Sex-related trends in non-conversion of new smear-positive tuberculosis patients in the Free State, South Africa

Mycobacterium africanum (Lineage 6) shows slower sputum smear conversion on tuberculosis treatment than Mycobacterium tuberculosis (Lineage 4) in Bamako, Mali

Objective

Ancestral M. tuberculosis complex lineages such as M. africanum are underrepresented among retreatment patients and those with drug resistance. To test the hypothesis that they respond faster to TB treatment, we determined the rate of smear conversion of new pulmonary tuberculosis patients in Bamako, Mali by the main MTBc lineages.

Methods

Between 2015 and 2017, we conducted a prospective cohort study of new smear positive pulmonary tuberculosis patients in Bamako. Confirmed MTBc isolates underwent genotyping by spoligotyping for lineage classification. Patients were followed at 1 month (M), 2M and 5M to measure smear conversion in auramine (AR) and Fluorescein DiAcetate (FDA) vital stain microscopy.

Result

All the first six human MTBc lineages were represented in the population, plus M. bovis in 0.8% of the patients. The most widely represented lineage was the modern Euro-American lineage (L) 4, 57%, predominantly the T family, followed by L6 (M. africanum type 2) in 22.9%. Ancestral lineages 1, 5, 6 and M. bovis combined amounted to 28.8%. Excluding 25 patients with rifampicin resistance, smear conversion, both by AR and FDA, occurred later in L6 compared to L4 (HR 0.80 (95% CI 0.66–0.97) for AR, and HR 0.81 (95%CI 0.68–0.97) for FDA). In addition we found that HIV negative status, higher BMI at day 0, and patients with smear grade at baseline ≤ 1+ were associated with earlier smear conversion.

Conclusion

The six major human lineages of the MTBc all circulate in Bamako. Counter to our hypothesis, we found that patients diseased with modern M. tuberculosis complex L4 respond faster to TB treatment than those with M. africanum L6.

Factors influencing treatment default among tuberculosis patients in a high burden province of South Africa

OBJECTIVE

To determine and describe the factors influencing treatment default of tuberculosis (TB) patients in the Free State Province of South Africa.

METHODS

A retrospective records review of pulmonary TB cases captured in the ETR.Net electronic TB register between 2003 and 2012 was performed. Subjects were >15 years of age and had a recorded pre-treatment smear result. The demographic and clinical characteristics of defaulters were described. Multivariate logistic regression analysis was used to determine factors associated with treatment default. The odds ratios (OR) together with their corresponding 95% confidence intervals (CI) were estimated. Statistical significance was considered at 0.05.

RESULTS

A total of 7980 out of 110 349 (7.2%) cases defaulted treatment. Significantly higher proportions of cases were male (8.3% vs. female: 5.8%; p<0.001), <25 years old (9.1% vs. 25-34 years: 8.7%; 35-44 years: 7.0%; 45-54 years: 5.2%; 55-64 years: 4.4%; >64 years: 3.9%; p<0.001), undergoing TB retreatment (11.0% vs. new cases: 6.3%; p<0.001), had a negative pre-treatment sputum smear result (7.8% vs. positive smear results: 7.1%; p<0.001), were in the first 2 months of treatment (95.5% vs. >2 months: 4.8%; p<0.001), and had unknown HIV status (7.8% vs. HIV-positive: 7.0% and HIV-negative: 5.7%; p<0.001). After controlling for potential confounders, multivariate analysis revealed a two-fold increased risk of defaulting treatment when being retreated compared to being treated for the first time for TB (adjusted OR (AOR) 2.0, 95% CI 1.85-2.25). Female cases were 40% less likely to default treatment compared to their male counterparts (AOR 0.6, 95% CI 0.51-0.71). Treatment default was less likely among cases >24 years old compared to younger cases (25-34 years: AOR 0.8, 95% CI 0.77-0.87; 35-44 years: AOR 0.6, 95% CI 0.50-0.64; 45-54 years: AOR 0.4, 95% CI 0.32-0.49; 55-64 years: AOR 0.3, 95% CI 0.21-0.43; >64 years: AOR 0.3, 95% CI 0.19-0.35). Co-infected cases receiving antiretroviral therapy (ART) were 40% less likely to default TB treatment relative to those whose ART status was unknown (AOR 0.6, 95% CI 0.46-0.57).

CONCLUSIONS

Salient factors influence TB patient treatment default in the Free State Province. Therefore, the strengthening of clinical and programmatic interventions for patients at high risk of treatment default is recommended. In particular, ART provision to co-infected cases facilitates TB treatment adherence and outcomes.

