May 19, 2000 / Vol. 49 / No. 19 U.S. DEPARTMENT OF HEALTH & HUMAN SERVICES Misdiagnoses of Tuberculosis Resulting From Laboratory Cross-Contamination of Mycobacterium Tuberculosis Cultures — New Jersey, 1998 A diagnosis of tuberculosis (TB) is rarely disputed if Mycobacterium tuberculosis is isolated from a clinical specimen; however, specimen contamination may occur (1–3 ). Identification of TB strain patterns through molecular typing or DNA fingerprinting is a recent advancement in TB laboratory techniques (3–7 ). CDC’s National Tuberculosis Genotyping and Surveillance Network (NTGSN) performs DNA fingerprinting on TB iso- lates to determine the frequency of clustering among M. tuberculosis strains in project surveillance sites. In November 1998, NTGSN detected 11 isolates from previously re- ported TB cases among persons in New Jersey whose DNA fingerprints matched the avirulent laboratory M. tuberculosis control strain H37Ra. H37Ra does not cause active TB in humans, but it has been reported as a source of cross-contamination (8 ). In collabo- ration with the New Jersey Department of Health and Senior Services, CDC investi- gated H37Ra as a possible cause of TB disease and/or TB misdiagnoses caused by laboratory cross-contamination in the 11 case-patients. This report describes findings from two of the 11 cases and summarizes the results of this investigation, which indicate that TB was misdiagnosed and demonstrate the value of DNA fingerprinting to identify occurrences of cross-contamination of patient specimens. Case Findings Case 1. In October 1998, a 44-year-old woman with multiple sclerosis and no known exposure to a person with active TB had TB diagnosed on the basis of a positive culture result. Cerebrospinal fluid revealed no signs of infection, but the culture grew M. tuber- culosis at 7 weeks. Her chest radiograph was normal, and a tuberculin skin test (TST) was not documented. Anti-TB therapy was not initiated because no development or progression of symptoms consistent with TB occurred. The cerebrospinal fluid was retested in the same laboratory (7 weeks after the original specimen was obtained) and revealed a stain with 1+ acid-fast bacilli (AFB). The patient was started on anti-TB medications. The culture for the second specimen was negative for TB. This patient had received 4 months of anti-TB treatment at the time of the investigation. Case 2. A 58-year-old woman with a history of reactive airway disease and angioedema was taken to a local emergency department with shortness of breath and cough. Her chest radiograph was normal, and a TST was not documented. A sputum specimen obtained at that time was AFB smear-negative, but M. tuberculosis culture 413 Misdiagnoses of Tuberculosis Resulting From Laboratory Cross-Contamination 416 Cause-Specific Adult Mortality: Evidence From Community-Based Surveillance — Selected Sites, Tanzania, 1992–1998 420 Prevalence of Leisure-Time and Occupational Physical Activity Among Employed Adults — U.S. 424 Notices to Readers
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May 19, 2000 / Vol. 49 / No. 19
U.S. DEPARTMENT OF HEALTH & HUMAN SERVICES
Misdiagnoses of Tuberculosis Resulting From LaboratoryCross-Contamination of Mycobacterium Tuberculosis Cultures —
New Jersey, 1998
A diagnosis of tuberculosis (TB) is rarely disputed if Mycobacterium tuberculosis isisolated from a clinical specimen; however, specimen contamination may occur (1–3 ).Identification of TB strain patterns through molecular typing or DNA fingerprinting is arecent advancement in TB laboratory techniques (3–7 ). CDC’s National TuberculosisGenotyping and Surveillance Network (NTGSN) performs DNA fingerprinting on TB iso-lates to determine the frequency of clustering among M. tuberculosis strains in projectsurveillance sites. In November 1998, NTGSN detected 11 isolates from previously re-ported TB cases among persons in New Jersey whose DNA fingerprints matched theavirulent laboratory M. tuberculosis control strain H37Ra. H37Ra does not cause activeTB in humans, but it has been reported as a source of cross-contamination (8 ). In collabo-ration with the New Jersey Department of Health and Senior Services, CDC investi-gated H37Ra as a possible cause of TB disease and/or TB misdiagnoses caused bylaboratory cross-contamination in the 11 case-patients. This report describes findingsfrom two of the 11 cases and summarizes the results of this investigation, which indicatethat TB was misdiagnosed and demonstrate the value of DNA fingerprinting to identifyoccurrences of cross-contamination of patient specimens.
Case Findings
Case 1. In October 1998, a 44-year-old woman with multiple sclerosis and no knownexposure to a person with active TB had TB diagnosed on the basis of a positive cultureresult. Cerebrospinal fluid revealed no signs of infection, but the culture grew M. tuber-culosis at 7 weeks. Her chest radiograph was normal, and a tuberculin skin test (TST)was not documented. Anti-TB therapy was not initiated because no development orprogression of symptoms consistent with TB occurred. The cerebrospinal fluid wasretested in the same laboratory (7 weeks after the original specimen was obtained) andrevealed a stain with 1+ acid-fast bacilli (AFB). The patient was started on anti-TBmedications. The culture for the second specimen was negative for TB. This patient hadreceived 4 months of anti-TB treatment at the time of the investigation.
