Reviews

The Impact of Human Immunodeficiency Virus Infection on Tuberculosis and Its Control

HIV and tuberculosis co-infection interact in fundamentally important ways. This interaction is evident patho-physiologically, clinically and epidemiologically. There are several differences between HIV-infected and HIV-uninfected patients with tuberculosis (TB) that have practical diagnostic implications. TB is more likely to be disseminated in nature and more difficult to diagnose by conventional diagnostic procedures as immunosuppression progresses. As TB rates continue to increase in HIV-endemic regions, improved diagnostic techniques merit consideration as TB-control strategies. There is a need to develop more user friendly techniques, which can be adapted for use in the high-burden and low-income countries. This review focuses on the diagnostic challenges in HIV–TB co-infection with an update on the current techniques and future prospects in an era of HIV pandemic.

While pulmonary Mycobacterium tuberculosis infections are recognized for their public health implications, less is known about the infectiousness of extrapulmonary tuberculosis, specifically, spinal tuberculosis or Pott's disease. We present a case of spinal tuberculosis with concomitant active pulmonary tuberculosis in the absence of chest radiographic abnormalities or symptoms, and review the literature regarding infectiousness of concomitant spinal and pulmonary tuberculosis.

En España, la tuberculosis es una enfermedad con importante relevancia en la práctica clínica diaria. En ocasiones su diagnóstico sorprende como hallazgo en la necropsia. El objetivo de este trabajo ha sido analizar las características clínico-anatomopatológicas que presentan los pacientes diagnosticados de tuberculosis activa en la necropsia.

Se revisaron retrospectivamente todas las autopsias de adultos realizadas en el Hospital Universitario 12 de Octubre de Madrid entre los años 1974 y 2002. En aquellos pacientes en los que se llegó al diagnóstico de tuberculosis activa se revisó la historia clínica y el informe anatomopatológico según protocolo establecido previamente.

Se encontraron 92 casos de tuberculosis activa. El 57% correspondía a hombres. La edad media de los pacientes era de 64 años. El 90% de los casos presentaba alguno de los factores predisponentes controlados. El 20% falleció en las primeras 48 horas tras el ingreso. Los motivos de consulta más frecuentes fueron la disnea (24% de los casos) y el síndrome constitucional (23%). Hasta el 30% de los casos presentaba una radiografía de tórax normal a su ingreso. Sólo en el 46% de los casos se sospechó la tuberculosis previa al fallecimiento y en el 61% fue ésta la causa del éxitus. El 52% presentaba una tuberculosis pulmonar, el 28% una tuberculosis miliar y el 20% extrapulmonar. El órgano más frecuentemente afectado fue el pulmón. En los 92 casos se encontraron granulomas epitelioides.

La tuberculosis es en España una causa poco frecuente de muerte en la autopsia. La presencia de sintomatología inespecífica, la escasa rentabilidad de las pruebas diagnósticas y el fallecimiento precoz hacen que un importante porcentaje de casos de tuberculosis lleguen sin diagnóstico a la necropsia.

Tuberculosis is an infectious disease currently having great importance in the daily clinical practice in Spain. Some cases of active tuberculosis are not identified until after the patient had died and an autopsy has been performed. This study has analyzed the clinical and pathological characteristics of patients diagnosed with active tuberculosis in the autopsy.

We reviewed all the autopsies performed in the University Hospital 12 de Octubre of Madrid between 1974 and 2002. The autopsy reports and clinical records were examined in those cases in which active tuberculosis was found.

We found 92 cases of active tuberculosis, 57% corresponding to men. Mean age of this group was 64 years. A total of 20% of the patients died within 48 hours after admission. Predisposing factors were identified in 90% of the cases. Dyspnea (24% of cases) and wasting syndrome (23%) were the main symptoms that motivated patients to request medical attention. Up to 30% of cases had normal chest X-ray. Tuberculosis was suspected in only 46% of patients before death. Principal cause of death was tuberculosis in 61% of patients, 52% of patients had pulmonary tuberculosis, 28% suffered from miliary tuberculosis and 20% from extra-pulmonary tuberculosis. The lungs were the most frequently affected organ. Epithelioid granulomas were found in all patients.

Tuberculosis is an uncommon finding in the autopsy as the cause of death. The presence of unspecific symptomatology, insufficient costeffectiveness of the diagnostic tests and precocious death, are identified as the most frequent causes of undiagnosed tuberculosis.

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.

Tuberculosis of muscles without coexistent active skeletal or extraskeletal involvement is very rare. A case of tuberculous abscess of biceps brachii muscle in a young immunocompetent male is presented. A good response was seen with antitubercular treatment. Tuberculosis should be considered in the differential diagnosis of any unexplained soft tissue swelling in people born in tubercular endemic areas, who are immunosuppressed or had an injury to the affected area.

To describe the early symptoms of pulmonary tuberculosis (TB) when the chest radiograph (CXR) is normal.

Centralized, provincial TB control program.

Twenty-five patients with culture-positive pulmonary TB and a normal CXR were identified from a review of 518 consecutive patients with culture-positive pulmonary TB in the province of Saskatchewan from January 1, 1988 to March 31, 1997. Patients with abnormal CXRs at the time of diagnosis were excluded from the analysis.

Twenty-three of the 25 patients (92%) were symptomatic at the time of diagnosis, with cough/sputum (76%) being reported most commonly. Eleven patients were identified because of contact tracing from cases of infectious pulmonary TB, while the other 14 patients were identified because of an investigation of symptoms. Twenty-four patients (96%) exhibited one or more symptoms of cough for > 1 month, fever for > 1 week, or skin-test conversion after contact with infectious TB. The sputum smear of only one patient was positive. Two patients were pregnant at the time of diagnosis, one patient was HIV-positive, and one patient demonstrated isoniazid-resistant organisms on sensitivity testing. Five patients were diagnosed as having primary TB associated with Mantoux skin-test conversion. The incidence of culture-positive pulmonary TB with a normal chest radiograph was < 1% in the period from 1988 to 1989 and steadily increased to 10% in the period from 1996 to 1997.

Culture-positive pulmonary TB with a normal CXR is not uncommon, and the incidence of this presentation is increasing. Patients with this presentation of TB are typically symptomatic and/or are detected by contact tracing to infectious cases of pulmonary TB. The results suggest that patients presenting with a cough for > 1 month, with a fever for > 1 week, or with documented skin-test conversion < 2 years after known exposure to infectious TB should have sputum submitted for a Mycobacterium tuberculosis smear and culture despite a normal CXR.