1 Interdisciplinary Program of Biomedical Sciences, Faculty of the Graduate School, Chulalongkorn
2 Departments of Medical Entomology, Faculty of Tropical Medicines, Mahidol University, Bangkok
3 National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Nonthaburi
4 Departments of Parasitology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
Aedes albopictus C6/36 cell line was used to evaluate dengue virus serotype-3 (DENV-3) and chikungunya virus (CHIKV) co-infection. Virus infection was determined using a one-step duplex reverse transcriptase polymerase chain reaction (D-PT-PCR). D-PT-PCR was positive for both viruses when equal multi-plicity of infection (MOI) was utilized. Co-infection with diffent titers between a higher CHIKV titer (MOI = 1.0) than DENV-3 titer (MOI = 1.0) showed similar results with that of equal titer. However, Co-infection with a lower CHIKV titer (MOI = 1.0) than DENV-3 titer (MOI = 1.0) revealed positive results for only dengue virus infection, suggesting DENV competitive suppression of CHIKV. This competitive suppression occurred in mixed-infection samples but not in individually double infection (super infection) samples which produced both dengue anf chikungunya virus progenies. Both virus replications depend on the amount of virus titer rather than serial infection. These findings have provided information regarding pathogen-pathogen interaction in host cell, Which could be used to predict outbreaks and to develop virus detection and vector control.