Case 2. A 58-year-old woman with a history of reactive airway disease andangioedema was taken to a local emergency department with shortness of breath andcough. Her chest radiograph was normal, and a TST was not documented. A sputumspecimen obtained at that time was AFB smear-negative, but M. tuberculosis culture
413 Misdiagnoses of TuberculosisResulting From LaboratoryCross-Contamination
416 Cause-Specific Adult Mortality:Evidence From Community-BasedSurveillance — Selected Sites,Tanzania, 1992–1998
420 Prevalence of Leisure-Time andOccupational Physical Activity AmongEmployed Adults — U.S.
424 Notices to Readers
414 MMWR May 19, 2000
Cross-Contamination of Mycobacterium Tuberculosis — Continued
was positive at 6 weeks. Although the patient had recovered after treatment for acuteasthma, she was started on anti-TB treatment. Treatment was discontinued after 2 weekswhen health-care providers determined her illness was not TB.
Summary Findings
A list of the 11 case-patients with an isolate with a fingerprint matching H37Ra wascompiled, and information on the origin of each case-specimen was obtained. Investiga-tors reviewed hospital, clinic, and health department records for each case-patient toestablish the clinical events leading to TB diagnosis. Investigators visited the laboratorieswhere the 11 specimens were processed to interview laboratory personnel about speci-men processing techniques and to review laboratory logs for mycobacterial specimentesting.
The 11 case-patients had TB diagnosed and reported during 1996–1998. Mean age ofpatients was 60 years (range: 36–81 years); eight were women, and three were humanimmunodeficiency virus (HIV)-positive. Eight cases were classified as pulmonary andthree as extrapulmonary. Seven patients had abnormal chest radiograph findings, andtwo had documented positive TSTs. All case-patients received partial or full-coursetherapy for TB; treatment durations ranged from 2 weeks to 6 months. Seven patientshad contact investigations performed; four of the 32 contacts identified were tested andtreated for latent TB infection. Each case met at least one criterion for suspectedlaboratory cross-contamination with M. tuberculosis*. In addition, each of the eight pul-monary patients had clinical courses suggestive of an illness other than TB (i.e., bacterialpneumonia [four], reactive airways disease [two], interstitial lung disease [one], andcongestive heart failure [one]).
The laboratory investigation revealed that the 11 specimens were processed duringFebruary 1996–October 1998 at four laboratories in New Jersey (three hospital labora-tories and one commercial laboratory). Each of the laboratories either used the strainH37Ra or participated in laboratory proficiency testing using H37Ra; however, labora-tory logs did not include the specific times when H37Ra was handled on the same day asany of the 11 specimens. In addition, personnel at the laboratories could not recall in-stances when the control strain may have been mishandled. The average number ofspecimens collected for AFB culture per patient was four (range: two to 12). All culture-positive patient specimens were smear-negative. Mean number of days to M. tuberculo-sis growth for patient specimens was 38 (range: 17–54 days).Reported by: K Shilkret, Z Liu, F Santos, M Dillon, ME Schulman, New Jersey Dept of Health andSenior Svcs. B Kreiswirth, P Bifani, S Moghazeh, B Mathema, Public Health Research Institute–TB Center, New York, New York. Surveillance and Epidemiology Br, Div of Tuberculosis Elimina-tion, National Center for HIV, STD, and TB Prevention; and an EIS Officer, CDC.
Editorial Note: These misdiagnosed cases of TB illustrate the need for heightenedawareness of laboratory cross-contamination with M. tuberculosis. Clinicians and healthdepartment personnel did not suspect laboratory cross-contamination in these 11 cases;therefore, this oversight would not have been detected without the use of DNA
*Suspected laboratory cross-contamination with M. tuberculosis may include at least one ofthe following: 1) patient’s clinical course is inconsistent with TB; 2) single positiveM. tuberculosis culture with no AFB seen in any specimen; 3) culture-positive specimenfrom a different patient processed or handled on the same day has an identical DNAfingerprint, and no epidemiologic connections exist between patients; 4) laboratory controlstrain has an identical fingerprint; and 5) time to growth detection is >30 days.
Vol. 49 / No. 19 MMWR 415
Cross-Contamination of Mycobacterium Tuberculosis — Continued
fingerprinting through NTGSN. The putative source of cross-contamination for the11 cases, H37Ra, is a laboratory control strain that is used weekly in some laboratoriesfor routine drug susceptibility testing. H37Ra also is distributed to mycobacteriologylaboratories as part of a biyearly proficiency testing required by the Clinical LaboratoryImprovement Amendments (9 ). The control strains for proficiency testing often areprocessed simultaneously with patient specimens, but many laboratories do not documentconsistently specific times when proficiency testing is conducted. As a result, it is difficultto prove that the control strain is the source of cross-contamination in a specific case. Inaddition, several opportunities exist for specimen carryover, spillage, or inadvertentcontamination during specimen processing, but these occurrences are difficult to discoverretrospectively. Given these obstacles in discovering cross-contamination, NTGSN hasestablished criteria for suspected laboratory cross-contamination of TB (CDC, unpublisheddata, 1998).
