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

Challenges in treating tuberculosis in the elderly population in tertiary institute

Tuberculosis (TB) epidemic is most prevalent in the India with increase in mortality and morbidity. Ongoing elderly population as a result of increase in health care facilities are at high risk of TB. Elderly people are four-fold more prone to TB. Most cases of TB in the elderly result from reactivation of latent TB due to immunosenescence. Major challenge in dealing with therapeutic aspects of elderly patients is recognising frailty to prevent loss of independence. Challenges facing with elderly TB are difficult to reach out to hospital because of poor health seeking behaviour especially elderly female either due to ignorance or neglected by the family members, atypical presentation mimicking other disorders leading to diagnostic delay, if at all diagnosed impoverished tolerance and adherence to treatment due to various factors like associated comorbidities leading to pill load, impaired renal and hepatic functions with aging and stigma. Emerging resistance with usage of non-standard treatment regimens lead to unpropitious outcomes and increases mortality. The mortality rate is six times higher in elderly compared to younger individuals. Hence elderly people need tertiary level health care facilities for enhancing the diagnosis and appropriate management of tuberculosis and its complications. New set of guidelines to be made for elderly to increase adherence and tolerance thereby decreasing drug interactions and adverse drug reactions. With the increased prevalence of TB in the elderly, it is the need of the hour for India, to focus on this vulnerable population as they are a potential source of infection in the community. Awareness to be created among the elderly community regarding this deadly disease and its outcomes to increase their health consciousness and medical attention. Priming the special focus on females coterie as they are the most neglected population in our society.

A narrative review of tuberculosis in the United States among persons aged 65 years and older

Tuberculosis (TB) is a preventable infectious disease that confers significant morbidity, mortality, and psychosocial challenges. As TB incidence in the United States (U.S.) decreased from 9.7/100,000 to 2.2/100,000 from 1993 to 2020, the proportion of cases occurring among adults aged 65 and older increased. We conducted a review of published literature in the U.S. and other similar low-TB-burden settings to characterize the epidemiology and unique diagnostic challenges of TB in older adults. This narrative review also provides an overview of treatment characteristics, outcomes, and research gaps in this patient population. Older adults had a 30% higher likelihood of delayed TB diagnosis, with contributing factors such as acid-fast bacilli sputum smear-negative disease (56%) and non-classical clinical presentation. At least 90% of TB cases among older adults resulted from reactivation of latent TB infection (LTBI), but guidance around when to screen and treat LTBI in these patients is lacking. In addition, routine TB testing methods such as interferon-gamma release assays were two times more likely to have false-negative results among older adults. Advanced age was also often accompanied by complex comorbidities and impaired drug metabolism, increasing the risk of treatment failure (23%) and death (19%). A greater understanding of the unique factors of TB among older adults will inform clinical and public health efforts to improve outcomes in this complex patient population and TB control in the U.S.

Multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis strains in geriatrics: An analysis and its implications in tuberculosis control

Objective

This study aimed to analyze the trends of tuberculosis (TB) disease, drugs susceptibility patterns in geriatric TB over a period of three years (from 2010 to 2012).

Materials & methods

In this study, laboratory data on diagnosis of geriatric tuberculosis suspected patients (age ≥60 years) was analyzed retrospectively at National Reference Laboratory (NRL).

Results

Among 12,140 geriatric TB suspects, 1621 (13%) were acid-fast bacillus (AFB) smear-positive and 10,519 (87%) were smear-negative. Analysis of 915 culture results showed 470 (51%) as positive for Mycobacterium tuberculosis complex (MTBC), 63 (7%) contaminated and 36 (4%) identified as mycobacteria other than tuberculosis (MOTT). A total 210/470 (45%) were multidrug-resistant TB (MDR-TB) strains. Among the mono-resistant strains, isoniazid mono-resistant was found more frequently (134/470, 28%) whereas, it was least among rifampicin mono-resistant 5/470 (1%). The second-line drug susceptibility testing (DST) results showed 7% (17/240) extensively drug-resistant TB (XDR-TB) strains. Most common second line mono-resistant strain was observed with ofloxacin, 16% (38/240).

Conclusion

This study shows high number of MDR/XDR geriatric TB patients at tertiary care TB hospital. The study highlighted the need of separate line of early identification, diagnosis and treatment of geriatric TB patients. However, further study with improved sample size may needed to confirm the findings.

Tuberculosis Screening via Chest X-Ray is Financially Burdensome in Previously Independently Living Elective Total Knee Arthroplasty Patients

BACKGROUND

In 1995, to reduce the transmission of Tuberculosis (TB) the Centers for Disease Control and Prevention recommended that all patients discharged from hospitals be required to have chest x-rays (i.e., radiography) performed before admission to long term care facilities (LTCFs). Previously independently living patients (PILPs) who undergo elective total knee replacement (TKA) surgery are a population at higher risk to end up in LTCFs for rehabilitation. By 2017, the incidence of TB was 9,105 cases compared to 22,762 in 1995. However, the recommendations that hospitals be required to perform a chest x-ray in all patients (including PILPs) being transferred to LTCF's have remained in place. The purposes of this study were to: a) determine the incidence of TB-positive chest x-rays in PILPS discharged to LTCFs after undergoing elective TKA surgery, and b) assess the cost (i.e., both financial and possible exposure to unnecessary radiation) of mandated chest x-rays before hospital discharge to LTCF for PILPs.

METHODS

Retrospective 2012-2017 patient chart data were collected from the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) to identify all elective TKAs for PILPs performed at two Ascension participating centers. Study data included sex, age, body mass index (BMI), length of stay, comorbidities, and chest x-ray results before discharge. Patients who underwent surgery for fracture, infection, trauma, or malignancy were excluded from the study. Categorical data were analyzed using Fisher's exact test and Student's t-test were used for continuous data.

