The legal basis for implementing Aedes invasive mosquito surveillance varies over responding countries: as part of a legal framework on disease surveillance (5/20) countries; linked to the International Health Regulations (Greece, Ireland, Portugal, and Spain); based on specific legislation related to mosquito surveillance (Croatia, The Netherlands and Portugal). Greece mentioned that the surveillance is embedded in Ministry of Health (Ministry of Health) circular on 'Vector management plan as response to DENV, CHIKV, ZIKV cases (2016)', and that mosquito surveillance targeting Aedes invasive species is implemented at points of entry according to the International Health Regulation, and referred to a circular of the Ministry of Health on basic hygiene requirements of the country's points of entry (ports) for preparedness and response against infectious diseases' cases (2023). The plan of prevention and control of vector-borne diseases is part of Portugal's legal and institutional response to protect public health from diseases such as dengue, chikungunya virus disease, and Zika virus disease, which can be transmitted by Aedes mosquitoes. Legal justification is also tied to the need for early detection of Aedes invasive species and rapid containment of outbreaks, which are essential under both national and international health regulations. The plan mandates coordinated action among health authorities, regional and local health entities, and other stakeholders, reinforcing the context for a legal and operational basis. This is under the Ministry of Health and funded by the state budget. The UK has a contingency plan which is actioned by the UK National Security Risk Assessment and the National Adaptation Programme, which is related to the UK Climate Change Act.
Ten of the 20 countries implementing Aedes invasive mosquito surveillance state that the Ministry of Health at the national level is responsible for the surveillance. In one country (Italy), the Ministry of Environment at the national level has the responsibility. One country (Montenegro) mentions that the Ministry of Health at subnational has overall responsibility and oversight of vector surveillance. One country (Serbia) refers to the Ministry of Agriculture at the sub-national level, one country (Croatia) refers to both the Ministry of Health at the subnational level and the Ministry of Agriculture at the sub-national level, and one country (Belgium) to both the Ministry of Health at the sub-national level and the Ministry of Environment at the sub-national level. In Spain, the responsibility of entomological surveillance lies with each of the 17 regions, and Aedes invasive mosquito surveillance at point of entry is the responsibility of the Ministry of Health. In Greece, the Ministry of Health (National Public Health Organization) is responsible for mosquito surveillance at the national level, and the Ministry of Health is responsible for the regional and municipal authorities which are responsible for mosquito management at the local level. Also, in Hungary, the Ministry of Interior is responsible for the Aedes invasive mosquito surveillance. In the UK, the UKHSA coordinates mosquito surveillance, local authorities are required to help support this as per the national contingency plan.
In 14 out of the 20 countries, the Aedes invasive mosquito surveillance plan is designed at the national level by scientific or academic institutions (10/17 countries). Other entities responsible for the design of the surveillance plan are: public or veterinary health agencies (9/20 countries), a working group within a Ministry (Italy, Luxembourg, and Portugal), dedicated agency (The Netherlands), or working group between ministries (Belgium). In Spain this is the responsibility of the Regions and for points of entry the Ministry of Health organizes the surveillance subcontracting academic institutions. In Greece the surveillance plan is designed by a Public Health Agency (the National Public Health Organization) at national level, and by the regional, municipal public health and mosquito management authorities at sub-national (regional and municipal) level.
The evaluation and possible re-adjustments of the mosquito vector surveillance plan in most countries (18/20 countries) is done by the same organization or agency that develops the surveillance plan. In the Netherlands, the Dutch National Institute of Health organises an interdisciplinary group meeting twice a year and discusses the results of the previous year and the plans for the next. Nine of the 20 countries evaluate and re-adjust the surveillance plan annually, four countries (Italy, Luxembourg, Spain, UK) do this every two to five years and four countries (Austria, Slovakia, Slovenia, Serbia) said that they never evaluate and re-adjustment their surveillance plans.
The execution of the vector surveillance is mostly done by public or veterinary health agencies (11/20) or scientific institutions (11/20 countries). One country (Netherlands) has a dedicated agency for the execution of surveillance. In three countries (Greece, Luxembourg, Spain), mosquito surveillance is executed by private companies. In Greece, the national mosquito surveillance plan is executed by a Public Health Agency and scientific, academic, or research institutions, whereas the regional municipal public health and mosquito management authorities execute the mosquito surveillance activities through contracts with private companies, at subnational and local levels. In Portugal day-to-day mosquito surveillance activities are executed by Local Public Health Units under the coordination of regional public health entities and the Reference Laboratory for Acarology and Entomology of INSA. Additionally, efforts in these areas are occasionally carried out within the scope of research projects developed by academia or by public and private Portuguese research institutes. In Austria, the management of the traps is organised by the federal health directorates for national monitoring. This is organised differently depending on the federal state: in some, one person or institution is responsible for looking after all traps, while in others individual locations are managed by employees of federal offices, employees of AGES, or private individuals.