The U-shaped curve of concern

Suppurative myositis in children

Three cases are reported of pyogenic (non-tuberculous) myositis involving the ilio-psoas and/or iliacus muscles in children presenting to John Hunter Hospital, Newcastle, Australia, in a 12-month period. In one, cultures grew Haemophilus influenzae type B and in the other two Staphylococcus aureus was isolated. Biopsy of the abscess cavity from the second child confirmed an antecedent haematoma as the underlying cause. The third had underlying sacroiliac septic arthritis with a history of antecedent trauma. The classification, investigation, and treatment of myositis is discussed.

Tuberculosis in the AIDS era

A resurgence of tuberculosis has occurred in recent years in the United States and abroad. Deteriorating public health services, increasing numbers of immigrants from countries of endemicity, and coinfection with the human immunodeficiency virus (HIV) have contributed to the rise in the number of cases diagnosed in the United States. Outbreaks of resistant tuberculosis, which responds poorly to therapy, have occurred in hospitals and other settings, affecting patients and health care workers. This review covers the pathogenesis, epidemiology, clinical presentation, laboratory diagnosis, and treatment of Mycobacterium tuberculosis infection and disease. In addition, public health and hospital infection control strategies are detailed. Newer approaches to epidemiologic investigation, including use of restriction fragment length polymorphism analysis, are discussed. Detailed consideration of the interaction between HIV infection and tuberculosis is given. We also review the latest techniques in laboratory evaluation, including the radiometric culture system, DNA probes, and PCR. Current recommendations for therapy of tuberculosis, including multidrug-resistant tuberculosis, are given. Finally, the special problem of prophylaxis of persons exposed to multidrug-resistant tuberculosis is considered.

Tuberculosis in young adults and the elderly. A prospective comparison study

OBJECTIVES

To compare the clinical, bacteriologic, and radiologic features of pulmonary and pleural tuberculosis in young adults and the elderly and determine if any differences exist between both groups.

DESIGN

Prospective recruitment of all patients diagnosed as having pulmonary and pleural tuberculosis in British Columbia, Canada.

SETTING

A population-based sample from a provincial control program TB registry.

PATIENTS

A total of 218 consecutive patients whose conditions were diagnosed between January 1990 and May 1991. We excluded 15 HIV-positive patients whose conditions were diagnosed during this study.

INTERVENTION

Standardized data collection of symptoms, bacteriology, and review of radiology by two readers blind to the clinical and epidemiologic data.

MAIN RESULTS

There were 142 young adult patients and 76 elderly patients. The young adults had a mean age of 41.2 years and the elderly group had a mean age of 75 years of age. Fever (p = 0.002) and night sweats (p = 0.02) were more common in young adults. In culture-proven disease, hemoptysis, fever, and cough were more common in young adult (p = 0.03, 0.02, and 0.01, respectively). There was no difference in the duration of symptoms between the two groups. The odds ratio for cancers other than lung cancer, 3.98 (confidence interval, 1.49, 10.65) in the elderly group was the only significant risk factor to differ between the two groups. Skin test responses to 5TU PPD were positive in 86.2 percent of young adults and 67.6 percent of elderly patients tested (p = 0.03). A total of 79.6 percent of young adults and 88.15 percent of the elderly patients (not significant) were culture positive. Comparison of radiologic findings in young adults vs elderly patients showed no significant differences apart from those with miliary TB 0.7 percent vs 6.7 percent (p = 0.04).

CONCLUSIONS

In this population-based study, young adults were more likely to have hemoptysis, fever, and cough and to have a positive PPD response. Cancer was significantly associated as a risk factor in the older age group. There was no difference in bacteriologically proven disease or radiologic findings between the two groups, apart from the more common occurrence of miliary TB in the elderly.