RESULTS

The authors identified 4,041 total elective TKA's, from which 500 PILPs were discharged to a LTCF due to functional, medical and/or social concerns. Chest x-rays were associated with 500 (100%) negative findings for TB. Overall hospital costs for chest x-rays for patient's being discharged to an extended care facility totaled $90,848.

CONCLUSIONS

The mandated use of chest x-rays for TB screening of PILPs undergoing elective surgery TKA prior to discharge to LTCFs appear to place an unnecessary financial burden on the healthcare system. The mandatory use of x-rays for assessment of possible TB infection before transfer to LTCFs appears to also expose PILPs unnecessarily to radiation. Although further studies are needed to verify these results, the authors recommend that perhaps instead chest x-rays should be reserved for patients with specific comorbidities (e.g., patients on immunosuppressive therapy, with HIV, etc.) or for those patients residing in LTCFs prior to surgery.

Review of Evidence for Using Chest X-Rays for Active Tuberculosis Screening in Long-Term Care in Canada

Background: People living in long-term care facilities (LTCF) are at high risk to develop active tuberculosis primarily as a result of reactivation of a latent TB infection, or endemic transmission between residents. Current national guidelines in Canada are to use a posterior-anterior and lateral chest X-ray to screen for TB for those over 65 years old, upon admission to a LTCF.

Objective: To assess the available evidence for cost benefits of universal chest X-ray screening for new LTCF residents.

Methodology: We conducted a search for all articles published until September 2018, in PubMed and WorlCat databases, in English, using a combination of key words: chest X-ray, chest radiography or CXR, long-term care, elderly, screening, and tuberculosis. We also reviewed publicly available guidelines for screening new residents to LTCF from across Canada. We report on a qualitative synthesis of the evidence in the documents retrieved.

Results: The final review yielded four cost-effectiveness studies (2 of 4 conducted in countries with low incidence), one systematic review, one recommendation/editorial, and one cohort study. We found that in a tuberculosis low-incidence country the CXR cost per identified case was $672,298 CAD. Enacting a more targeted screening program, perhaps one that tests only those who previously had TB, or other high-risk medical conditions may enhance the cost-effectiveness.

Recommendations: We suggest reviewing the screening policy for active TB in people entering LTCF, which is based on a CXR. The results indicate that a targeted search for active TB in people with symptoms or other high-risk medical conditions may be more cost-effective.

Mycobacterium bovis BCG and New Vaccines for the Prevention of Tuberculosis

Tuberculosis infects millions of people worldwide and remains a leading global killer despite widespread neonatal administration of the tuberculosis vaccine, bacillus Calmette-Guérin (BCG). BCG has clear and sustained efficacy, but after 10 years, its efficacy appears to wane, at least in some populations. Fortunately, there are many new tuberculosis vaccines in development today, some in advanced stages of clinical trial testing. Here we review the epidemiological need for tuberculosis vaccination, including evolving standards for administration to at risk individuals in developing countries. We also examine proven sources of immune protection from tuberculosis, which to date have exclusively involved natural or vaccine exposure to whole cell mycobacteria. After summarizing evidence for the use and efficacy of BCG, we detail the most promising new candidate vaccines against tuberculosis. The global need for a new tuberculosis vaccine is acute and huge, but clinical trials to be completed in the coming few years are likely either to identify a new tuberculosis vaccine or to substantially reframe how we understand immune protection from this historical scourge.

Epidemiology and Host Factors

In 2014, WHO reported approximately 9.6 million new cases of tuberculosis (TB) in the world, more than half of which are contributed by developing countries in Asia and Africa. Lack of modern diagnostic tools, underreporting of the new cases and underutilization of directly observed therapy (DOT) remain a concern in developing countries. Transient resurgence of TB during the HIV epidemic has subsided and the annual decline has resumed in developed countries including the USA. In 2014 though, the rate of decline has slowed down resulting in leveling of TB incidence in the USA. In developed countries like the USA, the incidence of TB remains high in those with certain risk factors for TB. This group includes immunocompromised patients, particularly those with positive HIV infection. Others at high risk include those with diabetes, cancer, those taking immunosuppressive drugs, and those with other medical conditions that reduce host immunity. If we look at age and ethnicity, elderly patients are at higher risk of developing TB. African-American, foreign-born, and homeless populations are also at higher risk of developing tuberculosis. Virulence of the mycobacteria, and immunological and genetically mediated factors are also mentioned, but these topics are not the primary goal of this article. This review, thus discusses the epidemiology, host factors, and those at high risk for developing active TB. A brief review of the current trends in drug resistance of mycobacteria is also presented.

