A.D. Harries

Treatment outcome of an unselected cohort of tuberculosis patients in relation to human immunodeficiency virus serostatus in Zomba hospital, Malawi

There is little information about treatment outcome in patients with smear-negative pulmonary tuberculosis (PTB) or extrapulmonary tuberculosis (EPTB) treated under routine programme conditions in subsaharan Africa. A prospective study was carried out to determine treatment outcome in an unselected cohort of TB patients admitted to Zomba General Hospital, Malawi. Eight hundred and twenty-seven adult TB patients (451 men and 376 women) were registered between 1 July and 31 December 1995. Standardized treatment outcomes of treatment completion, death, default, and transfer to another district were assessed in relation to type of TB, human immunodeficiency virus (HIV) serostatus, age and gender. Two hundred and fifty-four patients (31%) died by the end of treatment, half of the deaths occurring in the first month. Death rates were 19% among 386 patients with smear-positive PTB, 46% among 211 patients with smear-negative PTB, and 37% among 230 patients with EPTB; 77% of the patients were HIV seropositive. Among new patients, HIV-positive patients had higher death rates than HIV-negative patients (hazard ratio [HR] 2.5; 95% confidence interval [95% CI] 1.6-3.8). Smear-negative patients had the highest death rates (HR 3.9; 95% CI 2.7-5.5 compared to smear-positive patients), followed by EPTB patients (HR 2.6, 95% CI 1.8-3.7 compared to smear-positive patients). Death rates increased with age but were similar in men and women. Adult patients in Malawi with smear-negative PTB and EPTB have low treatment completion and high death rates, related to high levels of HIV infection. National TB control programmes in areas of high HIV prevalence should no longer ignore treatment outcomes in patients with smear-negative PTB or EPTB.

Tuberculosis in a prison population in Malawi

BACKGROUNDnMuch concern has been expressed about the high prevalence of tuberculosis in prisons in industrialised countries. Since there is almost no information from developing countries, we investigated the rate of pulmonary tuberculosis in a large prison in Malawi.nnnMETHODSnBetween May and July, 1996; we carried out an active case-finding survey in Zomba Central Prison, Malawi, through the National Tuberculosis Control Programme. We interviewed prisoners, and those with a cough of at least 1 weeks duration were screened by sputum-smear microscopy. If microscopy was negative, prisoners underwent chest radiography. We offered HIV testing, with voluntary consent and counselling before and after tests, to all prisoners, whether positive or negative for pulmonary tuberculosis.nnnFINDINGSn914 (70%) of 1315 prisoners were screened (905 men, nine women; mean age 30 years [SD 11]). 47 (5%) screened prisoners (all men) had pulmonary tuberculosis: 14 were taking antituberculosis treatment and 33 were undiagnosed at the start of the study; 18 were sputum-smear positive and 15 were sputum-smear negative. 16 (73%) of 22 prisoners with previously undiagnosed pulmonary tuberculosis and 30 (75%) of 40 prisoners with cough but no evidence of pulmonary tuberculosis were HIV seropositive. In all prisoners, except one, symptoms of pulmonary tuberculosis had developed after they had entered prison.nnnINTERPRETATIONnWe found a high rate of pulmonary tuberculosis in Zomba Central Prison, which suggests active transmission of tuberculosis. As a result of this study, the National Tuberculosis Control Programme has implemented interventions in eight prisons in Malawi to improve tuberculosis control, including collection of health data, education of prisoners and clinical staff about tuberculosis, active screening of prisoners for pulmonary tuberculosis by sputum-smear microscopy, and active case-finding in the prisons.

