The challenge of tuberculosis: statements on global control and prevention

Tuberculosis and stigma: predictors of prejudice against people with tuberculosis

Tuberculosis is a main cause of mortality and morbidity in developing countries. Although diagnostic and curative means are well known, they are not always available and affordable. Also, the disease has a worldwide stigma, which adds to the suffering. A survey exploring the correlates of prejudice, as an attitudinal component of this stigma, was carried out in Cali, Colombia. Results show that scientifically unfounded beliefs about the transmission of the disease are the main significant predictor of the instrumental function of this attitude. Health education and, arguably, more successful control programmes could help to reduce the social isolation suffered by people with tuberculosis.

Evolução espaço-temporal dos casos de tuberculose em Ribeirão Preto (SP), nos anos de 1998 a 2002

OBJETIVO: Estabelecer a distribuição espacial da tuberculose no Município de Ribeirão Preto (SP) de 1998 a 2002, buscando verificar a dependência entre sua ocorrência e o espaço. MÉTODOS: Foi utilizada a base de dados secundários Epi-Tb da Secretaria Municipal de Saúde de Ribeirão Preto. O georreferenciamento dos casos de tuberculose foi realizado através do software MapInfo 6.5 e a análise estatística espacial através do software Spring. RESULTADOS: Por meio da análise do padrão espacial existente no decorrer dos anos estudados, foi concluído que para cada ano houve um padrão para a distribuição espacial da tuberculose em Ribeirão Preto, tendo sido identificadas áreas homogêneas de risco para a doença, embora os casos estivessem sempre concentrados em uma faixa da região noroeste do município, que consiste de bairros de classe média e/ou média baixa da população. CONCLUSÃO: Os resultados contribuíram para o conhecimento da distribuição espacial da tuberculose em Ribeirão Preto, em diferentes períodos, ressaltando a importância da categoria espaço como alternativa metodológica para auxiliar no planejamento, monitoramento e avaliação das ações em saúde, com direcionamento mais adequado das intervenções para diminuir as iniqüidades.

Epidemiological trend in tuberculosis in the Italian region of Liguria: impact of immigration and AIDS

BACKGROUND

Tuberculosis (TB) uniformly decreased in all industrialized countries from 1950 to 1985. However, since 1985 an upsurge of the disease has been observed, probably due to the increases in AIDS and immigration. It is for this reason that in the last decade all industrialized countries have intensified their controls on TB and a new reduction has been recently observed.

METHODS

In this study we collected epidemiological data (mortalities and reported cases) for the region of Liguria over the last 15 years. We then calculated the incidence rate of TB per 100,000 residents according to age, HIV infection and nationality, making a distinction between European Union (EU) citizens and immigrants coming from countries outside the EU.

RESULTS

The rate of mortality, after the last peak at the end of the Second World War, has progressively decreased from 1946 to today, so much so that presently we record fewer than two cases per 100,000 people. We observed a consistent downward trend in the incidence rate up to 1987, but from 1988 onwards this trend stopped and, in subsequent years, we detected an increase in the incidence rate, which peaked in 1996. This led to increased interventions, which has resulted in a considerably decreased overall rate of cases of TB during the last few years. The number of TB cases specifically among foreigners increased considerably during the last 5 years, whereas there was a drastic reduction in the number of total TB cases, as well as an interesting reduction in AIDS cases. During the same period there was a progressive decrease in tuberculin skin positivity in all school classes.

CONCLUSIONS

The reduction in TB notifications is probably due to an increase in surveillance and control of social and health conditions. These results show that immigrant workers are considered to be a high-risk group, whereas the risk has progressively decreased in the HIV group.

Perception of tuberculosis in the Democratic Republic of Congo: wali ya nkumu in the Mai Ndombe district

To implement effective tuberculosis (TB) control programs, we must first understand the health culture in a given region. The authors organized eight focus group sessions in the Mai Ndombe district in the Democratic Republic of Congo to study the underlying attitudes toward TB and to describe the TB context with special reference to gender differences. They then analyzed the focus group data using a grounded theory design. TB is called "the disease of distance" and is described as a person invading people. Isolation and stigmatization are the methods being used to protect society from the TB threat. The authors observed no gender differences in the collected data.

[Factors related to non-compliance with active tuberculosis treatment in Montreal 1992-1995]

OBJECTIVE

To determine the extent of non-compliance with antituberculosis treatment in Montreal and whether it is influenced by the characteristics of the health care setting.

METHODS

Retrospective medical and public health chart review of tuberculosis patients reported to the Montreal-Centre Department of Public Health between 1992-1995. A non-compliant patient is defined as one who has taken less than 80% of prescribed antituberculosis medication.

