Diseases
How the 2026 European heatwave is fuelling mosquito-borne disease, and how to protect your family
The European Centre for Disease Prevention and Control has now matched a season of sustained heat to a measurable rise in mosquito-borne illness. As of the first week of August 2026, forty-nine NUTS-3 areas across seven European countries have reported West Nile virus circulation, and the autochthonous dengue, chikungunya and Zika transmission events that Italy, France and Spain have each recorded in recent summers are running ahead of last year's curve. This piece sets out what the data actually says, why heat makes it worse, which households carry the most exposure, and the chemical-free physical-barrier layer a household can put in place this week, from a treated long-lasting insecticidal net over the bed to an untreated mesh gazebo over the terrace.
Read →Mediterranean mosquito season 2026: what the Rome and Greece West Nile signals mean
Two Mediterranean signals stand out in the summer of 2026: Italy has the widest West Nile spread in Europe and Greece the fastest recent rise. Neither is a new arrival. The tiger mosquito is established across Italy, and West Nile has recurred in Greece almost every year since 2010. This brief reads both as established seasonal presence, sets out the dated surveillance figures, and shows the practical steps households can control.
Read →France's first autochthonous chikungunya of 2026: what one local case in the Tarn means for households
Chikungunya is now transmitting locally in mainland France for the 2026 season, with a first autochthonous case confirmed in the Tarn in Santé publique France's 29 July bulletin. It is a documented, expected event for a day-biting tiger mosquito that has spread across most of the country. The illness is rarely fatal but the joint pain can be genuinely debilitating, and there is no specific treatment. The practical control is the ordinary one: stop the daytime mosquito from reaching people, and remove the small pockets of standing water where it breeds.
Read →West Nile virus is now established in Berlin: what Germany's 2025 numbers mean for the bedroom, and why this is not the tiger mosquito story
West Nile virus is endemic in Berlin. A Charite research team has shown the virus overwinters and circulates locally in the city's Culex mosquitoes, and Germany logged four locally acquired human West Nile cases in 2025. This is a night-biting Culex risk answered by a net over the bed and a screen on the window, and it is a separate problem from the day-biting tiger mosquito headlines out of Bonn, Koln and the wider Rhineland.
Read →France's first autochthonous West Nile cases of 2026: what two local infections actually mean for households
West Nile virus is now transmitting locally in mainland France for the 2026 season, with a first autochthonous case confirmed in the Pyrénées-Orientales in mid-July and a second reported in the Bouches-du-Rhône. Both are documented, expected events for a virus that Culex mosquitoes carry along the Mediterranean each summer. The disease is mostly silent, there is no vaccine and no specific treatment, so the practical control is the same one every household already owns: keep the biting mosquito away from the people in the room.
Read →West Nile virus in Romania 2026: what households in the affected counties need to know
Romania is a historically recurring West Nile virus country in central-eastern Europe. The 2026 season is under way, and the most recent completed season that ECDC summarises is 2025, when Romania reported 49 locally acquired cases. The 1996 Bucharest-centred outbreak was the first major WNV outbreak recorded in Europe. This landing covers the 2026 season, the historical Romanian geography, the household protection layer, and the Romanian reporting infrastructure that a household should know about.
Read →West Nile virus in Greece 2026: what households in the affected regions need to know
Greece is on the ECDC West Nile virus weekly platform and had 65 locally acquired cases by the ECDC and EFSA monthly report of 5 August 2026. The country has had locally acquired human cases in almost every year since the 2010 Central Macedonia outbreak, and the 2018 Athens-centred outbreak was the largest ever recorded in Greece. This landing covers the 2026 signal, the historical Greek geography, the household protection layer, and the EODY reporting infrastructure that a Greek household should know about.
Read →West Nile virus in Italy 2026: what households in the affected regions need to know
Italy is the leading West Nile virus country in the 2026 European season. By the ECDC and EFSA monthly report of 5 August 2026, Italy had reported 139 of Europe's 245 locally acquired cases. This landing covers the 2026 surveillance signal, the historically affected regions, the household protection layer, and the national reporting infrastructure that an Italian household should know about.