Risk factors for tuberculosis smear non-conversion in Eden district, Western Cape, South Africa, 2007-2013: a retrospective cohort study

Background

Tuberculosis (TB) continues to be a major global health problem. While progress has been made to improve TB cure rates, South Africa’s 76 % smear-positive pulmonary TB (PTB) case cure rate remains below the WHO target of 85 %. We report on the trends of TB smear non-conversion and their predictors at the end of an intensive phase of treatment, and how this impacted on treatment outcomes of smear-positive PTB cases in Eden District, Western Cape Province, South Africa.

Methods

Routinely collected, retrospective data of smear-positive PTB cases from the electronic TB register in Eden District between 2007 and 2013 was extracted. Non-conversion was defined as persistent sputum smear-positive PTB cases at the end of the two or three month intensive phase of treatment. Chi-square test for linear trend and simple linear regression analysis were used to analyse the change in percentages and slope of TB smear non-conversion rates over time. Risk factors for TB non-conversion, and their impact on treatment outcomes, were evaluated using logistic regression models.

Results

Of 12,742 total smear-positive PTB cases included in our study, 12.8 % (n = 1627) did not sputum smear convert; 13.3 % (1411 of 10,574) of new cases and 9.9 % (216 of 2168) of re-treatment cases. Although not statistically significant in either new or re-treatment cases, between 2007 and 2013, smear non-conversion decreased from 16.4 to 12.7 % (slope = −0.60; 95 % CI: −1.49 to 0.29; p = 0.142) in new cases, and from 11.3 to 10.8 % in re-treatment cases (slope = −0.29; 95 % CI: −1.06 to 0.48; p = 0.376). Male gender, HIV co-infection and a >2+ acid fast bacilli (AFB) smear grading at the start of TB treatment were independent risk factors for non-conversion (p < 0.001). Age was a risk factor for non-conversion in new cases, but not for re-treatment cases. Non-conversion was also associated with unsuccessful treatment outcomes (p < 0.01), including treatment default and treatment failure.

Conclusions

Smear-positive PTB cases, especially men and those with identified risk factors for non-conversion, should be closely monitored throughout their treatment period. The South African TB control program should invest in patient adherence counselling and education to mitigate TB non-conversion risk factors, and to improve conversion and TB cure rates.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1712-y) contains supplementary material, which is available to authorized users.

Determinants of multidrug-resistant tuberculosis in Henan province in China: a case control study

BACKGROUND

Multi-drug resistance (MDR) has been a cause of concern for tuberculosis (TB) control in both developed and developing countries. This study described the characteristics and risk factors associated with MDR-TB among 287 cases and 291 controls in Henan province, China.

METHODS

A hospital-based case-control study was conducted between June 2012 and December 2013. The study subjects were selected using multistage probability sampling. Multivariate conditional logistic regression models were used to determine the risk factors associated with MDR-TB.

RESULTS

The following risk factors for MDR-TB were identified: previous TB treatment (AOR = 4.51, 95% CI: 3.55-5.56), male sex (AOR = 1.09, 95% CI: 0.24-1.88), high school or lower education degree (AOR = 1.87, 95% CI: 1.27-2.69), unemployment (AOR = 1.30, 95% CI: 0.78-2.52), long distance of residence from the health facility (AOR = 6.66,95% CI: 5.92-7.72), smoking (AOR = 2.07, 95% CI: 1.66-3.19), poor knowledge regarding MDR-TB (AOR = 2.06, 95% CI: 1.66-2.92), traveling by foot to reach the health facility (AOR = 1.85, 95% CI: 1.12-3.09), estimated amount of time to reach the health facility was greater than 3 h (AOR = 1.42, 95% CI: 0.51-2.35), social stigma (AOR = 1.17, 95% CI: 0.27-2.03), having an opportunistic infection (AOR = 1.45, 95% CI: 0.58-2.4), more than 3 TB foci in the lungs (AOR = 1.98, 95% CI: 1.49-3.25), total time of first treatment was more than 8 months (AOR = 1.39, 95% CI: 0.65-2.54), adverse effects of anti-TB medication (AOR = 2.39, 95% CI: 1.40-3.26), and more than 3 prior episodes of anti-TB treatment (AOR = 1.83, 95% CI: 1.26-2.80).

CONCLUSION

The identified risk factors should be given priority in TB control programs. Additionally, there is a compelling need for better management and control of MDR-TB, particularly through increasing laboratory capacity, regular screening, enhancing drug sensitivity testing, novel MDR-TB drug regimens, and adherence to medication.