RESULTS

Among patients for whom the compliance status was available, 19.8% were non-compliant. In univariate analysis, risk factors significantly associated with non-compliance included: living alone, birth in an endemic country for tuberculosis, side effects related to the medication, and follow-up in a clinic not specialized for tuberculosis. In multivariate analysis, increase of age by one unit (OR: 1.1; 95% CI: 1.02-1.1), and risk factors such as alcoholism (OR: 33.8; 95% CI: 5.8-194.4) and being HIV positive (OR: 8.9; 95% CI: 2.9-26.6) were independently associated with non-compliance.

CONCLUSION

Non-observance seemed to be associated with patients' characteristics rather than health care system characteristics.

An immunochromatographic serological assay for the diagnosis of Mycobacterium tuberculosis

A rapid serological test for tuberculosis (TB) infection was designed using antigens specific to Mycobacterium tuberculosis. Tuberculosis infection, TB vaccination and exposure to environmental Mycobacteria cannot be distinguished using skin tests based on tuberculin protein derivatives. The standard diagnostic techniques such as skin tests, X-rays and DNA techniques are time consuming, expensive, and not practical for screening large populations. We used the 38, 63, 64, 14, 59-kDa antigens of M. tuberculosis to develop a rapid immunochromatographic test kit. This study evaluates the diagnostic potential of the rapid test kit using TB positive and TB negative serum samples from various hospitals in India. The samples were obtained from patients infected with or exposed to bacteria and viral pathogens. The results demonstrated that the combination of antigens improved the diagnostic specificity and sensitivity. The specificity of the test was 99.42% with sensitivity of 98.52% (n = 241). In case of multiple infections, the specificity was 93.15% with a low sensitivity of 73.52% n = 141). The test kit may offer an improved alternative to purified protein derivative (PPD). This rapid TB test kit may be a useful tool for first-line testing of suspected cases, epidemiological studies and in designing a quality health system to reduce health hazards in resource-poor countries.

Hospital control and multidrug-resistant pulmonary tuberculosis in female patients, Lima, Peru

We examined the prevalence of tuberculosis (TB), rate of multidrug-resistant (MDR) TB, and characteristics of TB on a female general medicine ward in Peru. Of 250 patients, 40 (16%) were positive by sputum culture and 27 (11%) by smear, and 8 (3%) had MDRTB. Thirteen (33%) of 40 culture-positive patients had not been suspected of having TB on admission. Six (46%) of 13 patients whose TB was unsuspected on admission had MDRTB, compared with 2 (7%) of 27 suspected cases (p = 0.009). Five (63%) of 8 MDRTB patients were smear positive and therefore highly infective. In developing countries, hospital control, a simple method of reducing the spread of MDRTB, is neglected.

Encompassing treatment with prevention: the path for a lasting control of tuberculosis

Tuberculosis is an important cause of death, mainly in the less developed countries. Thus far the strategy for its control had relied on the diagnosis of sick individuals and provision of chemotherapy. However, this strategy is problematic for several reasons: poor education about the disease and the low income of people with tuberculosis are important barriers for them to have access to early diagnosis and to keep adherence to treatment; provision of 'preventive therapy' to the enormous pool of people infected with tuberculosis is not feasible in less developed countries; and finally, long-term political commitment with the strategy is unlikely. Several facts indicate that tuberculosis patterns in different populations are shaped by biological, behavioral and socio-economic factors. This paper argues that a lasting control of tuberculosis requires a strategy based on a broader model of causality, which takes account of all these three causal factors.

Tuberculosis II: the failure of the BCG vaccine

BCG (bacille Calmette-Guerin) is an attenuated pathogen characterized by its capacity to induce cellular and humoral immune responses primarily against a nonpeptidic antigen, lipoarabinomannan. Immune responses against this substance contribute to the immunoprotection of the patient if the production of IL-2 and INF-gamma is not impaired. The most adequate production of INF-gamma and IL-2 is obtained by immunoreactivity against proteinic antigens. The formation of IgG-type antibodies and of cellular immunity against mycobacterial peptidic and proteinic antigens is an additional immunological response essential for a good protection. This is achieved by the BCG vaccine in only a small proportion of the vaccinees. A vaccine adjuvant that also finds application as an immunotherapeutic agent is composed of proteinic antigens such as sonicates of Mycobacterium vaccae and antigen 60 of Mycobacterium bovis. These enhance the beneficial Th1-pole of the immune response. In addition, A60 induces the formation of antibodies against species-specific proteinic antigens. Despite the questioning of its innocuousness and efficacy, the BCG vaccine was imposed worldwide in 1950 by medical and political organizations that showed no concern for these questions. The contemporary structures of research administration in this area make it unlikely that the efficacious means recently developed to complement the action of the vaccine and of chemotherapies to face the surge of tuberculosis (TB) will be readily adopted.

Tuberculosis control in less developed countries: can culture explain the whole picture?

Healthcare practices, adherence to treatment, and organizational behaviour of healthcare workers are the main issues concerning tuberculosis (TB) control influenced by culture. A review of research findings published in the English language literature concerning these issues, and the way in which they are affected by cultural and structural factors is presented and discussed. These findings suggest that structural rather than cultural factors may be the main explanation for the questionable behaviour of healthcare workers and patients suffering from TB in less developed countries.

