Tuberculosis as an endemic and nosocomial infection among the elderly in nursing homes

Human immune response to Mycobacterium tuberculosis antigens

Little is known about the immunodominant or protective antigens of Mycobacterium tuberculosis in humans. Cell-mediated immunity is necessary for protection, and healthy tuberculin-positive individuals are relatively resistant to exogenous reinfection. We compared the targets of the cell-mediated immune response in healthy tuberculin-positive individuals to those of tuberculosis patients and tuberculin-negative persons. By using T-cell Western blotting (immunoblotting) of nitrocellulose-bound M. tuberculosis culture filtrate, peaks of T-cell blastogenic activity were identified in the healthy tuberculin reactors at 30, 37, 44, 57, 64, 71 and 88 kDa. Three of these fractions (30, 64, and 71 kDa) coincided with previously characterized proteins: antigen 6/alpha antigen, HSP60, and HSP70, respectively. The blastogenic responses to purified M. tuberculosis antigen 6/alpha antigen and BCG HSP60 were assessed. When cultured with purified antigen 6/alpha antigen, lymphocytes of healthy tuberculin reactors demonstrated greater [3H]thymidine incorporation than either healthy tuberculin-negative controls or tuberculous patients (8,113 +/- 1,939 delta cpm versus 645 +/- 425 delta cpm and 1,019 +/- 710 delta cpm, respectively; P less than 0.01). Healthy reactors also responded to HSP60, although to a lesser degree than antigen 6/alpha antigen (4,276 +/- 1,095 delta cpm; P less than 0.05). Partially purified HSP70 bound to nitrocellulose paper elicited a significant lymphocyte blastogenic response in two of six of the tuberculous patients but in none of the eight healthy tuberculin reactors. Lymphocytes of none of five tuberculin-negative controls responded to recombinant antigens at 14 or 19 kDa or to HSP70. Antibody reactivity generally was inversely correlated with blastogenic response: tuberculous sera had high titer antibody to M. tuberculosis culture filtrate in a range from 35 to 180 kDa. This is the first systematic evaluation of the human response to a panel of native and recombinant antigens in healthy tuberculin reactors and tuberculous patients. Antigens which stimulated prominent lymphocyte blastogenic responses were identified in seven fractions on T-cell Western blot analysis. Two of these may represent previously characterized proteins; the others may contain immunodominant proteins that will require further characterization.

The spectrum of tuberculosis in a New York City men's shelter clinic (1982-1988)

The objective of this study was to determine the prevalence of tuberculous infection and the incidence of active tuberculosis in homeless men attending a shelter-based clinic and to examine risk factors for acquisition of infection and development of active disease. The design was a prospective cross-sectional survey. Men were evaluated by standardized interviews using a questionnaire. Where indicated, skin testing with PPD, collection of sputum for smear and culture for acid-fast bacilli, and chest x-ray films were performed. The setting was an on-site clinic at a men's shelter in New York City. The patients were men attending the clinic for physical examinations for the work program or requesting evaluation of various medical problems. A total of 1,853 men were evaluated over a 73-month period. The overall rate of infection was 42.8 percent, including 27.0 percent with a positive PPD test, 9.8 percent with a history of a positive PPD test, and 6.0 percent with active tuberculosis. Increasing age, length of stay in the shelter system, black race, and intravenous drug use were found to be independently associated with tuberculous infection. Age, length of stay in the shelter system, and intravenous drug use were independently associated with active tuberculosis. We achieved a compliance rate of 36 percent completing treatment and 13 percent receiving treatment at the conclusion of the study.

