The acquired immune deficiency syndrome: with special reference to tuberculosis

Prevalence of HIV-1 infection among patients with leprosy and pulmonary tuberculosis in a semi-arid region, Nigeria

Much evidence exists on pulmonary tuberculosis (PTB) as a presenting feature of HIV infection or AIDS-related complex, while few reports exist of a direct association between HIV infection and leprosy. This study was carried out to see whether or not an association between leprosy and HIV infection existed, similar to that of PTB in the region of Maiduguri, Nigeria. Of 105 patients with leprosy, 11(10.5%) were positive for HIV antibody. Of 58 patients with suspected PTB, 11(19%) were positive for HIV antibody. Twenty-seven (47%) of the 58 had active PTB, with results of sputum smear and culture positive for mycobacterium, and six of these (22.2%) were also positive for HIV antibody. Odds ratios (OR) obtained by conditional logistic regression (matched) analysis were 3.52 (95%, CI 1.03-12.07) and 2.53 (95%, CI 1.04-6.15) for association between HIV-1 and PTB and leprosy, respectively. HIV infection was more prevalent among leprosy patients aged under 30 years, OR = 4.25 (95%, CI 1.25-14.42). The prevalence of HIV-1 infection was at borderline significance, higher in PTB and leprosy patients than in blood donors, Fisher's exact test (two-tailed) p = 0.07 and p = 0.05, respectively.

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.

The epidemiology of Mycobacterium bovis infections in animals and man: a review

Tuberculosis is primarily a respiratory disease and transmission of infection within and between species is mainly by the airborne route. Mycobacterium bovis, the cause of bovine-type tuberculosis, has an exceptionally wide host range. Susceptible species include cattle, humans, non-human primates, goats, cats dogs, pigs, buffalo, badgers, possums, deer and bison. Many susceptible species, including man, are spillover hosts in which infection is not self-maintaining. In countries where there is transmission of infection from endemically infected wildlife populations to cattle or other farmed animals, eradication is not feasible and control measures must be applied indefinitely. Possible methods of limiting spread of infection from wildlife to cattle including the use of vaccines are outlined. The usefulness of DNA fingerprinting of M. bovis strains as an epidemiological tool and of BCG vaccination of humans and cattle as a control measure are reviewed. The factors determining susceptibility to infection and clinical disease, and the infectiousness of infected hosts and transmission of infection, are detailed. Reports of the epidemiology of M. bovis infections in man and a variety of animal species are reviewed. M. bovis infection was recognised as a major public health problem when this organism was transmitted to man via milk from infected cows. The introduction of pasteurization helped eliminate this problem. Those occupational groups working with M. bovis infected cattle or deer, on the farm or in the slaughter house, are more likely to develop pulmonary disease than alimentary disease. In recent years, tuberculosis in farmed cervidae has become a disease of economic as well as public health importance in several countries. Nowadays, the human immunodeficiency virus (HIV) is associated with a greatly increased risk of overt disease in humans infected with Myobacterium tuberculosis. It is believed this increased risk also occurs in the case of M. bovis infections in humans.

Current and potential treatment of tuberculosis

A recent resurgence of interest in tuberculosis as a global health problem has accompanied the resurgence of tuberculosis in both industrialised and developing countries. It has also been demonstrated recently that tuberculosis treatment and control is one of the most cost effective of all medical interventions. The human immunodeficiency virus (HIV) epidemic and increasing resistance to antituberculous drugs complicate our response to the problem of tuberculosis. Chemotherapy with currently available agents is highly effective, not only in pulmonary tuberculosis in adults, but also in extrapulmonary disease, and in disease in children and even patients with concomitant HIV infection. Short course chemotherapy and intermittent therapy are as effective as older regimens. Measures, including directly observed therapy, to maximise compliance with therapy, are of utmost importance. An efficient programme which assures compliance with effective antituberculosis chemotherapy should be a priority for health spending even in those countries with fewest resources.

Deaths from pulmonary tuberculosis in a low-incidence country

OBJECTIVES

To study the validity of official mortality statistics regarding deaths from pulmonary tuberculosis, and to identify factors contributing to death.

