Investigation on the epidemic risk and prevention and control status of dengue fever at construction sites in Longgang District,Shenzhen,China
Objective To investigate the current situation of dengue fever prevention and control at construction sites in Longgang District,Shenzhen,China,and to propose targeted prevention and control suggestions.Methods A field survey on mosquito density and breeding sites was conducted in September 2023 to investigate the Breteau index,the types of mosquito breeding sites,and the rate of mosquito density exceeding the standard at construction sites,and to analyze the influence of mosquito control measures and regulations and the management's knowledge of dengue fever prevention and control on the control of vector mosquitoes at construction sites.The Chi-square test or Fisher's exact test was used to compare the rates,and the changes in rates were tested by the Chi-square test for trend.Results A total of 48 construction sites,30 sheds,and 41 basements were investigated.The average Breteau index values of the sheds and basements were 4.62 and 4.51,respectively,and the mosquito density below the standard limit of the sheds by 33.33%and of the basement by 31.71%.The shed-related breeding places mainly included standing water around domestic waste,standing water around construction waste,and domestic water storage containers,and the basement-related breeding places mainly included low-lying standing water on the ground,drainage ditches,and shafts.For dengue prevention and control requirements,14.58%of the site managers had a good knowledge,79.17%had a fair knowledge,and 6.25%had no knowledge.A higher level of knowledge of dengue prevention and control of site managers was associated with a higher rate of mosquito density reaching the standard at construction sites(the Chi-square test for trend,x2=5.070,P=0.038).Regular mosquito control was conducted at 95.83%of the construction sites(once every two weeks or more,68.78%;once every one or two months,27.08%);43.75%of the construction sites did not regularly apply sustained-release larvicides to standing water,with the rate of mosquito density reaching the standard being 45.00%,and the remaining 56.25%sites regularly used sustained-release larvicides,with the rate of mosquito density reaching the standard being 77.77%,showing a significant difference between the two(x2=5.347,P=0.032).Conclusions The construction sites in Longgang District are densely populated and the density of vector mosquitoes is high,indicating a high risk of dengue fever outbreaks.The site management should pay attention to the prevention and control of dengue fever,and reduce the risk of transmission of dengue fever through environmental modification and the use of mosquito larvae control pesticides.
Construction siteDengue feverMosquito vector controlSurvey