second, the proportion of positive tests is not the same as the proportion of persons who tested positive. Some persons were tested multiple times; therefore, the proportion of persons who tested positive was not available. Finally, some test sites report summary data, which could not be used in this analysis, rather than individual client test records; the analyzed individual client record data represent 87% of all federally funded tests provided in 1997.

CDC encourages every adult and adolescent to assess their risk for HIV infection based on past behavior. Persons who believe they might have been exposed to HIV but who have not been tested should seek CT for HIV. Additional information about HIV CT is available on the World-Wide Web at http://www.hivtest.org* or from the National AIDS Hotline, telephone (800) 342-2437.

References: 9 available

*References to sites of nonfederal organizations on the World-Wide Web are provided as a service to MMWR readers and do not constitute or imply endorsement of these organizations or their programs by CDC or the U.S. Department of Health and Human Services. CDC is not responsible for the content of pages found at these sites.