DESIGN

A retrospective study.

SETTING

Cases were enrolled from the data of the Central Bureau of Statistics from where the official mortality statistics are issued, the National Tuberculosis Register and all Autopsy Registers in the region.

SUBJECTS

Case and autopsy reports from all patients who died from active pulmonary tuberculosis in two Norwegian counties between 1977 and 1989.

MAIN OUTCOME MEASURES

Patients identified from all three registers with active pulmonary tuberculosis, concomitant diseases/risk-factors, chest X-rays, symptoms, number of patients investigated and treated for tuberculosis, duration from hospital admission until start of treatment and/or death.

RESULTS

Ninety-six patients, median age 75 years, died from pulmonary tuberculosis, 51 without treatment. Thirty-four patients had not been registered at the Central Bureau of Statistics. Thirty-nine patients had cough on admission. Weight loss and generalized malaise occurred just as frequently. Forty-two patients had infiltrates on chest X-ray located elsewhere than in the apical region. In 42 patients, no diagnostic tests for tuberculosis were performed. The median length of stay in hospital was 24 days before death in the untreated group, and 21 days before start of treatment in the treated group.

CONCLUSION

Reliable figures of patients who died from pulmonary tuberculosis could not be obtained from the official statistics because of under-notification and erroneous codification of diseases. Deaths occurred mainly because the diagnosis was established too late: in half of the patients at autopsy. Eighty-one patients had concomitant diseases known to lower resistance against tuberculosis. Lack of diagnostic suspicion may have been caused by nonspecific symptoms and atypical chest X-ray findings.

The association of tuberculosis and HIV infection in Harare, Zimbabwe

SETTING

The tuberculosis (TB) service responsible for all TB treatment in Harare, Zimbabwe.

OBJECTIVES

(1) To determine HIV seroprevalence among TB patients and controls. (2) To compare clinical and demographic characteristics of HIV-infected and uninfected TB patients.

DESIGN

Cohort study. Entry criterion: TB diagnosed during the 18 month study period. Assessment included HIV serology. Matched community controls were HIV serotested.

RESULTS

In 1434 TB patients tested, HIV seroprevalence was 48% in men and 44% in women, peaked in the 25-34 year age group and was higher than in controls (relative risk [RR] = 3.1, 95% confidence interval [CI] = 2.6-3.7). In adults, seroprevalence was 34%, 49% and 58% in successive 6 month periods. A history of entry of prior TB treatment was less common in the HIV-seropositive (RR = 0.57, CI = 0.37-0.88). In adults, tuberculin negativity, TB at 2 sites, lymph node, pericardial and miliary TB, hilar adenopathy and pleural effusion were significantly more common in HIV-seropositive patients; cavitation and upper lobe involvement were significantly less frequent. Pulmonary TB and sputum smear positivity had similar frequencies in the 2 groups.

CONCLUSION

HIV was strongly and increasingly associated with TB in Harare and altered the clinical and radiologic features of TB. Failed standard TB treatment in HIV-infected individuals contributed minimally to new cases of TB.

Tuberculosis and HIV infection association in a rural district of northern Uganda: epidemiological and clinical considerations

59 (18.3%) of 323 patients with tuberculosis (TB) tested for HIV-1 antibody by ELISA technique (Wellcozyme) were seropositive. In the control group selected among the health personnel working in the Arua Hospital, 7.7% were found positive for HIV-1 antibody, thus showing a significantly lower prevalence compared with the TB patients (P < 0.005). The prevalence of HIV infection was 50% in the urban TB patients, 7% in TB patients living in rural areas surrounding Arua town and 1.6% in the peripheral rural setting. Of 27 TB patients with clinical AIDS, 18 died during the course of the study. The AIDS patients' survival rate was 46.4% 6 months after diagnosis, and 21.4% after 16 months, the median period of survival being 5.0 months. Risk factors, sputum conversion rate, clinical and radiological findings were analysed. No significant difference was found between seropositive and seronegative TB patients for clinical drug-related toxicity (P > 0.05).

