Determinants of the change in empiric antibiotic therapy upon receipt of microbiological data: results from a nationwide antibiotic resistance and use surveillance programme in Madagascar, the TSARA project.

OBJECTIVES

The overuse of antibiotics is a primary driver of resistance development, particularly in low-resource settings such as Madagascar where broad-spectrum antibiotic use is excessive. The objective was to identify factors that could influence changes to the initial antibiotic regimen upon receipt of the microbiological results in Malagasy hospitals.

METHODS

This study was part of the TSARA antibiotic resistance surveillance system implemented in eight hospitals in Madagascar belonging to the RESAMAD (Réseau des Laboratoires à Madagascar) network. The outcome was the change in the spectrum or the discontinuation of the empiric antibiotic regimen upon receiving the laboratory results.

RESULTS

Across the eight participating hospitals, 793 patients were included and the majority of the antibiotic regimens were broad-spectrum (78.8%) which were prescribed in 208 (99.1%) of 210 blood samples. Third-generation cephalosporins were most common (441, 32.1%), with ceftriaxone being the most frequently used antibiotic (421, 30.6%). Upon the receipt of the laboratory results, 21 (2.6%) patients had their empiric antibiotic therapy changed and 530 (66.8%) stopped. A total of 269 (33.9%) patients had positive cultures, with 105 (13.3%) infected by multi-drug-resistant bacteria - primarily third-generation cephalosporin-resistant Enterobacterales. The use of ≥3 empiric antibiotics mainly ceftriaxone, gentamicin, and metronidazole, increased the likelihood of discontinuation (adjusted odds ratio (aOR) = 2.85, P<0.001). Conversely, the availability of antibiotics susceptibility test results decreased the odds of antibiotic discontinuation (aOR = 0.37, P=0.004).

CONCLUSION

This study based in the TSARA surveillance system in Madagascar highlights the influence of clinical factors and microbiological data on antibiotic therapy adjustments. Broad-spectrum antibiotics were widely used as empiric treatment. Availability of the microbiological results decreased the odds of antibiotic discontinuation.