Reliance on clinical judgment and the presence of corroborating clinical signs andsymptoms play pivotal roles in interpreting laboratory data. Systemic symptoms of fe-ver, loss of appetite, weight loss, weakness, night sweats, and malaise are common butnot specific for TB. Other signs and symptoms vary according to the site involved. Inpulmonary TB, prolonged cough with or without sputum production, and ensuing pulmo-nary inflammation and necrosis are manifest. Chest radiograph findings of adenopathy,lung infiltrates, and pleural reaction are important correlates in the diagnosis, but thesefindings may be due to illnesses other than TB, particularly in the presence of HIV. Thesescenarios often create clinical dilemmas when initial laboratory data support a TB diag-nosis. A positive TST is evidence for TB, but the positive predictive value depends on thecut-off value used to determine a positive test and the prevalence of TB infection in thepopulation (10 ). In the appropriate clinical setting, the presence of a positive AFB smearshould raise suspicion for TB; however, a positive smear with a concomitant inconsistentclinical history may represent the presence of H37Ra, a nontuberculous organism, suchas Mycobacterium avium complex, or environmental contamination with a ubiquitousacid-fast species such as Mycobacterium gordonae. H37Ra and nontuberculous organ-isms are indistinguishable from pathogenic strains of M. tuberculosis on a laboratorysmear.
For some patients, signs, symptoms, and test results are lacking or conflicting, asillustrated by the case-patients described in this report. If discrepancies exist amongclinical and laboratory data, and at least one criterion for laboratory cross-contaminationis met, an investigation should ensue to determine whether the patient has a potential TBexposure, whether specimens from the laboratory strain or other TB patients were pro-cessed simultaneously with the specimen in question, and whether performance of DNAfingerprinting is appropriate. To identify occurrences and sources of cross-contamina-tion, it also is important for mycobacteriology laboratories to determine the DNA finger-print pattern of the M. tuberculosis control strain used in their respective laboratories.
The patients described in this report received unnecessary treatment for TB andmore than half had a contact investigation initiated. Recognition by health-care profes-sionals and laboratorians of the potential for laboratory cross-contamination with M.tuberculosis should help avert erroneous TB diagnoses and avoid unnecessary treat-ment and associated toxicity. In addition, this awareness assists TB-control programs inavoiding unnecessary patient care costs and futile contact investigations and helps main-tain accurate TB case reporting.
416 MMWR May 19, 2000
Cross-Contamination of Mycobacterium Tuberculosis — Continued
tion revisited: the role of laboratory environmental control in a pseudo-outbreak. InfectControl Hosp Epid 1998;19:101–5.
2. Dunlap N, Harris R, Benjamin W, et al. Laboratory contamination of Mycobacterium tuber-culosis cultures. Am J Respir Crit Care Med 1995;152:1702–4.
3. Braden C, Templeton G, Stead W, et al. Retrospective detection of laboratory cross-contamination of Mycobacterium tuberculosis cultures with the use of DNA fingerprintanalysis. Clin Infect Dis 1997;24:35–40.
4. Small P, Hopewell P, Singh S, et al. The epidemiology of tuberculosis in San Francisco: apopulation-based study using conventional and molecular methods. N Engl J Med1994;330:1703–9.
5. Alland D, Kalkut G, Moss A, et al. Transmission of tuberculosis in New York City: ananalysis by DNA fingerprinting and conventional epidemiologic methods. N Engl J Med1994;330:1710–6.
6. French A, Welbel S, Dietrich S, et al. Use of DNA fingerprinting to assess tuberculosisinfection control. Ann Intern Med 1998;129:856–61.
7. Braden C, Templeton G, Cave M, et al. Interpretation of restriction length polymorphismanalysis of Mycobacterium tuberculosis isolates from a state with a large rural popula-tion. J Infect Dis 1997;175:1446–528.
8. Burman W, Stone B, Reves R, et al. The incidence of false-positive cultures for Mycobac-terium tuberculosis. Am J Respir Crit Care Med 1997;155:321–6.
9. CDC. Laboratory practices for diagnosis of tuberculosis—United States, 1994. MMWR1995;44:586–9.
10. American Thoracic Society. Diagnostic standards and classification of tuberculosis inadults and children. Am J Respir Crit Care Med 2000;161:1376–95.
Cause-Specific Adult Mortality:Evidence From Community-Based Surveillance —
Selected Sites, Tanzania, 1992–1998
Mortality data are a standard information resource to guide public health action.Because Tanzania did not have a representative mortality surveillance system, in 1992the Adult Morbidity and Mortality Project (AMMP)* was established by the MuhimbiliUniversity College of Health Sciences, the Ministry of Health of Tanzania (MOH), and theUniversity of Newcastle upon Tyne, United Kingdom. The purpose of the surveillancesystem is to provide cause-specific death rates among adults in three areas of Tanzaniaand to link community-based mortality surveillance to evidence-based planning for healthcare. This report describes the results of AMMP surveillance during 1992–1998, whichindicated that human immunodeficiency virus infection/acquired immunodeficiency syn-drome (HIV/AIDS) was the leading cause of death reported by decedents’ relatives andcaretakers for adults of both sexes in all study areas, and suggests that a range of othercauses of death exist across the three surveillance sites.
The AMMP surveillance project was conducted in a low-income and in a middle-income section of the city of Dar es Salaam, which is part of a region ranked by the
*AMMP is a project of the Ministry of Health of Tanzania, is funded by the Department forInternational Development, United Kingdom, and is implemented in partnership with theUniversity of Newcastle upon Tyne, United Kingdom.
