Three out of 36 dengue fever cases in Shanghai last year were infections through local spreading. Shanghai has found local infections of dengue fever in both 2017 and 2018, health officials said on Wednesday as they launched a citywide anti-mosquito campaign.
The city has recorded 14 imported dengue fever cases so far this year, while there were only seven in the same period last year.
Dengue fever infection is presenting a challenge to the city with more convenient transport and outbreaks in some southern and eastern regions of the country in recent years, officials said.
Shanghai is at risk of dengue fever spreading as previous monitoring in the city had found a high density of mosquito eggs and larvae in homes and communities.
“Shanghai has imported dengue fever cases every year, which means people get infections in other regions. However, we have a high awareness of local infected cases,” said Yuan Zheng’an with the Shanghai Center for Disease Control and Prevention. “Immediate action such as drug sprays and health education are conducted after reports of local dengue fever cases.”
The peak season for mosquitoes is from June to September. The density will rise along with the increasing rainfall and higher temperatures. “Each subdistrict has established monitoring spots and mosquito prevention and control measures have been widely adopted,” Yuan said.