A 24-year female with abdominal pain and fever for 4 days was admitted. The blood culture showed Leuconostoc growth, and sputum culture showed positive Acinetobacterbaumannii. The diagnosis Leuconostoclactis bacteremia following small intestinal perforation was confirmed; surgical treatment was performed and the infection was controlled by piperacillin sodium and tazobactam combined with tegacycline. Wanfang database, CNKI, PubMed and Embase database up to September 2020 were searched with the keywords of " Leuconostoc lactis" "infection" "bacteraemia" for relevant literature. A total of 32 cases were reported in the literature, of whom 13 (39.4%) were infants, 17 (51.5%) had catheter-related bloodstream infection, and one healthy adult male had bacteremia through gastrointestinal perforation. In 20 patients treated with penicillins-based antibiotics, 18 were cured with an effective rate of 90.0%. The results suggest that Leuconostoc infection is likely to occur in the infants, but adults can still get community-acquired Leuconostoc infection. Most β-lactams are susceptible to Leuconostoc, but some exhibit resistance, so it is recommended to select antimicrobial agents based on drug susceptibility.

OBJECTIVE To assess the cost-effectiveness of durvalumab combined with chemotherapy as a first-line treatment for advanced biliary tract cancer from the perspective of the Chinese healthcare system. METHODS Using data from the TOPAZ-1 clinical trial， a three-state Markov model comprising progression-free survival （PFS）， progressive disease （PD） and death was developed， with a cycle length of 21 days and a 10-year time horizon. Patients in the observation group received durvalumab in combination with gemcitabine and cisplatin， whereas those in the control group received placebo plus the same chemotherapy regimen. The evaluation indexes were quality-adjusted life year （QALY） and the incremental cost-effectiveness ratio （ICER）. The willingness-to-pay （WTP） threshold was set at three times the 2024 Chinese per capita gross domestic product （GDP） （287 247 yuan/QALY）. The sensitivity analyses， along with scenario analyses， were performed. RESULTS In the base-case analysis， the ICER of observation group compared to control group was 1 166 344.46 yuan/QALY， far exceeding the WTP threshold， indicating that the regimen was not cost-effective. One-way sensitivity analysis identified the PD state utility， discount rate， cost of durvalumab， and PFS state utility as the main drivers of ICER variation. Probabilistic sensitivity analysis showed that， at the above WTP threshold， the probability of the acceeptance of this regimen was 0， further supporting the robustness of the base-case findings. In the scenario analysis， inclusion of a patient assistance program reduced the ICER to 235 885.16 yuan/ QALY， below the above WTP threshold， suggesting cost-effectiveness under this assistance program. However， when applying a regional WTP threshold set at three times the per capita GDP （158 475 yuan/QALY） of Gansu Province （the province with the lowest GDP in China in 2024）， the ICER remained above the threshold， indicating that the regimen was not cost-effective at the regional level. CONCLUSIONS At current pricing， durvalumab plus chemotherapy as a first-line treatment for advanced biliary tract cancer is not cost-effective in China. Although the introduction of a patient assistance program can substantially reduce the ICER and achieve cost-effectiveness at a WTP threshold set at three times the 2024 per capita GDP of China， due to limited affordability in low-income areas， the program remains not cost-effective.