Vol. 49 / No. 19 MMWR 417
Mortality in Tanzania — Continued
Tanzanian government among the 50% most deprived in Tanzania (i.e., Morogoro RuralDistrict in Morogoro Region), and in part of a region ranked as one of the 15% leastdeprived (i.e., Hai District in Kilimanjaro Region) (1 ). These areas were selected to com-pare urban with rural conditions and high-income with low-income conditions. Populationdenominators were determined by semi-annual census rounds in Dar es Salaam andannual census rounds in Morogoro Rural and Hai. Mortality monitoring was conductedby trained volunteers who reported deaths to a team of supervisors. Supervisors thenconducted “verbal autopsy” interviews with the decedents’ relatives and caretakers todetermine the cause of death (2 ). Family and caretakers were used as sources to deter-mine cause of death because up to 80% of deaths occur outside health facilities and mostdeaths are not medically certified (3 ). The interviews usually occurred within a month ofa supervisor’s receipt of the death report (4 ). The completed interview forms were codedby three physicians using the International Classification of Diseases and Related HealthProblems, 10th Revision (3–5 ).
During 1992–1998, 10,517 persons aged 15–59 years died in the three locations; acause of death was assigned by AMMP in 95% of cases. Death rates per 100,000 popu-lation were calculated for persons aged 15–59 years and for men and women by studyarea. Cause-specific death rates were calculated for persons aged 15–59, 15–29, 30–44,and 45–59 years, by sex, and by study area; probability of death by age 60 years at age15 years was calculated by sex and study area. Death rates were standardized to WorldHealth Organization standard populations (6 ). The probability of death by age 60 years atage 15 years was 45% for women and 42% for men in Dar es Salaam, 43% for womenand 51% for men in Morogoro Rural, and 26% for women and 37% for men in Hai.
In addition to indicating 6-year total death rates and death rates from the 10 leadingcauses of death for men and women (Table 1), the data reflected large variations incause-specific death by sex and geographic area and are ranked according to an age-adjusted death rate for each district; no causes of death were excluded from ranking.HIV/AIDS, tuberculosis (TB), malaria, and diarrhea were major causes of death. HIV/AIDSand TB were particularly high in Dar es Salaam, especially among women aged 15–29years (325 and 62 per 100,000, respectively) and men aged 30–59 years (1199 and 426,respectively). The HIV/AIDS death rate was 608 among men aged 30–44 years in Dar esSalaam, and the TB death rate was 232. HIV/AIDS was the leading cause of death amongpersons of both sexes aged 15–59 years; the rate ranged from 246 among men inMorogoro Rural to 534 among women in Dar es Salaam. However, stroke and TB deathrates were 3.0 and 6.7 times higher, respectively, among women in Dar es Salaam thanamong women in the other areas, and anemia death rates in Morogoro Rural were 3.0times higher than in the other districts. In Morogoro Rural, the rate of maternal mortalitywas 114, with a maternal mortality ratio of 1183 per 100,000 live births, more than eighttimes the official regional estimate (AMMP, unpublished data, 2000). Among men, ma-laria, acute diarrheal disease, and anemia death rates were 3.0, 4.3, and 21.7 timeshigher, respectively, in Morogoro Rural than in the other two districts. Stroke and cancerdeath rates for both sexes were higher in Dar es Salaam and Hai than in Morogoro Rural.Among men, injury was a substantial cause of death, and injury rates for both sexeswere higher in rural than urban areas.Reported by: PW Setel, PhD, N Unwin, MFPHM, KGMM Alberti, DPhil, Univ of Newcastle uponTyne, Newcastle upon Tyne, United Kingdom. Y Hemed, MBChB, Ministry of Health, AdultMorbidity and Mortality Project Team. Adult Morbidity and Mortality Project Team, Dar esSalaam, Tanzania.
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TABLE 1. Cause-specific death rates* for 10 leading causes of death among persons aged 15–59 years†, by sex —selected sites, Tanzania, 1992–1998
15–29 30–44 45–59 TotalDar es Morogoro Dar es Morogoro Dar es Morogoro Dar es Morogoro
Sex/Cause of death Salaam Rural Hai Salaam Rural Hai Salaam Rural Hai Salaam Rural Hai
All cause death rate 547 818 843 1451 1892 1346 2191 2697 1641 1171 1545 997
* Per 100,000 population.† Age adjusted to World Health Organization standard population (6 ).§ Includes malaria.¶ Includes cholera.
Vol. 49 / No. 19 MMWR 419
Mortality in Tanzania — Continued
Editorial Note: AMMP is being developed as a prototype of a routine mortality datacollection system to be integrated into the local health system of Tanzania. The datafrom the selected districts show that substantial variation in overall and cause-specificdeaths exist in conditions of extreme poverty relative to other countries. In 1997, Tanzaniahad the third lowest gross national product per capita in the world (7 ). In 1990, estimatesof the probability of death at age 15 years by age 60 years in sub-Saharan Africa were39% for men and approximately 30% for women (8 ). On the basis of data in this report,the probability of death is considerably higher for the three study areas; the data alsoshow that in these areas important differences exist by sex and geography. Infectiousdiseases predominated in Dar es Salaam and Morogoro Rural, and noninfectious diseaseand injury rates were greater in Hai than in Dar es Salaam and Morogoro Rural.
