S. Gathua

Increased recurrence of tuberculosis in HIV-1-infected patients in Kenya

There is evidence that in human immunodeficiency virus 1 (HIV-1) infected patients with tuberculosis the rate of recurrence of tuberculosis is increased in those patients treated with a standard thiacetazone-containing regimen. To assess the impact of HIV-1 on tuberculosis in Kenya, patients with tuberculosis were studied prospectively. After treatment with either a standard thiacetazone plus isoniazid regimen or a short-course thiacetazone-containing regimen, overall recurrence rate of tuberculosis was 34 times greater in 58 HIV-1-positive patients than in 138 HIV-1-negative patients (adjusted rate ratio 33.8, 95% CI 4.3-264). Recurrence in the HIV-1-positive group was strongly associated with a cutaneous hypersensitivity reaction due to thiacetazone during initial treatment (rate ratio 13.2, 95% CI 3.1-56.2). In all patients with a cutaneous hypersensitivity reaction ethambutol was substituted for thiacetazone. No significant association was found between recurrence among HIV-1-positive patients and initial resistance, initial treatment regimen, a diagnosis of AIDS (WHO definition), or poor compliance. DNA fingerprinting suggested that both relapse and new infection may have produced recurrence of tuberculosis. In patients who had a cutaneous hypersensitivity reaction, increased recurrence rate may have been related to interruption of treatment, subsequent poor compliance, or more advanced immunosuppression. Alternatively, a change to the combination of ethambutol and isoniazid in the continuation phase for 11 months only may not be adequate.

Cohort study of HIV-positive and HIV-negative tuberculosis, Nairobi, Kenya: comparison of bacteriological results

We have set up a cohort of human immunodeficiency virus (HIV) positive and negative patients with tuberculosis in order to address the problems associated with HIV-related tuberculosis. We present here the results of sputum smear microscopy, culture, mycobacterial identification tests and drug susceptibility assays from specimens taken at presentation. In this selected population of largely pulmonary tuberculosis cases, HIV infection is not associated with significant differences in sputum smear positivity rate, culture positivity rate or initial drug resistance. No atypical mycobacteria were found. Direct sputum smear examination remains specific for the diagnosis of tuberculosis in Kenya in spite of the presence of HIV. HIV infection was not associated with an increase in the proportion of pulmonary cases still culture-positive at 6 months. However a significant increase in the proportion of cases still culture-positive at 6 months was seen in those with initially resistant strains and also in those treated with standard regimen (streptomycin, thiacetazone and isoniazid for 1 month followed by thiacetazone and isoniazid for 11 months, 1STH/11TH) rather than a short-course, rifampicin-containing regimen (rifampicin, pyrazinamide and isoniazid for 2 months, together with streptomycin for the first month and followed by 6 months of thiacetazone and isoniazid, SHRZ/6TH).

Cross-sectional survey of HIV infection among patients with tuberculosis in Nairobi, Kenya.

Evidence from many countries suggests an association of human immunodeficiency virus (HIV) infection and tuberculosis of major public health significance. In order to begin assessing the impact of HIV on tuberculosis in Kenya, we have determined the HIV-1 seroprevalence among tuberculosis patients and compared the clinical characteristics of tuberculosis in HIV-positive and HIV-negative patients in two cross-sectional studies at the Infectious Disease Hospital (IDH) and the Ngaira Avenue Chest Clinic (NACC), Nairobi, Kenya. The diagnosis in 92% of all patients with pulmonary tuberculosis was confirmed by culture. The remainder were diagnosed on histological, clinical or radiological grounds. HIV seroprevalence among tuberculosis patients at IDH was 26.5% (52/196) compared to 9.2% (18/195) at NACC (P less than 0.001). There was no association between numbers of streptomycin injections in the previous 5 years and HIV infection. Positive sputum smear rates in HIV-positive patients were slightly lower than in HIV-negative patients at both study sites (71% vs 83% at IDH and 73% vs 82% at NACC) but the difference was not significant. Only Mycobacterium tuberculosis was isolated. Miliary disease was not associated with HIV infection. Persistent diarrhoea, oral candidiasis, generalized itchy rash, herpes zoster and generalized lymphadenopathy were all associated with HIV infection, but 46% (95% CI:38-54%) of all HIV-positive patients had none of the clinical features listed in the WHO Clinical Criteria for the Diagnosis of AIDS, apart from fever, cough and weight loss. Stevens-Johnson Syndrome was reported in 7/52 (13%) patients with HIV infection, and in 4/144 (3%) patients without (RR 4.85, 95% CI: 1.45-15.88).(ABSTRACT TRUNCATED AT 250 WORDS)

Impact of human immunodeficiency virus on transmission and severity of tuberculosis

It is now clear that tuberculosis is one of the major diseases associated with human immunodeficiency virus (HIV) infection and the acquired immune deficiency syndrome both in developing countries and in disadvantaged groups in the northern hemisphere. In the USA, and probably several other countries, the annual incidence of tuberculosis is rising as a result of the HIV epidemic. This is probably a result of an increase in both pulmonary and, especially, extrapulmonary tuberculosis, due to reactivation of latent infections, but a secondary increase in the infection rate is also possible. The hard-won gains in tuberculosis control of the last 30 years are thus in jeopardy. This article focuses on the effect HIV is likely to have on the known risk factors for infection with Mycobacterium tuberculosis and for reactivation. Whilst HIV-associated tuberculosis may be indistinguishable from HIV-negative disease, it is likely in other cases to present diagnostic difficulties, to respond poorly to treatment with more adverse effects, and to result in high early mortality, although this may not be due directly to tuberculosis. HIV-associated tuberculosis thus represents a major challenge to physicians, especially in developing countries, but like other forms of tuberculosis it is (i) treatable and (ii) preventable.

Tuberculosis and HIV Infection in Kenya

To the Editors: In his editorial (1), Dr. Pitchenik expresses fears that the heavy reliance placed in developing countries on chest radiography and sputum smears for the diagnosis of pulmonary tube...

No increased prevalence of adrenocortical insufficiency in human immunodeficiency virus-associated tuberculosis

SETTING Acute medical wards, Kenyatta National Hospital, Nairobi, Kenya. OBJECTIVE To determine the prevalence of adrenocortical insufficiency in human immunodeficiency virus (HIV)-1 infected and non-infected patients with tuberculosis. DESIGN One hundred and seventy-four patients with proven tuberculosis (90 HIV-1 positive and 84 HIV-1 negative) were assessed for adrenocortical insufficiency with a 30 min synacthen stimulation test. RESULTS Fifty-one percent of those with pulmonary tuberculosis and 56% of those with extra-pulmonary tuberculosis had a subnormal cortisol response. However there was no statistically significant difference between the HIV-1 infected and non-infected patients in either group. CONCLUSION While an impaired cortisol response is common in tuberculosis, it is no more prevalent in HIV-1 infected patients than non-infected patients with tuberculosis.