Table 2.

Summary points of urban transmission of mosquito-borne flavivirus in Vietnam.

Flavivirus	Vector	Amplifying host in cities	Risks in the cities	Summary
Japanese encephalitis virus	The major vector Culex tritaeniorhynchus prefers breeding in rice paddies but can be found in cities. Other vectors, such as Cx. quinquefasciatus can breed in sewers in the urban areas	Pigs present in urban agriculture or transported for slaughter	JEV is circulating with low risk in cities	JEV has potential for transmission in urban areas mainly whereurban livestock keeping is presented.
Dengue virus	Both Aedes aegypti (principal vector) and Aedes albopictus (competent vector) breeds easily in cities	Humans	Dengue is hyperendemic from 1960s in large Vietnamese cities	Dengue is circulating all year round with all four serotypes but higher risk in the warmest season. Outbreaks mainly occur in urban areas across the country.
Zika virus	Sameas dengue	Humans	ZIKV is re-emerging as an outbreak in 2016 – early 2017, and but fewer case have been confirmed afterwards	ZIKV has been more common in cities and peri-urban areas of central, central highlands and southern region.
Quang Binh virus	Limited information on epidemiology
Yellow Fever virus	Not found but could potentially be introduced in urban Vietnam
West Nile virus	Not found but could potentially be introduced in urban Vietnam