In addition, the data reflect age-specific patterns of HIV/AIDS and the need for HIVprevention intervention and improved home care for persons with HIV/AIDS. Malariaand diarrhea also should be public health priorities, as should noninfectious diseases thatrepresented major causes of death, particularly stroke, cancer, and diabetes for thepopulations residing in Dar es Salaam and Hai. Stroke death rates among persons aged45–60 years in Dar es Salaam are several times higher than rates in the United Kingdomor North America (8 ).
The results of this study are subject to at least three limitations. First, because thestudy population has had little to moderate formal education, age reporting may beinaccurate, especially among older age groups. Second, the exact cause of death maynot have been known (3 ), particularly for conditions such as anemia, septicemia, geni-tourinary disorders, and some cancers. Third, an unknown amount of overlap may existamong HIV/AIDS, TB, chronic diarrhea, and other causes of death.
The high mortality reported from these three areas highlights the need to establishadult health as a priority in Tanzania. For many of the important causes of death, effectiveand inexpensive preventive or treatment measures are available, including condoms,insecticide-treated bednets, oral rehydration therapy for acute diarrhea, treatment forhypertension, directly observed therapy for TB, improved nutrition, and access to cleanwater. MOH has used these data to design a National Essential Health Package, a mini-mum standard of care that all districts in Tanzania will be expected to provide by 2010.References1. United Republic of Tanzania. Poverty and welfare monitoring indicators. Dar es Salaam,
Tanzania: United Republic of Tanzania, Office of the Vice President, November 1999.2. Chandramohan, D, Maude GH, Rodrigues LC, Hayes RJ. Verbal autopsies for adult deaths:
issues in their development and validation. Int J Epidemiol 1994;23:213–22.3. Ministry of Health, Adult Morbidity and Mortality Project. The policy implications of adult
morbidity and mortality: end of phase 1 report. Dar es Salaam, Tanzania: United Republic ofTanzania, 1997.
4. Kitange HM, Machibya H, Black J, et al. Outlook for survivors of childhood in sub-SaharanAfrica: adult mortality in Tanzania. British Medical Journal 1996;312:216–20.
5. World Health Organization. International classification of diseases and related health prob-lems, 10th revision. Geneva, Switzerland: World Health Organization, 1993.
6. World Health Organization. World health statistics annual. Geneva, Switzerland: WorldHealth Organization, 1994.
7. World Bank. World development report 1997: the state in a changing world. New York:World Bank/Oxford University Press, 1997.
8. Murray CJL, Lopez AD. The global burden of disease: global burden of disease and injury.Boston, Massachusetts: Harvard School of Public Health, 1996.
420 MMWR May 19, 2000
Prevalence of Leisure-Time and Occupational Physical Activity AmongEmployed Adults — United States, 1990
Regular physical activity and high levels of physical fitness offer numerous healthbenefits, such as reduced risk for cardiovascular disease, diabetes, obesity, some can-cers, and musculoskeletal conditions (1 ). National rates for participation in leisure-timephysical activity are consistently low for women, older adults, persons with low educa-tional attainment, and racial/ethnic minorities (2 ). Public health recommendations forpromoting physical activity emphasize moderate-intensity activities, building on recom-mendations for vigorous exercise to improve fitness (3,4 ). To determine the prevalenceof leisure-time and occupational physical activity, data were analyzed for employedadults aged �18 years in the 1990 National Health Interview Survey (NHIS). This reportsummarizes the results of the survey, which indicate that approximately half of adultswho reported no physical activity during leisure time also reported that they performedat least 1 hour per day of hard physical activity at work.
The survey used a probability sample of the U.S. civilian, noninstitutionalized popula-tion aged �18 years (5 ); 20,766 persons responded to the survey. Respondents wereasked to identify the frequency and duration of their participation in 24 sports and condi-tioning activities during the 2 weeks preceding the survey, and to list the number of hoursper day they spent doing hard physical work on the job (2 ).
Leisure-time physical activities were scored by the intensity (i.e., metabolic equiva-lents [METs]), frequency, and duration of effort. METs for each leisure-time physicalactivity were based on the Compendium of Physical Activities (6 ). Respondents werecategorized as 1) sedentary (no leisure-time activity), 2) irregularly active (not meetingpublic health recommendations), 3) moderately active (meeting the current public healthrecommendation)*, or 4) vigorously active (meeting the fitness recommendation)†. Hardphysical activity at work was categorized as no hard labor, 1–4 hours per day, and�5 hours per day. Prevalence of activity was calculated by age, sex, race/ethnicity, andeducation level using SUDAAN to adjust for the complex sampling frame.
Approximately one third of adults reported an adequate level of leisure-time physicalactivity: 31.5% were moderately active, and 4.6% were vigorously active (Table 1). Menwere more active than women at both the moderate and vigorous level. At the moderatelevel, whites were more active than Hispanics. The prevalence of both moderate andvigorous activity increased with education level and decreased with age (Table 1).
