Tuberculosis and human immunodeficiency virus infection

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.

Investigation of geo-spatial hotspots for the occurrence of tuberculosis in Almora district, India, using GIS and spatial scan statistic

BACKGROUND

The World Health Organization has declared tuberculosis a global emergency in 1993. It has been estimated that one third of the world population is infected with Mycobacterium tuberculosis, the causative agent of tuberculosis. The emergence of TB/HIV co-infection poses an additional challenge for the control of tuberculosis throughout the world. The World Health Organization is supporting many developing countries to eradicate tuberculosis. It is an agony that one fifth of the tuberculosis patients worldwide are in India. The eradication of tuberculosis is the greatest public health challenge for this developing country. The aim of the present population based study on Mycobacterium tuberculosis is to test a large set of tuberculosis cases for the presence of statistically significant geographical clusters. A spatial scan statistic is used to identify purely spatial and space-time clusters of tuberculosis.

RESULTS

Significant (p < 0.05 for primary clusters and p < 0.1 for secondary clusters) high rate spatial and space-time clusters were identified in three areas of the district.

CONCLUSION

There is sufficient evidence about the existence of statistically significant tuberculosis clusters in Almora district of Uttaranchal, India. The spatial scan statistics methodology used in this study has a potential use in surveillance of tuberculosis for detecting the true clusters of the disease.

Susceptibility of Mycobacterium tuberculosis strains to gatifloxacin and moxifloxacin by different methods

BACKGROUND

Considering the potentials of gatifloxacin and moxifloxacin in the treatment of tuberculosis, the present study was aimed to define resistance to both these drugs.

METHODS

Fifty Mycobacterium tuberculosis isolates, consisting of 30 ofloxacin-susceptible and 20 ofloxacin-resistant strains, were tested for their susceptibility to gatifloxacin and moxifloxacin using different susceptibility testing methods, namely the absolute concentration method on Lowenstein-Jensen medium (LJ), the proportion susceptibility testing method (PST) on LJ and 7H11 agar media, and the BACTEC radiometric method.

RESULT

The minimal inhibitory concentration (MIC) of gatifloxacin and moxifloxacin was 1 microg/ml by the absolute concentration method on LJ. In the PST method on LJ and 7H11, using a criterion of > or =1% growth as resistant, there was 100% agreement with the absolute concentration method at a concentration of 0.5 microg/ml for gatifloxacin, and 96% agreement with the BACTEC method at a concentration of 0.25 microg/ml. For moxifloxacin, results by the PST method showed 96% agreement with the absolute concentration method on LJ at a concentration of 1 microg/ml and 92% agreement at a concentration of 0.5 microg/ml for both the absolute concentration method on 7H11 and the BACTEC method.

CONCLUSIONS

The MICs of gatifloxacin and moxifloxacin were much lower than the MICs of other quinolones like ofloxacin and ciprofloxacin. Additionally, these two drugs have shown a low mean MIC and low concentration as a definition of resistance, which might help in treating the patients with low levels of quinolone resistance.

Tuberculosis of the chest

The relationship between tuberculosis and mankind has been known for many centuries, with the disease being one of the major causes of illness and death. During the early 1980s, there was a widespread belief that the disease was being controlled, but by the mid-1980s, the number of cases increased. This change in the epidemiological picture has several causes, of which the AIDS epidemic, the progression of poverty in developing countries, the increase in the number of elderly people with an altered immune status and the emergence of multidrug-resistant tuberculosis are the most important. Mainly due to this epidemiological change, the radiological patterns of the disease are also being altered, with the classical distinction between primary and postprimary disease fading and atypical presentations in groups with an altered immune response being increasingly reported. Therefore, the radiologist must be able not only to recognize the classical features of primary and postprimary tuberculosis but also to be familiar with the atypical patterns found in immuno-compromised and elderly patients, since an early diagnosis is generally associated with a greater therapeutic efficacy. Radiologists are, in this way, presented with a new challenge at the beginning of this millennium.

Características clínicas e epidemiológicas do adulto contagiante da criança com tuberculose

