A category of patients with tuberculosis concomitant with HIV infection, who were admitted for inpatient care to the infection department of Tuberculosis Clinical Hospital No. 7, Moscow, during 1996-2001, was analyzed. Peculiarities of the mentioned patients' category (205 subjects) were studied at the anti-TB facility. It was established that males (83.4%), aged 21-30 (48.9%), as well as unemployed (71%) prevailed. As much as 14% of them were homeless and 33% had a prison history. Drug-addiction (76%) and hepatitis C and B (77%) were found to be the key concomitant pathologies in them. HIV was primarily diagnosed at the anti-TB facility in 52% of patients, while tuberculosis had set on before HIV in 34.8% of patients. A major part of patients with tuberculosis concomitant with HIV, who were at the anti-TB facility, had early HIV stages. Specific features of the clinical course of tuberculosis were defined for patients with early HIV stages. It was established that tuberculosis concomitant with early HIV stages is deprived of any peculiarities except for the primary signs' stage, if it has the form of an acute infection. An exacerbation of the tuberculosis process, which quite often leads to its generalization and fatal outcome, can happen during the mentioned period due to a pronounced immunodeficiency.
The dynamics of epidemic parameters and the specific features of development of tuberculosis were analyzed in prisoners in 1989-2001. It was ascertained that 98.7% of them were infected with tuberculosis and most of them belonged to a tuberculosis high-risk group. In 67.5% of those who had fallen ill, the process was detected within the first 3 years of their confinement. A scheme of interaction of main propulsive forces of an epidemic process in tuberculosis (exogenous and endogenous infections and risk factors) is presented. It has been found that surveys for tuberculosis are not a deterrent for a rise in the incidence rates due to endogenous infection. The use of factorial analysis and systems approach in the epidemiology of tuberculosis has explained some regularities in the development of an epidemic process, revealed reasons for the aggravated tuberculosis situation in penitentiary institutions, and considered prospects for its improvement.
Bacillus Calmette-Guerin (BCG) revaccination was discontinued in Finland in 1990. The objective of this study was to assess the impact of BCG revaccination of tuberculin-negative school-children in prevention of tuberculosis. The tuberculosis cases in 1990-1995 were calculated among age cohorts born 1979-1984 and no longer covered by the BCG revaccination program. Corresponding data were collected for comparison from the period of revaccination in 1980-1985 among age cohorts born in 1969-1974. The National Tuberculosis Register was reviewed in order to observe the tuberculosis trend since 1980 in the age groups of 10-14 and 15-19 yr. Three cases of tuberculosis have been registered among non-BCG-revaccinated children during 6 yr after discontinuation of the program, i.e., 2.23 cases (95% CI 0.72 to 6.90) per million person yr. The control group revealed five cases, 3.78 (95% CI 1.57 to 9.07) per million person yr. The relative risk of tuberculosis in non-BCG-revaccinated children is 0.59 (95% CI 0.14 to 2.47) compared with the control group. The incidence of tuberculosis has continued to decline among adolescents since 1980. The follow-up data confirm that the cessation of BCG revaccination program had no effect on the continuing overall decline of tuberculosis in Finland. The efficacy of BCG revaccination seems to be low or nonexistent in countries with low tuberculosis incidence.
The Russian Federation has the eleventh highest tuberculosis burden in the world in terms of the total estimated number of new cases that occur each year. In 2003, 26% of the population was covered by the internationally recommended control strategy known as directly observed treatment (DOT) compared to an overall average of 61% among the 22 countries with the highest burden of tuberculosis. The Director-General of WHO has identified two necessary starting points for the scaling-up of interventions to control emerging infectious diseases. These are a comprehensive engagement with the health system and a strengthening of the health system. The success of programmes aimed at controlling infectious diseases is often determined by constraints posed by the health system. We analyse and evaluate the impact of the arrangements for delivering tuberculosis services in the Russian Federation, drawing on detailed analyses of barriers and incentives created by the organizational structures, and financing and provider-payment systems. We demonstrate that the systems offer few incentives to improve the efficiency of services or the effectiveness of tuberculosis control. Instead, the system encourages prolonged supervision through specialized outpatient departments in hospitals (known as dispensaries), multiple admissions to hospital and lengthy hospitalization. The implementation, and expansion and sustainability of WHO-approved methods of tuberculosis control in the Russian Federation are unlikely to be realized under the prevailing system of service delivery. This is because implementation does not take into account the wider context of the health system. In order for the control programme to be sustainable, the health system will need to be changed to enable services to be reconfigured so that incentives are created to reward improvements in efficiency and outcomes.
Estimations of prevalence of latent tuberculous infection (LTBI) are confounded by factors known to influence the results of the tuberculin skin test (TST) such as age, contact history and bacille Calmette-Guerin (BCG) vaccination. Appropriate interpretation of TST results is necessary to ensure LTBI treatment for those at greatest risk.
To document the prevalence of LTBI in Aboriginal people living on a reserve in British Columbia (BC) and to determine the influence of BCG.
A population-based, retrospective descriptive analysis of all epidemiological data collected for the on-reserve Aboriginal programme in BC (1951-1996).
Of 17615 persons who received a TST during the study period, 42% had received BCG. During the study period, an average of 2517 TSTs were completed per year (SD = 1228) among persons with an average age of 26 years (SD = 16). Among all subjects, the average prevalence of LTBI was 25% (95 %CI 24-25). The presence of BCG (OR = 3.1, 95%CI 2.8-3.4) and multiple BCGs (OR = 10.2, 95%CI 7.7-13.6) were both associated with a positive TST. A positive TST was also associated with a shorter duration in years between the most recent BCG and the TST.
The average prevalence of LTBI in a sequential sample of Aboriginal people living on a reserve in BC was estimated at 25%. BCG, especially in multiple doses, increased the likelihood of a positive TST.
It is evident from follow-up studies of tuberculosis in the Netherlands (without BCG vaccination), Sweden (discontinuation of BCG vaccination since 1975) and in both parts of Germany (FRG discontinuation since 1975), as well as from the favourable tuberculosis situation in both parts of Germany (low tuberculosis incidence and very low infection risk) that general vaccination of babies is no longer warranted. For this reason the German Central Committee for Combatting Tuberculosis is considering in consultation with the Federal Bureau of Health to abstain from continuing to recommend general BCG vaccination of all newborn. BCG vaccination should be recommended only in enhanced-risk groups (children of foreign parents and children sharing their living quarters or household with a person suffering from acute, i.e. infectious tuberculosis).