Estimating the economic burden of respiratory syncytial virus infections in infants in Vietnam: a cohort study

BACKGROUND

Little information is available on the costs of respiratory syncytial virus (RSV) in Vietnam or other low- and middle-income countries. Our study estimated the costs of LRTIs associated with RSV infection among children in southern Vietnam.

METHODS

We conducted a prospective cohort study evaluating household and societal costs associated with LRTIs stratified by RSV status and severity among children under 2 years old who sought care at a major pediatric referral hospital in southern Vietnam. Enrollment periods were September 2019-December 2019, October 2020-June 2021 and October 2021-December 2021. RSV status was confirmed by a validated RT-PCR assay. RSV rapid detection antigen (RDA) test performance was also evaluated. Data on resource utilization, direct medical and non-medical costs, and indirect costs were collected from billing records and supplemented by patient-level questionnaires. All costs are reported in 2022 US dollars.

RESULTS

536 children were enrolled in the study, with a median age of 7 months (interquartile range [IQR] 3-12). This included 210 (39.2%) children from the outpatient department, 318 children (59.3%) from the inpatient respiratory department (RD), and 8 children (1.5%) from the intensive care unit (ICU). Nearly 20% (105/536) were RSV positive: 3.9 percent (21/536) from the outpatient department, 15.7% (84/536) from the RD, and none from the ICU. The median total cost associated with LRTI per patient was US$52 (IQR 32-86) for outpatients and US$184 (IQR 109-287) for RD inpatients. For RSV-associated LRTIs, the median total cost per infection episode per patient was US$52 (IQR 32-85) for outpatients and US$165 (IQR 95-249) for RD inpatients. Total out-of-pocket costs of one non-ICU admission of RSV-associated LRTI ranged from 32%-70% of the monthly minimum wage per person (US$160) in Ho Chi Minh City. The sensitivity and the specificity of RSV RDA test were 88.2% (95% CI 63.6-98.5%) and 100% (95% CI 93.3-100%), respectively.

CONCLUSION

These are the first data reporting the substantial economic burden of RSV-associated illness in young children in Vietnam. This study informs policymakers in planning health care resources and highlights the urgency of RSV disease prevention.

Clinical, Virological, and Cytokine Profiles of Children Infected with Dengue Virus during the Outbreak in Southern Vietnam in 2017

Dengue virus (DENV) infection is a major cause of morbidity and mortality in Vietnam, and the incidence is higher and more consistent in the southern part of the country. This study investigated the circulation of DENV serotypes, viremia levels, immunological status, and cytokine levels, with disease severities among children infected in 2017 in Ho Chi Minh City, Southern Vietnam. Acute and convalescent serum samples were collected from clinically diagnosed dengue children. They were confirmed to have DENV infection by NS1 antigen, IgM and IgG ELISAs, virus isolation, and conventional and real-time RT-PCR. Measurement of 10 cytokine levels was performed in the serum samples. All the children were dengue IgM positive; 28% and 72% of them had primary and secondary DENV infections, respectively, whereas 54% of those with secondary infection were children with dengue with warning signs and with severe dengue. Any or mixed infection of the four serotypes of DENV RNA was detected in 58 children. Twenty DENV strains (DENV-1 = 16 and DENV-4 = 4) were isolated. Levels of IFN-γ, TNF-α, MCP-1, IL-10, and IL-6 were significantly higher in severe dengue cases. We report the predominance of DENV-1 over other serotypes in the 2017 dengue outbreak in Southern Vietnam. Our data showed that cytokine expressions were correlated with dengue pathogenesis and may help in identifying an effective therapeutic strategy.

Risk factors for HIV-1 seropositivity in drug users under 30 years old in Haiphong, Vietnam

AIMS

To assess the prevalence of HIV infection among young drug users in Haiphong and, secondarily, to document the current patterns of drug use and sexual behavior in them. Design, setting and participants. A cross-sectional survey of drug users 15-30 years old, identified from police lists and by the snowballing method between March 15 and May 30, 1999, was conducted in Haiphong City.

MEASUREMENTS

Subjects (n = 520: 514 males and six females) were interviewed and donated blood specimens for HIV-1 antibody testing.

FINDINGS

Mean age of the subjects was 25 years (range 15-30 years). The prevalence of HIV among injecting drug users (IDUs) was 74% and among drug users not reporting injecting was 46% (92/201). Sixty-one per cent (319) reported injecting drugs. Among injectors, 72% used heroin, and 68% had shared needles. Factors related to the presence of HIV antibody among IDUs were sharing needles (OR: 4.12) and injecting more than 31 times per month (OR: 2.37). Extramarital sex within the last 6 months was reported by 44% of single and 24% of married IDUs.

CONCLUSION

The high HIV-1 prevalence in drug users and their frequent sexual mixing with the non-drug-using population suggests that preventive interventions for reduction of high-risk drug taking and sexual activities are urgently needed in these populations. Interventions through public sexually transmitted infection (STI) clinics are unlikely to have much impact, as only 16% of IDUs with an STI attended a public STI clinic.