In vitro activity of thiacetazone on mycobacterial species belonging to the Mycobacterium tuberculosis complex

Thiacetazone, despite frequent side-effects, may still be considered for the treatment of new tuberculosis cases when there is a shortage of drugs and for the management of multidrug-resistant tuberculosis. Fifty-four strains of M. tuberculosis complex were characterised based on the minimum inhibitory concentration (MIC) of thiacetazone and the growth pattern in the presence of different concentrations of the drug. The results showed that the MIC of thiacetazone to type II M. africanum strains was significantly higher than for other strains in the study (P < 0.01). Thiacetazone showed a paradoxical effect on 63% of strains where lower concentrations exhibited a better inhibiting activity than higher concentrations.

Drug-resistant tuberculosis in Ethiopia: problem scenarios and recommendation

Tuberculosis (TB) is a major public health problem in Ethiopia. This review is prepared to indicate possible future challenges related to tuberculosis control and it includes previous reports of drug-resistant surveys in Ethiopia. Drug-resistant TB, both initial and acquired, was reported from different regions of the country. In studies from 1984 to 2001, the initial resistance to isoniazid ranges from 2% to 21% and initial resistance to streptomycin ranges from 2 to 20%. Multidrug-resistance (MDR) TB defined as resistance to at least isoniazid and rifampicin was also reported in about 1.2% of new cases and 12% of re-treatment cases. In all studies which included ethambutol susceptibility test, ethambutol resistance is either nil or very low (below 0.5%). All MDR isolates were susceptible to ethambutol. Treatment and re-treatment regimens recommended by the National TB/Leprosy Control Program could be effective on all cases other than those with MDR-TB. MDR-TB is difficult to cure. Therefore, special emphasis should be given to control the spread of MDR-TB. Lack of control efforts may lead to the increased resistance to both first- and second-line drugs. A well supported and controlled special treatment unit, which uses both first-line and second-line drugs is required for a proper management of these cases and for effective control of the spread of MDR-TB. A uniform susceptibility to ethambutol can be taken as an advantage to develop standard low-cost re-treatment regimen for MDR-TB patients.

Characterization of isoniazid-resistant strains of Mycobacterium tuberculosis on the basis of phenotypic properties and mutations in katG

Forty isoniazid-resistant Mycobacterium tuberculosis isolates were characterized on the basis of phenotypic properties (i.e., catalase activity, MIC of isoniazid, and growth pattern in the presence of 7 different concentrations of isoniazid) and alterations in the katG gene (codons 315 and 463). Three different growth patterns could be distinguished: concentration-dependent inhibition of growth was observed in 29 strains, similar growth at all concentrations was seen in 7 strains, and enhanced growth at low concentrations of isoniazid was evident in 4 strains. The MIC of isoniazid was < or = microg/ml for 29 of 40 strains. Mutation at codon 315 of the katG was detected in 28 of 40 strains. However, only one of the seven strains for which the MIC of isoniazid was > or = 16 microg/ml had mutation at this codon. Five of these seven strains for which the MIC was > or = 16 microg/ml had no catalase activity. The results indicate that the MIC of isoniazid for a majority of strains is below the level achievable in serum. Therefore, isoniazid may be beneficial for the treatment of some cases of multidrug-resistant tuberculosis. Determination of catalase activity aids in the detection of isolates for which MICs are high and could, in conjunction with molecular methods, provide rapid detection of most isoniazid-resistant strains.

A comparison of indapamide SR 1.5 mg with both amlodipine 5 mg and hydrochlorothiazide 25 mg in elderly hypertensive patients: a randomized double-blind controlled study

OBJECTIVE

To analyse the efficacy of indapamide sustained-release (SR) 1.5 mg in reducing blood pressure versus amlodipine 5 mg and hydrochlorothiazide 25 mg, in elderly hypertensive patients.

DESIGN

Double-blind, randomized, 12 week study using three parallel groups.

SETTING

European teaching hospitals and general practices.

PATIENTS

Randomized patients, (n = 524) including 128 patients with isolated systolic hypertension (ISH); mean age: 72.4 years; mean systolic/diastolic blood pressures (SBP/DBP): 174.5/97.9 mmHg.

MAIN OUTCOME MEASURES

Clinic systolic and diastolic blood pressure variations.