The strategic framework of tuberculosis control and prevention in the elderly: a scoping review towards End TB targets

With the rapid pace of population ageing, tuberculosis (TB) in the elderly increasingly becomes a public health challenge. Despite the increasing burden and high risks for TB in the elderly, targeted strategy has not been well understood and evaluated. We undertook a scoping review to identify current TB strategies, research and policy gaps in the elderly and summarized the results within a strategic framework towards End TB targets. Databases of Embase, MEDLINE, Global health and EBM reviews were searched for original studies, review articles, and policy papers published in English between January 1990 and December 2015. Articles examining TB strategy, program, guideline or intervention in the elderly from public health perspective were included.Nineteen articles met the inclusion criteria. Most of them were qualitative studies, issued in high- and middle-income countries and after 2000. To break the chain of TB transmission and reactivation in the elderly, infection control, interventions of avoiding delay in diagnosis and containment are essential for preventing transmission, especially in elderly institutions and aged immigrants; screening of latent TB infection and preventive therapy had effective impacts on reducing the risk of reactivation and should be used less reluctantly in older people; optimizing early case-finding with a high index of suspicion, systematic screening for prioritized high-risk groups, initial empirical and adequate follow-up treatment with close monitoring and evaluation, as well as enhanced programmatic management are fundamental pillars for active TB elimination. Evaluation of TB epidemiology, risk factors, impacts and cost-effectiveness of interventions, adopting accurate and rapid diagnostic tools, shorter and less toxic preventive therapy, are critical issues for developing strategy in the elderly towards End TB targets.TB control strategies in the elderly were comprehensively mapped in a causal link pathway. The framework and principals identified in this study will help to evaluate and improve current program, develop targeted strategy, as well as raise more discussions on the research priority settings and policy transitions. Given the scarceness of policy and evaluated interventions, as well as the unawareness of shifting TB epidemiology and strategy especially in developing countries, the increasing need of a ready TB program for the elderly warrants further research.

Latent Tuberculosis Infection Testing Practices in Long-Term Care Facilities, Boston, Massachusetts

OBJECTIVES

To describe latent tuberculosis infection (LTBI) testing practices in long-term care facilities (LTCFs).

DESIGN

Retrospective cohort study.

SETTING

Three Boston-area LTCFs.

PARTICIPANTS

Residents admitted between January 1 and December 31, 2011.

MEASUREMENTS

Resident demographic characteristics, comorbidities, LTCF stay, and LTBI testing and treatment.

RESULTS

Data for 291 LTCF residents admitted in 2011 were reviewed. Of the 257 without a history of LTBI and with documentation of testing, 162 (63%) were tested; 114 of 186 (61%) with a stay less than 90 days and 48 of 71 (68%) with a stay of 90 days or longer were tested. Of 196 residents with data on prior LTBI testing, 39 (19.9%) had LTBI; 12 of these (30.8%) were diagnosed at the LTCF. Hispanic participants were more likely than black participants to undergo LTBI testing (adjusted odds ratio (aOR) = 2.4, P = .003). Having a length of stay of less than 90 days (aOR = 0.7, P < .001) and history of illicit drug use (aOR = 0.7, P < .001) were associated with lower odds of LTBI testing.

CONCLUSION

One-fifth of LTCF residents had LTBI, but testing was not always performed. The high prevalence of LTBI in older adults combined with the risk of an outbreak if a case of tuberculosis occurs in a LTCF make LTBI testing and treatment an important prevention opportunity. The importance of LTBI testing in LTCFs needs to be reinforced.

Tuberculosis in Long-Term Care Facilities

Persons age 65 and over constitute the largest reservoir of Mycobacterium tuberculosis infection 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).

False-positive QuantiFERON TB-Gold test due to Mycobacterium gordonae

We report a case of QuantiFERON TB-Gold conversion associated to Mycobacterium gordonae in an elderly male from an assisted living facility without known risk factors for tuberculosis. This knowledge of environmental mycobacteria causing positive quantiferon assays is important to avoid unnecessary treatment of false-positive latent tuberculosis, especially in the absence of well-established positive predictive value of quantiferon conversion.

Trends in Tuberculosis Cases Among Nursing Home Residents, California, 2000 to 2009

OBJECTIVES

To examine trends in tuberculosis (TB) incidence and to compare demographic and clinical characteristics of nursing home (NH) residents and community-dwelling older adults.

DESIGN

Prospective TB surveillance.

SETTING

TB cases reported in California from 2000 to 2009.

PARTICIPANTS

TB patients aged 65 and older.

MEASUREMENTS

Trends in TB incidence per 100,000 population were assessed using Poisson regression. Demographic and clinical characteristics were compared using the chi-square or Wilcoxon rank-sum test. Among NH residents, risk factors for death during TB treatment were identified using logistic regression.

RESULTS

From 2000 to 2009, TB incidence rates decreased significantly, from 15.9/100,000 to 8.4/100,000 (-44%, 95% confidence interval (CI) = -66% to -7%) for NH residents and from 21.2/100,000 to 15.0/100,000 (-27%, 95% CI = -29% to -24%) for community-dwelling older adults. Overall, 211 TB cases among NH residents and 6,518 cases among community-dwelling older adults were reported. NH residents were more likely than community-dwelling older adults to be older (median age 81 vs 75, P < .001), have a negative acid-fast bacilli sputum smear and positive culture (37% vs 28%, P < .001), and die while undergoing TB treatment (44% vs 14%, P < .001), and were less likely to have a positive tuberculin skin test (TST) (28% vs 44%, P < .001) and have TB care provided by a health department (20% vs 59%, P < .001). In multivariable analysis, NH residents who had a positive TST were less likely to die while undergoing TB treatment (odds ratio = 0.39, 95% CI = 0.16-0.96).

CONCLUSION

TB incidence rates were lower, and reductions in incidence were greater among NH residents; community-dwelling older adults had higher TB rates and smaller reductions in incidence. Interventions that promote timely detection and treatment of TB infection and disease may be needed to reduce morbidity and mortality among NH residents.

Is early tuberculosis death associated with increased tuberculosis transmission?

INTRODUCTION

Tuberculosis (TB) is now a relatively uncommon disease in high income countries. As such, its diagnosis may be missed or delayed resulting in death before or shortly after the introduction of treatment. Whether early TB death is associated with increased TB transmission is unknown. To determine the transmission risk attributable to early TB death we undertook a case-control study.

