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

Clinical presentation and survival of smear-positive pulmonary tuberculosis patients of a university general hospital in a developing country

From January 1995 to August 1997 we evaluated prospectively the clinical presentation, laboratory findings and short-term survival of smear-positive pulmonary tuberculosis (TB) patients who sought care at our hospital. After providing informed, written consent, the patients were interviewed and laboratory tests were performed. Information about survivorship and death was collected through September 1998. Eighty-six smear-positive pulmonary TB patients were enrolled; 26.7% were HIV-seropositive. Seventeen HIV-seronegative pulmonary TB patients (19.8%) presented chronic diseases in addition to TB. In the multiple logistic regression analysis a CD4+ cell count <= 200 cell/mm was independently associated with HIV seropositivity. In the Cox regression model, fitted to all patients, HIV seropositivity and age > or = 50 years were independently associated with decreased survival. Among HIV-seronegative persons, the presence of an additional disease increased the risk of death of almost six-fold. Use of antiretroviral drugs was associated with a lower risk of death among HIV-seropositive smear-positive pulmonary TB patients (RH = 0.32, 95% CI 0.10-0.92). In our study smear-positive pulmonary TB patients had a low short-term survival rate that was strongly associated with HIV infection, age and co-morbidities. Therapy with antiretroviral drugs reduced the short-term risk of death among HIV-seropositive patients after TB diagnosis.

Nursing home-acquired pneumonia

Pneumonia is the most serious of the common infections that occur in nursing homes, with a high case-fatality rate and considerable mortality among survivors. Risk factors for nursing home-acquired pneumonia (NHAP) have been defined, and prediction models for death due to NHAP have been developed. The bacterial etiology of NHAP has been debated, but "typical" bacterial pathogens (Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis) are most important. Clinical presentation of NHAP is said to be "atypical," but this may be confounded by dementia in the nursing home resident. A recent guideline has made recommendations regarding the minimal diagnostic workup when a resident has a suspected case of pneumonia. Until recently, most guidelines for the treatment of pneumonia did not specifically address NHAP; there is some evidence that use of a quinolone alone may be an acceptable first choice of therapy for most cases. Pneumococcal and influenza vaccination have been the primary prevention measures. However, additional methods to prevent NHAP should be evaluated, including improving the oral hygiene of residents and instituting pharmacological interventions.

Tuberculosis in older people: a retrospective and comparative study from Hong Kong

OBJECTIVES

To compare tuberculosis (TB) in older and younger patients.

DESIGN

A retrospective and comparative observational study.

SETTING

Four chest clinics and two chest hospitals in Hong Kong.

PARTICIPANTS

All notifications from the participating hospitals and clinics in 1996 were extracted from the TB notification registry. The characteristics of patients aged 65 and older were compared with a one-in-three random sampling of those aged 16 to 64.

MEASUREMENTS

Demographic, clinical, radiological, and laboratory data of the two groups were compared alongside treatment and outcomes.

RESULTS

Older people with TB were more likely to be male, to smoke, to have had TB previously, to have coexisting medical diseases, to be socioeconomically disadvantaged, and to weigh less than younger people with TB. Dyspnea, weight loss, and malaise were more common, whereas extrathoracic lymph node enlargement was less common. Chest radiograph showed more extensive disease and lower zone involvement. Positive tuberculin test was present in only 61.9%. Sputum bacteriology was more likely to be positive. There was a longer delay in presentation and commencement of treatment, and 77.2% required at least one admission. Adverse effects of treatment, notably hepatic dysfunction, occurred more commonly. Fluoroquinolones appeared well tolerated. Only 72.5% of the older people were cured or completed their treatment. Mortality was 16%. Age of 65 and older, comorbidity, socioeconomic disadvantage, moderate-extensive disease, positive sputum smear, and poor adherence were factors independently associated with unfavorable outcomes (P <.001 to P = .01; odds ratios = 1.61-27.02).

CONCLUSION

Substantial differences were found between older and younger TB patients. Many of these were associated with unfavorable outcome. Increased awareness in disease recognition and better medical and social support are therefore needed in addressing the growing problem of TB in older people.

Unrecognized tuberculosis in a nursing home causing death with spread of tuberculosis to the community

OBJECTIVES

To determine the reason for an increase in tuberculin skin test (TST) conversion in employees in a nursing home and to determine the source case responsible for spread of tuberculosis (TB) in two nursing homes and a hospital in a rural part of Arkansas using molecular and traditional epidemiological methods.

DESIGN

TB contact investigation of residents and employees of two nursing homes and a hospital.

SETTING

Two nursing homes and a hospital in rural part of Arkansas.

PARTICIPANTS

One hundred fifty-seven employees and 117 residents of two nursing homes and 211 employees of a hospital in rural part of Arkansas.

MEASUREMENTS

Tuberculin skin test.

RESULTS

Analysis of room and work assignments of residents and employees who converted their TSTs in Nursing Home A showed that residents and employees in the same wing as the suspect source case were significantly more likely to have converted their TST than residents and employees in other wings (P = .01). A nurse from the local hospital where the suspected source case had been sent developed a tuberculous cervical abscess, and one employee in Nursing Home A developed pulmonary TB. A visitor to Nursing Home A was diagnosed with culture-positive pulmonary TB 2 years later. Genotyping of the Mycobacterium tuberculosis isolates from the four secondary cases showed identical patterns.

