Youth Agricultural Work–Related Injuries Treated in Emergency Departments—United States, October 1995-September 1997 FREE

MMWR. 1998;47:733-737

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NATIONAL estimates and descriptions of agricultural injuries occurring to youths are limited.^1- 2 In 1996, the National Committee for Childhood Agricultural Injury Prevention recommended establishing and maintaining a comprehensive national surveillance system of fatal and nonfatal childhood agricultural injuries.² In response to these recommendations, CDC's National Institute for Occupational Safety and Health (NIOSH) began analyzing existing surveillance data while exploring new data collection strategies. The goals of these efforts are to add to knowledge about the incidence and circumstances of childhood agricultural injuries and to improve collection and analysis of data regarding childhood agricultural injuries.³ This report presents an analysis of data from the National Electronic Injury Surveillance System (NEISS)* during October 1995-September 1997 for youths aged <20 years, which indicates that youths in this age group are at increased risk for agricultural work–related injuries.

NEISS collects data on all work-related injury cases from a probability sample of 65 U.S. hospitals with emergency departments.⁴ A work-related case is defined as any injury sustained during performance of (1) work for compensation, (2) volunteer work for an organized group, or (3) a work task on a farm. Estimates of agricultural work-related injuries are rounded to the nearest 100.

NEISS data were analyzed for agricultural work–related injuries that occurred to youths aged <20 years during October 1, 1995-September 30, 1997. To identify agricultural injuries, keyword searches of narrative information were conducted.† Incidents identified were reviewed on a case-by-case basis to determine which injuries to include in the analyses. Injuries associated with crop production, livestock production, and agricultural services were included in the analyses.

Injury rates were calculated using employment data from the Current Population Survey (CPS) of the Bureau of Labor Statistics, a monthly, national population-based household survey that includes approximately 60,000 households.⁵ Rates are presented per 100 full-time equivalents (FTE)‡; injury rates per FTE are preferred to rates per worker when analyzing occupational injury data for youths, who typically work part-time, because hours of work are a proxy measure for exposure.^4,6

During October 1, 1995-September 30, 1997, 1208 agricultural work–related injuries among persons of all ages were reported to NEISS, corresponding to a national estimate of 117,700 injuries (95% confidence interval [CI]=79,600-155,800) that were treated in emergency departments in the United States. Of the 1208 cases, 104 (9%) were among youths aged <20 years, corresponding to a national estimate of approximately 10,700 injuries (95% CI=6,500-14,900)—an average of approximately 5400 youth injuries each year. Of the injured youths aged <20 years, 96% were treated and released from the emergency departments; no fatal agricultural injuries among youths aged <20 years were reported in the NEISS data. The highest rates for injury were among workers aged 18-19 years and 20-24 years (2.7 injuries per 100 FTE), which differed significantly from injury rates for workers aged 45-64 years. Injury rates for 15-17-year-olds (1.8 per 100 FTE) were similar to those for workers aged 25-34 years (1.9 per 100 FTE) and 35-44 years (1.7 per 100 FTE) and were higher than, but not significantly different from, workers aged ≥45 years. An estimated 1600 youths aged <15 years were injured while working in agriculture, representing 15% of the cases among youths aged <20 years; the rate of injury for this age group was not calculated because employment data are not collected for youths aged <15 years.

Among youths aged <20 years, 89 injuries were to males, corresponding to a national estimate of 9300 injuries (95% CI=5,600-12,900). Injuries to males accounted for 86% of all injuries to youths. The overall injury rate for 15-19-year-olds was 2.3 per 100 FTE (95% CI=1.5-3.1); the rate for males was 2.4 per 100 FTE (95% CI=1.7-3.2), and the rate for females was 1.5 per 100 FTE (95% CI=0.4-2.2).

Contusions and/or abrasions were the most common types of injury among youths aged <20 years, accounting for 24.0% of the injuries; lacerations accounted for 23.3%. The body parts most commonly injured by persons in this age group were the fingers or hands (23.5%) and the knee, ankle, or foot (23.0%).