Racial differences in susceptibility to infection by Mycobacterium tuberculosis

The prevalence of tuberculosis among blacks is known to be about twice that among whites. When we looked at infection rates among the initially tuberculin-negative residents of 165 racially integrated nursing homes in Arkansas, we were stimulated to investigate whether this difference could be due in part to racial differences in susceptibility to Mycobacterium tuberculosis infection. A new infection was defined by an increase of greater than or equal to 12 mm of induration after a tuberculin skin test (5 tuberculin units) administered at least 60 days after a negative two-step test. On repeat skin testing of the 25,398 initially tuberculin-negative nursing home residents, we found that 13.8 percent of the blacks and only 7.2 percent of the whites had evidence of a new infection (relative risk, 1.9; 95 percent confidence interval, 1.7 to 2.1). Blacks were infected more frequently, regardless of the race of the source patient. In homes with a single source patient who was white, 17.4 percent of the black and 11.7 percent of the white residents became infected (relative risk, 1.5; 95 percent confidence interval, 1.2 to 1.9); in homes with a single source patient who was black, 12.4 percent of the black and 7.7 percent of the white residents became infected (relative risk, 1.6; 95 percent confidence interval, 1.2 to 2.1). However, there was no racial difference in the percentage of residents who had recently converted to positive status who, in the absence of preventive therapy, were later found to have clinical tuberculosis (blacks, 11.5 percent; whites, 10.6 percent). Data from three outbreaks of tuberculosis in two prisons also showed that blacks have about twice the relative risk of whites of becoming infected with M. tuberculosis. We conclude that blacks are more readily infected by M. tuberculosis than are whites. The data also suggest that susceptibility to M. tuberculosis infection varies independently of the factors governing the progression to clinical disease.

Anterior segment upper lobe tuberculosis in the adult. Occurrence in primary and reactivation disease

Nine patients with pulmonary tuberculosis involving predominantly or exclusively the anterior segment of one or both upper lobes were seen over a five-year period. The incidence of anterior segment upper lobe tuberculosis was 6.3 percent of 142 patients presenting with pulmonary tuberculosis during the same time period. Five of the nine patients with anterior segment upper lobe involvement had reactivation disease. An increased incidence of advanced age, diabetes, associated malignant neoplasms, alcoholism, and steroid use were noted in those patients with anterior segment involvement, although only the occurrence of diabetes was statistically significant. We suggest vigilance with regard to the diagnosis of tuberculosis in patients who are elderly, diabetic, or alcohol abusers, particularly where the roentgenographic appearance of anterior segment upper lobe involvement would tend to favor an alternative diagnosis.

Tuberculosis in long-term care facilities

Persons age 65 and over constitute the largest reservoir ofMycobacterium tuberculosisinfection in the United States today. During 1987, 6,150 tuberculosis cases were reported among this high-risk group. These cases represent 27% of the total US tuberculosis morbidity, although this age group constitutes only 12% of the US population. Tuberculosis case rates in the United States are higher among the elderly (20.6 per 100,000) than among all other age groups (average 9.3 per 100,000).

More Americans live in nursing homes than in any other type of residential institution; on any given day approximately 5% of all elderly persons are living in a nursing home. Elderly nursing home residents are at greater risk for tuberculosis than elderly persons living in the community. In a Centers for Disease Control (CDC)-sponsored survey of 15,379 routinely-reported tuberculosis cases from 29 states, 8% of the 4,919 cases that occurred among elderly persons occurred among residents of nursing homes. The incidence of tuberculosis among nursing home residents was 39.2 per 100,000 person years, whereas the incidence of tuberculosis among elderly persons living in the community was 21.5 per 100,000. The observed rate of tuberculosis among nursing home employees was three times the rate expected in employed adults of similar age, race and sex (CDC, unpublished data).

Abdominal mycobacterial infections in immunocompromised patients

A review of the discharge diagnoses and mycobacterial cultures of patients admitted to a major New York City hospital over an 18-month period revealed 21 patients with abdominal mycobacterial infections (17 male, 4 female) with an average age of 36 years. Acquired immunodeficiency syndrome (AIDS) or an identifiable AIDS risk was present in 14. The disease was manifest by peritoneal (eight patients), ileocecal (seven), and hepatic involvement (three), and psoas abscess (three). Diffuse abdominal pain was the most frequent presenting symptom. However, absence of pain (19 percent) and lack of abdominal findings (28 percent) were not uncommon. The erythrocyte sedimentation rate was significantly elevated (mean 72 mm/hour), whereas the white blood cell count was normal in 18 patients. Computed tomography findings were abnormal in all patients studied and suggested mycobacterial infection in 67 percent. Ten patients (48 percent) required surgery. Although there were no individual differences in clinical or laboratory presentation between the operative and nonoperative patient groups, more patients with pain and higher fever were operated upon. There was one postoperative death. The overall mortality rate was 24 percent, and the mean survival and follow-up 10.2 months and 12.2 months, respectively.