CONCLUSION

Molecular and traditional epidemiological studies revealed an outbreak of TB that began in a nursing home and spread to a second nursing home, a local hospital, and the community.

Tuberculosis and aging: a global health problem

Despite the World Health Organization's declaration that the spread of tuberculosis is a global emergency and despite the implementation of strong tuberculosis-control initiatives, this highly infectious disease continues to affect all vulnerable populations, including the elderly population (age > or =65 years). Tuberculosis in aging adults remains a clinical and epidemiological challenge. Atypical clinical manifestations of tuberculosis in older persons can result in delay in diagnosis and initiation of treatment; thus, unfortunately, higher rates of morbidity and mortality from this treatable infection can occur. Underlying illnesses, age-related diminution in immune function, the increased frequency of adverse drug reactions, and institutionalization can complicate the overall clinical approach to tuberculosis in elderly patients; maintenance of a high index of suspicion for tuberculosis in this vulnerable population is, thus, undoubtedly justifiable.

The role of the laboratory in infection prevention and control programs in long-term-care facilities for the elderly

Hospital infection prevention and control programs rely extensively on diagnostic microbiology laboratory testing. However, specimens for microbiological evaluation are less likely to be obtained from elderly residents of long-term-care facilities (LTCFs). In this article, issues regarding laboratory utilization and the potential role of the microbiology laboratory in infection prevention and control programs in LTCFs are reviewed. The role of the laboratory in infection surveillance, in the management of antimicrobial resistance, and in outbreak investigation are highlighted.

Pulmonary tuberculosis and associated factors in areas of high levels of poverty in Chiapas, Mexico

OBJECTIVES

To estimate the prevalence of pulmonary tuberculosis (PTB) and factors associated with PTB in areas of high levels of poverty in Chiapas, Mexico.

METHODS

In 1998 active case-finding was carried out among those aged over 14 years who had a cough of > or =15 days duration, in a convenience sample of 1894 households in 32 communities selected at random based on the level of poverty and on the level of access to health services, measured by travelling time (<1 hour, > or =1 hour) from the community to the nearest health care unit. Of the 277 identified with a productive cough, we obtained sputum samples from 228 for the purposes of detecting PTB through acid-fast smears and cultures. Mycobacteria characterization was carried out using the BACTEC method. The identification of factors associated with PTB was performed using bivariate analysis and via logistic regression models.

RESULTS

A PTB rate of 276.9 per 100 000 persons aged > or =15 years was found (95% CI : 161-443). Blood in sputum was the only factor associated with PTB (none of the demographic or socioeconomic characteristics were). Of 16 positive cultures, 14 became contaminated. The two cultures characterized were Mycobacterium tuberculosis (one being multiresistant).

CONCLUSION

The high prevalence of PTB detected indicates the need, both in the area studied and in others with similar conditions, to develop PTB control programmes which give priority to early diagnosis and to the provision of adequate treatment.

Control and prevention of tuberculosis in the United Kingdom: code of practice 2000. Joint Tuberculosis Committee of the British Thoracic Society

BACKGROUND

The guidelines on control and prevention of tuberculosis in the United Kingdom have been reviewed and updated.

METHODS

A subcommittee was appointed by the Joint Tuberculosis Committee (JTC) of the British Thoracic Society to revise the guidelines published in 1994 by the JTC, including representatives of the Royal College of Nursing, Public Health Medicine Environmental Group, and Medical Society for Study of Venereal Diseases. In preparing the revised guidelines the authors took account of new published evidence and graded the strength of evidence for their recommendations. The guidelines have been approved by the JTC and the Standards of Care Committee of the British Thoracic Society.

RECOMMENDATIONS

Tuberculosis services in each district should have staffing and resources to fulfil both the control and prevention recommendations in this document and to ensure adequate treatment monitoring. Notification of tuberculosis is required for surveillance and to initiate contact tracing (where appropriate). The following areas are discussed and recommendations made where appropriate: (1) public health law in relation to tuberculosis; (2) the organisational requirements for tuberculosis services; (3) measures for control of tuberculosis in hospitals, including segregation of patients; (4) the requirements for health care worker protection, including HIV infected health care workers; (5) measures for control of tuberculosis in prisons; (6) protection for other groups with potential exposure to tuberculosis; (7) awareness of the high rates of tuberculosis in the homeless together with local plans for detection and action; (8) detailed advice on contact tracing; (9) contact tracing required for close contacts of bovine tuberculosis; (10) management of tuberculosis in schools; (11) screening of new immigrants and how this should be performed; (12) outbreak contingency investigation; and (13) BCG vaccination and the management of positive reactors found in the schools programme.