RESULTS

Indapamide SR 1.5 mg demonstrates a similar efficacy to that of amlodipine 5 mg, as well as to that of hydrochlorothiazide 25 mg (equivalence P < 0.001); the mean decreases in SBP/DBP were -22.7/-11.8 mmHg, -22.2/-10.7 mmHg and -19.4/-10.8 mmHg, respectively. In the ISH subgroup, indapamide SR 1.5 mg tends to have greater efficacy than hydrochlorothiazide 25 mg in reducing the SBP (-24.7 versus -18.5 mmHg, respectively; equivalence P = 0.117), while similar results are obtained with amlodipine 5 mg (-23 mmHg, equivalence P < 0.001). The normalization rate was relatively high for indapamide SR 1.5 mg (75.3%), when compared with amlodipine (66.9%) and hydrochlorothiazide (67.3%), especially in the subgroup of isolated systolic hypertensive patients: 84.2 versus 80.0% for amlodipine, and versus 71.4% for hydrochlorothiazide.

CONCLUSIONS

Indapamide SR 1.5 mg shows similar antihypertensive efficacy to amlodipine 5 mg and hydrochlorothiazide 25 mg in elderly hypertensive patients, while in patients with isolated systolic hypertension, indapamide SR 1.5 mg shows a similar efficacy to amlodipine 5 mg but a greater efficacy than hydrochlorothiazide 25 mg.

Health seeking and hygiene behaviours predict nutritional status of pre-school children in a slum area of Addis Ababa, Ethiopia

A cross-sectional study was done from March to May 1997 in four selected slum kebeles (villages) of Addis Ababa in which nutritional status of 758 children aged 6 to 36 months was examined and stratified into malnourished and well nourished groups. Analysis of hygiene and health seeking practices of randomly selected households of the two sets of children determined practices that significantly exacerbate childhood malnutrition. The rates of immunization for the malnourished (80.2%) and well nourished households (77.6%) were practically the same. No significant difference was found in the prevalence of home treatment or food withholding habits at times of diarrhoea episodes between the two groups. The study established six variables to predict childhood malnutrition in the slum section of Addis Ababa: 1) presence of child waste inside house (Odds Ratio = 7.44; p < 0.0001), 2) diarrhoea treatment at the hospital (OR = 0.47;p < 0.05), 3) prolonged storage of cooked foods (OR = 2.86;p < 0.05), 4) feeding with washed hands (OR = 0.44; p < 0.01), and 5) poor handling of drinking water (OR = 3.18; p < 0.01) and 6) foods (OR = 3.52; p < 0.01). Hence strong and sustainable advice with a view of changing the behaviours of households towards good personal and household hygiene practices, and increased utilization of health settings is recommended as these may limit the overall success of public health programmes.

Impact of the earthquake of September 26, 1997 in Umbria, Italy on the socioenvironmental and psychophysical conditions of an elderly population

The consequences of natural disasters on the social and health status of older people have not been deeply considered. The aim of this study was to evaluate the socioenvironmental and psychophysical conditions of an elderly population after a devastating earthquake. A randomly selected group of 332 older people (> or =64 years) was selected among 1548 eligible subjects living in the city of Nocera Umbra four months after an earthquake of 5.6 magnitude on the Richter scale. Three geriatricians evaluated the study subjects by means of a structured interview, and standardized scales, which considered physical and mental status, mood and anxiety, and self-perception of well-being, as well as the characteristics of family composition and social interactions. Of the study subjects, 11.1% lived alone, and 33.4% with the spouse only. Most were self-sufficient in the basic activities of daily life. Musculoskeletal diseases and hypertension were the most frequently observed pathologies in this geriatric population. In addition, 47.9% of the subjects lived in temporary houses; this group more frequently suffered from hypertension, and had a higher score of comorbidity as measured by Cumulative Illness Rating Scale (CIRS) compared to people who remained at home. People living in the pre-fabricated huts also showed a higher score on the Geriatric Depression Scale and the Hamilton scale for anxiety, and complained more often of their health status, evaluated as self-perception of well-being, when compared to the home dwellers. Although all the studied subjects suffered from the discomforts caused by the earthquake, the precariousness of living in temporary houses, whose structural characteristics do not take the needs of elderly subjects into account, could justify the higher distress experienced by persons housed in the huts. These observations suggest that, after natural disasters, emergency programs should be more adapted to elderly people, whose needs and expectations are often different from those of young adults.

Stop-flow in mediastinum and thorax for resistant lymphoma

BACKGROUND/AIMS

Management of patients with heavily pretreated malignant lymphoma failing frontline treatment and salvage high-dose chemotherapy and autologous peripheral stem cell rescue, is problematic. A pilot study was conducted to evaluate isolated thoracic perfusion of drugs by means of stopflow technique.