Read →West Nile virus in Europe 2026: what you need to know
West Nile virus is now endemic in southern and southeast Europe, and the 2026 season had widened to seven countries with 245 locally acquired cases by 5 August. This is the evergreen hub on the disease, the vector, the 2026 season, and the protection layer every household in the affected region has under its own control.
Read →How to protect yourself from West Nile virus mosquito bites: the household physical-barrier layer, with truthful claims about nets, screens, treated products, and repellents
There is no human vaccine against West Nile virus and no specific antiviral. The protection layer sits in the household, not the clinic. This article is the practical guide to the four-part barrier that works: a net over the bed, screens on the windows, source reduction around the house, and age-appropriate repellent use at dusk. Every claim is sourced; every product class is treated separately.
Read →West Nile is usually mild, but its neuroinvasive form can be fatal: an Italian clinical review puts the case-fatality of the neuroinvasive form as high as 17 percent with no licensed treatment, while the US season spreads county by county, and the consumer-protection reading is that bite prevention is the layer available now
A clinical review from Rome's Spallanzani Institute frames West Nile virus as a climate-sensitive flavivirus now endemic in Europe, with Italy's Lazio region an emerging epicentre (Reviews in Medical Virology, PMID 42431607). It notes that fewer than 1 percent of infections become neuroinvasive, but that this severe form carries a case-fatality rate as high as 17 percent, and that no antiviral or human vaccine is licensed, so care remains supportive. The review lands as the US 2026 season runs ahead of the historical average, with the highest early-season CDC case count since 2004. The message is sober, not alarmist: most West Nile infections are mild or symptomless, but the rare neuroinvasive form is serious, and because there is no vaccine or specific antiviral, bite prevention through physical barriers, correct repellent use, and standing-water source reduction is the reliable layer at the human-vector interface.
Read →Wild foxes and stone martens in the Netherlands are testing positive for West Nile and Usutu virus: a One Health sentinel study extends the European mosquito-borne flavivirus map into the north-west, and the consumer-protection reading is that bite prevention is the layer available now
Dutch researchers report Usutu virus RNA in nine of 818 wild carnivores, and West Nile or Usutu antibodies in red foxes and stone martens, with viral sequences clustering with local birds and mosquitoes (npj Viruses, Erasmus MC and Utrecht University, PMID 42436284, online 11 July 2026). The authors argue wild mammals may act as sentinel hosts for both mosquito-borne flaviviruses, extending the European surveillance map into the north-west beyond the Mediterranean-heavy footprint that the ECDC weekly surveillance records. It is a One Health signal about how these viruses circulate, not an alarm: West Nile is endemic in Europe, most infections are mild or symptomless, and because there is no licensed human vaccine and no specific antiviral, bite prevention through physical barriers, repellents, and standing-water source reduction is the reliable layer at the human-vector interface.
Read →Dengue in Germany and Austria 2026: is your city at risk, and what an ECDC-informed household can do this season
Aedes albopictus, the Asian tiger mosquito, is now established in parts of southern Germany and Austria, which places several districts in the ECDC risk category where household-level prevention becomes a reasonable behaviour. Germany and Austria recorded no local dengue transmission in 2026. Their cases remain travel-imported, while autochthonous chains further south in the EU/EEA are tracked in the ECDC weekly threats reporting. This article lays out what the data actually says, where the current risk sits in Germany and Austria, and how a household can act on it without buying into fear.
Read →Europe's 2026 West Nile virus season has expanded to five countries and eleven affected areas as of 8 July: Italy (five), North Macedonia (two), Romania (two), Greece (one) and Spain (one), with Greece and Spain as first-time entries and Italy doubling its affected-area count, while a fatal lineage-2 neuroinvasive Italian case underlines why the consumer-protection layer is the front line
Europe's 2026 West Nile virus season has widened. The ECDC week-28 communicable disease threats report records that, as of 8 July, 11 areas affected by West Nile virus have been identified in five countries: Italy (five), North Macedonia (two), Romania (two), Greece (one) and Spain (one). Greece and Spain are first-time 2026-affected countries and Italy has gone from three to five areas, a structural mid-July expansion from the earlier three-country picture, with ECDC noting that seasonal weather conditions currently favour mosquito-borne transmission and that more cases are expected in the coming weeks. A newly indexed Italian case report of a fatal lineage-2 neuroinvasive infection presenting as Guillain-Barre syndrome, co-authored from Italy's national arbovirus reference laboratory, anchors the severity dimension. With no approved human WNV vaccine and no specific antiviral, the consumer-protection layer at the human-vector interface is the front line.
