Vector competence of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) for the DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus in Fujian, China

• The study provide the first assessment of vector competence of Aedes mosquitoes for the DEN2-FJ10 and DEN2-FJ11 strains of dengue virus.
• The replicative ability of the DEN2-FJ11 strain was greater than that of the DEN2-FJ10 strain in infected Ae. albopictus.
• In infected Ae. aegypti, rapid proliferation of the DEN2-FJ10 strain occurred earlier than in the DEN2-FJ11 strain.
• Although DEN2-FJ10 and DEN2-FJ11 strains differ in their virulence to neonatal rats, there was no significant difference in the ability of Aedes mosquitoes to transmit two dengue strains.

Dengue is an acute, emerging, infectious disease transmitted by Aedes mosquitoes that has become a serious global public health problem. The DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus were originally isolated from the serum of a patient with dengue fever in Fujian Province, China, in 1999. Our data provide the first assessment of the vector competence of Aedes mosquitoes with respect to the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus. There were significant differences in the replication rates of these two viral strains in Aedes albopictus and Aedes aegypti (P < 0.05); replication of the DEN2-FJ10 strain was greater in Ae. aegypti than in Ae. albopictus 5 days post infection whereas replication of the DEN2-FJ11 was greater in Ae. albopictus than in Ae. aegypti 7 days post infection. The replicative ability of the DEN2-FJ11 strain was greater than that of the DEN2-FJ10 strain in infected Ae. albopictus. In infected Ae. aegypti, rapid proliferation of the DEN2-FJ10 strain occurred earlier than in the DEN2-FJ11 strain. There were no significant differences in the midgut and salivary gland infection rates of Ae. albopictus and Ae. aegypti with respect to either viral strain. Although the DEN2-FJ10 and DEN2-FJ11 strains differ in their virulence to neonatal rats, there was no significant difference in the ability of either Ae. albopictus or Ae. aegypti to transmit the DEN2-FJ10 and DEN2-FJ10 strains of the dengue 2 virus (P > 0.05). In summary, our results indicate that Ae. albopictus and Ae. aegypti mosquitoes are moderately competent vectors of the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus and provide the first evidence of the effect of these two viral strains on the vector competence of mosquitoes in China.