New developments in tuberculosis and HIV infection: an opportunity for prevention

As we approach 2010, the year by which we were to have eliminated TB, we find this ancient disease is making a comeback. This comeback is due to many factors, but the role of HIV infection is clearly important. HIV infection can result in changes in the pathogenesis and presentation of infection with the tubercle bacillus. Consequently, as health care providers, we must respond with changes in our usual methods of prevention, treatment, and infection control. Whereas the increase in TB is currently limited to certain geographic areas, it is likely to spread more widely. All health care providers should be aware of the changing face of TB and have a high clinical index of suspicion for this disease.

The evolution of tuberculosis infection among schoolchildren in Barcelona and the HIV epidemic

SETTING

First grade students in primary schools in the city of Barcelona, Spain.

OBJECTIVE

To estimate the prevalence of tuberculin reaction and sources of infection; to analyse trends in comparison with previous data.

DESIGN

Tuberculin screening of first grade schoolchildren (1985 birth cohort) was undertaken in 1991-92 using 2 TU of PPD RT23.

RESULTS

The prevalence of reactors among the 12,007 children tested from the 1985 cohort was 0.87%, varying among districts between 0.13% and 3.03%. Follow-up of positive tests was completed for 75 children, which led to the identification of 6 cases of previously unknown clinical tuberculosis among these children, while for 14 infected children index cases were found, one of whom was a confirmed HIV-infected IVDU.

CONCLUSION

The comparison of results with data from previous studies suggests that tuberculosis infection among schoolchildren in Barcelona may not be declining as in previous years, especially in areas such as the inner city, where poverty combines with HIV infection and with increasing migration from countries with a higher tuberculosis prevalence.

Infection caused by Mycobacterium tuberculosis

OBJECTIVE

To update readers on the clinical management of infections caused by Mycobacterium tuberculosis, to provide a general description of the organism, culture and susceptibility testing, and clinical manifestations of the disease, and to provide several aspects of the treatment of the disease, including historical perspective, current approaches, and research opportunities for the future.

DATA SOURCES

The current medical literature, including abstracts presented at recent international meetings, is reviewed. References were identified through MEDLINE, MEDLARS II, Current Contents, and published meeting abstracts.

STUDY SELECTION

Data regarding the epidemiology, clinical manifestations, culture and susceptibility testing, and treatment of tuberculosis are cited. Specific attention has been focused on the clinical management of patients with noncontagious infection and potentially contagious active disease (TB) caused by M. tuberculosis.

DATA EXTRACTION

Information contributing to the discussion of the topics selected by the authors is reviewed. Data supporting and disputing specific conclusions are presented.

DATA SYNTHESIS

The incidence of TB is increasing in the US, despite the fact that available technologies are capable of controlling the vast majority of existing cases. Fueling the fire is the problem of coinfection with HIV and M. tuberculosis. Very few drugs are available for the treatment of TB, and few of these approach the potency of isoniazid and rifampin. Preventive therapy of patients exposed to multiple-drug-resistant M. tuberculosis (MDR-TB) is controversial and of unknown efficacy. Treatment of active disease caused by MDR-TB requires up to four times longer, is associated with increased toxicity, and is far less successful than the treatment of drug-susceptible TB. Strategies for the management of such cases are presented. The rising incidence of TB in the US reflects a breakdown in the healthcare systems responsible for controlling the disease, which reflects the past budgetary reductions. Although TB control is one of the most cost-effective public health strategies, funding has been cut repeatedly despite the fact that TB was never eliminated. This has helped to produce the current crisis, including the spread of MDR-TB in many urban areas. The elimination of TB will now take decades longer, cost hundreds of millions of dollars more, and result in vastly higher morbidity and mortality rates than would have occurred with timely, adequate measures.

CONCLUSIONS

Tremendous effort and far more funding will be required to eliminate TB in the US. The selection of drug therapy must be based on the susceptibility data for each isolate. Multiple-drug therapy must be continued for 6 to > or = 24 months, and patient adherence to prescribed regimens must be verified in all cases of TB. Significant antimycobacterial drug malabsorption has been documented in AIDS patients with TB, and may result in treatment failure. New agents are needed to improve the clinical outcome in patients with MDR-TB.