METHODS

All adults who were: (1) diagnosed with culture-positive pulmonary TB in the Province of Alberta, Canada between 1996 and 2012, and (2) died a TB-related death before or within the first 60 days of treatment, were identified. For each of these "cases" two sets of "controls" were randomly selected from among culture-positive pulmonary TB cases that survived beyond 60 days of treatment. "Controls" were matched by age, sex, population group, +/- smear status. Secondary cases of "cases" and "controls" were identified using conventional and molecular epidemiologic tools and compared. In addition, new infections were identified and compared in contacts of "cases" that died before treatment and contacts of their smear-matched "controls". Conditional logistic regression was used to find associations in both univariate and multivariate analysis.

RESULTS

"Cases" were as, but not more, likely than "controls" to transmit. This was so whether transmission was measured in terms of the number of "cases" and smear-unmatched or -matched "controls" that had a secondary case, the number of secondary cases that they had or the number of new infections found in contacts of "cases" that died before treatment and their smear-matched "controls".

CONCLUSION

In a low TB incidence/low HIV prevalence country, pulmonary TB patients that die a TB-related death before or in the initial phase of treatment and pulmonary TB patients that survive beyond the initial phase of treatment are equally likely to transmit.

Infection Prevention and Control in the Long-Term-Care Facility

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 programs 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.

Modeling socio-demography to capture tuberculosis transmission dynamics in a low burden setting

Evidence of preferential mixing through selected social routes has been suggested for the transmission of tuberculosis (TB) infection in low burden settings. A realistic modelization of these contact routes is needed to appropriately assess the impact of individually targeted control strategies, such as contact network investigation of index cases and treatment of latent TB infection (LTBI). We propose an age-structured, socio-demographic individual based model (IBM) with a realistic, time-evolving structure of preferential contacts in a population. In particular, transmission within households, schools and workplaces, together with a component of casual, distance-dependent contacts are considered. We also compared the model against two other formulations having no social structure of contacts (homogeneous mixing transmission): a baseline deterministic model without age structure and an age-structured IBM. The socio-demographic IBM better fitted recent longitudinal data on TB epidemiology in Arkansas, USA, which serves as an example of a low burden setting. Inclusion of age structure in the model proved fundamental to capturing actual proportions of reactivated TB cases (as opposed to recently transmitted) as well as profiling age-group specific incidence. The socio-demographic structure additionally provides a prediction of TB transmission rates (the rate of infection in household contacts and the rate of secondary cases in household and workplace contacts). These results suggest that the socio-demographic IBM is an optimal choice for evaluating current control strategies, including contact network investigation of index cases, and the simulation of alternative scenarios, particularly for TB eradication targets.

Tuberculosis in special populations

The susceptibility to infection, the pathogenesis and the clinical manifestations of tuberculosis (TB) depend on the immunological status of the host. Immunological status is largely determined by age and comorbidities, but is also affected by other less well known factors. In Spain, most incidental cases of TB arise from the reactivation of remotely acquired latent infections and are favored by the aging of the population and the use of aggressive immunosuppressive therapies. The diagnosis and management of TB in these circumstances is often challenging. On the one hand, the atypical presentation with extrapulmonary involvement may delay diagnosis, and on the other, the toxicity and interactions of the antituberculous drugs frequently make treatment difficult. Immigration from resource-poor, high incidence TB countries, where the social and economic conditions are often suboptimal, adds a new challenge to the control of the disease in Spain. This chapter summarizes our current knowledge of epidemiological, clinical and treatment aspects of TB in particularly susceptible populations.

Tuberculosis in the global aging population

Despite the decline in the overall incidence of tuberculosis (TB) in many developed countries, it remains an important problem among the older population. The control of TB in the elderly remains a major challenge because of the limitations of the existing tools for the diagnosis and treatment of latent TB infection and clinically active disease. This article examines the current and possible future status of TB in the elderly, focusing on epidemiology, risk factors, preventive treatment strategies, and clinical disease.

Revisiting rates of reactivation tuberculosis: a population-based approach

RATIONALE

Reactivation tuberculosis (TB) occurs as a result of reactivation of latent TB infection (LTBI), and was reported to occur in the United States at a rate of 0.10 to 0.16 cases per 100 person-years in the 1950s; it has not been measured since.

OBJECTIVES

To calculate the rate of reactivation TB in a U.S. community.

METHODS

A population-based tuberculin skin test survey for LTBI was performed in western Palm Beach County, Florida, from 1998 to 2000 along with a cluster analysis of TB case isolates in the same area from 1997 to 2001. Reactivation (unclustered) TB was presumed to have arisen from the population with LTBI.

MEASUREMENTS AND MAIN RESULTS

The rate of reactivation TB among persons with LTBI without HIV infection was 0.040 cases per 100 person-years (95% confidence interval [CI], 0.024-0.067) using the n method and 0.058 cases per 100 person-years (95% CI, 0.038-0.089) using the n-1 method. HIV infection was the strongest risk factor for reactivation (rate ratio [RR], 57; 95% CI, 27-120; P < 0.001). Among persons without HIV infection, reactivation was increased among those older than 50 years (RR, 3.8; 95% CI, 1.3-11) and among those born in the United States (RR, 3.2; 95% CI, 1.1-9.3).

CONCLUSIONS

Rates of reactivation TB in this area have declined substantially since the 1950s. The greatest part of this decline may be attributed to the disappearance of old, healed TB in the population. If similar declines are seen in other areas of the United States, the cost-effectiveness of screening and treatment of LTBI may be substantially less than previously estimated.

Tuberculosis in Europe: a problem of drug resistance or much more?