Community-acquired pneumonia in the elderly

Pneumonia in the elderly is a common and serious problem with a clinical presentation that can differ from that in younger patients. Older patients with pneumonia complain of significantly fewer symptoms than do younger patients, and delirium commonly occurs. Indeed, delirium may be the only manifestation of pneumonia in this group of patients. Alcoholism, asthma, immunosuppression, and age >70 years are risk factors for community-acquired pneumonia in the elderly. Among nursing home residents, the following are risk factors for pneumonia: advanced age, male sex, difficulty in swallowing, inability to take oral medications, profound disability, bedridden state, and urinary incontinence. Streptococcus pneumoniae is the most common cause of pneumonia among the elderly. Aspiration pneumonia is underdiagnosed in this group of patients, and tuberculosis always should be considered. In this population an etiologic diagnosis is rarely available when antimicrobial therapy must be instituted. Use of the guidelines for treatment of pneumonia issued by the Infectious Diseases Society of America, with modification for treatment in the nursing home setting, is recommended.

Tuberculosis in long-term-care facilities

The geriatric population represents the largest reservoir of Mycobacterium tuberculosis infection in developed nations, including the United States. Tuberculosis (TB) case rates in the United States are highest for this age group compared with other age categories. The subtle clinical manifestations of TB in the elderly often can pose potential diagnostic dilemmas and therapeutic challenges, resulting in increased morbidity and mortality in this age group; this treatable infection unfortunately often is detected only at autopsy. Compared with their community-dwelling counterparts, the institutionalized elderly are at a greater risk both for reactivation of latent TB and for the acquisition of new TB infection. Prevention and control of TB in facilities providing long-term care to the elderly thus cannot be overemphasized.

Risk factors for tuberculosis among human immunodeficiency virus-infected persons. A case-control study in Belo Horizonte, Minas Gerais, Brazil (1985-1996)

The objective of this study was to identify tuberculosis risk factors and possible surrogate markers among human immunodeficiency virus (HIV)-infected persons. A retrospective case-control study was carried out at the HIV outpatient clinic of the Universidade Federal de Minas Gerais in Belo Horizonte. We reviewed the demographic, social-economical and medical data of 477 HIV-infected individuals evaluated from 1985 to 1996. The variables were submitted to an univariate and stratified analysis. Aids related complex (ARC), past history of pneumonia, past history of hospitalization, CD4 count and no antiretroviral use were identified as possible effect modifiers and confounding variables, and were submitted to logistic regression analysis by the stepwise method. ARC had an odds ratio (OR) of 3.5 (CI 95% - 1.2-10.8) for tuberculosis development. Past history of pneumonia (OR 1.7 - CI 95% 0.6-5.2) and the CD4 count (OR 0.4 - CI 0. 2-1.2) had no statistical significance. These results show that ARC is an important clinical surrogate for tuberculosis in HIV-infected patients. Despite the need of confirmation in future studies, these results suggest that the ideal moment for tuberculosis chemoprophylaxis could be previous to the introduction of antiretroviral treatment or even just after the diagnosis of HIV infection.

Residential care and the elderly: the burden of infection

Long term care facilities (LTCFs) include a variety of different types of healthcare settings, each with their own unique infectious disease problems. This report focuses on the epidemiological considerations, risk factors and types of infections that occur in elderly patients institutionalized in nursing home settings. In the US, the number of patients in nursing homes continues to grow as the population ages. Today, patients in nursing homes have more complicated medical conditions than they did five years ago as they become even more elderly and the trend continues towards shorter and shorter hospital stays in acute care facilities. The patient population in nursing homes is uniquely susceptible to infections because of the physiological changes that occur with ageing, the underlying chronic diseases of the patients and the institutional environment within which residents socialize and live. In addition, in nursing home settings, problems with infections may be more difficult to diagnose because of their subtle presentations, the presence of co-morbid illnesses which obscure the symptoms of infection and the lack of on site diagnostic facilities. Delays in diagnosing and treating infections allow transmission to occur within the facility. Both endemic and epidemic infections occur relatively commonly in nursing homes. The incidence of endemic infections, such as catheter-associated urinary tract infections, lower respiratory infections and skin infections, is influenced by the debility level of the patients. Calculations of infection rates are influenced by the intensity of surveillance methods at each institution. Many endemic infections are unpreventable. Epidemic infections account for 10-20% of nursing home infections. These include clusters of upper or lower respiratory infections, gastroenteritis, diarrhoea, and catheter-associated UTI's. Epidemic infections are potentially preventable with sound infection control practices. Special attention must be paid to promote universal precautions and give certain patients, such as those with known infection or colonization with Clostridium difficile, MRSA or VRE, special consideration. The potential for epidemic infections with antibiotic-resistant organisms is real. In the nursing home setting, attention must be given to develop and support strong infection control programmes that can monitor the occurrence of institutionally-acquired infections and initiate control strategies to prevent the spread of epidemic infections. Education in infection control issues and attention to employee health is essential to enable staff to care appropriately for today's nursing home population and to prepare them for the even more complicated patients who will be cared for in this type of setting in future.

Soil, seed and climate: developing a strategy for prevention and management of infections in UK nursing homes

Most studies of nursing home (NH) infections come from the USA and very few from the UK. USA studies lead us to anticipate a rate of 7 infections per 1000 patient days with a point prevalence as high as 16% in UK NH residents. Pneumonia, skin and urine infections would be the most frequent, followed by enteric infection and bacteraemia. Colonization with resistant organisms is increasing in UK NH residents (e.g., MRSA in 4-17%). Surveillance studies are needed in UK NHs to report incidence of infection, residents' characteristics, existence of and adherence to above standards and policies. Trials of effectiveness of different infection control programmes and of NH vs hospital management are required. Management of infection may be a useful marker of quality of care in NHs and therefore of interest to health and local authorities.