The events most likely to result in injuries to youths were contact with objects or equipment (e.g., struck by a falling object, struck by a slipping object, and caught in equipment or between objects), accounting for approximately 55.4% of the injuries, and falls (both to a lower level and on the same level), accounting for 14.7% of injuries. The sources of injury varied: persons, plants, animals, and minerals contributed to 17.4% of the injuries; tools (primarily nonpowered hand tools), 15.2%; machinery (primarily agricultural and garden), 15.2%; structures and surfaces (e.g., floors, walkways, and ground surfaces), 14.9%; and parts and materials (primarily materials used in the construction of buildings and other structures, such as bricks and lumber), 14.7%.

Div of Safety Research, National Institute for Occupational Safety and Health, CDC.

Information about the incidence and circumstances of agricultural work–related injuries among youths is needed to target and develop effective injury-prevention efforts. This report estimates that each year approximately 5400 youths aged <20 years working on farms or in agricultural service jobs sustain occupational injuries that are treated in hospital emergency departments and indicates that youths are among the age groups at greatest risk for such injuries.

In this report, work-related data were collected using an existing emergency department surveillance system. Emergency department visits represent only a fraction (approximately 36%)⁴ of the work injuries that occur to agricultural workers, and surveillance limited to this setting does not include injuries treated on site, at private physicians' offices or clinics, or in other medical treatment facilities. Further research is needed to clarify the treatment patterns of agricultural work-related injuries; to determine the proportion and characteristics of injuries that can be expected to be captured by emergency department surveillance; and to assess whether any differences in treatment patterns by demographic characteristics (e.g., age, sex, race/ethnicity) or relationship of the worker to the farm owner (e.g., family member or employee) exist. Such information would guide assessments about using emergency departments for routine and ongoing collection of data on childhood agricultural injuries and whether special surveys are needed to provide supplementary data about groups not well represented in emergency department data.

Although NEISS surveillance of work injuries can provide information on the incidence of youth agricultural work–related injuries requiring emergency department treatment, the small number of cases each year—and the limited information available from the system—precludes analyses that can focus prevention efforts, such as estimates and rates by specific agricultural sectors or by particular machinery or circumstances. Furthermore, it is unknown how well NEISS captured agricultural work injury cases, given the difficulty in distinguishing work, chores, and exposure to agricultural production hazards in settings that serve as both a place of work and a residence for youths. Children can be exposed to and injured by agricultural production hazards without direct participation in farm work when they live on farms, visit farms, or accompany their working parents into the fields.² However, NEISS can provide a valuable mechanism for gathering detailed information on the circumstances and associated risk factors for injuries through follow-back surveys. NIOSH will conduct follow-back interviews of youths identified through the NEISS as having sustained agricultural injuries, regardless of their work-relatedness. This study will assess the ability of the NEISS to characterize childhood agricultural injuries.

Although much remains to be learned about the incidence of, contributors to, and prevention of youth agricultural work injuries,^2- 3 there are numerous recommendations and programs aimed at preventing agricultural injuries, both in general and among children. To provide technical assistance, professional training, and consensus development for preventing childhood agricultural injuries, NIOSH helped establish the National Children's Center for Rural and Agricultural Health and Safety, telephone (888) 924-7233 or (715) 389-4999; or World-Wide Web, http://www.marshmed.org/nfmc/children. Additional information about prevention strategies is also available from county agricultural extension agents; the Wage and Hour Office of the U.S. Department of Labor World-Wide Web site, http://www.dol.gov/dol/teensafety.htm; the National Safety Council, telephone (800) 621-7615, ext. 2379 or (630) 285-1121, or World-Wide Web site, http://www.nsc.org/farmsafe.htm; Farm Safety 4 Just Kids, telephone (800) 423-5437 or (515) 758-2827, World-Wide Web site, http://www.fs4jk.org; and NIOSH, telephone (800) 356-4674 or (513) 533-8328.

*The Consumer Product Safety Commission (CPSC) developed NEISS to monitor injuries involving consumer products and to serve as a source for follow-up investigation of selected product-related injuries. CPSC collects all work-related injuries for NIOSH regardless of consumer product involvement.

† Keyword searches were conducted on the following narrative fields: business type, business name, occupation type, and injury description fields. Examples of keywords in each field include: business type—farm, orchard, fruit, and grain; business name—farm, nursery, landscape, and veterinary; occupation type—farm; and comment fields—farm, tractor, cattle, cow, livestock, tobacco, and landscape.

‡ An FTE is defined as 2000 hours of work during a calendar year and was calculated from the CPS microdata files because published estimates were not available.

