Urban-rural disparities in treatment outcomes among recurrent TB cases in Southern Province, Zambia

BMC Infectious Diseases

Summary by: Jessica Wenclawiak

Tuberculosis (TB) is a bacterial infection caused by Mycobacterium tuberculosis that affects millions of people each year. Although treatments are generally successful, recurrences can occur. Some of these strains do not respond to traditional medication and increase the risk of death; these strains are known as Multi-Drug Resistant TB (MDR-TB). Zambia is one country with a high prevalence of TB, and infection rates vary between urban and rural areas. Cases of TB are more frequent in cities, but better access to healthcare and medication improves patients’ prognoses. To quantify the differences in TB recurrence in rural and urban settings, a research team, including CEID member Christopher Whalen, analyzed case reports and identified the groups most vulnerable to recurrence or treatment failure.

Between January 2006 and January 2013, there were over 25,000 diagnoses of TB in Southern Province, Zambia. 3,555 of these patients suffered from recurrent TB, and the most common cause of recurrence was relapse. The majority of cases occurred in cities, where rates of unfinished treatments and death were lower than rural areas. Over 80% of patients in the study completed treatment, and 7.5% were cured. Compared to urban areas, rural patients were 70% more likely to die or encounter treatment failure. These risks were also higher in patients infected with human immunodeficiency virus (HIV) in addition to TB. Overall, these results suggested that rural communities experience higher rates of treatment failure and death, even when TB recurrence is more common in urban areas.

When treatments are unsuccessful or patients fail to finish their medication, they become more susceptible to MDR-TB. Because these strains are difficult to cure, preventing their spread is essential in vulnerable rural areas. Implementing Directly Observed Treatment Short-Course (DOTS) plans can improve treatment outcomes and reduce mortality through earlier detection and more vigilant monitoring.

Mutembo, S. et al. (2019). Urban-rural disparities in treatment outcomes among recurrent TB cases in Southern Province, Zambia. BMC Infectious Diseases, 19:1087. https://doi.org/10.1186/s12879-019-4709-5.