Does aging modify pulmonary tuberculosis?: A meta-analytical review

STUDY OBJECTIVES

To evaluate the differences in the clinical, radiologic, and laboratory features of pulmonary tuberculosis (TB) in older patients, as compared to younger patients.

DESIGN

A meta-analysis (the Schmidt-Hunter method) of published works found in MEDLINE and other sources was performed. A total of 12 studies were collected, and each variable was submitted to meta-analysis.

RESULTS

No differences were found between older (>/= 60 years old) and younger TB patients with respect to male predominance, evolution time before diagnosis, prevalence of cough, sputum production, weight loss, fatigue/malaise, radiographic upper lobes lesions, positive acid-fast bacilli in sputum, anemia or hemoglobin level, and serum aminotransferases. A lower prevalence of fever, sweating, hemoptysis, cavitary disease, and positive purified protein derivative, as well as lower levels of serum albumin and blood leukocytes were noticed among older patients. In addition, the older population had a greater prevalence of dyspnea and some concomitant conditions, such as cardiovascular disorders, COPD, diabetes, gastrectomy history, and malignancies.

CONCLUSIONS

This meta-analytical review identified the main differences of older TB patients, as compared to younger TB patients, that should be considered during the diagnostic evaluation. Most of these differences are explained by the already known physiologic changes that occur during aging.

Nonresolving or slowly resolving pneumonia

Given the variability in rate of radiographic resolution, it remains controversial to decide when to initiate an invasive diagnostic work-up for nonresolving or slowly resolving pulmonary infiltrates. In immunocompetent patients who present with classical features of CAP (i.e., fever, chills, productive cough, new pulmonary infiltrate), clinical response to therapy is the most important determinant for further diagnostic studies. Within the first few days, persistence or even progression of infiltrates on chest radiographs is not unusual. Defervescence, diminished symptoms, and resolution of leukocytosis strongly support a response to antibiotic therapy, even when chest radiographic abnormalities persist. In this context, observation alone is reasonable, and invasive procedures can be deferred. Serial radiographs and clinical examinations dictate subsequent evaluation. In contrast, when clinical improvement has not occurred and chest radiographs are unchanged or worse, a more aggressive approach is warranted. In this setting, we advise fiberoptic bronchoscopy with BAL and appropriate cultures for bacteria, legionella, fungi, and mycobacteria. When endobronchial anatomy is normal and there is no purulence to suggest infection, TBBs should be done to exclude noninfectious causes (discussed earlier) or infections attributable to mycobacteria or fungi. An aggressive approach is also warranted in patients who are clinically stable or improving when the rate of radiographic resolution is delayed. As discussed earlier, what constitutes excessive delay is controversial, and depends upon the acuity of illness, specific pathogen, extent of involvement (i.e., lobar versus multilobar), comorbidities, and diverse host factors. Stable infiltrates even 2 to 4 weeks after institution of antibiotic therapy does not mandate intervention provided patients are improving clinically. Invasive techniques can also be deferred when unequivocal, albeit incomplete, radiographic resolution can be demonstrated. Lack of at least partial radiographic resolution by 6 weeks, even in asymptomatic patients, however, deserves consideration of alternative causes (e.g., endobronchial obstructing lesions, or noninfectious causes). Fiberoptic bronchoscopy with BAL and TBBs has minimal morbidity and is the preferred initial invasive procedure for detecting endobronchial lesions or substantiating noninfectious causes. The yield of bronchoscopy depends on demographics, radiographic features, and pre-test likelihood. In the absence of specific risk factors, the incidence of obstructing lesions (e.g., bronchogenic carcinomas, bronchial adenomas, obstructive foreign body) is low. Bronchogenic carcinoma is rare in nonsmoking, young (< 50 years) patients but is a legitimate consideration in older patients with a history of tobacco abuse. Non-neoplastic causes (e.g., pulmonary vasculitis, hypersensitivity pneumonia, etc.) should be considered when specific features are present (e.g., hematuria, appropriate epidemiologic exposures). Ancillary serologic tests or biopsies of extrapulmonary sites are invaluable in some cases. In rare instances, surgical (open or VATS) biopsy is necessary to diagnose refractory or non-resolving "pneumonias."

Nursing home-acquired pneumonia

Nursing Home-Acquired Pneumonia is a significant infection that is often seen in the long-term care setting. It is associated with substantial morbidity, healthcare expenditure, and mortality rates as high as 44%. Uniform diagnosis and therapeutic strategies have not been specifically established for pneumonia in the nursing home setting. This paper will update the long-term care provider with the unique features and challenges of pneumonia in this setting and review the approaches to the diagnosis and treatment of this important illness. The discussion will conclude with details regarding overall prevention of nursing home-acquired pneumonia and the critical role played by the nursing home medical director in this process.