Tuberculosis has re-emerged as a public health concern in high-income countries in the last few decades. The European region accounts for only 5% of world TB cases. The incidence of new TB cases in Europe varies from very low rates in Scandinavian countries (six to eight cases/100,000 population) to rates as high as 231 cases/100,000 population in Tajikistan; the Russian Federation is eleventh among the 22 high-burden TB countries. The estimated detection rate of new sputum smear-positive pulmonary cases and the treatment success rate in 2007 were poor compared with other WHO regions: 51% of cases were diagnosed and 70% of them completed a full course of anti-TB therapy, which is still a long way from the World Health Assembly targets (detection of 70% of infectious cases and successful treatment of 85% of them). The low success rate is largely attributable to the increasing number of drug-resistant TB cases: Eastern European countries are among those with the highest rates of multidrug-resistant (MDR)-TB (TB resistant to rifampicin and isoniazid) in the world. By the end of September 2009, at least one case of extensively drug-resistant TB (named XDR-TB and defined as a MDR-TB strain with additional resistance to any fluoroquinolone, and to at least one of three injectable drugs used in anti-TB treatment) had been reported by 25 countries in the WHO European Region. In Western Europe, TB continues to cause disease among elderly native-born individuals, although high-risk groups including immigrants, prisoners, HIV-infected persons and drug addicts significantly contribute to the overall burden. Improved TB control in Europe requires a large coordinated effort by all stakeholders, including governments, governmental and non-governmental institutions, as well as the academic and private sectors and affected communities.

Tuberculosis at extremes of age

ABSTRACT Although tuberculosis (TB) has its highest burden among young adults, especially since the advent of HIV infection, two other groups with low immunity, the very young (<1 year) with immature immunity and the elderly (>65 years) with waning immunity, are vulnerable groups not to be forgotten. This review describes the epidemiology, clinical aspects, public health aspects and outcome of TB in patients at the extremes of age. The epidemiology differs therein that TB in infants occurs in developing countries with high incidences of TB and HIV, while TB in the elderly occurs in developed countries with ageing populations. The clinical presentation may be non-specific, history of contact with TB is often not known and TB is often not considered at these age extremes, and when the diagnosis is considered, disease progression may already be advanced. Anti-TB treatment regimens are the same as in other age groups, but drug dosages may need adjustment according to weight, renal function, liver function and other potentially complicating factors. Adverse events are more difficult to observe and both the young and the elderly are reliant on others for adherence to treatment. Mortality at both age extremes is higher than in the general TB population. For all the above reasons, public health measures to: prevent transmission of infection; identify those infected and providing preventive therapy; high index of suspicion in order to make an early diagnosis; and timely initiation of treatment are important in both the very young and the elderly.

Positive tuberculin skin tests in nursing home residents in Southern Taiwan

In Taiwan, the tuberculin skin test (TST) is not recommended as a screening test for Mycobacterium tuberculosis (TB) infections. The aim of this study is to determine the prevalence and predictors of positive tuberculin reactivity and its association with TB infections among nursing home residents in Taiwan. A cross-sectional study and review of medical records were conducted at four nursing homes in Tainan City. A one-stage TST was performed by study nurses using two tuberculin units of purified protein derivative (PPD) of the RT23 strain. An induration ≥10 mm at 72 h was considered to be a positive reaction. Chest radiographs, acid-fast stains and mycobacterial cultures of three sputum samples were performed for those with a positive TST result. Of 115 residents (66.5% participation, mean age 73.1 years) who underwent a TST, 26 (22.6%) had a positive reaction. One woman was microbiologically diagnosed to have pulmonary TB. On multivariate analysis, a Bacille Calmette-Guérin (BCG) scar and a history of myocardial infarction were significantly associated with a positive TST. In conclusions, this study shows a considerable rate of positive TST among nursing home residents in southern Taiwan. A BCG scar and a history of myocardial infarction were associated with a positive TST.

Pneumonia in the elderly: a review of the epidemiology, pathogenesis, microbiology, and clinical features

Pneumonia is a common and important disease in the elderly. The incidence is expected to rise as the population ages, and, therefore, it will become an increasingly significant problem in hospitals and the community. A comprehensive literature review was performed in order to look at the characteristics of pneumonia in the elderly population. In particular, the epidemiology, etiology and pathogenesis--including risk factors, microbiology, and clinical features--were evaluated. While aging causes physiological changes which make elderly patients more susceptible to pneumonia, it was found that comorbidities, rather than age, are also an important risk factor. The most common micro-organism responsible for pneumonia is Streptococcus pneumoniae, but other organisms need to be considered, depending on the environment of presentation. Elderly patients are more likely than younger adults to present with an absence of fever and an altered mental state. Nursing home residents tend to present with more atypical and less characteristic symptoms.

Prevalence of tuberculous infection and active tuberculosis in old age homes in Hong Kong

OBJECTIVES

To assess the prevalence of tuberculous infection and active tuberculosis (TB) in old age homes in Hong Kong and to determine whether there is institutional transmission in these homes.

DESIGN

Cross-sectional.

SETTING

Old age homes.

PARTICIPANTS

Total of 2,243 residents, representing 84.6% of all residents in 15 old age homes; 1,698 were women, and 545 were men, with an average age of 82.

MEASUREMENTS

All residents had a questionnaire-based interview, medical record review, two-stage tuberculin testing using two units purified protein derivative-RT23, and a chest x-ray. Those with radiological abnormalities had sputum examined for acid-fast bacilli.

