The Mosticare Mosquito Risk Explainer: how ECDC's four risk levels for Aedes-borne disease map to the protection you actually need

Europe's mosquito risk is no longer one number. The risk of catching dengue, chikungunya or Zika from a mosquito bite in Lisbon is not the risk in Munich, and neither is the risk in a town on the French Mediterranean coast where a cluster of local cases was confirmed last summer. For years that variation was left implicit. It is now written down.

In July 2025 the European Centre for Disease Prevention and Control (ECDC) published Public health guidance for assessing and mitigating the risk of locally-acquired Aedes-borne viral diseases in the EU/EEA. The guidance sorts every area in the EU/EEA into one of four risk levels, from areas with no established mosquito vectors to areas where the viruses circulate independently of travel. It was written for public-health authorities, laboratories and emergency planners. But the framework is genuinely useful to anyone deciding how much mosquito protection a household actually needs, because it answers the first question honestly: where, on the risk map, are you?

This explainer does two things. First, it sets out the four levels as ECDC defines them, in plain terms. Second, it translates each level into a proportionate protection choice, grounded in World Health Organization personal-protection guidance rather than in fear. The framework is the ECDC's. The protection mapping is ours, and we will be clear about which is which.

Why Europe needed a tiered framework

Two mosquitoes drive this. Aedes albopictus, the Asian tiger mosquito, can transmit dengue, chikungunya and Zika viruses. Aedes aegypti, the yellow fever mosquito, can transmit the same viruses and yellow fever. Both are invasive in Europe, and both are day-biting, which matters later when we talk about protection.

The epidemiological picture changed quickly. ECDC's guidance records that Aedes albopictus has been reported in 13 countries in the European Union, and that Aedes aegypti has been detected in parts of the EU including Cyprus, the Canary Islands (Spain) and Madeira (Portugal). Warmer, longer summers extend the window in which these mosquitoes can breed and in which a virus can complete its cycle inside them. At the same time, international travel keeps importing the viruses in the blood of returning travellers. A single imported case in a place where the vector is established and the weather is warm is all it takes to start a local chain of transmission.

That is why a single European risk number would be misleading. The risk is local, and it moves. The four-level framework is ECDC's way of describing that movement so that the response can be proportionate: light where the risk is low, intensive where it is high.

The four levels, as ECDC defines them

ECDC divides areas at risk of autochthonous (locally acquired) transmission into four levels, with two sub-levels each for Levels 2 and 3. The dividing lines are not arbitrary. They track three things: whether the mosquito is established, whether local transmission has actually happened, and how well it can be traced.

Level 1: no established vectors. Areas without established populations of the Aedes vectors sit at Level 1. There is no local mosquito capable of passing these viruses on, so there is no locally acquired risk.

Level 2: predisposed areas. Here the vectors are established, meaning ECDC has evidence of populations that over-winter and reproduce, but no local transmission of the virus has been detected in the current season. ECDC splits this into two sub-levels using two ideas worth learning:

• Receptivity is how suitable the area is for transmission: the presence and density of Aedes mosquitoes plus the ecological and climatic conditions that favour the virus.
• Vulnerability is how likely the virus is to arrive and spread undetected: the influx of infected travellers and the health system's capacity to catch and contain infections quickly.

Level 2a is a predisposed area with low receptivity and/or vulnerability, for example only locally established mosquitoes, low density, unfavourable climate, and few travellers arriving from higher-risk areas. Level 2b is a predisposed area with medium to high receptivity and vulnerability. Areas that have seen sporadic local transmission in previous years also sit at this level.

Level 3: local transmission this season. An area affected by autochthonous transmission in the current transmission season is Level 3, again with two sub-levels that turn on scale and traceability:

• Level 3a: at least one confirmed locally acquired case from probable local mosquito-borne transmission this year, but the number of cases and clusters is low and the transmission chains can still be traced.
• Level 3b: the number of cases and clusters is high enough to overwhelm the capacity to trace them.

Level 4: endemo-epidemic. At Level 4 the virus circulates locally without depending on importation from elsewhere. Transmission is self-sustaining. In practice, no EU/EEA area currently sits at Level 4 for these viruses; it describes the endemic situation found in parts of the tropics and sub-tropics, and it is the level a European traveller should have in mind when visiting those regions.

For each level, ECDC sets out triggers for re-assessment and the appropriate public-health actions. The shape of the response is the useful headline: at Levels 1 and 2, the emphasis is on surveillance and prevention; at Levels 3 and 4, it shifts to response and control.

From risk level to protection: a proportionate ladder

The ECDC framework is written for institutions. It does not tell a household what to buy, and we are not going to pretend it does. What it does give you is the honest input to a personal decision: the level of your area sets how much protection is proportionate. The ladder below applies ECDC's levels to WHO's long-standing personal-protection principles. It is Mosticare's interpretation, offered as guidance, not as a clinical instruction.

One fact shapes every rung: Aedes mosquitoes bite mainly during the day, with peaks around dawn and dusk. That is different from the night-biting mosquitoes most bed-net advice was written for. It means daytime protection matters, and it means that nets do their most useful work over people who are resting during the day, above all babies and young children napping.

At Level 1, protection is about awareness, not hardware. If your area has no established vector, there is no locally acquired risk to defend against at home. The one thing worth doing is knowing the level of anywhere you travel to, and protecting yourself there.