Pneumonia in residents of long-term care facilities: epidemiology, etiology, management, and prevention

Pneumonia is a leading cause of morbidity and mortality among patients in long-term care facilities; the median reported incidence is 1 per 1,000 patient-days. Risk factors include functional dependency, chronic pulmonary disease, and conditions causing aspiration. The frequency of etiologic agents varies widely among reports; for example; Streptococcus pneumoniae ranges from 0% to 39% of cases, and gram negative bacilli ranges from 0% to 51% of reported cases. Viral respiratory infections, particularly influenza and respiratory syncytial virus, typically occur in outbreaks. Mortality varies from 5% to 40%; functional status is the major determinant of survival. Many patients receive inadequate initial evaluations, and as many as 40% receive no physician visit during the episode. Although transfer to an acute care facility occurs in 9% to 51% of cases, most transferred patients could be managed in the nursing home with minimal additional support. Appropriate evaluation includes examination by a practitioner, recording of vital signs, chest radiograph, and examination of an adequate sputum sample, if available. Patients without contraindications to oral therapy or severe abnormalities of vital signs (pulse > 120 beats per minute, respirations >30 per minute, systolic blood pressure < 90) may initially receive oral therapy. Appropriate oral agents include amoxicillin/clavulanate, second generation cephalosporins, quinolones active against S pneumoniae, or trimethoprim/sulfamethoxazole. Appropriate parenteral agents include beta-lactam/beta-lactamase inhibitor combinations, second or third generation cephalosporins, or quinolones. Pneumococcal and influenza vaccines should be administered to all residents. Future studies should focus on identifying risk factors for pneumonia that are amenable to intervention and to identifying highly effective, preferably oral, antimicrobial regimens in randomized trials.

[Distinctive features of tuberculosis in the aged]

INTRODUCTION

Current recrudescence of human tuberculosis is ascribed to HIV. Nevertheless, other at-risk individuals, particularly the elderly, have been reported.

METHODS

A retrospective study aimed at defining distinctive features of tuberculosis in the elderly was conducted. Eighty-two records of patients aged 18 to 64 years were compared to those of 58 patients of 65 years of age and over.

RESULTS

In the French area considered in this study, the elderly represent the most at-risk group. Institutionalization is a significant risk factor for tuberculosis (RR = 4). Despite a past history of tuberculosis and public awareness campaigns, first-intent diagnosis was evoked in only 22% of the older patients. The mean number of infectious localizations was higher in the elderly (1.3/patient) than in younger patients (1.1/patient). Results of tuberculin skin tests are unreliable. Prognosis is poor in the elderly. In the present study, 14 of the 18 encountered deaths occurred in the elderly, of which eight were due to tuberculosis.

CONCLUSION

To decrease the current incidence of tuberculosis, evaluations of preventive measures in the elderly should be validated and implemented, especially in institutionalized patients.

Intestinal tuberculosis: return of an old disease

OBJECTIVE

Tuberculosis (TB) can no longer be considered a rare disease in the United States due, in part, to the AIDS epidemic. Because the signs and symptoms of intestinal TB are nonspecific, a high index of suspicion must be maintained to ensure a timely diagnosis. The aim of this article is to review the history, epidemiology, pathophysiology, and treatment of TB.

METHODS

This review is based on an examination of the world literature.

RESULTS

In only 20% of TB patients is there associated active pulmonary TB. Areas most commonly affected are the jejunoileum and ileocecum, which comprise >75% of gastrointestinal TB sites. Diagnosis requires colonoscopy with multiple biopsies at the ulcer margins and tissue sent for routine histology, smear, and culture. If intestinal TB is suspected, empiric treatment is warranted despite negative histology, smear, and culture results. Treatment is medical, and all patients should receive a full course of antituberculous chemotherapy. Exploratory laparotomy is necessary if the diagnosis is in doubt, in cases in which there is concern about a neoplasm, or for complications that include perforation, obstruction, hemorrhage, or fistulization.

CONCLUSIONS

This review draws attention to the resurgence of tuberculosis in the United States. An increased awareness of intestinal tuberculosis, coupled with knowledge of the pathophysiology, diagnostic methods, and treatment should increase the number of cases diagnosed, thus improving the outcome for patients with this disease.

Hospital-acquired infection in elderly patients

Increasing numbers of elderly people are being treated in hospitals and are at particular risk of acquiring infections. The incidence, risk factors and types of hospital-acquired infection (HAI) in the elderly are reviewed. Special reference is made to urinary tract infections, respiratory tract infections, gastrointestinal infections including Clostridium difficile, bacteraemia, skin and soft tissue infections and infections with antibiotic-resistant organisms.

Infection prevention and control in the long-term-care facility. SHEA Long-Term-Care Committee and APIC Guidelines Committee

More than 1.5 million residents reside in US nursing homes. In recent years, the acuity of illness of nursing home residents has increased. Long-term-care facility residents have a risk of developing nosocomial infection that is similar to acute-care hospital patients. A great deal of information has been published concerning infections in the long-term-care facility, and infection control programs are nearly universal. This position paper reviews the literature on infections and infection control program in the long-term-care facility, covering such topics as tuberculosis, bloodborne pathogens, epidemics, isolation systems, immunization, and antibiotic-resistant bacteria. Recommendations are developed for long-term-care infection control programs based on interpretation of currently available evidence. The recommendations cover the structure and function of the infection control program, including surveillance, isolation, outbreak control, resident care, and employee health. Infection control resources also are presented.