RESULTS

The estimated prevalence rate of active TB in this population was 669 per 100,000, significantly higher in men than in women (1,101 per 100,000 vs 530 per 100,000). The proportion with positive tuberculin reactivity (> or =10 mm induration) after two-stage testing was 68.6%, significantly higher in men than in women. There was no evidence of active transmission of disease in these old age homes, with restriction fragment length polymorphism (RFLP) analysis performed on five cases of active pulmonary TB in the home with the highest rate of TB showing unique RFLP patterns.

CONCLUSION

The rate of active TB and TB infection in old age homes in Hong Kong is still high. Because treatment for latent TB carries a high risk for liver dysfunction in this population, clinicians and other healthcare workers need a high index of suspicion and to diagnose and treat this disease as early as possible to prevent transmission.

Pulmonary Emergencies in the Elderly

The aging process results in changes in pulmonary physiology that make the elderly population more susceptible to pulmonary disease. These physiologic changes also alter the clinical presentation of such diseases, making the diagnosis and treatment of pulmonary disorders particularly challenging for the clinician. It is important for the clinician to have a high index of suspicion for pulmonary disorders to make the proper diagnosis. It is essential to keep in mind the subtle differences between pulmonary diseases in the elderly compared with younger patients.

[Prevention of tuberculosis in care settings]

INTRODUCTION

The hospital is a favourable setting for the transmission of tubercle bacilli. The presence of susceptible subjects, often immunocompromised, increases the dangers. This risk extends to the patients' visitors and to the staff. It is therefore the responsibility of the hospital to establish preventative measures capable of reducing the risk of transmission or to reduce the effects by appropriate management of exposed subjects.

BACKGROUND

The modes and vectors of transmission are well established. The standardised prevention of transmission is achieved by isolation, the indications and duration of which are based on incomplete information. The surveillance of the carers by the doctor in charge, is based on precise recommendations depending on the risk of exposure.

VIEWPOINT

The objectives are a reduction diagnostic delay, a better determination of infectivity and its duration during treatment, and a more complete census of cases of hospital acquired tuberculosis.

CONCLUSIONS

The management of tuberculosis in hospital requires co-ordination of all involved including those outside the institution and a deliberate policy in the institution itself.

Neumonías comunitarias graves del adulto

Las neumonías agudas comunitarias son causa frecuente de hospitalización y mortalidad. El reconocimiento inmediato de las formas graves según criterios simples, clínicos, radiológicos y de laboratorio, es una etapa esencial para un tratamiento rápido en el servicio de reanimación con el fin de controlar los fallos orgánicos. La obtención de muestras apropiadas para realizar estudios microbiológicos precede al tratamiento antibiótico, que se debe instaurar con rapidez después de diagnosticar la neumonía. Pese a las técnicas de identificación, sólo la mitad de las neumonías se documentan adecuadamente. El tratamiento antibiótico, en principio empírico, integra los gérmenes patógenos, tanto extracelulares como intracelulares, que producen neumonías con mayor frecuencia; siempre debe ser activo contra el neumococo, la bacteria implicada más a menudo. La asociación de un betalactámico y un macrólido o una fluoroquinolona es la que mejor responde a este objetivo. En las recomendaciones más comunes, las fluoroquinolonas activas contra los neumococos sustituyen a los fármacos precedentes. En el caso excepcional de los pacientes con factores de riesgo especiales, el tratamiento empírico debe tener en cuenta Pseudomonas aeruginosa. La gravedad de parte de las neumonías comunitarias justifica el que se recurra a tratamientos complementarios. Se debe evaluar de nuevo el tratamiento antibiótico en las 72 horas siguientes a su instauración, a fin de valorar su eficacia, adaptar el tratamiento en caso necesario y simplificarlo. El mantenimiento de antibióticos de amplio espectro expone al paciente a efectos secundarios y contribuye a producir resistencias bacterianas. En cuanto a las neumonías neumocócicas, las fluoroquinolonas activas contra el neumococo podrían representar una alternativa en caso de que el neumococo desarrolle resistencia a los betalactámicos. La mortalidad persistente de las neumonías sigue siendo notable. Esto debe fomentar la mejora del tratamiento inicial y la búsqueda de nuevas opciones terapéuticas.

Age Transition of Tuberculosis Patients in Taiwan, 1957-2001

BACKGROUND

The incidence of tuberculosis (TB) has been falling in many developed countries; however, there is a trend of an increasing proportion of TB among the elderly. The aim of this study was to evaluate the age transition of patients with TB in Taiwan from 1957 to 2001.

METHODS

Data on the number of TB cases and patient age were collected from the National Tuberculosis Registry for three different 5-year periods: 1957-1961, 1977-1981, and 1997-2001. The distribution of TB cases in these three different periods was analyzed.

RESULTS

The age distributions of TB patients were different among the 1957-61 (n = 26,000), 1977-81 (n = 31,363) and 1997-2001 (n = 71,447) groups. During the 1957-61 period, the most common age group was 25-44 years (50.9%). During 1977-81, the most common age group was 45-64 years (44.9%). In 1997-2001, the most common age group had shifted to people aged 65 years or older (43.7%). For the whole period from 1957 to 2001, after adjusting for age shifts in the general population, the proportion of TB patients had significantly increased in persons 65 years or older, slightly increased in persons aged 0-14 years, and decreased in the 15-24, 25-44, and 45-64-year-old age groups. For the period 1977-2001, age-specific registered case rates increased with age.

CONCLUSION

The age of TB patients in Taiwan showed a rising trend from 1957 to 2001. A high index of suspicion and prompt investigation of elderly patients with signs and symptoms characteristic of TB may allow earlier diagnosis and treatment.

