Orthohantavirus seoulense as a cause of acute, dengue-negative febrile illness in southern Vietnam.

BACKGROUND

Dengue fever has surged in Vietnam since 2021; however, the aetiology of non-dengue undifferentiated febrile illnesses remains poorly understood.

METHODS

Fifty whole blood samples that tested negative in rapid tests for anti-dengue virus antibodies (IgM and IgG) and NS1 viral antigen at Vung Tau General Hospital, southern Vietnam, were subjected to nucleic acid amplification tests for flaviviruses, hantaviruses, Leptospira spp. and Orientia tsutsugamushi, followed by DNA sequencing. The plasma samples were also tested for anti-hantavirus IgM and IgG antibodies using ELISA.

RESULTS

Of the 50 samples, eight were PCR-positive for flaviviruses and two were positive for hantaviruses. Sequencing analysis revealed that three and five of the eight flavivirus-positive samples were dengue virus type 1 and dengue virus type 2, respectively. The hantavirus species was identified as Orthohantavirus seoulense (SEOV). None of the patients tested positive for Leptospira spp. or O. tsutsugamushi. Anti-hantavirus IgM and IgG antibodies were detected in five and four patients, respectively.

CONCLUSIONS

This study suggests that SEOV is a notable contributor to dengue-negative febrile illnesses in southern Vietnam.

ACCESSION NUMBER

LC822654.