Controlling resurgent tuberculosis: public health agencies, public policy, and law

The reappearance of tuberculosis as a serious public health threat points up the fallacy of the widely held assumption that medical science had conquered the communicable diseases that were once leading causes of morbidity and mortality. In devising a strategy to prevent the spread of TB, public policymakers must adapt traditional TB control measures to reflect the current problem. Such a strategy can and should include the appropriate use of governmental coercion to compel observance of public health TB control measures. Public health approaches to control of human immunodeficiency virus, with their emphasis on the voluntary cooperation of those infected and at high risk for infection, are not a model for effective TB control. Additional resources, while needed, will not alone enable public health agencies to bring TB and other communicable diseases under control. In the present debate over health care reform, little attention has been paid to the importance of public health agencies in protecting the public health. The resurgence of TB is a warning of the consequences of neglecting public health agencies and ignoring the socioeconomic problems that underlie it and other communicable diseases.

The epidemiology of multidrug-resistant tuberculosis in the United States

There has been a significant increase in the number of cases of MDR-TB in the United States. Although cases of MDR-TB have been reported from many areas of the country, the majority of the cases are concentrated in large urban areas. MDR-TB is difficult and expensive to treat. CDC has developed a National Action Plan to Combat Multidrug-Resistant Tuberculosis. The main elements of this plan include (1) greater surveillance and epidemiologic studies of drug-resistant TB; (2) initiatives to make the laboratory diagnosis of MDR-TB more rapid, sensitive, and reliable; (3) education of health care professionals about MDR-TB, its prevention, control, and treatment; and (4) measures to facilitate the development of new antituberculous drugs. CDC has published guidelines for the prevention of nosocomial spread of MDR-TB. to prevent the development and spread of MDR-TB, medical practitioners must suspect TB and make the diagnosis as rapidly as possible. Once a patient is diagnosed with TB, the most important step to prevent the development of drug-resistant disease is to ensure that patients take all of their medication. Directly observed therapy is the best way of ensuring this. In addition, more specific interventions, such as the use of incentives to improve compliance in certain situations, may need to be applied to groups in which high rates of drug resistance have been found, such as HIV-positive persons, IDUs, homeless persons, and persons who have been exposed to persons with MDR-TB. Quick and effective public health interventions targeted at these defined groups should help to control the spread of both drug-susceptible and drug-resistant TB.

The role of the public health department in tuberculosis

The role of the public health department in TB is a critical component of the overall TB control effort. This article illustrates both the traditional public health methods of surveillance, containment and prevention, and some of the newer strategies being employed to address TB control in today's multifaceted environment. It shows that controlling TB will require an intensification of collaborative efforts between public, private and community providers. In particular, the role of public health and health care workers in institutional settings is emphasized as it relates to shared community efforts. In light of the recent outbreaks of drug-resistant disease and the associated dramatic increasing TB morbidity and mortality, the need for these partnerships is urgent. Given the legal mandate for TB control, health departments will continue to play a major role in the elimination of this disease. The deterioration of these public health services, however, will require immediate attention lest the very foundation of TB control be allowed to crumble.

Commentary: tuberculosis in New York City--the consequences and lessons of failure

The resurgent tuberculosis epidemic represents--especially in New York City--a failure to maintain a public health infrastructure that was focused on preventing active disease in high-risk populations (i.e., individuals with the human immunodeficiency virus [HIV]) and on treating active tuberculosis patients until cured. Although the tuberculosis problem in New York City and other localities is worsened by homelessness, poverty, and substance abuse, it is possible to bring tuberculosis under control by directing public health resources into targeted programs that enhance compliance with tuberculosis treatment regimen and expand chemoprophylaxis efforts among HIV-infected individuals. These two avenues will decrease, respectively, the number of cases of multidrug-resistant tuberculosis and the total number of new cases.