Tuberculosis in health care workers in Malawi

Although sub-Saharan Africa has the highest rates of tuberculosis (TB) and human immunodeficiency virus (HIV) infection in the world, the rates of TB amongst its health care workers (HCWs) are poorly documented. We therefore conducted a country-wide investigation. All district/government and mission hospitals in Malawi that diagnose and care for TB patients were visited in order to obtain information on hospital-based HCWs and their incidence of TB in 1996. Hospital TB case loads, country-wide TB notification numbers and national population estimates for 1996 were obtained, which enabled TB case notification rates to be calculated. In 1996, 108 (3.6%) of 3042 HCWs from 40 hospitals were registered and treated for TB: 22 with smear-positive pulmonary TB (PTB), 40 with smear-negative PTB and 46 with extrapulmonary TB. The overall case fatality rate was 24%. Compared with the adult general population aged > or = 15 years, the relative risk [95% confidence interval (CI)] in HCWs of all types of TB was 11.9 [9.8-14.4], of smear-positive PTB 5.9 [3.9-9.0], of smear-negative PTB 13.0 [9.5-17.7] and of extrapulmonary TB 18.4 [13.8-24.6], P < 0.05. The 1996 hospital TB case load ranged from 29 to 915: there were no cases of TB in HCWs in hospitals whose case load was < or = 100 patients, while the TB case rate among HCWs was similar in hospitals with annual case loads of 101-300 or > 300. The annual risk of TB was high among all categories of HCW, especially clinical officers. This study shows a high rate of TB in HCWs in Malawi, and emphasizes the need for practical and affordable control measures for the protection of HCWs from TB in low-income countries.

Delays in diagnosis and treatment of smear-positive tuberculosis and the incidence of tuberculosis in hospital nurses in Blantyre, Malawi

There is little information about nosocomial transmission of tuberculosis (TB) in sub-Saharan Africa. A study was carried out to examine the process of diagnosis and treatment of smear-positive pulmonary TB patients in Queen Elizabeth Central Hospital, Blantyre, Malawi, and the incidence of TB in nurses working in specific departments of the hospital. Case notes of 1365 patients with smear-positive pulmonary TB, diagnosed and treated at the hospital in 1993 and 1994, were analysed. The number of qualified nurses who worked in specific departments of the hospital between 1993 and 1994 and the number who were diagnosed and treated for TB during this period were obtained from nursing records. 787 patients (58%) were diagnosed as out-patients and 578 (42%) were diagnosed in hospital wards, 544 from medical wards. In medical wards, there were long delays from the time of admission to diagnosis and start of anti-TB treatment in new and previously treated TB patients. Of 310 qualified nurses, 12 (4%) were treated for TB in 1993-1994; 4 (14%) of 29 nurses working in the medical wards developed TB. The results indicate the importance of finding simple measures in resource-poor countries to improve the diagnosis and treatment of TB in hospital patients in order to decrease the risk of nosocomial TB transmission.

Screening pulmonary tuberculosis suspects in Malawi: testing different strategies

Alternative strategies for screening tuberculosis (TB) suspects are needed in sub-saharan Africa. Ambulatory adult TB suspects who were seen in the chronic cough room of Queen Elizabeth Central Hospital, Blantyre, Malawi, were assessed with respect to appropriateness of referral. Appropriate referrals (patients with cough 3 weeks or longer, weight loss and no antibiotic response) were screened by 3 sputum specimens for microscopy and culture of Mycobacterium tuberculosis and chest radiography (CXR). Hypothetical strategy A (screening by sputum smear examination followed by CXR in patients with negative sputum smears) was compared with strategy B (screening by CXR followed by sputum smear examination in patients with a CXR consistent with TB) in terms of diagnostic efficacy and cost. Of 1127 patients referred to the cough room, 402 (38%) were appropriate TB suspect referrals. Of these, 111 (28%) were sputum smear-positive, 213 (53%) were culture-positive, and 221 (55%) had smear and/or culture-positive evidence of TB. Routine CXR was consistent with pulmonary (P) TB in 230 patients (57%). With strategy A, 243 (60%) patients were diagnosed as PTB, but 40 (25%) of those not diagnosed as PTB had positive mycobacterial cultures. With strategy B, 230 patients (57%) were diagnosed as PTB, but 53 (31%) of those not diagnosed as PTB had positive mycobacterial cultures, including 13 with smear-positive sputum. The cost per diagnosed case of PTB was US

Treatment outcome of patients with smear-negative and smear-positive pulmonary tuberculosis in the National Tuberculosis Control Programme, Malawi.

