Modelling the progression of pandemic influenza A (H1N1) in Vietnam and the opportunities for reassortment with other influenza viruses

BACKGROUND: A novel variant of influenza A (H1N1) is causing a pandemic and, although the illness is usually mild, there are concerns that its virulence could change through reassortment with other influenza viruses. This is of greater concern in parts of Southeast Asia, where the population density is high, influenza is less seasonal, human-animal contact is common and avian influenza is still endemic. METHODS: We developed an age- and spatially-structured mathematical model in order to estimate the potential impact of pandemic H1N1 in Vietnam and the opportunities for reassortment with animal influenza viruses. The model tracks human infection among domestic animal owners and non-owners and also estimates the numbers of animals may be exposed to infected humans. RESULTS: In the absence of effective interventions, the model predicts that the introduction of pandemic H1N1 will result in an epidemic that spreads to half of Vietnam's provinces within 57 days (interquartile range (IQR): 45-86.5) and peaks 81 days after introduction (IQR: 62.5-121 days). For the current published range of the 2009 H1N1 influenza's basic reproductive number (1.2-3.1), we estimate a median of 410,000 cases among swine owners (IQR: 220,000-670,000) with 460,000 exposed swine (IQR: 260,000-740,000), 350,000 cases among chicken owners (IQR: 170,000-630,000) with 3.7 million exposed chickens (IQR: 1.9 M-6.4 M), and 51,000 cases among duck owners (IQR: 24,000 - 96,000), with 1.2 million exposed ducks (IQR: 0.6 M-2.1 M). The median number of overall human infections in Vietnam for this range of the basic reproductive number is 6.4 million (IQR: 4.4 M-8.0 M). CONCLUSION: It is likely that, in the absence of effective interventions, the introduction of a novel H1N1 into a densely populated country such as Vietnam will result in a widespread epidemic. A large epidemic in a country with intense human-animal interaction and continued co-circulation of other seasonal and avian viruses would provide substantial opportunities for H1N1 to acquire new genes

Antimicrobial Resistance Patterns of Staphylococcus Aureus Isolated at a General Hospital in Vietnam Between 2014 and 2021

Nguyen Van An,1,* Le Ha long Hai,2,3,* Vu Huy Luong,4,5 Nguyen Thi Ha Vinh,5,6 Pham Quynh Hoa,7 Le Van Hung,5,7 Nguyen Thai Son,1 Le Thu Hong,1 Dinh Viet Hung,8 Hoang Trung Kien,9 Minh Nhat Le,10,11 Nguyen Hoang Viet,12 Duc Hoang Nguyen,13 Ngai Van Pham,14 Ta Ba Thang,15 Tran Viet Tien,16 Le Huy Hoang17 1Department of Microbiology, Military Hospital 103, Vietnam Military Medical University, Hanoi, Vietnam; 2Department of Clinical Microbiology and Parasitology, Faculty of Medical Technology, Hanoi Medical University, Hanoi, Vietnam; 3Department of Biochemistry, Hematology and Immunology, National Hospital of Dermatology and Venereology, Hanoi, Vietnam; 4Department of Laser and Skin Care, National hospital of Dermatology and Venereology, Hanoi, Vietnam; 5Department of Dermatology and Venereology, Hanoi Medical University, Hanoi, Vietnam; 6Department of General Planning, National hospital of Dermatology and Venereology, Hanoi, Vietnam; 7Department of Microbiology, Mycology and Parasitology, National hospital of Dermatology and Venereology, Hanoi, Vietnam; 8Department of Psychiatry, Military Medical 103, Vietnam Military Medical University, Hanoi, Vietnam; 9Department of Immunology, Vietnam Military Medical University, Hanoi, Vietnam; 10Tay Nguyen Institute of Science Research, Vietnam Academy of Science and Technology, VAST, Hanoi, Vietnam; 11Antimicrobial Resistance Research Center, National Institute of Infectious Disease, Tokyo, Japan; 12Molecular Pathology Department, Faculty of Medical Technology, Hanoi Medical University, Hanoi, Vietnam; 13Cardiovascular Laboratories, Methodist Hospital, Merrillville, Indiana, USA; 14Medical Testing Center, Medlatec Group, Hanoi, Vietnam; 15Respiratory Center, Military Hospital 103, Vietnam Military Medical University, Hanoi, Vietnam; 16Department of Infectious diseases, Military Hospital 103, Vietnam Medical Military University, Hanoi, Vietnam; 17Department of Bacteriology, National of Hygiene and Epidemiology, Hanoi, Vietnam*These authors contributed equally to this workCorrespondence: Le Huy Hoang, Department of Bacteriology, National of Hygiene and Epidemiology, Hanoi, 100000, Vietnam, Tel + 84 977 803 986, Email [email protected]: Staphylococcus aureus is a commensal bacteria species that can cause various illnesses, from mild skin infections to severe diseases, such as bacteremia. The distribution and antimicrobial resistance (AMR) pattern of S. aureus varies by population, time, geographic location, and hospital wards. In this study, we elucidated the epidemiology and AMR patterns of S. aureus isolated from a general hospital in Vietnam.Methods: This was a cross-sectional study. Data on all S. aureus infections from 2014 to 2021 were collected from the Microbiology department of Military Hospital 103, Vietnam. Only the first isolation from each kind of specimen from a particular patient was analyzed using the Cochran–Armitage and chi-square tests.Results: A total of 1130 individuals were diagnosed as S. aureus infection. Among them, 1087 strains were tested for AMR features. Most patients with S. aureus infection were in the age group of 41– 65 years (39.82%). S. aureus isolates were predominant in the surgery wards, and pus specimens were the most common source of isolates (50.62%). S. aureus was most resistant to azithromycin (82.28%), erythromycin (82.82%), and clindamycin (82.32%) and least resistant to teicoplanin (0.0%), tigecycline (0.16%), quinupristin-dalfopristin (0.43%), linezolid (0.62%), and vancomycin (2.92%). Methicillin-resistant S. aureus (MRSA) and multidrug-resistant (MDR) S. aureus were prevalent, accounting for 73.02% and 60.90% of the total strains respectively, and the strains isolated from the intensive care unit (ICU) had the highest percentage of multidrug resistance (77.78%) among the wards.Conclusion: These findings highlight the urgent need for continuous AMR surveillance and updated treatment guidelines, particularly considering high resistance in MRSA, MDR strains, and ICU isolates. Future research focusing on specific resistant populations and potential intervention strategies is crucial to combat this rising threat.Keywords: Staphylococcus aureus, antimicrobial resistance, methicillin-resistant S. aureus, multidrug resistance, Hanoi, Vietna