Prevalence and Characterization of Gastroenteritis Viruses among Hospitalized Children during a Pilot Rotavirus Vaccine Introduction in Vietnam.

Rotavirus (RV), norovirus (NoV), sapovirus (SaV), and human astrovirus (HAstV) are the most common viral causes of gastroenteritis in children worldwide. From 2016 to 2021, we conducted a cross-sectional descriptive study to determine the prevalence of these viruses in hospitalized children under five years old in Nam Dinh and Thua Thien Hue provinces in Vietnam during the pilot introduction of the RV vaccine, Rotavin-M1 (POLYVAC, Hanoi, Vietnam). We randomly selected 2317/6718 (34%) acute diarrheal samples from children <5 years of age enrolled at seven sentinel hospitals from December 2016 to May 2021; this period included one year surveillance pre-vaccination from December 2016 to November 2017. An ELISA kit (Premier Rotaclone®, Meridian Bioscience, Inc., Cincinnati, OH, USA) was used to detect RV, and two multiplex real-time RT-PCR assays were used for the detection of NoV, SaV and HAstV. The prevalence of RV (single infection) was reduced from 41.6% to 22.7% (p < 0.0001) between pre- and post-vaccination periods, while the single NoV infection prevalence more than doubled from 8.8% to 21.8% (p < 0.0001). The SaV and HAstV prevalences slightly increased from 1.9% to 3.4% (p = 0.03) and 2.1% to 3.3% (p = 0.09), respectively, during the same period. Viral co-infections decreased from 7.2% to 6.0% (p = 0.24), mainly due to a reduction in RV infection. Among the genotypeable samples, NoV GII.4, SaV GI.1, and HAstV-1 were the dominant types, representing 57.3%, 32.1%, and 55.0% among the individual viral groups, respectively. As the prevalence of RV decreases following the national RV vaccine introduction in Vietnam, other viral pathogens account for a larger proportion of the remaining diarrhea burden and require continuing close monitoring.

Outpatient antibiotic prescribing for acute respiratory infections in Vietnamese primary care settings by the WHO AWaRe (Access, Watch and Reserve) classification: An analysis using routinely collected electronic prescription data.

Background: This study aims to investigate patterns of antibiotic prescribing and to determine patient-specific factors associated with the choice of antibiotics by the World Health Organization's Access-Watch-Reserve (WHO AWaRe) class for acute respiratory infections (ARIs) in rural primary care settings in northern Vietnam. Methods: We retrospectively reviewed health records for outpatients who were registered with the Vietnamese Health Insurance Scheme, visited one of 112 commune health centres in 6 rural districts of Nam Dinh province, Vietnam during 2019, and were diagnosed with ARIs. Patient-level prescription data were collected from the electronic patient databases. We used descriptive statistics to investigate patterns of antibiotic prescribing, with the primary outcomes including total antibiotic prescriptions and prescriptions by WHO AWaRe group. We identified patient-specific factors associated with watch-group antibiotic prescribing through multivariable logistic regression analysis. Findings: Among 193,010 outpatient visits for ARIs observed in this study, 187,144 (97.0%) resulted in an antibiotic prescription, of which 172,976 (92.5%) were access-antibiotics, 10,765 (5.6%) were watch-antibiotics, 3366 (1.8%) were not-recommended antibiotics. No patients were treated with reserve-antibiotics. The proportion of watch-antibiotic prescription was highest amongst children under 5-years old (18.1%, compared to 9.5% for 5-17-years, 4.9% for 18-49-years, 4.3% for 50-64-years, and 3.7% for 65-and-above-years). In multivariable logistic regression, children, district, ARI-type, comobid chronic respiratory illness, and follow-up visit were associated with higher likelihood of prescribing watch-group antibiotics. Interpretation: The alarmingly high proportion of antibiotic prescriptions for ARIs in primary care, and the frequent use of watch-antibiotics for children, heighten concerns around antibiotic overuse at the community level. Antimicrobial stewardship interventions and policy attention are needed in primary care settings to tackle the growing threat of antibiotic resistance. Funding: This work was supported through Australian government and UK aid from the UK government funding to FIND (Foundation for Innovative New Diagnostics) grant number FO17-0015, in addition to a Wellcome Trust grant (213920/Z/18/Z), and an Oxford University Clinical Research Unit internal grant from the Wellcome Trust Africa Asia Programme core grant in Vietnam (106680/Z/14/Z).