Molecular epidemiology of dengue in a setting of low reported endemicity: Kupang, East Nusa Tenggara province, Indonesia

Background: Most regions in Indonesia experience annual dengue epidemics. However, the province of East Nusa Tenggara has consistently reported Low incidence. We conducted a dengue molecular epidemiology study in Ku pang, the capital of the province. Methods: Dengue patients were recruited from May 2016 to September 2017. Dengue virus (DENV) screening was performed using NS1 and immunoglobulin G (IgG)/IgM detection. Serotype was determined using reverse transcription polymerase chain reaction and the envelope genes were sequenced to infer the genetic identity and phylogeny. Results: From 119 patients, dengue was confirmed in 62 (52%). Compared with official data, underreporting of dengue incidence was observed. The majority (36%) of patients were children <10 y of age. Most patients (80%) experienced mild fever. ALL serotypes were detected, with DENV-3 as the predominant (57%). Kupang DENV-1 isolate was classified as genotype IV, an old and endemic strain, DENV-2 as cosmopolitan, DENV-3 as genotype I and DENV-4 as genotype II. Most isolates showed relatively Low evolutionary rates and are closely related with strains from Bali and Timor Leste. Conclusions: The Low dengue incidence was most Likely caused by sustained Local circulation of endemic viruses. This study provides information on the epidemiology of dengue in a low-endemicity setting that should help future mitigation and disease management.

Automated summary

The province of East Nusa Tenggara in Indonesia has consistently reported low incidence of dengue, with children under 10 years old being the majority of patients experiencing mild fever. All dengue serotypes were detected, with DENV-3 being the predominant strain.