Read →Fondazione Bruno Kessler and Istituto Superiore di Sanita reconstruct Italy's 2024 DENV-2 outbreaks in Eurosurveillance: what 296 locally acquired dengue cases, the largest autochthonous dengue event ever recorded in mainland Europe, mean for the consumer-protection layer as Aedes albopictus establishes across the Mediterranean basin
Molina Grane C and colleagues at Fondazione Bruno Kessler and the Istituto Superiore di Sanita, working with the Toscana Centro and Emilia-Romagna public-health departments, published "Autochthonous transmission patterns of dengue virus serotype 2 in Italy: evidence from outbreaks in 2024" in Eurosurveillance in July 2026 (PMID 42428999). The reconstruction analyses 296 locally acquired DENV-2 cases with symptom onset from 31 July to 31 October 2024 across four Italian regions, the largest number of autochthonous dengue cases ever recorded in mainland Europe. Using a Bayesian framework to reconstruct transmission chains between well-documented exposure sites, the authors estimate the generation time and the net reproduction number, moving the Italian dengue picture from imported-case risk to a quantified account of sustained local transmission on Aedes albopictus. The study is the upstream surveillance anchor for the consumer-protection layer at the human-vector interface across the Mediterranean basin.
Read →The US West Nile virus season is running at a 22-year high: 48 human cases, 38 neuroinvasive, across 23 states with Arizona's Maricopa County as the epicentre as of 7 July 2026, and CDC's own guidance is EPA-registered repellent plus screens plus dusk-to-dawn avoidance, mapping the transatlantic WNV arc onto the consumer-protection layer
The CDC current-year West Nile virus dashboard, frozen for several weeks, has updated to data current as of 7 July 2026 and reports a two-decade seasonal high: 48 human cases through end-June against a historical late-June average of roughly 10, the highest at this point in the year since 2004, with 38 of the 48 being severe neuroinvasive disease, 23 states reporting activity (the highest in 10 years), and Arizona as the epicentre at 32 cases, 29 of them in Maricopa County, where 4 deaths have been recorded. Peak US activity is normally August to September, so the most dangerous weeks are still ahead. Europe's 2026 season is formally open but lower, with ECDC recording 12 locally acquired cases across five countries as of 8 July. CDC's own guidance, EPA-registered repellent plus window and door screens plus dusk-to-dawn avoidance, maps onto the consumer-protection layer at the human-vector interface, which CDC notes is the only reliable prevention given no approved human WNV vaccine and no specific antiviral.
Read →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 uniform. In July 2025 the European Centre for Disease Prevention and Control published guidance that sorts every EU/EEA area into four risk levels for locally acquired Aedes-borne disease. This explainer sets out what each level means, and how to match your protection to it, honestly.
Read →The tiger mosquito is moving north across Europe, and what a household can do about it
Aedes albopictus, the Asian tiger mosquito, is now established across 369 regions in 16 European countries, up from 114 a decade ago. As its range moves north and locally-acquired chikungunya and dengue seasons lengthen, the practical question for a household is simple: what keeps biting mosquitoes out of a bedroom. This is a look at what Europe's monitoring data show, why the vector is expanding, and why the durable answer at home is the physical barrier, the untreated net, the window screen and the emptied saucer of standing water.
