Molecular detection and spatial distribution of circulating dengue virus serotypes in an urban high-incidence area of Mataram, Indonesia (2024–2025)

Abstract Dengue fever (DF) is a mosquito-borne viral disease caused by four dengue virus serotypes (DENV-1 to DENV-4) and remains a major public health concern in tropical regions, including Indonesia. In 2024, Mataram City reported 364 confirmed dengue cases, indicating a substantial local burden. This observational cross-sectional study was conducted from November 2024 to January 2025 in eight high-incidence neighborhood associations within the Karang Pule Health Center working area, Mataram City. Mosquito larvae and ovitrap samples were collected from case-based households following WHO entomological surveillance guidelines, reared to F1 adult females, and pooled (20 mosquitoes per site) for viral RNA extraction. Dengue virus detection and serotyping were performed using a one-step RT-PCR assay with serotype-specific primers, including appropriate positive and negative controls to ensure assay validity. Five of eight sampling locations were positive for DENV. DENV-3 was the predominant serotype, detected in three locations, while co-circulation of DENV-2 and DENV-3 was identified in two locations. No DENV-1 or DENV-4 was detected. Villages such as West Pagutan exhibited the highest proportion of reported cases and incidence rates. Environmental parameters (temperature, humidity, water temperature, and light intensity) were recorded at each site and analyzed descriptively. The detection of DENV in F1-generation Aedes aegypti supports evidence of ongoing local viral circulation and suggests the potential contribution of vertical (transovarial) transmission in maintaining the virus reservoir. This study provides fine-scale, sub-district-level mapping of dengue serotype distribution in an urban Indonesian setting, offering localized evidence to support targeted vector control strategies while acknowledging limitations related to sample size and geographic coverage.