Mycobacterial disease, immunosuppression, and acquired immunodeficiency syndrome

The mycobacteria are an important group of acid-fast pathogens ranging from obligate intracellular parasites such as Mycobacterium leprae to environmental species such as M. gordonae and M. fortuitum. The latter may behave as opportunistic human pathogens if the host defenses have been depleted in some manner. The number and severity of such infections have increased markedly with the emergence of the acquired immunodeficiency syndrome (AIDS) epidemic. These nontuberculous mycobacteria tend to be less virulent for humans than M. tuberculosis, usually giving rise to self-limiting infections involving the cervical and mesenteric lymph nodes of young children. However, the more virulent serovars of M. avium complex can colonize the bronchial and intestinal mucosal surfaces of healthy individuals, becoming virtual members of the commensal gut microflora and thus giving rise to low levels of skin hypersensitivity to tuberculins prepared from M. avium and M. intracellulare. Systemic disease develops when the normal T-cell-mediated defenses become depleted as a result of old age, cancer chemotherapy, or infection with human immunodeficiency virus. As many as 50% of human immunodeficiency virus antibody-positive individuals develop mycobacterial infections at some time during their disease. Most isolates of M. avium complex from AIDS patients fall into serotypes 4 and 8. The presence of these drug-resistant mycobacteria in the lungs of the AIDS patient makes their effective clinical treatment virtually impossible. More effective chemotherapeutic, prophylactic, and immunotherapeutic reagents are urgently needed to treat this rapidly increasing patient population.

Tuberculosis makes a comeback. Giving and interpreting the Mantoux test

Tuberculosis is on the increase in the United States, so physicians would be prudent to renew familiarity with the disease. Physicians should be prepared to administer the Mantoux test correctly and interpret the results according to the specific condition of each patient. Patients with certain diseases (eg, chronic renal failure, lymphoid disorders) are likely to be anergic but are also more likely than other persons to have tuberculosis. In these patients, the goal is to administer the test before they become anergic, so infection can be identified if it occurs. Preventive therapy is useful in some situations (eg, when public health is a factor) and should also be chosen on the basis of the individual patient, weighing the risk of disease against the risk of drug toxicity.

Recent surgical experience for pulmonary tuberculosis

Lung resection for pulmonary tuberculosis is unusual today. Over a 10-year-period 31 patients with pulmonary tuberculosis underwent thoracotomy at this Regional Centre. Five of these were for complications of known tuberculosis; two subsequently proved to be complications of pulmonary tuberculosis, and the remainder were for suspected malignancy. The clinical features, radiology, microbiology, and pathology are reviewed and the contemporary role of the surgeon in the management of pulmonary tuberculosis is examined.

Cutaneous-delayed hypersensitivity in nursing home and geriatric clinic patients. Implications for the tuberculin test

Cutaneous-delayed hypersensitivity was studied by one and two-step Mantoux-type skin tests to four standard antigens in 33 elderly nursing home residents, 34 geriatric clinic patients, and 20 healthy young adult controls. Demographic and anthropometric data were collected to determine the effects of nutrition and other variables on cutaneous-delayed hypersensitivity. Anergy (a lack of response greater than 5 mm of induration when read at 48 hours) to any of the four antigens occurred in 34% of nursing home residents, 17% of geriatric clinic patients, and none of the healthy young adults. Mean and maximal responses were less in the nursing home residents than the clinic patients or controls, even if anergic individuals were excluded from analysis, suggesting both a qualitative and quantitative decline in cell-mediated immune function in this elderly population. Repeat testing with each antigen for which there was a negative initial response revealed a "booster" affect of 7 to 19% and occurred as commonly in the healthy young adults as in the nursing home residents or geriatric clinic patients. The mumps antigen elicited strong responses in the healthy young adults, but weak reactions in the nursing home residents. An unexpectedly high prevalence of positive tuberculin (PPD) responses occurred in the nursing home residents, suggesting recent exposure. Analysis of anthropometric and demographic characteristics show that neither nutritional status nor age alone can account for differences in cutaneous-delayed hypersensitivity observed between populations. Cutaneous-delayed hypersensitivity may vary widely between elderly populations and have important practical implications for the tuberculin test.

