Laboratory-based surveillance of Shigella spp. from human clinical cases in Colombia, 1997-2018

INTRODUCTION: Shigellosis is endemic in low-and middle-income countries, causing approximately 125 million episodes of diarrhea and leading to approximately 160 .000 deaths annually one-third of which is associated with children. OBJECTIVE: To describe the characteristics and antimicrobial resistance profiles of Shigella species recovered in Colombia from 1997 to 2018. MATERIALS AND METHODS: We received isolates from laboratories in 29 Colombian departments. We serotyped with specific antiserum and determined antimicrobial resistance and minimal inhibitory concentrations for ten antibiotics with Kirby-Bauer tests following the Clinical and Laboratory Standards Institute recommendations. RESULTS: We analyzed 5,251 isolates of Shigella spp., most of them obtained from stools (96.4%); 2,511 (47.8%) were from children under five years of age. The two most common species were S. sonnei (55.1%) and S. flexneri (41.7%). The highest resistance rate was that of tetracycline (88.1%) followed by trimethoprim-sulfamethoxazole (79.3%) and ampicillin (65.5%); 50.8% of isolates were resistant to chloramphenicol, 43.6% to amoxicillin/clavulanic acid, and less than 1% to cefotaxime, ceftazidime, gentamicin, and ciprofloxacin. In S. sonnei, the most common resistance profile corresponded to trimethoprim-sulfamethoxazole (92%) whereas in S. flexneri the most common antibiotic profiles were multidrug resistance. CONCLUSIONS: In Colombia, children under five years are affected by all Shigella species. These findings should guide funders and public health officials to make evidence-based decisions for protection and prevention measures. The antimicrobial resistance characteristics found in this study underline the importance of combating the dissemination of the most frequently isolated species, S. sonnei and S. flexneri.