More than half (56.4%) of adults reported doing no hard physical activity during theworkday; however, 20% reported 1–4 hours per day, and 23.6% reported �5 hours ofhard occupational activity. Occupational activity was highest for persons who had<12 years of education, and was higher for blacks and Hispanics than whites. Occupa-tional exertion decreased with increased education level and age (Table 2).
The prevalence of hard occupational activity differed by level of leisure-time physicalactivity (Figure 1). Half (51.3%) of the respondents classified as sedentary in leisure timereported at least 1 hour of hard occupational activity per day. The prevalence of hardoccupational activity was lower among persons classified as irregularly (42.0%), moder-ately (40.7%), or vigorously (36.8%) active during leisure time.Reported by: Physical Activity and Health Br, Div of Nutrition and Physical Activity, and Cardio-vascular Health Br, Div of Adult and Community Health, National Center for Chronic DiseasePrevention and Health Promotion, CDC.
*Three or more METs, �30 minutes accumulated total, �5 days per week. .† More than six METs, �20 minutes continuous session, �3 days per week.
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TABLE 1. Percentage of employed adults reporting levels of leisure-time physical activity*, by selectedcharacteristics — United States, National Health Interview Survey, 1990
* Sedentary=no leisure-time activity; irregular=not meeting public health recommendations; moderate=three or more metabolic equiva-lents (METs), �30 minutes accumulated total, �5 days per week; vigorous=more than six METs, �20 minutes continuous session,�3 days per week.
† Confidence interval.§ Numbers for other racial/ethnic groups were too small for meaningful analysis.
Leisure-Tim
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edTABLE 2. Percentage of employed adults reporting hard occupational activity, by selected characteristics — UnitedStates, National Health Interview Survey, 1990
Total 20,766 56.4 (55.3–57.0) 20.0 (19.2–20.7) 23.6 (22.6–24.6)
* Confidence interval.† Numbers for other racial/ethnic groups were too small for meaningful analysis.
Vol. 49 / No. 19 MMWR 423
Leisure-Time and Occupational Physical Activity — Continued
FIGURE 1. Percentage of respondents reporting hard occupational activity (hours perday), by levels of leisure-time physical activity* — United States, National HealthInterview Survey, 1990
Editorial Note: The findings in this report indicate that during leisure time approximatelytwo thirds (63.9%) of employed adults in the United States do not meet currentrecommendations for participation in moderate or vigorous physical activity. The NHISfindings were consistent with previous reports that indicate women, older adults, personswith <12 years of education, or members of racial/ethnic minorities are most likely to beinactive during leisure time (7 ). However, other opportunities exist for obtainingrecommended amounts of physical activity, such as activities involved in commuting toand from work and those associated with certain occupations or maintaining a home.
Although the findings in this report suggest that adults may participate in physicalactivity at work, the frequency, intensity, and type of activity are not available from theNHIS data. Assessing activity patterns limited to leisure-time activity may underesti-mate the proportion of persons who obtain the recommended level of physical activity.Many persons from groups that are sedentary in their leisure time may be getting suffi-cient occupational physical activity to derive health benefits.
The findings in this report are subject to at least four limitations. First, estimates arebased on self-reported activity and may be overestimates. Second, recall of the 24 typesof leisure-time physical activity may have resulted in underreporting if seasonal or ir-regular activities were not performed during the 2-week recall period. Third, this studydoes not provide information on other sources of physical activity, such as transportationor housework, which may be disproportionately higher in certain population groups,such as women and racial/ethnic minorities. Finally, questions about occupational physi-cal activity have not been asked since the 1990 NHIS, and the level of physical activityduring work may have changed during the past decade.
* Sedentary=no leisure-time activity; irregular=not meeting public health recommendations;moderate=three or more metabolic equivalents (METs), �30 minutes accumulated total,�5 days per week; vigorous=more than six METs, �20 minutes continuous session, �3 daysper week.
0
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424 MMWR May 19, 2000
Leisure-Time and Occupational Physical Activity — Continued
CDC and the American College of Sports Medicine recommend that every U.S. adultaccumulate 30 minutes or more of moderate-intensity physical activity on most, prefer-ably all, days of the week (3 ). In 1990, only one third of employed adults met this recom-mendation or the recommendation for vigorous activity during leisure time. One of thenational health objectives for 2000 was to reduce to no more than 15% the proportion ofpersons who engage in no leisure-time physical activity (objective 1.5) (8 ).
Systems that collect information on physical activity should be expanded to includeadditional activities. Because of the demonstrated health benefits of moderate-intensityphysical activity, surveillance systems should be designed to assess activities such asoccupational, childcare, and transportation for future monitoring of health-related physi-cal activity.References1. Bouchard C, Stevens T, Shephard RJ. Proceedings from the 1992 International Conference
on Physical Activity, Fitness and Health. Champaign, Illinois: Human Kinetics Publisher,1994.
2. Piani A, Schoenborn D. Health promotion and disease prevention: United States, 1990.Hyattsville, Maryland: US Department of Health and Human Services, Public Health Service,CDC, National Center for Health Statistics, 1993;10:185.
3. Pate RR, Pratt M, Blair SN, et al. Physical activity and public health: a recommendation fromthe Centers for Disease Control and Prevention and the American College of Sports Medi-cine. JAMA 1995;273:402–7.