Diagnostic value of ascites adenosine deaminase in tuberculous peritonitis

The value of ascitic fluid adenosine deaminase activity in distinguishing tuberculosis from other causes of ascites was examined in a retrospective study of 41 patients with bacteriologically confirmed tuberculous peritonitis and 41 control patients, matched for age and sex, with ascites of other causes (12 alcoholic cirrhosis, 5 cryptogenic cirrhosis, 12 malignant disorders, 3 pancreatitis, and 9 miscellaneous causes). The mean ascites adenosine deaminase activity was 99.8 (SD 49.1) in tuberculous patients and 14.8 (8.4) U/l in control patients (p less than 0.0001). A cutoff of 32.3 U/l had a sensitivity of 95% and specificity of 98% in distinguishing between the two groups. In a subsequent prospective study of 64 patients with ascites, 11 were found to have tuberculosis. Of the others, 23 had cirrhosis (18 alcoholic, 5 cryptogenic), 17 malignant disorders, 3 pancreatitis, 5 cor pulmonale, 3 congestive cardiac failure, 1 systemic mastocytosis, and 1 renal failure and hypothyroidism. The mean ascites adenosine deaminase activity was 112.6 (45.0) U/l in the patients with tuberculous ascites and 16.3 (36.7) U/l (p less than 0.0001) in those with ascites of other causes. In this study, adenosine deaminase had a sensitivity of 100% and specificity of 96% in discriminating tuberculosis from other causes of ascites. These findings suggest that the ascitic fluid adenosine deaminase activity may be used to identify patients in whom the diagnosis of abdominal tuberculosis must be pursued.

Immunization coverage and social differentiation in urban Senegal

We studied sociocultural factors associated with immunization coverage among a random sample of 500 mothers in the underprivileged suburbs of Dakar, Senegal. Factors associated with immunization of children under age 5 were maternal educational level and socioeconomic conditions (especially husband's regular salary); maternal age on arrival in town was more influential than total number of resident years in town; no effect of ethnicity was evident.

Tuberculosis surveillance in a state prison system

After four inmates at two New Mexico prisons converted their tuberculosis skin tests, a mass screening program was carried out at all the State's adult correctional facilities (2,240 inmates). Previously unknown converters were found with a disproportionally high per cent of converters (6.8 per cent and 6.3 per cent) and reactors (14.4 per cent and 12.2 per cent) at the first two prisons. No index cases were found. State policy has been revised to include two-stage skin testing of new inmates, annual testing thereafter, and screening of all new correctional staff.

Occult endemic tuberculosis in a chronic care facility

During the course of a tuberculosis skin testing program at a chronic care Veterans Administration Medical Center, we uncovered evidence of occult transmission of endemic tuberculosis. Skin test conversion of eight patients (one of whom had unsuspected progressive primary tuberculosis) and two employees was ultimately traced to a patient in whom tuberculosis was first diagnosed at autopsy three years earlier. Identification of employee skin test conversions was a key factor in recognizing and terminating disease transmission. Throughout the institution, 33% of patients were tuberculin-positive; 10.8% demonstrated the booster phenomenon after initial negative skin tests. Prevalence of tuberculin positivity among employees was 28%. Twelve percent of initially tuberculin-negative employees converted during employment. Our experience documents the value of tuberculin testing of both patients and staff in a chronic care environment, and the necessity of vigorous investigation of skin test conversions.

Isoniazid preventive therapy for tuberculosis. Are we losing our enthusiasm?