Read →West Nile Virus in Southern and Southeast Europe: an evergreen explainer on the Culex dusk-biting pattern, household risk windows, and why a bedroom mosquito net is still the most reliable chemical-free protection
West Nile virus (WNV) is the mosquito-borne disease that asks the narrowest question of a household in Italy, Greece, Romania, Bulgaria or Croatia between July and September: can a Culex mosquito reach the bedroom between dusk and dawn. The protection answer is structural (a net over the bed, a screen on the window, source reduction around the house), not pharmaceutical.
Read →The tiger mosquito spreads inland and north across Spain, reaching Galicia and Extremadura
Spanish health surveillance and the Mosquito Alert citizen-science platform confirm the tiger mosquito is now established in Andalusia, has reached Galicia for the first time and has been detected inland in Extremadura. The ECDC now maps Aedes albopictus across 16 European countries and 369 regions.
Read →How the tiger mosquito breeds without biting: scientists map the genetics of autogeny
Some tiger mosquitoes can lay a first batch of eggs without ever taking a blood meal. A US research consortium, writing in BMC Biology, has identified the genetic and physiological basis of that trait, helping explain how Aedes albopictus keeps establishing across Europe even where hosts are scarce.
Read →West Nile virus is becoming endemic in Europe, two new 2026 studies show
A systematic review of 27 studies and the first nationwide survey of 44,490 French blood donors together show West Nile virus is shifting from sporadic outbreaks to an established European presence. Integrated surveillance and blood-donor screening are emerging as the front-line response to a climate-driven spread.
Read →Dengue emerges in the Sahel: a 2,022-patient Mali study maps a sharp rise
A 2,022-patient acute-fever study in Mali finds dengue is now the most frequently detected pathogen, with three virus serotypes co-circulating and chikungunya, West Nile, and Rift Valley fever viruses also detected. Published in PLoS Neglected Tropical Diseases, it identifies Mali as a multi-pathogen arbovirus hotspot for the Sahel.
Read →Australia confirms Aedes albopictus sustained a dengue outbreak alone, and Honduras confirms the species via a seaport
Two papers published on 4 July 2026 report first-of-kind findings on Aedes albopictus. Parasites & Vectors reports the first molecular detection of dengue virus serotype 3 in the species in Australia, on Masig Island, where Aedes aegypti was absent. Infection, Genetics and Evolution reports the first genetic evidence of the species establishing in Honduras, with the port of Puerto Cortés the most probable point of entry.
Read →Europe's 2026 West Nile virus season has formally opened: Romania has entered the platform, and the pan-European transmission window is now structurally open
ECDC's week 27 figures, with data to 1 July 2026, count six human West Nile virus cases in six areas across three countries: Italy, Romania and North Macedonia. Romania's first cases of the season, in a country with a long record of the virus, show the 2026 transmission window opening beyond the Mediterranean. Personal protection against Culex mosquitoes remains the main defence for households.
Read →Sri Lanka's Presidential Secretariat reviewed its dengue prevention circular and set four action items
Sri Lanka's Presidential Secretariat convened a dengue progress review on 3 July 2026, chaired by Secretary to the President Dr Nandika Sanath Kumanayake. The meeting reviewed the 23 June dengue-prevention circular and set four action items: strengthen the Public Health Inspectors, sustain household cleaning, use accurate data to clear high-risk breeding sites, and intensify fumigation. The communiqué stated that the public bore a significant responsibility in reducing mosquito breeding sites.
Read →Two papers document the first probable human West Nile virus infections in Bangladesh and sustained local chikungunya circulation
Maria et al. in the American Journal of Tropical Medicine and Hygiene documented the first probable human West Nile virus infections in Bangladesh. Seven of 300 Japanese-encephalitis-negative acute encephalitis sera tested IgM-positive, and two of the seven people died. Islam and Hasan, in the International Journal of Infectious Diseases, mapped seventeen years of chikungunya genomic evolution in Bangladesh and confirmed sustained local circulation of the Indian Ocean Lineage of the ECSA genotype. Both papers were published on 2 July 2026.
Read →ÖKO-TEST reports the 2026 German mosquito season may be heavier than usual
ÖKO-TEST reported in the first week of July 2026 that warm, humid conditions may drive a heavier German mosquito season. The article names the native Culex pipiens populations and the advancing Aedes albopictus populations. Its prevention guidance is barrier-first: long loose clothing, a registered repellent applied according to the label, and removal of standing water around the home.