American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America: Controlling Tuberculosis in the United States

During 1993-2003, incidence of tuberculosis (TB) in the United States decreased 44% and is now occurring at a historic low level (14,874 cases in 2003). The Advisory Council for the Elimination of Tuberculosis has called for a renewed commitment to eliminating TB in the United States, and the Institute of Medicine has published a detailed plan for achieving that goal. In this statement, the American Thoracic Society (ATS), Centers for Disease Control and Prevention (CDC), and the Infectious Diseases Society of America (IDSA) propose recommendations to improve the control and prevention of TB in the United States and to progress toward its elimination. This statement is one in a series issued periodically by the sponsoring organizations to guide the diagnosis, treatment, control, and prevention of TB. This statement supersedes the previous statement by ATS and CDC, which was also supported by IDSA and the American Academy of Pediatrics (AAP). This statement was drafted, after an evidence-based review of the subject, by a panel of representatives of the three sponsoring organizations. AAP, the National Tuberculosis Controllers Association, and the Canadian Thoracic Society were also represented on the panel. This statement integrates recent scientific advances with current epidemiologic data, other recent guidelines from this series, and other sources into a coherent and practical approach to the control of TB in the United States. Although drafted to apply to TB-control activities in the United States, this statement might be of use in other countries in which persons with TB generally have access to medical and public health services and resources necessary to make a precise diagnosis of the disease; achieve curative medical treatment; and otherwise provide substantial science-based protection of the population against TB. This statement is aimed at all persons who advocate, plan, and work at controlling and preventing TB in the United States, including persons who formulate public health policy and make decisions about allocation of resources for disease control and health maintenance and directors and staff members of state, county, and local public health agencies throughout the United States charged with control of TB. The audience also includes the full range of medical practitioners, organizations, and institutions involved in the health care of persons in the United States who are at risk for TB.

Pneumonies communautaires graves de l'adulte

Les pneumonies aiguës communautaires sont des causes fréquentes d'hospitalisation et de mortalité. La reconnaissance immédiate des formes sévères sur des critères simples, cliniques, radiologiques et biologiques, est une étape importante pour une prise en charge rapide en réanimation afin de contrôler les défaillances d'organes. Les prélèvements appropriés microbiologiques précèdent l'antibiothérapie qui doit être instituée très rapidement après le diagnostic de pneumonie. Malgré les techniques d'identification, la moitié seulement des pneumonies sont documentées. Cette antibiothérapie, initialement probabiliste, intègre les germes pathogènes les plus souvent responsables, extra- et intracellulaires ; elle doit toujours être active sur le pneumocoque, bactérie la plus fréquente. L'association d'une β-lactamine et d'un macrolide ou d'une fluoroquinolone répond le mieux à cet objectif. Les fluoroquinolones actives sur le pneumocoque se sont substituées aux précédentes dans les plus récentes recommandations. Dans le cas exceptionnel des patients ayant des facteurs de risque particuliers, le traitement probabiliste doit prendre en compte Pseudomonas aeruginosa. La gravité d'une partie des pneumonies communautaires justifie le recours à des traitements adjuvants. L'antibiothérapie doit être réévaluée dans les 72 heures dans le but d'apprécier son efficacité, de l'adapter éventuellement et de la simplifier. La poursuite des antibiotiques à large spectre expose le patient à des effets indésirables et contribue aux résistances bactériennes. Pour les pneumonies dues au pneumocoque, les fluoroquinolones actives sur le pneumocoque pourront constituer une alternative en cas d'évolution importante des résistances du pneumocoque aux β-lactamines. La mortalité persistante des pneumonies reste sévère. Ceci doit stimuler l'amélioration de la prise en charge initiale et faire rechercher de nouvelles thérapeutiques.

Tuberculosis prevention and control in long-term-care facilities for older adults

In the United States, older adults comprise 22% of cases of tuberculous disease but only 12% of the population. Most cases of tuberculosis (TB) occur in community dwellers, but attack rates are highest among frail residents of long-term-care facilities. The detection and treatment of latent TB infection and TB disease can pose special challenges in older adults. Rapid recognition of possible disease, diagnosis, and implementation of airborne precautions are essential to prevent spread. It is the intent of this evidence-based guideline to assist healthcare providers in the prevention and control of TB, specifically in skilled nursing facilities for the elderly.

Service learning: a tuberculosis screening clinic in an adult residential care facility

Service learning is an educational experience that equally benefits the educational institution and the organization where the service is provided.A tuberculosis screening clinic was a mutually agreed upon service learning project that was conducted by baccalaureate nursing students for residents of an adult residential care facility. The college, the adult care facility, and a local public health agency participated in the clinic. Each organization contributed significant resources for the clinic, making it a unique project that was mutually agreed upon and implemented, as well as mutually beneficial.

The immunological aspects of latency in tuberculosis

A unique feature of Mycobacterium tuberculosis is its ability to exist in the granuloma of an asymptomatic host in a latent state that can subsequently reactivate to cause active disease. The latent state of infection poses a major obstacle to eradicating tuberculosis. In latent tuberculosis, the host immune response is capable of controlling the infection and yet falls short of eradicating the pathogen. That the host immune response contributes to the maintenance of latent tuberculous infection is supported by the observation that certain immunodeficient states, including those associated with the human immunodeficiency virus and tumor necrosis factor neutralization therapy, are associated with increased risks for developing reactivation disease. Latent tuberculosis is the product of a complex set of interactions between M. tuberculosis and the host immune response. The molecular basis for the persistence phenotype of M. Tuberculosis and the pertinent host immune mechanisms that contribute to the maintenance of tuberculous latency are just beginning to be understood. This review discusses the interactions between M. tuberculosis and the macrophage, the primary host cell that the tubercle bacillus parasitizes.