4.63 with strategy A and US

High mortality rates in tuberculosis patients in Zomba Hospital, Malawi, during 32 months of follow-up

5.44 with strategy B. Screening patients with good criteria of TB has high diagnostic sensitivity, but screening by CXR is less effective and more costly than screening by sputum smear microscopy.

Prevalence of tuberculosis in TB suspects with short duration of cough

National tuberculosis control programmes (NTPs) in sub-Saharan Africa do not routinely record or report treatment outcome data on smear-negative pulmonary tuberculosis (PTB) patients. Twelve-month treatment outcome on patients with smear-negative PTB registered in all district and mission hospitals in Malawi during the year 1995 was collected, and was compared with 8-month treatment outcome in smear-positive PTB patients registered during the same period. Of 4240 patients with smear-negative PTB, 35% completed treatment, 25% died, 9% defaulted and 7% were transferred to another district with no treatment outcome results available. In 24% of patients treatment cards were lost and treatment outcome was unknown. These results were significantly inferior to those obtained in 4003 patients with smear-positive PTB in whom 72% completed treatment, 20% died, 4% defaulted, 2% were transferred and 1% had positive smears at the end of treatment. These differences between patients with smear-negative and smear-positive PTB were similar when analysed by sex and by most age-groups. Higher mortality rates in patients with smear-negative PTB are probably attributable to advanced HIV-related immunosuppression, and higher default and treatment unknown rates probably reflect the lack of attention paid by TB programme staff to this group of patients. As a result of this country-wide study the Malawi NTP has started to record routinely the treatment outcomes of smear-negative TB patients and has set treatment completion targets of 50% or higher for this group of patients.

Tuberculous lymphadenitis, a diagnostic problem in areas of high prevalence of HIV and tuberculosis

There is little information about long-term follow-up in patients with smear-negative pulmonary tuberculosis (PTB) or extrapulmonary tuberculosis (EPTB) who have been treated under routine programme conditions in sub-Saharan Africa. A prospective study was carried out to determine outcome 32 months from start of treatment in an unselected cohort of 827 adults TB inpatients registered at Zomba Hospital, Malawi, in 1 July-31 December 1995. By 32 months, 351 (42%) patients had died. Death rates were 30% (95% confidence interval [95% CI] 25-35%) in 386 patients with smear-positive PTB, 60% (95% CI 53-67%) in 211 patients with smear-negative PTB and 47% (95% CI 40-54%) in 230 patients with EPTB. Of the 793 patients with concordant HIV test results 612 (77%) were HIV seropositive: 47% HIV-positive patients were dead by 32 months compared with 27% HIV-negative patients (adjusted hazard ratio [HR] 2.3; 95% CI 1.7-3.1, P < 0.001). Smear-negative PTB patients had the highest death rates during the 32-month follow-up (HR 2.7; 95% CI 2.1-3.5, P < 0.001 compared to smear-positive patients), followed by EPTB patients (HR 1.9; 95% CI 1.5-2.5, P < 0.001 compared to smear-positive patients). When analysis was restricted to after the treatment period had finished (i.e., months 12-32), the differences in mortality were maintained for HIV-serostatus and for types of TB. Low-cost, easy to implement strategies for reducing mortality in HIV-positive TB patients in sub-Saharan Africa (such as the use of trimethoprim-sulphamethoxazole prophylaxis) need to be tested urgently in programme settings.

Differences in tuberculosis incidence rates in township and in rural populations in Ntcheu district, Malawi

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.