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.

Value of chest radiography in a tuberculosis prevention programme for HIV-infected people, Botswana

To exclude tuberculosis, WHO/UNAIDS recommends considering medical history, symptom screen, and chest radiograph before starting tuberculosis prevention in people infected with HIV. The value of a chest radiograph for this purpose is unknown. We prospectively assessed 935 HIV-infected outpatients seeking isoniazid preventive therapy. Of 935 patients, 692 (74%) had no signs or symptoms of tuberculosis. Of these 692, 123 (18%) were lost during the chest radiograph process, and one (0.2%) of the remaining 563 was diagnosed with tuberculosis on the basis of the chest radiograph. A screening chest radiograph should not be required routinely for asymptomatic people taking isoniazid as preventive treatment in settings able to screen for signs and symptoms of tuberculosis.

Cost-effectiveness of home-based care versus hospital care for chronically ill tuberculosis patients, Francistown, Botswana

SETTING

Francistown, Botswana, 1999.

OBJECTIVE

To determine the affordability and cost-effectiveness of home-based directly observed therapy (DOT) compared to hospital-based DOT for chronically ill tuberculosis (TB) patients, and to describe the characteristics of patients and their caregivers.

DESIGN

Costs for each alternative strategy were analysed from the perspective of the health system and caregivers, in 1998 US dollars. Caregiver costs were assessed using a structured questionnaire administered to a sample of 50 caregivers. Health system costs were assessed using interviews with relevant staff and documentary data such as medical records and expenditure files. These data were used to calculate the average cost of individual components of care, and, for each alternative strategy, the average cost per patient treated. Cost-effectiveness was calculated as the cost per patient compliant with treatment. The characteristics of caregivers and patients were assessed using demographic and socio-economic data collected during interviews, and medical records.

RESULTS

Overall, home-based care reduced the cost per patient treated by 44% compared with hospital-based treatment (dollars 1657 vs. dollars 2970). The cost to the caregiver was reduced by 23% (dollars 551 vs. dollars 720), while the cost to the health system was reduced by 50% (dollars 1106 vs. dollars 2206). The cost per patient complying with treatment was dollars 1726 for home-based care and dollars 2970 for hospitalisation. Caregivers were predominantly female relatives (88%), unemployed (48%), with primary school education or less (82%), and with an income of less than dollars 1000 per annum (71%). Of those patients with an HIV test result, 98% were HIV-positive.

CONCLUSION

Home-based care is more affordable and cost-effective than hospital-based care for chronically ill TB patients, although costs to caregivers remain high in relation to their incomes. Structured home-based DOT should be included as a component of the National Tuberculosis Control Programme in Botswana.