Field sampling methods for mosquitoes, sandflies, biting midges and ticks

Abstract

ECDC and EFSA have the mandate to assess the risk of infectious diseases affecting public and animal health and strengthen the capacity for their prevention and control in the EU. Vector-borne diseases, as a specific group of a (re-)emerging infections, pose a threat to European public health and require particular attention. One important aspect of preparedness for vector-borne diseases is the monitoring or surveillance of the introduction, establishment and spread of the main disease vectors. An efficient surveillance or monitoring campaign starts with the development of a well-considered sampling strategy. Depending on the target species, a range of sampling methods is available. This implies that different teams use different approaches and as operational vector sampling methods often lack standardisation, quantitative comparisons across different settings are very hard to make. This also implies that teams starting a disease surveillance project can get overwhelmed by the sheer amount of options and may end up choosing a strategy that is less than ideal to meet their objectives. Although some guidelines exist on the sampling of invasive and native mosquito species in Europe [1-3], there is no summary document on sampling strategies for the various vector species. In the framework of VectorNet, pan-European field campaigns were established to collect data on the presence/absence or seasonal distribution of mosquitoes, sandflies, biting midges and ticks. To standardise the efforts across different teams and to ensure comparable outcomes, a set of protocols were developed for every species group. These protocols describe a uniform way to sample specimens for the four above-mentioned groups. The protocols also describe the conservation of specimens, identification and quality control. Depending on the vector group, the protocols are subdivided according to activity (e.g. flying vs resting mosquitoes and sandflies), life stage (mosquitoes), or species (ticks). Each section describes in detail which traps should be used to meet specific study objectives, how to select a sampling site, when to sample and how long or how often, how to collect the samples, how to preserve them, how to identify them, and how to assess quality.

A quantitative comparison of West Nile virus incidence from 2013 to 2018 in Emilia-Romagna, Italy

“…The mosquito surveillance program in the study region is based on weekly captures performed between June and October each year with carbon dioxide baited traps [23] located across the area. Between 88 and 104 locations were chosen each year, to evenly monitor the entire surveillance area.…”

Surveillance of Mosquitoes (Diptera, Culicidae) in a Northern Central Region of Spain: Implications for the Medical Community

“…Traps were placed at dusk and checked the following morning and, at the same time, the mosquitoes were captured by human landing technique during 10 min per trap using mouth aspirators (30). Resting adults were captured from natural and artificial hiding places and the surrounding vegetation in breeding sites by vacuuming (31) using an InsectaZooka and an AC/DC aspirators (Bioquip Products, Rancho Dominguez, CA, USA).…”

“…The entomological programme also included the surveillance of Ae. albopictus using ovitraps (31) in the most important cities because it was known to be present in three border regions, the Basque country, Aragón (32), and in Navarra (unpublished data). A total of 80 ovitraps locations were chosen in selected municipalities (blue points and Logroño city, Figure 1).…”

Phlebotomine sand flies in Southwest Germany: an update with records in new locations

“…All locations were properly inspected, and habitat types were identified (animal shelters, farms, old quarries, caves) according to standard protocols [35]. In 2017, the area was extended to RLP, the area where P. perniciosus was trapped in 2001.…”