Abstract
OBJECTIVES: Many viruses can present with clinical symptoms resembling dengue fever (DF), including human parvovirus B19 (B19V). Therefore, patients with DF are not often tested for secondary pathogens. The current study aimed to investigate B19V infection and its association with clinical features in dengue patients. METHODS: A total of 230 subjects were recruited for this study, including patients with DF (n = 86), DF with warning signs (DWS, n = 53), and healthy controls (n = 91). Plasma samples were analyzed for B19V using enzyme-linked immunosorbent assay, nested polymerase chain reaction, sequencing, and phylogenetic analysis. The potential association between B19V infection and dengue progression was investigated. RESULTS: Anti-B19V immunoglobulin M antibodies were detected across all groups: 17.4% in the DF group, 7.5% in the DWS group, and 13.2% in healthy controls. Anti-B19V immunoglobulin G positivity was most prevalent in DF patients (26.7%), followed by healthy controls (22.0%) and DWS patients (20.8%). B19V DNA was identified in 10 of 139 dengue patients (7.2%), but not in healthy controls. The rate of B19V infection was significantly higher in DWS patients than in those with DF, suggesting that B19V infection during dengue may be associated with an increased risk of a more severe form of disease (odds ratio = 4.4, P = 0.043). B19V-positive dengue patients had lower platelet counts compared with B19V-negative patients (P = 0.046), although multivariate analysis revealed no significant difference. In addition, only genotype 1, specifically subgenotype 1A, was detected. CONCLUSIONS: This study reports the prevalence of B19V infection in Vietnamese dengue patients and reveals a potential association with dengue progression and clinical features.