The disconnect between a national tuberculosis drug resistance survey and treatment outcomes: a lost opportunity.

We linked results from the Fourth Botswana National Drug Resistance Survey (DRS), 2007-2008, to patient records from the national Electronic Tuberculosis Registry to determine treatment outcomes. Of 915 new patients, 651 (71%) had treatment data available. Completion or cure was achieved for 10/15 (67%, 95%CI 42-85) with isoniazid monoresistance, (6/16, 38%, 95%CI 18-61) with multidrug resistance, while 73% (391/537, 95%CI 69-76) were susceptible to first-line drugs. The analysis was limited because of unavailable treatment records and undocumented outcomes. Prospective analyses following DRSs should be considered to ensure adequate outcome data.

Increase in anti-tuberculosis drug resistance in Botswana: results from the fourth National Drug Resistance Survey.

SETTING: Although approximately 0.5 million cases of multidrug-resistant tuberculosis (MDR-TB) occur globally each year, surveillance data are limited. Botswana is one of the few high TB burden countries to have carried out multiple anti-tuberculosis drug resistance surveys (in 1995-1996, 1999 and 2002). OBJECTIVE: In 2007-2008, we conducted the fourth national survey of anti-tuberculosis drug resistance in Botswana to assess anti-tuberculosis drug resistance, including trends over time. In the previous survey, 0.8% (95%CI 0.4-1.5) of new patients and 10.4% (95%CI 5.6-17.3) of previously treated patients had MDR-TB. DESIGN: During the survey period, eligible specimens from all new sputum-smear positive TB patients and from all TB patients with history of previous anti-tuberculosis treatment underwent mycobacterial culture and anti-tuberculosis drug susceptibility testing (DST). RESULTS: Of 924 new TB patients and 137 with previous anti-tuberculosis treatment with DST results, respectively 23 (2.5%, 95%CI 1.6-3.7) and 9 (6.6%, 95%CI 3.3-11.7) had MDR-TB. The proportion of new TB patients with MDR-TB has tripled in Botswana since the previous survey. CONCLUSION: Combatting drug-resistant TB will require the scale-up of MDR-TB diagnosis and treatment to prevent the transmission of MDR-TB and strengthening of general TB control to prevent the emergence of resistance.

Lessons learned during tuberculosis screening in public medical clinics in Francistown, Botswana.

In Botswana, where one quarter of the adult population is infected with the human immunodeficiency virus and the annual tuberculosis (TB) incidence is among the highest globally, intensified TB case finding is needed in health care facilities to detect and treat TB cases early and prevent transmission. During August-December 2009, TB screening was implemented among adults at patient intake in five clinics in Francistown. Among 11 779 TB screenings at intake, 926 were positive. Nineteen patients were diagnosed with TB. Routine TB screening at intake was operationally feasible, but had low yield. Innovative case-finding strategies are needed in Botswana.

Epidemiological features of drug resistant tuberculosis in Harare, 1994 to 1996.

OBJECTIVES: To characterise the prevalence, clinical and radiological features of drug resistant tuberculosis in selected patients with pulmonary tuberculosis in Harare between 1994 and 1996. DESIGN: A retrospective review of medical and microbiological records. SETTING: Beatrice Road Infectious Diseases Hospital, Harare, Zimbabwe. SUBJECTS: 381 smear-positive tuberculosis patients who had samples submitted to the National Tuberculosis Reference Laboratory for culture and susceptibility testing. MAIN OUTCOME MEASURES: Prevalence of resistance of isolated cultures of Mycobacterium tuberculosis to anti-tuberculosis drugs; clinical, radiological and microbiological response to treatment with recommended anti-tuberculosis regimens. RESULTS: Resistance to one or more drugs was detected in 16 isolates (16/165, 9.7%), single drug resistance in five (3.0%) and resistance to two or more drugs in 11 (6.7%). There were no distinctive clinical or radiological features of drug-resistant tuberculosis, although a higher percent of drug resistant cases had evidence of pleural disease (25% vs 2.5%, p = 0.005). Neither past history of tuberculosis or known or suspected HIV infection was associated with the presence of drug resistance. CONCLUSIONS: In spite of the resurgence of tuberculosis and the high prevalence of HIV infection in Zimbabwe, the rates of drug resistance have remained relatively low, even among a selected population at high risk of resistance. A significant proportion of cases of drug-resistant tuberculosis appear to be due to new transmission of drug resistant strains, which reinforces the importance of maintaining a surveillance system for the monitoring of drug susceptibility. Ongoing prospective studies should provide more reliable estimates of the prevalence and determinants of drug resistance in Zimbabwe.

Pulmonary tuberculosis in Harare, Zimbabwe: analysis by spoligotyping.

BACKGROUND: Over the last 10 years there has been a fourfold increase in cases of tuberculosis in Harare, Zimbabwe. The use of molecular epidemiology to understand tuberculosis transmission in this epidemic has been hampered by the availability of suitable culture facilities. A study was therefore undertaken to explore the potential of spoligotyping, a polymerase chain reaction based technique that does not require tuberculosis culture. METHODS: Adults attending a chest clinic with clinical or radiological pulmonary tuberculosis and one smear positive sputum were enrolled over one month. Demographic, socioeconomic, and clinical data were gathered using a standardised questionnaire. Molecular fingerprinting of genomic DNA recovered from sputum was performed by spoligotyping. RESULTS: Sixty one subjects (median age 28 years (range 18-73); 61% men) were recruited and 57 provided adequate sputum samples. Recent rural-urban migration or immigration was not common; 40% of subjects lived in crowded living conditions. DNA suitable for spoligotyping was recovered from 28 patients and 20 different genotypes of Mycobacterium tuberculosis were identified. Fifteen patients were infected with an M tuberculosis strain shared by one or more individuals. Patients infected with a shared spoligotype were not closely linked geographically within Harare, but were more likely to live in overcrowded conditions (69% versus 23%; odds ratio 6.85 (95% CI 1.2 to 47), p = 0.026). Analysis of the patients' original rural family homes revealed two geographically related spoligotype clusters. CONCLUSIONS: Spoligotyping may yield valuable molecular typing information in populations where tuberculosis culture is not available. This novel technique requires further development and evaluation in larger epidemiological studies.