Prevalence of smear-positive pulmonary tuberculosis among prisoners in Malawi: a national survey.

A cross-sectional cell-to-cell survey was conducted in 18 of 22 prisons in Malawi to determine the period prevalence of smear-positive pulmonary tuberculosis (PTB). In each prison, prisoners were interviewed using a structured questionnaire. Prisoners with cough of >1 week's duration were investigated by sputum smear examination. Of 7661 prisoners, 3887 had cough of > or =1 week, of whom 3794 submitted three sputum specimens: 54 (0.7%) had smear-positive PTB. The prevalence of PTB was higher in large urban prisons (1.1%) than in district prisons (0.3%, P < 0.001). More needs to be done to improve TB control in urban prisons.

Short communication: antituberculosis drug-induced hepatotoxicity is unexpectedly low in HIV-infected pulmonary tuberculosis patients in Malawi.

The proportion of patients with antituberculosis drug-induced hepatotoxicity (ATDH) was unexpectedly low during a trial on cotrimoxazole prophylaxis in Malawian HIV-positive pulmonary tuberculosis patients. About 2% of the patients developed grade 2 or 3 hepatotoxicity during tuberculosis (TB) treatment, according to WHO definitions. Data on ATDH in sub-Saharan Africa are limited. Although the numbers are not very strong, our trial and other papers suggest that ATDH is uncommon in this region. These findings are encouraging in that hepatotoxicity may cause less problem than expected, especially in the light of combined HIV/TB treatment, where drug toxicity is a major cause of treatment interruption.

Viability of stored sputum specimens for smear microscopy and culture.

A laboratory study was performed to determine how long sputum specimens from smear-positive tuberculosis patients can be stored at room temperature or in the refrigerator and retain a positive acid-fast bacilli (AFB) smear or a positive mycobacterial culture. Sputum samples from 30 patients were examined up to 4 weeks and samples from 13 patients examined up to 8 weeks. Provided samples had not dried out, all sputum smears remained AFB positive up to 4 and 8 weeks. In both patient groups, at 4 weeks 37-39% of specimens at room temperature grew mycobacteria compared with 54-67% of specimens stored in the refrigerator. These results have implications for tuberculosis programme policy.

Care seeking behaviour and diagnostic processes in patients with smear-positive pulmonary tuberculosis in Malawi.

SETTING: Government hospitals in five districts in Malawi. OBJECTIVE: To determine care seeking behaviour and diagnostic processes in patients newly diagnosed with smear-positive pulmonary tuberculosis (PTB). DESIGN: Structured questionnaires completed by interview between January to September 1998. RESULTS: During the study period 1,518 patients were registered with PTB, of whom 1,099 (72%) were interviewed. The median delay between onset of cough and diagnosis was 8 weeks. There was a variable pattern of care seeking behaviour, with 70% of patients initially visiting a place of orthodox medical care and 30% visiting traditional healers, grocery shops, etc. Of these, 867 (79%) patients had one or more subsequent contacts for help, with these visits targeted more to orthodox medical care. At all stages, antibiotics resulted in symptomatic improvement in up to 40% of cases. There was a median time of 7 weeks between cough and first submission of sputum specimens. Almost all patients received sputum smear results after a median length of 4 days; 474 (43%) of patients were only aware of their diagnosis at the time of receiving smear results, this observation being significantly associated with lack of schooling and not knowing another person with TB. CONCLUSION: More needs to be done to educate communities and non-orthodox care providers about the diagnosis and treatment of TB.

Management of pulmonary tuberculosis suspects with negative sputum smears and normal or minimally abnormal chest radiographs in resource-poor settings.

SETTING: Queen Elizabeth Central Hospital, Blantyre, Malawi. OBJECTIVES: 1) To determine the proportion of pulmonary tuberculosis (PTB) suspects with negative sputum smears and a normal/minimally abnormal chest radiograph (CXR) who are culture-positive for Mycobacterium tuberculosis, and 2) to determine how many develop smear or radiographic evidence of PTB (TB CXR) during follow-up. METHODS: PTB suspects with negative sputum smears and a normal/minimally abnormal CXR were given a second course of antibiotics and followed up at 3-week intervals over 3 months with repeat sputum smears and chest radiography. RESULTS: Of 79 patients (38 men and 41 women, mean age 33 years) with negative smears and a normal/minimally abnormal CXR, 16 (21%) were culture-positive for M. tuberculosis. Of 15 culture-positive patients who were alive and attended follow-up, seven (47%) developed a TB-CXR by 3 months. Of 41 culture-negative patients who were alive and attended follow-up, 13 (32%) developed a TB-CXR, including one patient who became sputum smear-positive. TB-CXRs were found only in patients with a cough. CONCLUSION: TB suspects with negative smears and normal/minimally abnormal CXRs in high human immunodeficiency virus (HIV) prevalent countries should be given a second course of antibiotics. If cough improves, patients can be advised not to return for further follow-up. If cough continues, patients should return for further follow-up with sputum smear examination and chest radiography. Approximately 50% of those who have culture-positive PTB will develop a TB-CXR by 3 months and can be identified if radiographic facilities are available.

Prevalence of tuberculosis in TB suspects with short duration of cough.

The prevalence of pulmonary tuberculosis (PTB) in patients with short duration of cough was determined. Ninety-eight adult out-patients (60 men, 38 women; mean age 32 years) at Queen Elizabeth Central Hospital, Blantyre, Malawi, who had cough for 1-3 weeks which was unresponsive to a course of antibiotics, were successfully screened by microscopy and culture of 2 or 3 sputum specimens and chest radiography; 34 (35%) had PTB. Ten patients were sputum smear-positive and 24 were smear-negative and culture-positive. There was no difference in age, gender or clinical features of general illness, respiratory disease and HIV-related disease between patients with PTB and those with no evidence of PTB. Nine patients (26%) with microbiologically confirmed tuberculosis (TB) had chest radiograph abnormalities consistent with TB, compared with 5 (8%) of patients with no microbiological evidence of TB. Certain classes of patients with a short history of cough would benefit from PTB screening strategies with the emphasis on sputum examination rather than chest radiography, which is unreliable in such patients. The classes include (i) patients with other features of TB whose cough has not improved with antibiotic therapy, (ii) seriously ill patients, and (iii) patients in high risk institutions such as prisons and refugee camps.