[Microepidemics of tuberculosis; apropos of 2 school outbreaks in the area 15 of the Valencia community]

Schools are settings with high concentrations of young people with little exposure to Mycobacterium tuberculosis and greater risk of developing disease when infection occurs as the result of sporadic localized outbreaks. We studied two outbreaks in two elementary schools (A and B) after two cases of bacilliferous pulmonary tuberculosis were detected in teachers in 1990 and 1994. Contacts were trace din school A by the primary care physician and in school B by the pneumologist and public health authorities. Contacts were classified as belonging to the risk group (RG) or the low risk group (LRG). The RG was composed of 187 contacts in school A and 59 in school B. Individuals in the LRG numbered 429 and 116 respectively. Mantoux positives numbered 108 in the RG and 45 in the LRG in school A (p < 0.001). In school B 50 RG individuals and 29 LRG individuals were positive (p < 0.001). The proportion of Mantoux positives was greater in the RG of school B than in the RG of school A (p < 0.01), probably owing to longer time of evolution of disease and possible laryngeal involvement in the index case. Likewise, tuberculin positives were fewer in the LRG of school A than in the LRG of school B (p < 0.001), owing to the small size of the LRG in school A. Thirteen cases of tuberculosis were seen in school A, six of which called for drug prophylaxis after contacts were traced. The nature of the index case and the conditions of exposure are both important in such outbreaks, demonstrating the need to act appropriately to trace contacts, preferably under the supervision of a pneumologists.

Resurgence of tuberculosis: implications for emergency nurses

An emergency nurse is often the first person with contact with patients with suspected or known TB when they come to the emergency department. With rapid recognition of signs and symptoms of active TB and prompt implementation of precautions, emergency nurses can reduce the transmission of the "greatest killer of mankind" to other patients, visitors, health care workers, and ourselves.

High resolution chest CT in tuberculosis: evolutive patterns and signs of activity

PURPOSE

The purpose of our study was to determine evolutive patterns and signs of active tuberculosis on high resolution CT (HRCT) scans.

METHOD

We followed up over 15 months 27 patients with postprimary pulmonary tuberculosis that was proven bacteriologically. CT scans were performed before, during, and after 6 months of anti-tuberculosis treatment. Both 10-mm-thick sections and 1.5-mm-thick HRCT scans were performed.

RESULTS

Ground-glass pattern was noticed 26 times, 9 times after 2 month treatment and only 2 times after 6 month treatment. Among these two patients, one did not undergo his treatment properly and the other one had an additional bacterial infection. Centrilobular nodules (n = 17) and poorly marginated nodules (n = 21) were present only before treatment. Reticular pattern (intralobular and septal thickening), interstitial nodules, and fibrosis were seen both before and after treatment. Ground-glass pattern, poorly marginated nodules, and infiltrates as well as centrilobular nodules were related to an active infection.

CONCLUSION

This HRCT may be helpful to demonstrate activity in patients suspected of having tuberculosis and to assess antituberculous treatment efficiency.

The changing face of the epidemiology of tuberculosis due to molecular strain typing--a review

About one third of the world population is infected with tubercle bacilli, causing eight million new cases of tuberculosis (TB) and three million deaths each year. After years of lack of interest in the disease, World Health Organization recently declared TB a global emergency and it is clear that there is need for more efficient national TB programs and newly defined research priorities. A more complete epidemiology of tuberculosis will lead to a better identification of index cases and to a more efficient treatment of the disease. Recently, new molecular tools became available for the identification of strains of Mycobacterium tuberculosis (M. tuberculosis), allowing a better recognition of transmission routes of defined strains. Both a standardized restriction-fragment-length-polymorphism-based methodology for epidemiological studies on a large scale and deoxyribonucleic acids (DNA) amplification-based methods that allow rapid detection of outbreaks with multidrug-resistant (MDR) strains, often characterized by high mortality rates, have been developed. This review comments on the existing methods of DNA-based recognition of M. tuberculosis strains and their peculiarities. It also summarizes literature data on the application of molecular fingerprinting for detection of outbreaks of M. tuberculosis, for identification of index cases, for study of interaction between TB and infection with the human immuno-deficiency virus, for analysis of the behavior of MDR strains, for a better understanding of risk factors for transmission of TB within communities and for population-based studies of TB transmission within and between countries.

The origin and erratic global spread of tuberculosis. How the past explains the present and is the key to the future

Although tuberculosis is a disease known in antiquity, it was not distributed equally or simultaneously throughout the world. Recent genetic studies of the various species of mycobacteria give strong evidence of evolution of M. tuberculosis from saprophytic soil bacteria to M. bovis, which attacks a wide spectrum of lower animals, and then to M. tuberculosis, with the pathogenicity largely limited to humans. The great discrepancies in the time of arrival of this organism to diverse parts of the world, and in its ability to kill the young, account for significant differences in the emergence of innate resistance to tuberculosis in various populations. Innate resistance to particular infections are highly specific, and are derived from whatever scourge one's ancestors had to survive.