INTRODUÇÃO: A tuberculose em crianças geralmente está associada ao convívio com um adulto contagiante. OBJETIVO: Descrever o perfil do adulto contagiante da criança com tuberculose identificada na rede pública de saúde. MÉTODO: Estudo de casos. Incluiram-se todas as crianças menores de quatorze anos com diagnóstico de tuberculose em tratamento na rede pública de saúde de Porto Alegre (RS). Foram feitas entrevistas com questionário estruturado com dados demográficos e da doença na criança e no contagiante. RESULTADOS: No período de 21 de julho de 2001 a 10 de agosto de 2002 foram selecionadas 50 crianças (96% dos diagnósticos em crianças no período) com média de idade de 76 meses, 60% do sexo feminino. As formas pulmonares clássicas (consolidação ou cavitação) foram observadas em 38% das crianças. A maioria dos pacientes fez o diagnóstico em nível hospitalar, vivia em famílias com seis pessoas em média, e com renda familiar inferior a dois salários mínimos regionais. A co-infecção pelo vírus da imunodeficiência humana foi identificada em 25% dos pacientes que realizaram o teste de ELISA. As crianças freqüentavam regularmente outro local além de sua residência. O contagiante foi identificado em 78% dos casos, sendo 56% do sexo masculino, com idade média de 32 anos e na maioria das vezes era um parente (79%), geralmente pai ou mãe. Neste grupo de adultos, a co-infecção pelo vírus da imunodeficiência humana foi identificada em 43% dos indivíduos testados. CONCLUSÃO: O contato intradomiciliar com adulto tuberculoso continua a ser a mais importante fonte de contágio para a criança. A co-infecção pelo vírus da imunodeficiência humana é um importante achado tanto na criança quanto no adulto. Enfatiza-se a necessidade de se investigar a criança contato e se buscar o caso índice em toda criança com diagnóstico de tuberculose.

Characteristics of pulmonary tuberculosis in HIV seropositive and seronegative patients in a Northeastern region of Brazil

The aim of this study was to analyse the clinical, epidemiological and bacteriological features present in 60 pulmonary tuberculosis patients who were also infected with human immunodeficiency virus (HIV) and to compare these with 120 TB patients who were not infected with HIV. The patients with pulmonary tuberculosis and HIV coinfection were mostly male (p = 0.001), showed a higher frequency of weight loss >10 kilos (p <0.001), had a higher rate of non-reaction result to the tuberculin skin test (p <0.001), a higher frequency of negative sputum smear examination for acid-fast bacilli (p = 0.001) and negative sputum culture for Mycobacterium tuberculosis (p = 0.001). Treatment failure was more common in those who were HIV positive (p <0.000). No higher frequency of resistance to antituberculosis drugs was found to be associated with TB/HIV coinfection (p = 0.407). Association between extrapulmonary and pulmonary tuberculosis was more frequent in those seropositive to HIV than those without HIV virus, 30% and 1.6% respectively. These findings showed a predominance of atypical clinical laboratory features in co-infected patients, and suggest that health care personnel should consider the possibility this diagnosis.

Evaluation of the concentration sputum smear technique for the laboratory diagnosis of pulmonary tuberculosis

The microbiological diagnosis of pulmonary tuberculosis (PTB) plays a key role in routine and Tuberculosis (TB) Control Programmes in developing countries. Concentration of acid-fast bacilli (AFB) in clinical specimens is an important step in the laboratory diagnosis of mycobacterial diseases. Microscopy of smears of sputum by direct and after mechanical sedimentation and centrifugation methods followed by treatment with 5% sodium hypochlorite (NaOCl) solution for concentration of the organisms were compared and evaluated. The rate of recovery of AFB from sputum was 8.5%, 25.5% and 38.0% for direct smear microscopy, concentration by sedimentation of NaOCl-treated sputa followed by Ziehl-Neelsen staining and concentration by centrifugation after use of NaOCl respectively. Both the concentration methods by the use of NaOCl solution increased the yield of theAFB by more than threefold compared with the direct microscopy of sputum (P < 0.05). The concentration methods by sedimentation, and centrifugation by the treatment of NaOCl, increased the sensitivity to 75% and 77.9%, respectively, and the specificity to 100% for both techniques. In conclusion, the use of NaOCl in the concentration of AFB in sputum is recommended for use in routine laboratory diagnosis of PTB in developing countries.

Second episode of tuberculosis in an HIV-infected child: relapse or reinfection?

We report a case of an HIV-infected child with a second episode of tuberculosis 22 months after completing antituberculosis treatment. DNA fingerprinting of organisms from both episodes showed an identical strain of Mycobacterium tuberculosis. We believe this to be the first case of confirmed relapsed tuberculosis in an HIV-infected child, and suggest that a longer course of antituberculosis treatment be given to such children. ¿ 2000 The British Infection Society.

Acquired immunodeficiency syndrome (AIDS) of the abdominal organs: imaging features

The liver, spleen, biliary tract, pancreas, and kidneys are commonly affected by opportunistic infection, malignancy, and inflammatory disorders during the course of human immunodeficiency virus (HIV) infection. Clinical manifestations of solid abdominal visceral involvement are protean and usually nonspecific, but it is important to establish a specific diagnosis promptly in these often critically ill patients. This presentation reviews the cross-sectional imaging spectrum of HIV-associated lesions of these organs.