Trombiculid “chigger” mites (Acari) are ectoparasites that feed blood on rodents and another animals. A crosssectional survey was conducted in 7 ecosystems of southern Vietnam from 2015 to 2016. Chigger mites were identified with morphological characteristics and assayed by polymerase chain reaction for detection of rickettsiaceae. Overall chigger infestation among rodents was 23.38%. The chigger index among infested rodents was 19.37 and a mean abundance of 4.61. A total of 2,770 chigger mites were identified belonging to 6 species, 3 genera, and 1 family, and pooled into 141 pools (10-20 chiggers per pool). Two pools (1.4%) of the chiggers were positive for Orientia tsutsugamushi. Ricketsia spp. was not detected in any pools of chiggers. Further studies are needed including a larger number and diverse hosts, and environmental factors to assess scrub typhus.

Backgroud: The aim of this study is to update on antibiotic resistance of common pathogenical bacteria isolated in Hue University of Medicine and Pharmacy Hospital (Hue UMP Hospital). Methodology: Use of the agar disk diffusion method to test the susceptibility to antimicrobial agents of 3709 bacterial strains from infected patients hospitalized in Hue UMP Hospital in 2020 - 2022. Results: Among 3709 strains of pathogenical bacteria isolated, S.aureus was found with the rate of 29.9%, followed by E. coli (24.5%), Pseudomonas aeruginasa (17.8%), Enterococcus spp. (11.8%), Klebsiella spp (9.7%) and Acinetobacter spp (4.1%). The proportion of bacterial isolates has changed, but Staphylococcus aureus is still highest rate. S.aureus is resistant to many antibiotics, but MRSA strains have decreased significantly, from 73.3% in 2020 to 62.5% in 2022. Pseudomonas aeruginosa was resistant to some of the group A recommended antibiotics such as ceftazidime, piperacillin-tazobactam with the rate of 56.6% and 48.7%. The percentage of E. coli with ESBL strains (+) was at 28.2% - 30.3%. Enterococus spp strains are still sensitive to vancomycin (83.1% - 91.9%). The rate of Klebsiella ESBL (+) is only 6.9% to 8.2%. The strains of Acinetobacter spp were highly resistant to Piperacillin (100%) and Ceftriaxone (96.5%) but they are still sensitive to imipenems 70 - 71%, highly sensitive to Doxycillin (95.2%) and Cefotaxime (88.4%). Conclusion: Many bacterial strains are resistant to many commonly antibiotics. Providing timely, regular, and effective management of antibiotic resistance patterns for common pathogenic bacteria in hospitals, will help reduce the risk of bacterial resistance.