Sero-diagnosis of tuberculosis with A60 antigen enzyme-linked immunosorbent assay: failure in HIV-infected individuals in Ghana

In order to assess the diagnostic usefulness of the A60 (ANDA Biological, Strassbourg, France) sero-diagnostic enzyme-linked immunosorbent assay (ELISA) kit for tuberculosis in Africa, sera of 53 pulmonary smear-positive tuberculosis (TB) patients, 30 apparently healthy control subjects and 6 AIDS suspects were sampled in Agogo Hospital in the forest area of Ghana. These sera were analyzed for antibodies to HIV-1 and HIV-2, and IgG-antibodies to the A60 BCG-antigen, while the non-HIV individuals were tested for total IgG levels. One healthy control subject, all of 6 AIDS suspects and 7 of the TB patients has HIV infections. In the non-HIV TB group, the sensitivity and specifity of the A60 ELISA was 78% and 86%, respectively, which was much poorer than expected from published reports about the A60 test. The A60 test failed, completely however, to discriminate between TB and non-TB in the HIV-positive group. In the non-HIV groups, total IgG levels were significantly higher in TB patients than in controls. It seems that the usefulness of the A60 ELISA test to diagnose tuberculosis is very limited in this high-incidence area, and that it seems to be of no value in patients infected with HIV.

Miliary tuberculosis presenting as skin lesions in a patient with acquired immunodeficiency syndrome

Acute miliary tuberculosis of the skin is an extremely rare infection that occurs in immunocompromised persons. We report an intravenous drug abuser with human immunodeficiency virus infection in whom erythematous papules developed on the trunk and proximal aspect of the extremities. Visceral lesions of unsuspected miliary tuberculosis were discovered at autopsy, and the cutaneous papules were found to contain Mycobacterium tuberculosis. This is the first reported case of this cutaneous infection in a patient with the acquired immunodeficiency syndrome.

The present and the future of AIDS and tuberculosis in Illinois

The relation between the acquired immune deficiency syndrome (AIDS) and tuberculosis (TB) was examined by matching the Illinois AIDS and TB registries. The match group was examined and compared with patients with only one disease by race, method of human immunodeficiency virus (HIV) transmission, site of tuberculous disease, radiographic findings, and results of Mantoux tests. The time of TB diagnosis was centrally distributed around the time of AIDS diagnosis; from this, it was determined that 4.1 percent of AIDS patients develop active TB. Projections for future AIDS cases were made by fitting a polynomial model to historical data. These projections were then used to predict the future impact of AIDS-related TB upon state TB rates. The rise in TB rates call for special efforts to minimize this impact.

Mycobacterial disease, immunosuppression, and acquired immunodeficiency syndrome

The mycobacteria are an important group of acid-fast pathogens ranging from obligate intracellular parasites such as Mycobacterium leprae to environmental species such as M. gordonae and M. fortuitum. The latter may behave as opportunistic human pathogens if the host defenses have been depleted in some manner. The number and severity of such infections have increased markedly with the emergence of the acquired immunodeficiency syndrome (AIDS) epidemic. These nontuberculous mycobacteria tend to be less virulent for humans than M. tuberculosis, usually giving rise to self-limiting infections involving the cervical and mesenteric lymph nodes of young children. However, the more virulent serovars of M. avium complex can colonize the bronchial and intestinal mucosal surfaces of healthy individuals, becoming virtual members of the commensal gut microflora and thus giving rise to low levels of skin hypersensitivity to tuberculins prepared from M. avium and M. intracellulare. Systemic disease develops when the normal T-cell-mediated defenses become depleted as a result of old age, cancer chemotherapy, or infection with human immunodeficiency virus. As many as 50% of human immunodeficiency virus antibody-positive individuals develop mycobacterial infections at some time during their disease. Most isolates of M. avium complex from AIDS patients fall into serotypes 4 and 8. The presence of these drug-resistant mycobacteria in the lungs of the AIDS patient makes their effective clinical treatment virtually impossible. More effective chemotherapeutic, prophylactic, and immunotherapeutic reagents are urgently needed to treat this rapidly increasing patient population.