METHODOLOGY

Six patients were enrolled in the study; diagnoses included 4 advanced Hodgkin's disease, 1 primary mediastinal B-cell lymphoma, and 1 anaplastic large cell lymphoma. Patients were aged 18-37 years; 4 presented with bulky mediastinum. They had never achieved a complete response since all had progressed from front-line treatment, and 3 had even failed salvage high-dose chemotherapy with autologous peripheral stem cell rescue. Cisplatin (100 mg/m2) and melphalan (35 mg/m2) were used. Carmustine (100 mg/m2) were added to these 2 drugs and cytarabine (2000 mg/m2) in patients not previously treated by carmustine, etoposide, cytarabine, and melphalan. Epidoxorubicin (70 mg/m2) was added in patients who previously received a suboptimal dosage of antracycline. Drugs were delivered monthly via aortic perfusion performed by means of Aigner's stop-flow technique.

RESULTS

Overall 13 cycles of perfusional chemotherapy were administered with a median number of 2 cycles. During the procedures there were no technical, hemodynamic, or vascular complications, and no deaths occurred during surgery. After 1 month, 6 (100%) objective responses after isolated thoracic perfusion were recorded, 3 (50%) of which were complete. Tolerance to therapy was excellent. Hematological toxicity was mild and transfusional support was needed only in one course. At the last follow-up, 2 patients are alive (1 complete response and 1 very good partial response, maintained).

CONCLUSIONS

This new therapeutical approach seems very active in recurrent/refractory malignant lymphoma and may play an important role in this setting.

CEOP-B/VIMB vs. promace-CytaBOM in the treatment of intermediate or high grade non-Hodgkin's lymphoma: A randomised multicenter study of Southern Italy Cooperative Group

From January 1992 to December 1995, 129 patients with previously untreated non-Hodgkin's lymphoma were randomised in a phase III multicenter trial to receive CEOP-B/VIMB or ProMACE-CytaBOM. Eligibility criteria included intermediate or high grade lymphoma (follicular large cell, diffuse small cleaved-cell, diffuse mixed, diffuse large-cell and immunoblastic) with an Ann Arbor stage II bulky, III or IV. All patients entered into the study were considered evaluable according to intent to treat analysis. At a median follow-up of 60 months there were no significant differences between the treatment response rates [82% (60%CR) for CEOP-B/VIMB vs. 81% (69% CR) for ProMACE-CytaBOM]. Conversely, with regard to disease-free survival, a significant difference was observed between the two treatment arms (42% for CEOP-B/VIMB vs. 24% for ProMACE-CytaBOM at 5 years; p=0.046). However, this difference did not translate in a significant difference in overall survival (45% vs. 39% at 5 years). Moreover, when response rates and outcome were analysed for different prognostic subgroups according to International Prognostic Index, no significant differences were observed between the treatment groups. It is important to note that neither regimen was able to improve outcome of poor risk patients who fared badly with both treatments (median survival 9 and 8 months respectively). Toxicity was also similar in both treatments with grade 3-4 leukopenia observed in 39% and 47% of cases and grade 3-4 thrombocytopenia in 24% and 27% of cases respectively. In conclusion, in this study CEOP-B/VIMB was not superior to ProMACE-CytaBOM in aggressive lymphomas and the alternating strategy failed to improve outcome of poor risk patients in which newer more aggressive treatments are needed.

Are vascular factors involved in Alzheimer's disease? Facts and theories

The hypothesis that vascular factors may contribute to the development of Alzheimer's disease (AD) is supported by epidemiologic and pathologic observations. Arterial hypertension and diabetes have been found to be associated not only with vascular dementia, but also with AD; in addition, the treatment of hypertension with calcium antagonists seems to prevent degenerative dementias. Hypertension and hyperinsulinemia favor the deposition of amyloid substance in the brain. The histopathology of AD is marked not only by neurofibrillary tangles and senile plaques, but also by macro and micro congophilic angiopathy and ischemic white matter rarefaction. The specific AD pathological lesions, if isolated, are not able to lead to an evident clinical picture of dementia, which, on the contrary, becomes evident when vascular, mainly subcortical, lesions are associated. These and other observations suggest that vascular factors may have a role in the development of AD. An aggressive approach to these factors could be of value in the prevention of AD.