4. American College of Sports Medicine. Position stand on the recommended quantity andquality of exercise for developing and maintaining cardiorespiratory and muscular fitnessin healthy adults. Med Sci Sports Exerc 1990;22:265–74.
5. National Center for Health Statistics, Massey JT, Moore TF, Parsons VL, et al. Design andestimation for the National Health Interview Survey, 1985–1994. Hyattsville, Maryland: USDepartment of Health and Human Services, Public Health Service, CDC, 1989; DHHS publi-cation no. (PHS)89-1384. (Vital and health statistics; series 2, no. 110).
6. Ainsworth BE, Haskell WL, Leon AS, et al. Compendium of physical activities: classificationof energy costs of human physical activities. Med Sci Sports Exerc 1993;25:71–80.
7. Jones DA, Ainsworth BE, Croft JB, et al. Moderate leisure-time physical activity: who ismeeting the public health recommendations? A national cross-sectional study. Arch FamMed 1998;7:285–9.
8. Public Health Service. Healthy people 2000: national health promotion and disease preven-tion objectives—full report, with commentary. Washington, DC: US Department of Healthand Human Services, Public Health Service, 1991; DHHS publication no. (PHS)91-50212.
Notice to Readers
Revision of Acute Hepatitis Panel
Current Procedural Terminology (CPT) codes are standardized codes developed andmaintained by the American Medical Association (AMA) for the classification and report-ing of medical services. The Health Care Financing Administration (HCFA) requires theuse of these codes for reporting services to Medicare and Medicaid for reimbursement.On January 1, 1998, the components of the test panel for acute viral hepatitis (CPT#80059)were changed to exclude the tests for IgM antibody to hepatitis A virus (IgM anti-HAV)and IgM antibody to hepatitis B core antigen (IgM anti-HBc), the tests that specificallyidentify recent infection with hepatitis A virus (HAV) and hepatitis B virus (HBV).
Vol. 49 / No. 19 MMWR 425
Effective January 1, 2000 (CPT 2000), the acute hepatitis panel has been revised(CPT#80074) to re-include the tests for IgM anti-HAV and IgM anti-HBc. This revisedpanel, which also includes tests for hepatitis B surface antigen (HBsAg) and antibody tohepatitis C virus (anti-HCV), should be used to diagnose any patient presenting with signsand/or symptoms of acute viral hepatitis. Additional information on CPT codes is avail-able at the AMA World-Wide Web site, http://www.ama-assn.org/med-sci/cpt/coding.htm.*
*References to sites of non-CDC organizations on the World-Wide Web are provided as aservice to MMWR readers and do not constitute or imply endorsement of these organizationsor their programs by CDC or the U.S. Department of Health and Human Services. CDC is notresponsible for the content of pages found at these sites.
Notice to Readers
New Web-Based Training on Hepatitis C for Health Professionals
On May 15, 2000, CDC posted on its World-Wide Web site an interactive web-basedtraining program titled “Hepatitis C: What Clinicians and Other Health ProfessionalsNeed to Know.” The program is at http://www.cdc.gov/hepatitis.
This program provides users with up-to-date information on the epidemiology, diag-nosis, and management of hepatitis C virus (HCV) infection and HCV-related chronicdisease. Users also can test their knowledge of the material through study questions atthe end of each section and case studies at the end of the program. Continuing medicaland nursing education credits are available free from CDC on completion of the training.The American Academy of Family Physicians also will grant the academy’s educationcredits on completion of training and filing with the academy.
FIGURE I. Selected notifiable disease reports, United States, comparison ofprovisional 4-week totals ending May 13, 2000, with historical data
*Ratio of current 4-week total to mean of 15 4-week totals (from previous, comparable, andsubsequent 4-week periods for the past 5 years). The point where the hatched area beginsis based on the mean and two standard deviations of these 4-week totals.
TABLE I. Summary of provisional cases of selected notifiable diseases,United States, cumulative, week ending May 13, 2000 (19th Week)
Cum. 2000 Cum. 2000
Anthrax - HIV infection, pediatric*§ 85Brucellosis* 15 Plague 2Cholera - Poliomyelitis, paralytic -Congenital rubella syndrome 4 Psittacosis* 5Cyclosporiasis* 6 Rabies, human -Diphtheria - Rocky Mountain spotted fever (RMSF) 44Encephalitis: California serogroup viral* 2 Streptococcal disease, invasive, group A 1,158
-:No reported cases. *Not notifiable in all states. † Updated weekly from reports to the Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases (NCID). § Updated monthly from reports to the Division of HIV/AIDS Prevention — Surveillance and Epidemiology, National Center for HIV,
STD, and TB Prevention (NCHSTP). Last update April 30, 2000. ¶ Updated from reports to the Division of STD Prevention, NCHSTP.