MMWR. 1998;47:737-740

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HAEMOPHILUS influenzae (Hi) causes a variety of severe clinical illnesses including meningitis, pneumonia, epiglottitis, and septic arthritis.¹ In the prevaccine era (i.e., before 1988),Haemophilus influenzae type b (Hib) caused approximately 95% of the Hi invasive disease among children aged <5 years.¹ In 1988, Hib conjugate vaccines were introduced for use among children aged 18 months-5 years; they were subsequently recommended for routine use in infants by the Advisory Committee on Immunization Practices (ACIP) in 1990.² During 1989-1995, Hib invasive disease among children aged <5 years declined 95% nationally.³ To document the decline of Hib invasive disease and to examine the epidemiology of reported nontype b Hi invasive disease among children aged <5 years, CDC, in collaboration with the California Department of Health Services, analyzed reported cases in California from 1990 to 1996. This report summarizes the results of the analysis and documents the decline of Hib without an increase of nontype b Hi invasive disease among children aged <5 years.

Hi invasive disease has been a reportable disease in California since 1989, and cases were collected passively from laboratories, clinics, and hospitals. In Los Angeles County, which accounts for 30% of the population in the state aged <5 years, active surveillance for Hi invasive disease was conducted during 1986-1992⁴ and 1995-1996 through monthly telephone calls to all local laboratories and periodic laboratory audits. In 1989, three counties in the San Francisco Bay area (Alameda, Contra Costa, and San Francisco), which account for 7% of the population aged <5 years, initiated active, laboratory-based surveillance. Laboratorians and infection-control practitioners were contacted biweekly, and laboratory audits were performed once in 1991, 1993, and 1994, and twice in 1995 and 1996. Cases were reported to CDC.

Data from these surveillance systems were combined (n=1090), and the 65 duplicate cases (i.e., cases with identical date of birth, onset, county of residence, and demographic data) and 11 reports that did not include age were eliminated. California census information for 1990 to 1996 was used to calculate race/ethnicity-, sex-, and county-specific incidence rates; county-specific incidence rates were mapped using the Atlas GIS mapping program. Census data from 1993 was used to calculate the average annual incidence of nontype b Hi invasive disease by race/ethnicity.

During 1990-1996 in California, 1014 cases of invasive Hi disease were reported among children aged <5 years: 591 (58%) cases of Hib, 160 (16%) cases of nontype b Hi, and 263 (26%) cases of unknown serotype; 71 (27%) of the 263 isolates with unknown serotype were from the three Bay area counties or Los Angeles County. From 1990 to 1996, the number of reported Hib cases decreased 99% (from 346 [13.9 per 100,000] to four [0.1 per 100,000]), and the number of reported Hi cases attributable to unknown serotype declined 93% (from 134 to 10). The proportion of isolates with unknown serotype (approximately 30%) remained relatively constant. During 1990-1996, the incidence of nontype b invasive disease remained stable; the average annual incidence was 0.9 per 100,000 children aged <5 years.

During 1990-1996, most (51% [82 of 160]) nontype b Hi invasive disease cases among children aged <5 years were reported from Los Angeles County, where the average annual incidence was 1.5 per 100,000 children aged <5 years. In the three Bay area counties, the number of nontype b Hi cases ranged from one to four per year (1.5 per 100,000 children aged <5 years). Overall, 20 (35%) of 58 counties in California reported at least one case of nontype b Hi invasive disease. The average annual incidence rates were higher for both the Bay area counties (1.5 per 100,000 children aged <5 years) and Los Angeles County (1.5), compared with the rate for all of California (0.9). The two counties with nontype b incidence rates of ≥3 per 100,000 children aged <5 years had populations of <20,000 children in this age group.

The average annual incidence rates of nontype b Hi invasive disease among non-Hispanic black children were higher than for other racial/ethnic groups. The average annual incidence rates of nontype b Hi invasive disease for each racial/ethnic group was higher in the active surveillance sites (the three Bay area counties and in Los Angeles County) than in the remainder of California. The proportion of case-patients aged <1 year was similar among nontype b Hi cases (59%) and Hib cases (61%). The average annual incidence of nontype b was similar for males (0.9) and females (0.8).