At Level 2, precaution becomes reasonable, and it can stay chemical-free. The mosquito is present but the virus is not circulating yet, so the sensible posture is to make your home and outdoor space less hospitable and to put physical barriers between people and mosquitoes. Two measures carry most of the weight, and neither puts anything on skin or into the air:

• Remove standing water. Aedes breeds in small containers: saucers under plant pots, blocked gutters, buckets, uncovered water butts. Emptying them weekly is the single most effective thing an individual can do, and it costs nothing.
• Add physical barriers. Window and door screens keep mosquitoes out of the house. An untreated bed canopy keeps them off a sleeping child or adult. An untreated outdoor structure keeps a terrace usable in the evening.

This is where Mosticare's untreated range is designed to sit. Untreated bedroom canopies provide a no-skin-contact barrier for night sleep and for daytime infant naps. The Terrazza TE-UNO and TE-DUE outdoor gazebos are EU-designed, zero-chemical structures for terraces, gardens and outdoor dining. They work by exclusion, not by chemistry: the mesh keeps the mosquito away from the person, with nothing to absorb, inhale or reapply. At Level 2a that is a precaution; at Level 2b, where receptivity and vulnerability are higher, it is a sensible default.

At Level 3, step the protection up and follow local advice. Local transmission is happening this season. This is the point to combine measures rather than rely on one: physical barriers for sleep and rest, daytime skin protection when you are outdoors in the affected area, and close attention to advisories from ECDC and your national health authority, which may add targeted measures during an active cluster. DEET and picaridin repellents are effective and appropriate here as a supplement to barriers, not as a replacement for them. For sleep and for infants resting during the day, a net remains the reliable barrier.

This is also the context in which treated nets have a role. Mosticare's permethrin-treated nets are built to WHO standards and are EU BPR authorised, and they are the right tool for higher-burden settings and for travel to areas with active transmission. The treated net is a different product doing different work from the untreated canopy; the regulatory standards that apply to treated nets, including the EU Biocidal Products Regulation, do not apply to the untreated Terrazza and canopy lines, and that distinction is worth keeping straight when you choose.

At Level 4, treated protection is a primary layer. Where transmission is self-sustaining, WHO-aligned protection for high-burden settings applies in full, and treated nets are part of the primary protective set rather than a precaution. For Europeans this is a travel scenario: if you are visiting an endemic region, protect yourself to the standard of that region, not the standard of home. Refer to ECDC travel guidance and the destination's national health authority before you go.

What the framework does not say, and we will not either

Honesty about a risk framework means naming its limits.

• A level is not a diagnosis. The classification describes an area, not a person. Being in a Level 3 area does not mean you are infected, and being in a Level 1 area does not mean you are immune to anything you might pick up travelling.
• Levels change within a season. ECDC builds in triggers for re-assessment precisely because an area can move up when a cluster appears and down when a season ends. Check the current level, not last year's.
• No single product is a guarantee. A physical barrier depends on mesh integrity and correct sizing; a torn or oversized canopy is not a barrier. A repellent depends on reapplication. Protection is a set of measures used together, and used correctly.
• We sell barriers, so read us with that in mind. Mosticare makes mosquito nets and outdoor structures. That is exactly why we tie every recommendation to a published standard, ECDC's framework and WHO's protection principles, rather than to our own say-so. If a measure is not proportionate to your level, we would rather you did not buy it.

How to find your area's level

The classification is a living picture, so use live sources:

• ECDC publishes a weekly Communicable Disease Threats Report and regularly updated dengue and chikungunya situation pages that track autochthonous transmission across the EU/EEA during the season.
• Your national public-health authority (for example Santé publique France, Istituto Superiore di Sanità, or the relevant body in your country) issues local advisories and confirms local clusters first.
• Before travelling, check both the ECDC travel guidance and the destination country's health authority.

Match your protection to the level you are actually in, review it when the level changes, and keep the measures simple: remove standing water, put a barrier between people and mosquitoes, and add treated protection where the burden is genuinely high. That is the whole framework, translated into a decision you can make tonight.

Medical disclaimer

This article is general public-health information, not medical advice. It does not replace guidance from ECDC, the WHO, or your national or local health authority, and it is not a substitute for consulting a qualified healthcare professional about your individual circumstances, travel plans, or symptoms. If you develop fever, rash, joint pain or other symptoms after mosquito exposure or travel, seek medical care and mention where you have been. Risk classifications change during and between seasons; always confirm the current status of your area with an official source before acting.

Sources

• European Centre for Disease Prevention and Control. Public health guidance for assessing and mitigating the risk of locally-acquired Aedes-borne viral diseases in the EU/EEA. Published 1 July 2025. https://www.ecdc.europa.eu/en/publications-data/public-health-guidance-assessing-and-mitigating-risk-locally-acquired-aedes-borne
• European Centre for Disease Prevention and Control. New ECDC weekly reports and guidance to tackle mosquito-borne diseases across Europe. 2025. https://www.ecdc.europa.eu/en/news-events/new-ecdc-weekly-reports-and-guidance-tackle-mosquito-borne-diseases-across-europe
• European Centre for Disease Prevention and Control. Dengue risk assessment and surveillance updates for mainland EU/EEA. https://www.ecdc.europa.eu/en/dengue/surveillance-and-updates/risk-assessment
• World Health Organization. Personal protection against mosquitoes: barrier measures, nets and repellents. (Cite specific chapter at point of use.)

Editorial note: this explainer applies the ECDC four-level risk framework. The framework and its definitions are ECDC's; the level-to-protection mapping is Mosticare Editorial's interpretation, grounded in WHO personal-protection guidance. Byline: Mosticare Editorial. Editor of record: Adrian Christiansen.