Meningococcal Infections
DISEASE DECREASE INCREASECASES CURREN
4 WEEKS
Ratio (Log Scale)*
Beyond Historical Limits
4210.50.25
548
388
81
27
7
134
19
267
26
Hepatitis A
Hepatitis B
Hepatitis C; Non-A, Non-B
Legionellosis
Measles, Total
Mumps
Pertussis
Rubella
428 MMWR May 19, 2000
TABLE II. Provisional cases of selected notifiable diseases, United States,weeks ending May 13, 2000, and May 15, 1999 (19th Week)
Guam 13 1 - 176 - - N N U UP.R. 284 494 142 U - - 2 8 U UV.I. 18 13 - U - U - U U UAmer. Samoa - - - U - U - U U UC.N.M.I. - - - U - U - U U U
N: Not notifiable. U: Unavailable. -: No reported cases. C.N.M.I.: Commonwealth of Northern Mariana Islands.* Individual cases can be reported through both the National Electronic Telecommunications System for Surveillance (NETSS) and the Public
Health Laboratory Information System (PHLIS).† Chlamydia refers to genital infections caused by C. trachomatis. Totals reported to the Division of STD Prevention, NCHSTP.§ Updated monthly from reports to the Division of HIV/AIDS Prevention — Surveillance and Epidemiology, National Center for HIV, STD, and
Guam - - - - - 20 U UP.R. - - 16 34 24 158 U UV.I. - U - U - U U UAmer. Samoa - U - U - U U UC.N.M.I. - U - U - U U U
N: Not notifiable. U: Unavailable. -: No reported cases.*Individual cases can be reported through both the National Electronic Telecommunications System for Surveillance (NETSS) and the Public Health Laboratory Information System (PHLIS).
TABLE II. (Cont’d) Provisional cases of selected notifiable diseases, United States,weeks ending May 13, 2000, and May 15, 1999 (19th Week)
Vol. 49 / No. 19 MMWR 431
TABLE II. (Cont’d) Provisional cases of selected notifiable diseases, United States,weeks ending May 13, 2000, and May 15, 1999 (19th Week)
Guam - 4 U U - - - -P.R. 1 32 U U 49 75 - 61V.I. - U U U - U - UAmer. Samoa - U U U - U - UC.N.M.I. - U U U - U - UN: Not notifiable. U: Unavailable. -: No reported cases.*Individual cases can be reported through both the National Electronic Telecommunications System for Surveillance (NETSS) and the Public Health Laboratory Information System (PHLIS).
†Cumulative reports of provisional tuberculosis cases for 1999 are unavailable (“U”) for some areas using the Tuberculosis Information System(TIMS).
432 MMWR May 19, 2000
TABLE III. Provisional cases of selected notifiable diseases preventableby vaccination, United States, weeks ending May 13, 2000,
Guam - - - 2 - 2 U - U - - 1P.R. - 1 40 110 24 105 - - - - - -V.I. - U - U - U U - U - - UAmer. Samoa - U - U - U U - U - - UC.N.M.I. - U - U - U U - U - - UN: Not notifiable. U: Unavailable. - : No reported cases.*For imported measles, cases include only those resulting from importation from other countries.†Of 99 cases among children aged <5 years, serotype was reported for 42 and of those, 9 were type b.
Guam - - U - 1 U - 1 U - -P.R. 2 7 - - - - - 5 - - -V.I. - U U - U U - U U - UAmer. Samoa - U U - U U - U U - UC.N.M.I. - U U - U U - U U - UN: Not notifiable. U: Unavailable. - : No reported cases.
434 MMWR May 19, 2000
TABLE IV. Deaths in 122 U.S. cities,* week endingMay 13, 2000 (19th Week)
PACIFIC 1,003 736 163 71 16 16 94Berkeley, Calif. 19 12 3 4 - - 3Fresno, Calif. 111 83 19 9 - - 10Glendale, Calif. U U U U U U UHonolulu, Hawaii 64 38 19 5 - 2 3Long Beach, Calif. 80 61 12 5 1 1 9Los Angeles, Calif. U U U U U U UPasadena, Calif. 23 16 3 3 1 - 5Portland, Oreg. 104 76 18 5 3 2 8Sacramento, Calif. 150 116 19 9 5 1 16San Diego, Calif. 169 127 18 16 2 6 11San Francisco, Calif. U U U U U U USan Jose, Calif. U U U U U U USanta Cruz, Calif. 27 19 6 2 - - 3Seattle, Wash. 122 84 23 9 2 4 17Spokane, Wash. 55 45 8 2 - - 6Tacoma, Wash. 79 59 15 2 2 - 3
TOTAL 11,002¶ 7,566 2,073 852 260 246 781
U: Unavailable. -:No reported cases.*Mortality data in this table are voluntarily reported from 122 cities in the United States, most of which have populations of �100,000. A deathis reported by the place of its occurrence and by the week that the death certificate was filed. Fetal deaths are not included.
†Pneumonia and influenza.§Because of changes in reporting methods in this Pennsylvania city, these numbers are partial counts for the current week. Complete countswill be available in 4 to 6 weeks.
¶Total includes unknown ages.
Vol. 49 / No. 19 MMWR 435
Contributors to the Production of the MMWR (Weekly)Weekly Notifiable Disease Morbidity Data and 122 Cities Mortality Data
Samuel L. Groseclose, D.V.M., M.P.H.
State Support Team CDC Operations TeamRobert Fagan Carol M. KnowlesJose Aponte Deborah A. AdamsPaul Gangarosa, M.P.H. Willie J. AndersonGerald Jones Patsy A. HallDavid Nitschke Pearl SharpCarol A. Worsham Kathryn Snavely
InformaticsT. Demetri Vacalis, Ph.D.
Michele D. Renshaw Erica R. Shaver
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