Read →Euro Surveill + Nature Communications + Nature Reviews Microbiology just published the three-pillar European WNV institutional peg: France has been silently exposed, Berlin amplifies locally, and urban land cover is the new vector variable
Three July 2026 papers closed the autochthonous-circulation question for West Nile virus in continental Europe. Jourdan et al. Euro Surveill 31(26) measured the first French mainland seroprevalence baseline at 0.87 to 0.97 percent across 44,490 blood donors in 2021 to 2022, with Nouvelle-Aquitaine at 1.13 percent and Ile-de-France at 1.81 percent preceding the first autochthonous human cases. Patzina-Mehling et al. Nat Commun 17:4597 documented fine-scale urban amplification in Berlin at a 4.8 percent mosquito infection rate, with residential and cemetery land cover sustaining monthly minimum infection rates of 15 and 21 respectively. Du Toit in Nature Reviews Microbiology pegged the Berlin study as a structural microbiology community finding, and the multi-year autochthonous-transmission window is now institutionally closed for France hexagonale and the EU/EEA mainland.
Read →The CDC reports the highest number of early-season West Nile virus cases in the United States since 2004
The Centers for Disease Control and Prevention reported in early July 2026 that the United States has recorded its highest number of early-season West Nile virus cases since 2004, with 23 states already reporting. The agency repeated its standing advice on long loose clothing, DEET-based repellent and the removal of standing water. In Europe, the ECDC Week 26 report recorded three autochthonous West Nile virus cases in Italy and North Macedonia, while mainland France recorded none.
Read →US West Nile virus is on track for its worst year in two decades. Europe should be paying attention.
US West Nile virus activity in 2026 is on track for the worst year in 22 years. The European reader should be paying attention because Culex, the mosquito genus carrying WNV in the US, is also the genus carrying it across most of the European map. The ECDC W26 weekly recorded three cases across two countries (Italy Caserta, Italy Firenze, North Macedonia Vardarski). The protection layer is the same regardless of jurisdiction.
Read →Sri Lanka has recorded more than 55,000 dengue cases, and the military is supporting the public-health response
Sri Lanka has recorded more than 55,000 dengue cases in 2026, with about 1,000 patients in hospital at any time and 29 deaths, according to The BMJ. The government has deployed the military and drones in support of the public-health response. The same Aedes albopictus vector is established in parts of Europe, and mainland France recorded 809 autochthonous chikungunya cases in 2025. This article sets out the case data, the conditions that favour the vector, and the household measures that reduce exposure.
Read →Lancet Regional Health Americas just named South American chikungunya resurgence a structural reality. Bolivia 2025 is the geographic-expansion closer.
Lancet Regional Health Americas has named the South American chikungunya resurgence as a structural reality in a 2026 editorial, and Emerging Infectious Diseases has documented the first chikungunya detection in Bolivia in 2025. The two publications together close the geographic-expansion question that has been open since the 2014-2016 South American wave. The 62 imported chikungunya cases year-to-date in France hexagonale (SpF 1 July 2026) are the upstream edge of an in-season autochthonous-transmission window that the South American reservoir now makes institutionally visible.
Read →France just got a quantitative accounting of what 809 autochthonous chikungunya cases really cost, and the paper lands while Mainland EU autochthonous dengue and chikungunya stays at zero through Q2 close
IJID Regions publishes the first 2026 cost-of-illness accounting for what 809 autochthonous chikungunya cases and 30 autochthonous dengue cases cost France in 2025. The paper lands in the same week that ECDC confirms Mainland EU autochthonous dengue and chikungunya stayed at zero through Q2 close. Two non-endemic countries, two institutional cost accounts, one direction of travel.
Read →ECDC and EFSA's June 2026 West Nile virus report: what it shows for the second half of summer
On 30 June 2026 ECDC and EFSA produced the June edition of their joint monthly West Nile virus report, with data to 24 June. It counts three locally acquired human cases, two in Italy and one in North Macedonia, and five outbreaks in horses and birds. The report is not new: a December 2024 edition already covered humans and animals. The numbers are small, and both agencies expect more cases before the usual August and September peak.