Persistent and chronic lung disease in HIV-1 infected and uninfected African children

OBJECTIVE

The causes of persistent lung disease (PLD) and chronic lung disease (CLD) are unknown in HIV-infected children in developing countries. We describe the causes and course of PLD and CLD in HIV-infected and uninfected children.

METHOD

Of 194 children with lung disease persisting for at least 1 month who were seen at the paediatric respiratory clinic over a 2-year period, 42 underwent invasive investigations after failed initial management over 3 months. PLD was defined as the presence of clinical and radiological features of lung disease for more than 1 month, and CLD as these features for more than 3 months.

RESULTS

One hundred and thirty-eight (71%) of the 194 children with PLD were HIV-infected, 52 (27%) were not infected and four (2%) were of undetermined HIV status. Forty-eight per cent of the HIV-infected children and 52% of the HIV-uninfected children responded to initial treatment over 3 months; the presumptive diagnoses in these were tuberculosis, interstitial pneumonitis, bronchiectasis and post-ventilation lung syndrome. Of the 28 HIV-infected children with CLD who underwent invasive investigations 16 (57%) had lymphoid interstitial pneumonitis, eight (29%) had tuberculosis and four (14%) had non-specific interstitial pneumonitis. Of the 14 HIV-uninfected children with CLD who had invasive testing there were four cases (29%) each of tuberculosis and interstitial pneumonitis, three (22%) cases of bronchiectasis and one case of each of extrinsic allergic alveolitis, crytogenic fibrosing alveolitis and non-Hodgkin's lymphoma.

CONCLUSION

This is the first set of data on the causes of CLD in HIV-infected children in a developing country. Every effort should be made to identify the infectious agent, whether M. tuberculosis or a secondary bacterial infection in LIP, in order to treat most appropriately these children with lung disease.

The spread of AIDS and the re-emergence of tuberculosis in Catalonia, Spain

OBJECTIVE

To assess the impact of HIV/AIDS on the incidence of tuberculosis (TB) and to analyse the determinants of TB presenting as the first indicative disease of AIDS.

DESIGN

Analysis of TB and AIDS surveillance data.

SETTING

Catalonia, north-east Spain.

PATIENTS

Two separate sources were used: (i) TB cases reported to the Catalan TB registry diagnosed between January 1982 and December 1993; (ii) AIDS cases reported to the AIDS Catalan registry diagnosed between January 1982 and December 1994.

MAIN OUTCOME MEASURES

Expected and observed TB cases, and number and characteristics of AIDS cases presenting with TB.

RESULTS

From 1987 to 1993 the annual TB crude incidence rate increased by 50% to a rate of 49.7 per 100,000, with a least 60% of the increase directly due to AIDS. During that period specific rates among children aged 0-4 years remained high at around 40 per 100,000. A total of 7,010 AIDS cases were diagnosed between 1988 and 1994, of whom 24.3% had TB. Multivariate analysis from those AIDS cases showed that besides male sex, young age, and urban residence, the strongest predictors of TB among AIDS cases were history of imprisonment (odds ratio, 2.16; P < 0.001) and intravenous drug use (odds ratio, 1.65; P < 0.001).

CONCLUSIONS

The high rates of TB among children and young adults suggest that TB transmission has increased during this period, especially among people at high risk of AIDS. The determinants of individual risk of TB among AIDS patients act together, especially in prisons. The HIV/TB coepidemic is an emerging threat potentially for all and requires expanding targeted measures to prevent and control both disease in our setting.

Impact of human immunodeficiency virus infection on abdominal tuberculosis in western India

We studied the seroprevalence of human immunodeficiency virus infection in patients with pulmonary tuberculosis and abdominal tuberculosis. We also assessed the clinical characteristics, risk factors, tuberculin status, site, and response to therapy of abdominal tuberculosis in human immunodeficiency virus (HIV)-seropositive and HIV-seronegative patients. Volunteer blood donors (n = 8,395), patients with pulmonary tuberculosis (n = 387), and patients with abdominal tuberculosis (n = 108) were screened for HIV 1 and/or HIV 2 by enzyme-linked immunosorbent assay (ELISA; Torrent, India) and positivity reconfirmed by a repeat ELISA and Western blot test. The HIV seroprevalence in the abdominal tuberculosis patients (16.6%) was significantly higher compared with those with pulmonary tuberculosis (6.9%, p < 0.05) and volunteer blood donors (1.4%, p < 0.01). Absolute lymphocyte counts did not differ between the HIV-seropositive and HIV-seronegative patients (2,044.94 +/- 830 vs 2,261.34 +/- 805/mm3, p = NS). The Mantoux reaction was larger in the HIV-seronegative group as compared with the HIV-seropositive group (14.8 mm vs. 9.5 mm, p < 0.05). Tuberculosis patients responded well to conventional antituberculosis drugs in standard doses regardless of their HIV status.