Contact investigation activities of the Tennessee Department of Health and Environment (TDHE) Tuberculosis (TB) Control Program from 1979 to 1985 were reviewed. Out of 32,722 identified contacts, 6,030 (20.1 percent) were infected (positive purified protein derivative [PPD]). Only 2,731 (45 percent) of the infected contacts were started on preventive therapy. Both the absolute number and the relative percentage of infected contacts starting on INH prevention therapy have gradually declined over the years. While 569 (67 percent) of the infected contacts were started on preventive treatment in 1979, only 296 (37.5 percent) received isoniazid (INH) preventive therapy in 1985. Although an increasing percentage of those starting preventive therapy completed the prescribed course, the enthusiasm for recommending preventive therapy has declined for the infected individuals above the age of 15. More enthusiasm and efforts are needed from physicians in initiating and maintaining INH preventive therapy to accomplish tuberculosis eradication.

Antituberculosis agents

Tuberculosis, once considered a problem solved, is now dramatically on the rise. New approaches to chemotherapy will hopefully help to control this again serious problem. This article reviews the current status of tuberculosis chemotherapy, including the management of drug-resistant cases.

An overview of infection control in dental practice

Although it is not possible to cover all of the ramifications of infection control in prosthodontics, currently available information may be summarized as follows: 1. All dental disciplines must be concerned with the dangers involved in the spread of certain infectious diseases. 2. Prosthodontists and their ancillary personnel may be exposed to certain diseases predominantly found in adult patients, such as hepatitis B and tuberculosis. 3. Dentists must ensure that at least six basic infection control procedures are observed when treating patients. 4. Additional control procedures should be observed in the fabrication and handling of impressions and dental prosthesis. 5. Dental offices and commercial laboratories should work closely together to coordinate control of potential cross-infection between the two disciplines. The control of infectious diseases in prosthodontics is not difficult. It requires the expenditure of a little time, a little money, and most important, a great deal of discipline. The rewards are well worth the additional effort and could even be lifesaving.

Conversion and reversion of tuberculin reactions in nursing home residents

To assess the consistency of tuberculin reactions over time, we performed tuberculin tests in a cohort of 495 nursing home residents in both 1982 and 1985. Significant reactions (greater than or equal to 10 mm of induration to 5 TU PPD) were found in 258 (52.1%) and 209 (42.2%) residents in 1982 and 1985, respectively. Males, nonwhites, and persons younger than 80 yr of age had a greater proportion of significant reactions (all, p less than 0.01). Of the 237 persons with nonsignificant reactions in 1982, 15 (6.3%) had a significant reaction in 1985. None of the 15 converters was found to have current tuberculosis. Tuberculin reversions occurred in 64 (24.8%) of 258 persons who had significant reactions in 1982. Of the patients who had a significant reaction only after boosting in 1982, 16 of 21 (76.2%) had nonsignificant reactions with up to 3 tests in 1985. Tuberculin reactions in nursing home residents may vary over time and may not be recalled by boosting, boosted reactions may be transient, and apparent conversions may be due to an extension of the booster phenomenon.

Enzyme-linked immunosorbent assay for the detection of antibodies against Mycobacterium tuberculosis in bronchial washings and serum

This prospective study evaluates an enzyme-linked immunosorbent assay (ELISA) for the detection of IgG antibodies against Mycobacterium tuberculosis when applied to serum and bronchial washings (BW) of patients requiring bronchoscopy for definitive diagnosis. The ELISA employed an adsorbed fraction of mycobacterial sonicates as antigen. Of the 57 patients tested, 12 had tuberculosis (TB), 13 had malignant disease, 14 acute pneumonia or chronic destructive pneumonia, 13 had no demonstrable disease, and five had miscellaneous diseases. The mean optical density (OD) at 492 nm for a 1 in 40 dilution of serum of patients with TB was 0.338 +/- 0.218 and for control subjects was 0.162 +/- 0.098 (p = 0.0323). Values for neat BW were 0.317 +/- 0.122 for TB patients and 0.191 +/- 0.140 for control subjects (p = 0.0084). Using stepwise discriminant analysis, the ELISA on serum gave a sensitivity of 70.0 percent and specificity of 86.4 percent and 83.3 percent correct classification. When applied to BW, there was a 72.7 percent sensitivity, a 82.2 percent specificity, and patients were correctly classified in 80.4 percent of cases. It is concluded that the assay is a useful and reliable adjunct to conventional tests for tuberculosis.