Combination of granulocyte-macrophage colony-stimulating factor (GM-CSF) anf erythropoietin (EPO) for the treatment of advanced non-responsive chronic lymphocytic leukemia

We report the use of a colony-stimulating granulocyte-macrophage factor (GM/CSF) and erythropoietin (EPO) combination as salvage treatment in four heavily-pretreated patients with refractory/ recurrent B-CLL. Induction therapy was subcutaneous GM-CSF 2.5 microg/ kg, and EPO, 150 units/kg both daily for the first 14 d. Maintenance therapy was GM-CSF on days 1, 3 and 5 and Epo on days 2, 4 and 6 at the same doses with weekly recycling. All the patients responded favourably. A significant reduction of lymphocytosis, lymphoadenomegaly, and organomegaly was obtained within one month of therapy. The number of infections and transfusional requirement decreased dramatically. The hemoglobin increased to over 11 g/dl in 3 out of 4 patients. With a median follow-up of 11 months (range 5-13) we observed 4 partial responses (NCI/IWCLL) and only one progression after a 10-month partial response. This combination regimen seems very active, safe and easy to administer. It may represent a promising therapeutical option in heavily pretreated patients. Further clinical and biological studies on a larger cohort of patients are needed to confirm these preliminary data, to clarify the hypothetical interactions between these cytokines and B-CLL cell proliferation pathways, and to establish if this therapy may have an impact on survival.

Chronic lymphocytic leukaemia and neuroendocrine cancer

We report a unique association between neuroendocrine cancer and chronic lymphocytic leukaemia (CLL) in a 63-year-old man. Neuroendocrine cancer was resistant to various conventional treatments and following locoregional progression we treated the patient with hypoxic pelvic perfusion of cisplatin 100 mg/m2 plus mitomycin 40 mg/m2, using the stopflow method, for three cycles: a dramatic and surprising reduction of > 75% in the evaluable lesions was observed. The cumulative effect of treatment produced a complete response from CLL. At cytogenetic examination the neuroendocrine cells were diploid, whereas CLL cells showed trisomy 12. Moreover, deletion of the short arm of chromosome 3 was found in both neoplastic populations. Whether the abnormality seen on chromosome 3 in the two diseases represents a critical event is not known.

Factors related to the length of in-hospital stay of geriatric patients

The aim of this study was to evaluate factors predicting length of stay in hospital of geriatric patients. Study participants were 402 patients (183 males and 219 females) consecutively admitted to four geriatric wards located in Chieti, Perugia, Pescara and Prato, Italy. Information on potential predictors of length of stay was collected; in particular, we assessed the presence and severity of specific chronic medical conditions, level of physical function, cognitive status, and depressive symptoms. Moreover, information on family and social support was obtained. In general, participants were old, often cognitively impaired and physically disabled. Average length of stay ranged from 9.4 +/- 3.3 days (Perugia) to 14.1 +/- 7.2 days (Chieti), and was statistically different across centers (p < 0.001). None of the specific medical diagnoses was associated with different length of stay. However, higher comorbidity score (p < 0.001), living alone (p < 0.01), lower MMSE score (p = 0.03), and poor functional status (p = 0.05) were all associated with longer length of stay. When these variables were included in a multivariate model predicting length of stay, differences between centers were no longer statistically significant. Findings of this study show that specific medical diagnoses are not adequate instruments to estimate length of stay in geriatric units. Other assessment systems based on extension of the social network, comorbidity, and the cognitive as well as the functional level need to be developed.

Treatment of hypertension in the elderly

Several trials performed in elderly patients have demonstrated that antihypertensive drugs are effective in both systo-diastolic and isolated systolic hypertension, reducing the incidence of fatal and nonfatal cardiovascular events. However because of technical and design problems, the studies carried out to date have involved highly selected patients, almost always without any target organ damage, independent, cognitively normal and with low comorbidity. Therefore, trial results may be transferred to clinical practice only with some caution. Therapeutic behavior could be different in the presence of diseases associated with hypertension: a) in case of associated specific cardiovascular complications and/or diseases, such as diabetes or dyslipidemia, which could increase cardiovascular risk, treatment must be more aggressive; b) in case of associated diseases with fatal prognosis, treatment is aimed at preventing hypertensive emergencies; c) in case of associated diseases, which are not life-threatening but require chronic pharmacological intervention, drug interaction must be carefully considered. Finally, sudden and significant blood pressure drops due both to overdosage of antihypertensive drugs and/or to intercurrent illnesses must be prevented, because the reduction of blood flow may induce severe target organ ischemia.