G Rothrock, MPH, A Reingold, MD, California Emerging Infections Program, Oakland; N Alexopoulos, MPH, Los Angeles County Dept of Health Svcs, Los Angeles; C O'Malley, PhD, NJ Smith, MD, SH Waterman, MD, State Epidemiologist, California Dept of Health Svcs. Meningitis and Special Pathogens Br, and Respiratory Diseases Br, Div of Bacterial and Mycotic Diseases, National Center for Infectious Diseases; Child Vaccine-Preventable Diseases Br, Epidemiology and Surveillance Div, National Immunization Program, CDC.

The decline of reported Hib invasive disease cases among children aged <5 years from 1990 to 1996 in California reflects the decline in Hib invasive disease cases reported nationally associated with the widespread use of Hib vaccine in children.³ The parallel decline in the number of Hi invasive disease cases attributable to unknown serotypes in California suggests that a large number of cases with unknown serotype had been serotype b. In California, the proportion of Hi isolates with unknown serotype information (26%) was lower than for national data in 1994 and 1995 (44%),³ suggesting more complete ascertainment of serotype information by the active surveillance sites and the California Department of Health Services.

The decline of Hib invasive disease raised concerns about an increase of Hi invasive disease caused by other serotypes.^5- 6 However, the rate of nontype b invasive disease has remained stable. The low number of reported nontype b Hi invasive disease cases in 1994 may be due to random variation in incidence. By year and by racial/ethnic groups, the rate of nontype b invasive disease was higher in the two regions of California with active surveillance compared with passive reporting from the remainder of California, a trend consistent with other analyses of reporting practices.⁷ The differences in disease incidence among racial/ethnic groups may be a marker for other risk factors, such as low socioeconomic status.³

Surveillance for all Hi invasive disease needs to be strengthened to document the remaining disease burden and to monitor vaccination program effectiveness.⁸ Because the clinical presentation of Hi invasive disease may not vary by serotype (a, b, c, d, e, f, and nontypeable strains), laboratory testing is necessary to identify an isolate's serotype. The identification of serotype b is needed because only Hib invasive disease can be prevented with vaccination. State health departments should identify laboratories that can perform serotyping on Hi isolates from children aged <15 years with invasive disease; if serotyping is not available, state health departments can contact CDC.

The incidence rate of nontype b Hi invasive disease is under evaluation by CDC as a tool to help jurisdictions assess whether their surveillance system is sensitive enough to detect a Hib case. If a standard rate can be identified, and if it is relatively stable over time and by geographic regions, it may serve as an external standard for monitoring the quality of reporting of Hib invasive disease.⁸ Additional studies are needed to establish a baseline rate of nontype b Hi invasive disease that could be used as a surveillance evaluation tool throughout the United States.

MMWR. 1998;47:544-547 .

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DENGUE IS a mosquito-transmitted acute disease caused by any of four dengue virus serotypes (DEN-1, DEN-2, DEN-3, and DEN-4) and characterized by the sudden onset of fever, headache, myalgia, arthralgia, rash, nausea, and vomiting. This disease is endemic in most tropical areas of the world and has occurred in U.S. residents returning from travel to such areas. CDC maintains a laboratory-based passive surveillance system for imported dengue among U.S. residents. This report summarizes information about cases of imported dengue among U.S. residents for 1996, which indicated that most persons for whom travel history was known probably acquired infection in the Caribbean islands or Asia.

Serum samples from 179 persons who had suspected dengue with onset of symptoms in 1996 were submitted to CDC for diagnostic testing from 32 states and the District of Columbia. From these samples, 43 (24%) cases from 18 states and the District of Columbia were diagnosed serologically as dengue (single high titers of IgG in acute serum samples or by IgM detection in early convalescent samples) or by isolation of dengue virus. A diagnosis of dengue infection was negative in 102 (57%) patients and could not be determined in 34 (19%) patients because of unavailability of convalescent samples for serologic testing.¹

Of the 43 persons with laboratory-diagnosed dengue, sex was known in 39; 22 (56%) were male. Age was reported for 30 persons and ranged from 5 to 69 years (median: 33 years). The virus serotype (DEN-1 and DEN-2) was identified for five cases. Travel histories, available for 37 persons, indicated that infections probably were acquired in the Caribbean islands (19 cases), Asia (11), Africa (three), the Pacific islands (two), Central America (one), and South America (one).