Read →South America's 2025 chikungunya wave, 313,000 cases later, exposes the regional Aedes surveillance gap that no country can fix alone
PAHO's 2025 chikungunya count, 313,000 cases and 170 deaths across 18 South American countries, is the headline. The structural lesson from a 21-author Lancet Regional Health Americas letter is that vertical, country-by-country Aedes control programmes are now structurally inadequate to a disease that does not respect borders, and the only credible regional architecture is the WINSA-led shift from passive case reporting to active, genomics-informed surveillance.
Read →Oropouche was first isolated in Trinidad in 1955: the first 2026 Ann Afr Med review reframes it as a three-continent threat
Oropouche was first isolated in Trinidad in 1955 and has been spreading across the Americas ever since. The first 2026 Annals of African Medicine clinical review reframes it as a three-continent threat, with confirmed severe fetal outcomes, a midge-driven transmission cycle that does not depend on mosquitoes, and travel-imported cases in the United States and Europe.
Read →Two countries. Three cases. Three areas. The European WNV surveillance platform just held its line through Q2 close, and a global host-prevalence dataset now offers the structural foundation for the second half of summer 2026
Two countries. Three cases. Three areas. ECDC's W25 and W26 West Nile virus weekly bulletins both report the same tallies, Italy Caserta, Italy Firenze, North Macedonia Vardarski, and the European surveillance platform has now held that line through Q2 close (30 June 2026). On 26 June 2026 a global host-prevalence and competence dataset (Richter-Boix et al., Scientific Data, PMID 42362577) was published, converting the clinical case counts into the transmission-cycle structure. Combined with Hungary's 2024 hub (Nagy 2026), the late-May heatwave excess-mortality bulletin published by Santé publique France on 30 June 2026, and the Riccetti, Patzina-Mehling and Heidecke papers on land cover, urban amplification and thermal R0, the second half of summer 2026 has its institutional foundation laid.
Read →Europe's third invasive Aedes just got a global data compendium: what Aedes japonicus, the Asian bush mosquito, means for the 2026 European summer alongside Aedes albopictus and Aedes koreicus
While Italy rolls out X-ray SIT and sterile-male trials to control Aedes albopictus, and Aedes koreicus expands across northern Italy, a third invasive Aedes, the Asian bush mosquito Aedes japonicus, has been quietly establishing itself across Belgium, the Netherlands, Germany, Switzerland, Austria, Luxembourg and northern France since the 2000s. The first global compendium on it was published last week.
Read →Italy's sterile-male Aedes trials: X-ray sterilisation in Bolzano, a pilot in Bologna, and the spread of Aedes koreicus
Italy's Aedes control programme in summer 2026 brings together X-ray sterilisation in Bolzano, a sterile-male pilot in Bologna, and municipal Aedes albopictus plans, while surveillance confirms the spread of Aedes koreicus, the second tiger mosquito.
Read →The chikungunya vaccine market just bifurcated, what Valneva's Ixchiq restriction and Bavarian Nordic's Vimkunya Canadian approval mean for chikungunya protection in 2026
The chikungunya vaccine market is structurally bifurcating. Valneva's live-attenuated platform narrows to high-risk populations under an EMA CHMP recommendation. Bavarian Nordic's inactivated platform broadens access with a Canadian approval. The only protection available to everyone, regardless of medical countermeasure access, contraindication status, or supply ceiling, remains physical barriers.
Read →Hungary is now Europe's West Nile virus hub, 111 autochthonous cases in 2024 mapped it
A new genomic and epidemiological study in *Eurosurveillance* maps Hungary as Europe's persistent West Nile virus hub. In 2024 the country recorded 113 human cases, 111 autochthonous, 92 percent neuroinvasive, 7.9 percent fatal, every one of 55 sequenced strains being lineage 2. Phylogeography identifies two persistent viral corridors out of Hungary: westward along the Danube into central Europe, and southeastward into the Balkans. The 2026 European WNV season will test whether the prediction holds.