Correlation between computed tomography findings of leukoaraiosis and 24-hour blood pressure variability in elderly subjects

BACKGROUND AND PURPOSE

Leukoaraiosis (LA) has been defined as low attenuation areas involving only the periventricular white matter, in the mild form, and extending to the subcortical region in the severe form. This study evaluates, in elderly patients, if brain computed tomography (CT) evidence of LA significantly correlates with the findings of 24-hour, blood pressure monitoring.

METHODS

Sixtysix neurologically nondiseased elderly patients underwent CT examination of the brain and 24-hour ambulatory blood pressure monitoring. The patients were divided in two groups (patients with none-to-mild LA in group 1; patients with severe LA in group 2) based on CT findings evaluated at level of foramina of Monro, body of lateral ventricles, and frontoparietal white matter (centrum semiovale). CT findings were compared with main 24-hour ambulatory blood pressure monitoring results (systolic and diastolic blood pressure and heart rate values).

RESULTS

Patients with severe LA showed a wider variability both in blood pressure and heart rate; in particular, major oscillations were found during the nighttime period. No significant 24-hour blood pressure variability was found in group 1.

CONCLUSION

Increased blood pressure variability can play a role in the pathogenesis of LA.

Blood pressure rhythm and prevalence of vascular events in hypertensive subjects

OBJECTIVES

To evaluate the influence of age on the day-night blood pressure rhythm and on the prevalence of vascular events in those whose systolic blood pressure (SBP) fell by <10% overnight (non-dippers).

DESIGN

Cross-sectional observational cohort study.

SETTING

Outpatient hypertension clinic.

PARTICIPANTS

419 Hypertensive patients (214 male, 205 female).

METHODS

All subjects were submitted to ambulatory blood pressure monitoring (Spacelabs 90207). The nocturnal fall of SBP was calculated from (day SBP--night SBP)/day SBP, where 'day' values were recorded between 0600 h and 2200 h and 'night' values between 2200 h and 0600 h. Dippers and non-dippers were divided in two subgroups according to age (under or over 65 years). Information on gender, smoking, diabetes mellitus and body mass index was collected and cerebrovascular and cardiovascular events, evaluated by history and medical records, were registered.

RESULTS

The day-night difference in blood pressure significantly decreased with age and the prevalence of non-dippers was greater in elderly than in younger subjects (65.1% vs. 29.8%). No difference was found between groups for cerebrovascular events, irrespective of age. A relationship between non-dipping pattern and cardiovascular events was found only in younger hypertensive non-dippers (odds ratio, 2.0; 95% confidence interval, 1.20-3.21); in elderly people the prevalence of cardiovascular events was similar in dippers and non-dippers.

CONCLUSIONS

Cardiovascular risk is not increased in elderly non-dipper hypertensive subjects. This contrasts with results in younger populations.

Evaluation of a colorimetric assay based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) for rapid detection of rifampicin resistance in Mycobacterium tuberculosis

OBJECTIVES

To standardise the colorimetric assay based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) for the rapid detection of rifampicin-resistant Mycobacterium tuberculosis in clinical practice and to evaluate the assay on a collection of 92 clinical isolates.

DESIGN

The Bactec method was used as the reference method. Rifampicin was used for the susceptibility testing in the Bactec method at a concentration of 2 microg/ml. The MTT assay was performed in tubes containing 3 ml Dubos broth; the assay is based on the principle that live cells convert the yellow tetrazolium salt into a blue formazan. A final concentration of 2 microg/ml rifampicin was used in the assay. Optical density (OD) values at 570 nm were recorded on the third and sixth day. A strain was defined as susceptible when the relative optical density unit (RODU) (i.e., OD of rifampicin containing tube/OD of undiluted control) was < or = 0.2, and when the OD value of the rifampicin-containing tube on the sixth day was lower than the OD value on the third day. A strain was defined as resistant when the RODU was more than 0.5, and when there was an increase in OD value in the rifampicin-containing tube on the sixth day. The tubes were also read visually.

RESULTS AND CONCLUSION

The result obtained by the MTT assay perfectly matched the result obtained by the Bactec method. The MTT assay was also interpretable by the naked eye. This simple, inexpensive assay could be used as a rapid screening method for identification of rifampicin-resistant strains in low-income countries.