Clinical information was available for 28 patients with laboratory-diagnosed dengue. The most commonly reported symptoms were consistent with classic dengue fever (e.g., fever [93%], headache [61%], myalgia [57%], rash [57%], and arthralgia [18%]). Less frequently reported manifestations included diarrhea (five); eye pain (four); skin hemorrhages (two); and jaundice and depression (one each); low platelet counts (61,000-127,000/mm³, average 98,000/mm³ [normal: 150,000-450,000/mm³]) (eight); low white blood cell count (1900-3100/mm³, average 2550/mm³ [normal: 3200-9800/mm³]) (six); and elevated liver enzymes (one). At least two patients were hospitalized, and no deaths were reported.

State and territorial health depts. Dengue Br, Div of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, CDC.

Dengue is transmitted by the mosquito Aedes aegypti, which is present in most tropical urban areas of the world. In the United States, the mosquito can be found during the summer in southeastern states, including parts of Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Texas. Dengue transmission in the United States is rare; however, autochthonous transmission of dengue was documented in Texas in 1980, 1986, and 1995.²

The incubation period of dengue is 4-7 days (range: 3-14 days). Most cases are characterized by mild manifestations, but infections in some persons can result in the more severe forms of the disease. Dengue hemorrhagic fever (DHF) is characterized by fever, low platelet count (≤100,000/mm³), hemorrhagic manifestations, and evidence of increased vascular permeability (e.g., hemoconcentration [hematocrit increased by ≥20% from baseline], pleural or abdominal effusions, or hypoalbuminemia). Dengue shock syndrome (DSS) is DHF plus narrow pulse pressure (≤20 mm Hg), hypotension, or shock.³ The fatality rate for patients with DSS can be as high as 44%.⁴

During 1987-1993, the average annual number of laboratory-diagnosed cases reported to CDC was 20, but in 1994 the number increased to 38.¹ In 1995, an unusually high number (n=86) of imported laboratory-diagnosed cases of dengue was identified by CDC, reflecting the occurrence of outbreaks in Central American and Caribbean countries and the high number of cases detected by an active surveillance system in Texas.^5,6 In 1996, the number of dengue and DHF cases reported to the Pan American Health Organization (n=276,758) was lower than the total for 1995 (n=316,187). Among persons in the United States with imported cases in 1996, five persons with history of travel to India reflect the DEN-2 epidemic that occurred in India.⁷ Among the imported infections acquired in the Caribbean islands during 1996, seven were diagnosed in persons from Maryland and Pennsylvania who traveled to the Caribbean during January.⁸

The number of cases in this report represents a minimum estimate of the number of U.S. travelers with dengue. Because dengue is not a notifiable disease nationally or in most states, diagnostic samples may not be sent for testing or they may be sent to laboratories other than CDC; therefore, many imported cases may not be counted. To provide a better estimate of the total number of cases, state epidemiologists were asked to provide a listing of all dengue cases reported in their state with onset of illness in 1996. Nineteen states reported 51 cases; 22 (43%) cases had not been reported previously.

There is no vaccine for preventing dengue, and persons traveling to areas where dengue is endemic should avoid exposure to mosquito bites by using mosquito repellents and protective clothing and remaining in well screened or air conditioned areas. Ae. aegypti is an urban mosquito usually found in or near human dwellings. In domestic settings, the mosquito can be found resting in dark areas including closets, bathrooms, behind curtains, and under beds. The species bites usually during the early morning and late afternoon.⁹ The risk for exposure is higher in urban residential areas, but may be lower for tourists in some settings (e.g., beaches, hotels with well-kept grounds, and areas away from human habitation).

The incidence and geographic distribution of dengue have increased greatly in recent years, and health-care providers should consider dengue in the differential diagnosis of illness in all patients who have fever and a history of travel to tropical areas within 2 weeks of onset of symptoms. Because of the anticoagulant properties of acetylsalicylic acid (i.e., aspirin) and other nonsteroidal anti-inflammatory agents, only acetaminophen products are recommended for the management of pain and fever. For diagnosis, acute- and convalescent-phase serum samples should be obtained and sent through state or territorial health departments to CDC's Dengue Branch, Division of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, 2 Calle Casia, San Juan, PR 00921-3200; telephone (787) 766-5181; fax (787) 766-6596. Serum samples should be accompanied by a summary of clinical and epidemiologic information, including date of onset of disease, date of collection of sample, and a detailed recent travel history.

References: 9 available.