Latent tuberculosis: mechanisms of host and bacillus that contribute to persistent infection

Most people infected with Mycobacterium tuberculosis contain the initial infection and develop latent tuberculosis. This state is characterised by evidence of an immune response against the bacterium (a positive tuberculin skin test) but no signs of active infection. It can be maintained for the lifetime of the infected person. However, reactivation of latent infection occurs in about 10% of infected individuals, leading to active and contagious tuberculosis. An estimated 2 billion people worldwide are infected with M tuberculosis--an enormous reservoir of potential tuberculosis cases. The establishment and reactivation of latent infection depend on several factors, related to both host and bacterium. Elucidation of the host immune mechanisms that control the initial infection and prevent reactivation has begun. The bacillus is well adapted to the human host and has a range of evasion mechanisms that contribute to its ability to avoid elimination by the immune system and establish a persistent infection. We discuss here current understanding of both host and bacterial factors that contribute to latent and reactivation tuberculosis.

Imaging of pulmonary tuberculosis

Tuberculosis, more than any other infectious disease, has always been a challenge, since it has been responsible for a great amount of morbidity and mortality in humans. After a steady decline in the number of new cases during the twentieth century, due to improved social and environmental conditions, early diagnosis, and the development of antituberculous medication, a stagnation and even an increase in the number of new cases was noted in the mid-1980s. The epidemiological alteration is multifactorial: global increase in developing countries; minority groups (HIV and other immunocompromised patients); and elderly patients due to an altered immune status. Other factors that may be responsible are a delayed diagnosis, especially in elderly patients, incomplete or inadequate therapy, and the emergence of multidrug-resistant tuberculosis. The course of the disease and its corresponding clinicoradiological pattern depends on the interaction between the organism and the host response. Classically, pulmonary tuberculosis has been classified in primary tuberculosis, which occurred previously in children, and postprimary tuberculosis, occurring in adult patients. In industrialized countries, however, there seems to be a shift of primary tuberculosis towards adults. Furthermore, due to an altered immunological response in certain groups, such as immunocompromised and elderly patients, an atypical radioclinical pattern may occur. The changing landscape, in which tuberculosis occurs, as well as the global resurgence, and the changed spectrum of the clinical and radiological presentation, justify a renewed interest of radiologists for the imaging features of pulmonary tuberculosis. This article deals with the usual imaging features of pulmonary tuberculosis as well as the atypical patterns encountered in immunodepressed and elderly patients.

A surgical revisitation of Pott distemper of the spine

BACKGROUND CONTEXT

Pott disease and tuberculosis have been with humans for countless millennia. Before the mid-twentieth century, the treatment of tuberculous spondylitis was primarily supportive and typically resulted in dismal neurological, functional and cosmetic outcomes. The contemporary development of effective antituberculous medications, imaging modalities, anesthesia, operative techniques and spinal instrumentation resulted in quantum improvements in the diagnosis, management and outcome of spinal tuberculosis. With the successful treatment of tuberculosis worldwide, interest in Pott disease has faded from the surgical forefront over the last 20 years. With the recent unchecked global pandemic of human immunodeficiency virus, the number of tuberculosis and secondary spondylitis cases is again increasing at an alarming rate. A surgical revisitation of Pott disease is thus essential to prepare spinal surgeons for this impending resurgence of tuberculosis.

PURPOSE

To revisit the numerous treatment modalities for Pott disease and their outcomes. From this information, a critical reappraisal of surgical nuances with regard to decision making, timing, operative approach, graft types and the use of instrumentation were conducted.

STUDY DESIGN

A concise review of the diagnosis, management and surgical treatment of Pott disease.

METHODS

A broad review of the literature was conducted with a particular focus on the different surgical treatment modalities for Pott disease and their outcomes regarding neurological deficit, kyphosis and spinal stability.

RESULTS

Whereas a variety of management schemes have been used for the debridement and reconstruction of tuberculous spondylitis, there has also been a spectrum of outcomes regarding neurological function and deformity. Medical treatment alone remains the cornerstone of therapy for the majority of Pott disease cases. Surgical intervention should be limited primarily to cases of severe or progressive deformity and/or neurological deficit. Based on the available evidence, radical ventral debridement and grafting appears to provide reproducibly good long-term neurological outcomes. Furthermore, recurrence of infection is lowest with such techniques. Posterior operative techniques are most effective in the reduction and prevention of spinal deformity.

CONCLUSIONS

Unlike historical times, effective medical and surgical management of tuberculous spondyitis is now possible. Proper selection of drug therapy and operative modalities, however, is needed to optimize functional outcomes for each individual case of Pott disease.

Tuberculosis in the elderly

As the result of the strengthening of TB-control programs nationwide, a decline in the overall number of reported TB cases in the United States has been observed within the last 10 years. Despite these declines in absolute numbers, the elderly continue to account for a disproportionate share of the cases. The high number of cases diagnosed at autopsy among the elderly suggests that this condition often remains unrecognized, possibly due to the subtle clinical manifestations in this age group. Evidence suggests that, compared with their community-dwelling counterparts, the institutionalized elderly are at a greater risk for re-activation of latent TB and for the acquisition of new TB infection. More studies are needed to make final conclusions. New guidelines for the treatment of LTBI emphasize targeted TST among persons at high risk for development of active TB and no longer use age as an exclusionary condition. All nursing home residents must therefore be regularly screened for LTBI and treated if necessary. Even though elderly persons are at greater risk for hepatic toxicity from TB treatment, the poor outcome of untreated TB in this age group warrants more aggressive treatment of this condition.