Emergence during unsuccessful chemotherapy of multiple drug resistance in a strain of Mycobacterium tuberculosis

Serial isolates of Mycobacterium tuberculosis were cultured from a patient who failed to respond to standard antituberculous chemotherapy. Isolates were cultured in March 1989, July 1989, December 1989 and May 1990. Each successive isolate was found to be resistant to a wider range of antituberculous drugs than its predecessors. The initial isolate was resistant to isoniazid and rifampin, the second isolate was also resistant to ethambutol, the third was also resistant to pyrazinamide, ansamycin (= rifabutin) and ofloxacin and the last isolate was also resistant to ciprofloxacin and sparfloxacin. All four isolates' bacteriophage typing profiles and DNA restriction fragment patterns determined by Southern blot hybridization using the IS6110/IS986 probes and the new probe pTBN12 were concordant. It was concluded that this patient was persistently infected with a single strain of Mycobacterium tuberculosis which developed resistance to a number of families of drugs but did not show any significant change in typing patterns. The problem of acquired multiple drug resistance, particularly to fluoroquinolones and rifamycins, represents a new challenge in tuberculosis therapy.

Tuberculosis and AIDS: epidemiologic, clinical, and social dimensions

In little more than a decade, the AIDS epidemic has exerted a profound effect on morbidity and mortality among young adults and children in many parts of the world. One of the more dramatic aspects of AIDS is that it seems to have arisen almost spontaneously as a new epidemic, spreading rapidly within at-risk populations in a way that is unprecedented for the serious infectious diseases of recent memory. Tuberculosis, on the other hand, had only recently been considered a disease of historical importance but of diminishing relevance to current public health priorities, especially in industrialized countries. Over the past decade, however, and in parallel with the AIDS epidemic, there has been a resurgence of tuberculosis in many of the same populations most affected by HIV infection. This has had important implications for clinical practice, public health, and the development of appropriate health policy. A number of elements have converged to promote the development of HIV-related tuberculosis, including biologic, social, and environmental factors. These will be discussed both to provide a context for understanding the relationship between the two epidemics, and as a basis for suggesting strategies for tuberculosis control in the AIDS era.

Tuberculosis--immunopathogenesis and therapy

Infection with Mycobacterium tuberculosis (TB) has returned to the forefront of public and medical concern because of the recent sharp increase in the number of cases. Major strides have been made in understanding the pathogenesis of TB, and some of these basic advances are being applied clinically. This review focuses on current concepts of the host response to TB, the changing epidemiology of TB, and optimal treatment strategies.

Comparative ability of human monocytes and macrophages to control the intracellular growth of Mycobacterium avium and Mycobacterium tuberculosis: effect of interferon-gamma and indomethacin

Intracellular growth of Mycobacterium avium and M. tuberculosis H37Rv was compared both in human peripheral blood monocytes and in cultured macrophages. The cells were treated with 300 U of human recombinant interferon-gamma (IFN gamma) either 48 h prior to phagocytosis or after infection. In some cases, indomethacin (IND, a potent inhibitor of prostaglandin-E2 synthesis), was added immediately after infection of macrophages. IFN gamma pretreatment of monocytes resulted in about 50% lesser uptake of both pathogens, but had no effect in macrophages. Macrophages, as compared to monocytes, were more permissive to M. avium growth suggesting that monocytes may be innately more efficient in controlling the intracellular growth of this pathogen. About ten-fold higher growth of M. avium as compared to M. tuberculosis was observed in both culture systems. IFN gamma-treatment alone did not confer any anti-M. avium activity to monocytes and macrophages alike and addition of IND did not change this unresponsiveness. In the case of M. tuberculosis, the IFN gamma treatment alone endowed both monocytes and macrophages with significant bacteriostatic activity which was further potentiated by the addition of IND. These observations show innate differences in the ability of human monocytes and macrophages to control the growth of two major mycobacterial pathogens and the immunoregulatory mechanisms involved.