Susceptibility of multidrug-resistant strains of Mycobacterium tuberculosis to amoxycillin in combination with clavulanic acid and ethambutol

Thirty clinical isolates of Mycobacterium tuberculosis, 20 of which were multidrug-resistant (MDR), were tested for susceptibility to different combinations of amoxycillin, clavulanic acid and subinhibitory concentrations of ethambutol. beta-Lactamase production was assessed semiquantitatively with the nitrocefin method and susceptibility testing was performed with the BACTEC method. All isolates were beta-lactamase positive and were resistant to 16 mg/L amoxycillin. The MIC of amoxycillin in combination with clavulanic acid was > or =2 mg/L for 27/30 (90%) isolates. Addition of subinhibitory concentrations of ethambutol significantly reduced the MIC of amoxycillin for all tested isolates. Twenty-nine (97%) isolates had an MIC of amoxycillin of < or =0.5 mg/L when subinhibitory concentrations of ethambutol were added; this is well below the concentrations achievable in serum and tissue.

Characteristics of geriatric patients related to early and late readmissions to hospital

The aim of the study was to evaluate which characteristics of geriatric patients account for readmission to hospital, 6 months after discharge. All patients (203 females, 176 males) consecutively admitted over a two-month period to four acute geriatric care units, located in the cities of Chieti, Perugia, Pescara and Prato, participated in the study. Data that could potentially explain early and late readmissions were collected for each patient. Prevalence of diseases and comorbidity were assessed with the Cumulative Illness Rating Scale (CIRS); physical function by self-report (ADL, IADL) and objective (Stand and Walking Speed) measures; cognitive level by MMSE; and depressive symptoms by the Geriatric Depression Scale (GDS). Information on family and social support were also obtained. After discharge, data on hospital readmissions were collected for six months. For each readmitted patient (cases), medical records were reviewed, and supplementary information was obtained from families and general practitioners. Readmissions were classified as "early" (within the first three months), "late" (within the third and sixth month), and "multiple" (2 or more readmissions irrespective of the period). Patients not readmitted (alive at home) were considered as controls. Systematic differences between centers and between periods of readmissions were evaluated using one-way analyses of variance, and Pearson's chi 2 test. Factors related to early, late, and multiple readmission were identified in multivariate logistic regression models. On univariate analysis, patients readmitted over the first three-month period were sicker than controls (CIRS classes 3-4: 52.1% vs 34.1%), had more social problems or behavioral symptoms, and were more functionally impaired (ADL dependencies 3.3 +/- 0.4 vs 2.1 +/- 0.2). Patients who were readmitted between the third and the sixth month after discharge had a significantly higher CIRS total score (p = 0.006). Patients with multiple readmissions had more severe diseases, and more social problems. On multivariate analysis, early readmission was associated with unsatisfactory social conditions, living alone, severity of diseases and cognitive impairment, while late readmission was associated with comorbidity only. Multiple readmissions were related only to social factors, and to hospital admission before the baseline evaluation. The findings of this study suggest that interventions aimed at improving unfavorable social conditions may reduce the rate of rehospitalization in geriatric patients.

Drug resistance in Mycobacterium tuberculosis strains isolated from re-treatment cases of pulmonary tuberculosis in Ethiopia: susceptibility to first-line and alternative drugs

SETTING

Addis Ababa Tuberculosis Demonstration and Training Center, Ethiopia.

OBJECTIVES

To determine the pattern of drug resistance among re-treatment cases of pulmonary tuberculosis (TB), to determine the risk factors associated with multi-drug resistant (MDR) TB, and to propose re-treatment regimens based on the patterns of susceptibility to first-line and alternative drugs.

DESIGN

One hundred and seven Mycobacterium tuberculosis strains isolated from an equal number of re-treatment cases of pulmonary TB were included in the study. Drug susceptibility was determined by the Bactec method.

RESULTS

About 50% of the strains were resistant to one or more of the first-line drugs and 12% of the strains were multi-drug resistant, i.e., resistant to both isoniazid and rifampicin. Previous treatment with rifampicin was the most important predictor of MDR-TB. All MDR strains were susceptible to amikacin, ciprofloxacin, ethambutol, ethionamide and clofazimine.

CONCLUSION

The WHO re-treatment regimen would theoretically be effective for the treatment of all non-MDR-TB patients in this study. A proposed 12-month re-treatment regimen for MDR-TB patients would include a fluoroquinolone in combination with streptomycin, pyrazinamide, isoniazid, ethambutol and clofazimine. There is an urgent need for more research to define safe and inexpensive treatment regimens for MDR-TB patients in low-income countries.