Read →Dengue without international travel, three 2026 papers map Europe's autochthonous pattern
Three peer-reviewed papers published in 2026, by teams in Spain, Italy and the UK, have built the institutional frame for autochthonous dengue in Europe. The 2025 French bilan recorded 809 autochthonous chikungunya and 30 autochthonous dengue cases, the highest chikungunya total since surveillance began in 2006. Read together, the three papers say what none says alone: autochthonous dengue in Europe is not a 2025 anomaly. It is the structural shape of what comes next.
Read →French Guiana chikungunya wave crosses 916 cases; Ile de Cayenne clusters triple in two weeks
French Guiana has crossed 916 confirmed chikungunya cases for 2026, a 27 percent jump in two weeks, and Ile de Cayenne active clusters have tripled to seven. The strain is ECSA lineage *without* the E1-A226V mutation, which reduces onward transmission risk to mainland Europe but leaves the Caribbean basin vulnerable. The 2026 wave is on track to be the largest chikungunya epidemic in the territory's recorded history.
Read →France's autochthonous arbovirus surveillance goes weekly, the first two bulletins land
France has become the only EU/EEA country publishing autochthonous arbovirus surveillance at weekly cadence. The first two bulletins of the new system (17 and 24 June 2026) report zero confirmed autochthonous cases, the expected baseline against a 2025 season that delivered 809 chikungunya and 30 dengue cases. The architecture, anchored in 83 *Aedes albopictus*-colonised départements, is the operational benchmark the rest of Europe will be measured against.
Read →Europe's 2026 West Nile virus season has opened, and held steady for two weeks running
Europe's 2026 West Nile virus season opened early and has now held still for two consecutive ECDC weeks. The W25 (data to 17 June) and W26 (data to 24 June) bulletins both report two countries, three cases and three affected areas, Italy in Caserta and Firenze, North Macedonia in Vardar, with no deaths. The structural question for July and August is whether the early, broad opening the land-cover and climate models predict will widen from this stable base.
Read →Sri Lanka reports 48,287 dengue cases as a newly introduced strain spreads
Sri Lanka's National Dengue Control Unit has reported 48,287 cumulative dengue cases as of 23 June 2026. Daily hospital admissions have exceeded 1,000, and the army has been asked to support vector control. A newly introduced dengue strain, different from the variants that previously circulated, is driving transmission across 14 high-risk districts, and most of the population has no prior exposure to it.
Read →ECDC Week 25: West Nile virus opens the 2026 EU/EEA mainland season in Italy
ECDC's Communicable Disease Threats Report for Week 25 (data to 17 June, published 18 June) confirms the EU/EEA West Nile virus 2026 season is open: two countries, three cases, three affected areas, zero deaths. Italy is the first mainland EU/EEA country with locally-acquired 2026 transmission.
Read →Dengue in 2026: A Complete Guide to the World's Fastest-Spreading Mosquito-Borne Virus
Dengue is the fastest-spreading mosquito-borne virus on Earth, and it is no longer only a tropical disease. This is the complete 2026 reference: the virus and its four serotypes, antibody-dependent enhancement, the Aedes vectors, the global and European picture, the full clinical course from silent infection to severe dengue, the vaccines (Dengvaxia, Qdenga, and Brazil's single-dose Butantan candidate), the Wolbachia and sterile-insect breakthroughs, and the warming climate that is turning dengue into a recurring Mediterranean summer. Updated for World Dengue Day 2026.
Read →CDC just flagged 11 countries for dengue. Here's where to pack smart
On 23 June 2026, the US Centers for Disease Control and Prevention refreshed its global dengue travel notice. Eleven countries made the list: Bolivia, Cambodia, Colombia, Guyana, the Maldives, Mali, New Caledonia, Samoa, Timor-Leste,...
Read →Italy opens 2026 West Nile season: Caserta and Firenze report the season's first cases
As of 17 June 2026, Italy and North Macedonia were the two European countries with locally acquired West Nile virus cases in the 2026 season. Two human cases, one in Caserta (Campania) and one in Firenze (Toscana), were confirmed in ECDC Week 25. A clean look at what the data, and Italy's surveillance system, actually say.