The prevention and control of mycobacterial infections in hospitals

Infections resulting from contamination of medical equipment and medications with opportunistic mycobacteria are reviewed and the mode of spread discussed. The prevention of Mycobacterium tuberculosis in patients and staff, by the implementation of occupational health schemes, infection control policies and disinfection policies is also reviewed. The problems relating to immunocompromised patients are also discussed.

Tuberculosis screening in the long-term care setting

Tuberculosis (TB) skin-testing practices in long-term care facilities (LTCFs) in North Carolina (NC) were assessed from a 56% (148/263) response to a comprehensive TB screening questionnaire. TB skin tests were administered to employees on initial employment by 98% and annually by 97% of the LTCFs, generally (74%) by the Mantoux method. Employee skin tests were read at the appropriate time interval of 48 to 72 hours by 91%, but less than half used diameter of induration when interpreting reactive tests. The booster test was performed on new employees at eight (6%) of the LTCFs. TB skin tests were routinely performed on newly admitted residents by 56% or conditionally required by 18%, generally (73%) by the Mantoux method. Resident skin tests were read at the appropriate time interval of 48 to 72 hours by 92%, but again only half correctly interpreted reactive tests as significant. Residents received routine annual skin tests at 71% of the LTCFs, generally (80%) by the Mantoux method. Eight (6%) facilities routinely performed the booster test on newly admitted residents. TB infection prevalence in new employees during 1983 was 8.1% (47/578) in seven LTCFs and in newly admitted residents was 6.4% (7/110) in three LTCFs supplying this data. The five-year mean TB skin test conversion rate among employees was 1.1% (101/9545) in 12 LTCFs and among residents was 0.9% (46/5216) in nine LTCFs supplying this data. Lack of compliance to established TB skin-testing guidelines in NC LTCF was prevalent. In recognition of described endemic and epidemic spread of TB in LTCFs, residents and employees of LTCFs should be screened for TB utilizing established skin-testing practices.

In vivo and in vitro characterization of murine T-cell clones reactive to Mycobacterium tuberculosis

Seventeen helper T-cell clones were derived by stimulating lymph node cells from sensitized C57BL/6 mice with Mycobacterium tuberculosis H37Ra, M. tuberculosis H37Rv, or purified protein derivative. Most clones cross-reacted with Mycobacterium bovis BCG, H37Ra, H37Rv, and purified protein derivative. However, four clones were able to differentiate H37Rv from H37Ra, or BCG from H37Ra and H37Rv. In addition, four other T-cell clones recognized recombinant antigens of 19 and 65 kilodaltons isolated from a genomic expression library of M. tuberculosis by using monoclonal antibodies. All clones were Ia restricted and had the Thy-1.2+ Lyt-1+ L3T4+ Lyt-2- phenotype. On stimulation with antigen, all of the clones tested secreted interleukin-2 and gamma interferon but not B-cell stimulatory factor 1. All of the clones tested induced an antigen-specific delayed-type hypersensitivity response upon local cell transfer, although the magnitude of this response differed markedly among clones.

Significance of the tuberculin test in the elderly

Nine hundred thirty-three persons over 65 years of age, residing in long-term or extended-care facilities in Vancouver, Canada, had tuberculin tests. In addition to PPD-tuberculin, 5 TU and 250 TU, we used PPD-Battey, Candida albicans, mumps, and Trichophyton antigens. Twenty-five percent reacted to 5 TU of tuberculin with reactions of 10 mm or more. There was a progressive, substantial loss of reactivity with advancing age. Reactions to PPD-Battey greater than to PPD-T 5 TU were infrequent, suggesting that atypical mycobacterial infections were uncommon and that positive reactions to PPD-T, 250 TU, were predominantly caused by infections with Mycobacterium tuberculosis. Based on the results of both 5 TU and 250 TU, the prevalence of tuberculous infection exceeded 60 percent. Waning of tuberculin sensitivity appears to be an integral part of the aging process. Testing with nonmycobacterial antigens used in this study shed no further light on the problem of anergy in the elderly, as the number of reactors was smaller than that obtained with PPD-tuberculin.

