Diagnostic challenges of arboviral infections and dengue virus serotype distribution in febrile patients in East Java, Indonesia.

Arboviruses pose significant public health threats worldwide, with Southeast Asia being a hotspot for these infections. This study aimed to reassess the incidence of dengue, Zika, and chikungunya viruses in patients clinically diagnosed with dengue in East Java, Indonesia in 2023. The study included 108 patients admitted to hospitals in Jember, with blood samples collected on admission. Multiplex reverse transcription-polymerase chain reaction was used to detect viral RNA for dengue, Zika, and chikungunya, whereas dengue serotypes were identified using real-time polymerase chain reaction. A total of 67 of 108 (62%) patients tested positive for dengue virus (DENV), one patient tested positive for chikungunya, and no cases of Zika were detected. Differences in laboratory parameters between patients who were DENV RNA-negative and confirmed dengue cases suggest possible misdiagnosis of dengue. Serotyping of DENV-positive samples revealed DENV serotype 3 as the predominant serotype in Jember, accounting for 34% of cases (n = 23 of 67), followed by DENV serotype 1 and DENV serotype 2 at 19% each (n = 13 of 67) and 6% for DENV-4 (n = 4 of 67), whereas 21% (n = 14 of 67) remained untyped. This study highlights the nature of the dengue outbreak in Jember in 2023, where all four DENV serotypes were in circulation, and underlines the need for serological or nucleic acid-based methods to improve arbovirus diagnosis in the region.