Read →England had 73 chikungunya cases last summer. Not one came from a British mosquito.
England logged 73 imported chikungunya cases between January and June 2025, mostly linked to travel to Sri Lanka, India and Mauritius. No onward transmission followed, because the vector, *Aedes albopictus*, is not established in the UK. ECDC lists it as established in France, Italy, Spain, Germany and Switzerland, and mainland France recorded 809 locally acquired cases in 2025, the largest season ECDC has recorded in the EU/EEA.
Read →Mauritius has its first large chikungunya outbreak in years, and a CDC travel notice
The US Centers for Disease Control and Prevention has issued a Level-2 travel notice for Mauritius after the island reported a large locally acquired chikungunya outbreak in 2026, its first in years. The vaccine is now part of the standard pre-travel preparation, with the standard pregnant-traveller caveats.
Read →Two deaths in Alice Springs from a virus carried by waterbirds and night-biting mosquitoes
Australia's Northern Territory has confirmed two Murray Valley encephalitis deaths in Alice Springs in April and May 2026, a flavivirus with a 15-30% case-fatality rate, no vaccine, and no antiviral. The 2026 cases sit south of the virus's usual northern foci, and the editorial story is what the geography means for the climate envelope.
Read →Malaria deaths edged up again in 2024. WHO's 2026 message is unusually anxious.
WHO's 2026 World Malaria Day campaign reads confident on the surface and anxious underneath. The numbers tell why: 282 million cases and 610,000 deaths in 2024, the first sustained uptick in years; drug, insecticide, and diagnostic resistance widening on three independent biological fronts; and a US$5.4 billion shortfall against the 2025 Global Technical Strategy target. The science of malaria is in a better state than the politics of malaria.
Read →Dengue in Europe in 2026: from tropical postcard to local outbreak
Locally acquired dengue cases on the European mainland rose from 71 in 2022 to 304 in 2024, with France, Spain, and Italy at the frontline. Aedes albopictus is now established in 16 EU/EEA countries and 369 regions, more than triple a decade ago. Climate change, urban adaptability, and daytime biting have turned a tropical disease into a Mediterranean summer threat. What that means for the 2026 season.
Read →World Malaria Day 2026: 2.3 Billion Cases Averted, and a Crisis That Isn't Over
On World Malaria Day 2026, the data tells two stories at once. Since 2000, coordinated global action has averted an estimated 2.3 billion malaria cases and 14 million deaths, and yet an estimated 282 million people contracted malaria in 2024, with deaths edging up again. Artemisinin resistance is spreading, Anopheles stephensi is urbanising the disease, and funding is falling short of global targets. Why physical barriers remain essential alongside the new vaccines.
Read →Chikungunya is back in three South American territories. PAHO has sounded the alert.
PAHO issued an epidemiological alert for the Americas on 10 February 2026, after 313,132 chikungunya cases across 18 countries in 2025 and a return of local transmission to Guyana, French Guiana, and Suriname after roughly a decade of silence. Here is what European travellers and public-health agencies should take from it.
Read →Brazil's dengue cases fell 75% in early 2026. Three things changed at once.
A coordinated rollout of the Butantan single-dose dengue vaccine, Wolbachia releases at biofactory scale, and an ovitrap surveillance network covering 1,600 municipalities reduced Brazil's first-quarter 2026 dengue cases by 75% year-on-year, from 916,400 to 227,500. The result reflects three established tools deployed at national scale at the same time, rather than a single intervention.
Read →Foshan recorded over 16,000 chikungunya cases in eight weeks. Europe has the same mosquito.
Between mid-June and late September 2025 the southern Chinese city of Foshan logged 16,452 locally transmitted chikungunya cases, the largest such outbreak in mainland Chinese history. The vector was Aedes albopictus, the same Asian tiger mosquito now established in 369 regions across 16 European countries, carrying a strain with three mutations tuned to it.
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