Clinical features of pulmonary tuberculosis in young and old veterans

Pulmonary tuberculosis (TB) continues to pose a health threat to the elderly population. In order to delineate age-related differences in disease presentation a comparison between young and old male veterans hospitalized over a five-year period with culture proven Mycobacterium tuberculosis is reported. The study sample included 27 patients 60 years of age and older (range, 60 to 85; mean, 70) and 52 patients under 60 years of age (range, 22 to 59; mean, 51). The elderly were significantly less likely to demonstrate cavitary lesions on admission radiographs or present with hemoptysis but were more likely to present with right lower lobe infiltrates and complaints of dyspnea. Symptoms prior to admission occurring with equal frequency in both young and old subjects included fever, anorexia, weight loss, and cough. Although treatment was delayed in the elderly, there were no age-related differences in mortality. Skin testing was underutilized in all patients regardless of age. The results support the notion that the clinical presentation of pulmonary TB is remarkably similar in young and old males.

Disseminated Mycobacterium bovis infection in an elderly patient

We report a fatal case of disseminated infection due to Mycobacterium bovis occurring in an elderly patient. The greatest incidence of tuberculosis is in the aged, who were likely to have been infected in childhood when the disease was more prevalent. However, the clinical or radiographic presentation of tuberculosis in the older patient may be atypical or nonspecific, contributing to delay in diagnosis, and greater morbidity and mortality.

Pulmonary tuberculosis in elderly men

The clinical manifestations, predisposing factors, and diagnostic approach to 29 young men and 35 elderly men with pulmonary tuberculosis admitted to a Veterans Administration hospital were compared. Elderly men had a higher number of underlying conditions such as atherosclerosis, previous gastrectomy, and malignancy, whereas alcoholism was more prevalent in the younger group. The classic symptoms and signs of tuberculosis were noted in a significantly higher proportion of the younger group: fever (62 percent versus 31 percent), weight loss (76 percent versus 34 percent), night sweats (48 percent versus 6 percent), sputum production (76 percent versus 48 percent), and hemoptysis (40 percent versus 17 percent) (p less than 0.05). Abnormal mentation was more common in the elderly group (31 percent versus 10 percent) (p less than 0.05). Radiographic findings were similar in both groups. Mortality related to tuberculosis was 20 percent in elderly men versus 3 percent in the younger men (p less than 0.05). Tuberculosis is frequently not considered in the differential diagnosis when elderly patients present with multiple medical problems and nonspecific complaints. Since there are differences in the clinical presentation and the outcome of pulmonary tuberculosis in elderly patients, a high index of suspicion for the disease should be maintained.

Two-stage tuberculin testing with control antigens in patients residing in two chronic disease hospitals

We studied the prevalence of tuberculin reactivity and anergy in 360 elderly patients residing in two municipal chronic disease hospitals. Eighty-five (26%) of the 323 patients tested had a positive reaction to a stage 1 tuberculin test and 12 (6%) of the 207 stage 1 tuberculin-negative patients exhibited a booster response to a stage 2 tuberculin test. Thirty percent of the same 207 patients had no response to an anergy panel of skin test antigens that included candida, mumps, and trichophyton. Nonresponders to tuberculin and the anergy panel had significantly higher one-year mortality rates compared to responders (44 v 20%, P = 0.001). Tuberculin-positivity among the 770 employees working in these facilities was 43%; 12 (4%) had a booster response. A survey of 29 randomly selected long-term care facilities in the Boston area indicated that all had a policy for pre-employment screening of employees, but less than 50% had a policy for patients and only one institution used two-stage testing. Routine tuberculin testing is recommended for long-term care facilities and the two-stage method is preferable in institutions with adequate resources.

Decision analysis for tuberculosis preventive treatment in nursing homes

There are differing opinions on whether or not to use isoniazid (INH) preventive treatment in older people with significantly reactive ("positive") tuberculin skin tests and fibrotic changes on chest roentgenogram. To assist the clinician facing this decision, a Decision Analysis was completed. Using available data, it is seen that using INH will not have much impact on five-year survivorship, but will reduce the number of tuberculosis disease cases, thus having an overall beneficial impact. Where tuberculosis incidence is higher, the benefit of INH preventive treatment is correspondingly higher.