A prospective clinical study of isoniazid-rifampicin-pyrazinamide-induced liver injury in an area endemic for hepatitis B

In order to evaluate the incidence, predisposing factors and clinical course of antituberculous drug-induced liver injury in hepatitis B surface antigen (HBsAg)-positive carriers and non-carriers, in an area endemic for hepatitis B, we prospectively followed 240 patients (154 male, 86 female; mean age 40 years) who had received daily isoniazid, rifampicin, ethambutol and pyrazinamide for the treatment of pulmonary tuberculosis. Patients with heavy alcohol consumption, with pretreatment serum alanine aminotransferase (ALT) elevation and who had less than 3 months post-treatment follow-up were excluded from the study. Thirty-one (13%) patients were positive for serum HBsAg before treatment. Sixty-three (26%; 95% CI: 21-32%) patients developed antituberculous drug-induced liver injury. The incidence of drug-induced liver injury was significantly more frequent in patients > 35 years of age than in patients < or = 35 years of age (33 vs 17%; P < 0.05), but was not different between HBsAg carriers and non-carriers (29 vs 26%; P > 0.05). Using step-wise logistic regression analysis, patient age > 35 years was the only independent variable for predicting antituberculous drug-induced liver injury, while sex, acetylator phenotype, HBsAg carrier status and severity of tuberculosis were not. The peak serum ALT levels in antituberculous drug-induced liver injury were not significantly different between HBsAg carriers and non-carriers. Only one 61-year-old HBsAg carrier developed severe jaundice after 6 months antituberculous therapy; he subsequently died of hepatic failure. In conclusion, the incidence of antituberculous drug-induced liver injury was significantly higher in patients > 35 years of age than in patients < or = 35 years of age, but was not different between HBsAg carriers and non-carriers. Mortality occurred in an aged HBsAg carrier superimposed with antituberculous drug-induced liver injury.

Nosocomial transmission of tuberculosis among mentally-handicapped patients in a long-term care facility

SETTING

A long-term care facility at Saint-Brieuc hospital, France.

OBJECTIVE

To investigate a nosocomial outbreak of culture-positive pulmonary tuberculosis in 6 (40%) of 15 mentally handicapped HIV-seronegative patients.

DESIGN

The factors contributing to the outbreak were analyzed and the restriction fragment length polymorphism (RFLP) patterns of the six Mycobacterium tuberculosis strains were compared.

RESULTS

RFLP analysis of the six strains demonstrated an identical banding pattern, thus confirming the spread of a unique strain. A prolonged period of contagiousness due to a delay in diagnosis of the source patient, as well as crowded living conditions in the facility, probably contributed to the outbreak. Surveillance of residents and staff in contact with the source patient resulted in the detection of five secondary cases. Because effective isolation of mentally handicapped patients in the long-term care facility turned out to be difficult, the six case-patients were transferred to the pneumology department, thus limiting the spread of tuberculosis to other residents and staff.

CONCLUSIONS

The present outbreak emphasizes the difficulties of implementing control measures for preventing the nosocomial transmission of tuberculosis in long-term care facilities for mentally handicapped patients.

Tuberculosis in the elderly. Epidemiology and optimal management

The problem with the emergence of HIV-associated tuberculosis (which usually occurs in young adults) is that attention has been diverted away from the fact that, in the developed world, the elderly represent the biggest pool of tubercular disease and therefore the greatest pool of infection within the community. Although the incidence rate of tuberculosis continues to decline in most countries, there is evidence from parts of the developing world that rates may be beginning to increase. The presentation of the disease in the elderly is often uncharacteristic, e.g. disease tending to be more insidious in onset, pyrexia often absent and haemoptysis less common. Chest x-ray changes may also mislead the clinician in that disease is frequently present in the mid or lower zones. The elderly are probably at greater risk of extrapulmonary tuberculosis, which also presents in uncharacteristic ways. The diagnosis remains based on clinical presentation and the presence of smear and culture positivity, although some patients may be treated in the absence of microbiological proof. Standard treatment is with a combination of isoniazid, rifampicin and pyrazinamide, with or without a fourth drug such as ethambutol. The incidence of adverse effects in the elderly is much greater than that in younger patients, often resulting in the need to change the medication to drugs which are better tolerated. This may require changing to regimens which are less effective and therefore have to be taken for a longer period of time. The presence of concomitant disease such as liver or renal failure may also necessitate the administration of a suboptimal regimen. Mortality in elderly patients with tuberculosis is considerably higher than that in younger patients, even when treatment appears to have been started on time; even in the developed world mortality exceeds 30% in those patients over 70 years of age.

Mycobacterial infections: are the observed enigmas and paradoxes explained by immunosuppression and immunodeficiency?

The enigmas and paradoxes observed in tuberculous patients, in Bacille Calmette-Guérin-vaccinated people and in Bacille Calmette-Guérin-treated cancer patients have been examined, in an attempt to explain them through the mechanisms of immunodeficiency and immunosuppression. A dual effect is postulated: an immunosuppression induced by the infecting mycobacteria that adds to a pre-existing or emerging state of immunodeficiency of the infected individual. The immunological cellular and humoral anergies observed at the beginning of a tuberculous therapy are usually lifted after the first two weeks of treatment. This restoration of immune responsiveness may be attributed to the destruction or to the growth inhibition of immunosuppressive mycobacteria. The observation that drugs cytocidal in vitro do not always sterilize the patients under treatment whereas bacteriostatic drugs do, may find an explanation in the dual immunosuppression induced by cytocidal drugs and mycobacteria. The fact that Bacille Calmette-Guérin applied as an immunotherapy to residual cancer has either a favorable or an unfavorable action may be due to the immunosuppressive activity attached to some Bacille Calmette-Guérin strains and to some cancers. The variable protective activity of Bacille Calmette-Guérin vaccines may be due to the immunological status of the vaccinated people and the compositional differences between strains. The protective activity of subunit vaccines in experimental models can be attributed to the elimination of immunosuppressive factors present in whole killed mycobacteria.

Geriatric incontinence

Regardless of age, mobility, mentation, or institutionalization, incontinence is never normal. By attenuating physiologic reserve, aging increases the likelihood of becoming incontinent in the setting of additional physiologic, pharmacologic, or pathologic insults. Because many of these problems lie outside the urinary tract, so too must the diagnostic and therapeutic focus. Such a strategy, however, coupled with a multifactorial, creative, persistent, and optimistic approach, increases the chances of a successful outcome and generally rewards patient and physician alike.

Infections and antibiotic resistance in nursing homes

Infections occur frequently in nursing home residents. The most common infections are pneumonia, urinary tract infection, and skin and soft tissue infection. Aging-associated physiologic and pathologic changes, functional disability, institutionalization, and invasive devices all contribute to the high occurrence of infection. Antimicrobial agent use in nursing homes is intense and usually empiric. All of these factors contribute to the increasing frequency of antimicrobial agent-resistant organisms in nursing homes. Programs that will limit the emergence and impact of antimicrobial resistance and infections in nursing homes need to be developed.

Hospital-acquired tuberculosis

The resurgence of tuberculosis and the emergence of drug-resistant strains, coupled with a growing number of immunocompromised patients and a high proportion of susceptible health care workers, have increased our awareness of the possibility of hospital-acquired tuberculosis. Infection control guidelines which aim to prevent dissemination and inhalation of infectious particles include early diagnosis and isolation of infectious patients, particular care during procedures likely to increase the density of the organism in the environment, and regular surveillance of hospital staff.

Isoniazid preventive therapy for pulmonary tuberculosis sequelae: which patients up to which age?

SETTING

Preventive therapy with isoniazid (INH) is usually recommended for all patients with pulmonary fibrotic lesions compatible with previous tuberculosis (TB).

OBJECTIVE

To determine the optimal strategy between a 6- to 12-month course of prophylactic INH and therapeutic abstention in different age groups and in patients with severe coexisting diseases that limit life expectancy, such as chronic heart failure (CHF) or chronic obstructive pulmonary disease (COPD).

DESIGN

A Markov decision analysis model that balances the risk of developing active TB against TB-related mortality, the risk of INH-related hepatitis, and INH-related death.

RESULTS

In all groups of patients, prophylactic INH clearly reduced the number of deaths from TB, whereas very few cases died from INH-related toxicity. However, because INH-related deaths occur early, and TB-related deaths occur early or late, the gain in life expectancy was small. Particularly for patients with short survival such as those older than 80 years and those with CHF or COPD, the average gain in life expectancy provided by prophylactic INH did not exceed one week.

CONCLUSIONS

Our analysis confirms that prophylactic INH is beneficial to all cohort groups of patients. However, in the case of very old age or severe disease, the gain in life expectancy is minimal. In these cases, the decision to give INH prophylaxis should be tailored on an individual basis with special consideration given to the patient and his environment.

Tuberculosis Surveillance Practices in Long-Term Care Institutions

Objecitves:

To identify the tuberculosis (TB) skin-testing practices of long-term care facilities for the elderly in Toronto, Ontario.

Design:

A telephone survey using a 25-item questionnaire.

Setting:

Twenty-nine nursing homes (NHs) and 26 Homes for the Aged (HFAs) in metropolitan Toronto.

Results:

Thirty-one percent of facilities (17 of 55) had no formal tuberculin skin-testing program, including 52% of NHs (15 of 29) versus 8% of HFAs (2 of 26; P= 0.001). Ninety-two percent of HFAs (24 of 26) compared with 45% of NHs (13 of 29), obtained preadmission or admission skin-test status of residents (P= 0.0005). Annual testing was performed at 46% of HFAs (12 of 26) and 27% of NHs (8 of 29; P= 0.28). Of facilities that carried out any skin testing, 64% of HFAs (16 of 25) versus 32% of NHs (6 of 19) measured induration to establish test positivity (P=0.068). Fifty-two percent of HFAs (13 of 25), compared with 21% of NHs (4 of 19), recorded the actual size of induration in the patient record (P=0.085). Only 28% of HFAs (7 of 25) and 21% of NHs (4 of 19) correctly defined a positive tuberculin skin test.

Conclusions:

TB surveillance practices in long-term care institutions in Toronto are inadequate and often yield results that do not predict the risk of infection and cannot be used to investigate outbreaks. Tuberculin skin-testing practices were better at HFAs, which are subject to provincial legislation regarding TB surveillance, than at NHs, which are not subject to this legislation. Staff at HFAs and NHs require education regarding tuberculin skin-testing policies and procedures.