Seasonal #surveillance in #humans in 2026 for #WNV (West Nile Virus) (ECDC, July 24 '26): 81 confirmed cases so far of which 46 in #Italy

 

{Excerpt}

Week 30, 2026 | Produced on 23 July 2026 at 09:45, based on data submitted up until and including 22 July 2026.

Current situation

    ° Since the beginning of the 2026 transmission season, and as at 22 July, 35 areas affected by West Nile virus (WNV) have been identified in six countries across Europe.

    ° These areas are located in: 

        § Italy (20), 

        § Greece (six), 

        § Romania (four), 

        § North Macedonia (two), 

        § Spain (two) and 

        § France (one).

    ° The six countries have reported 81 locally acquired human cases of WNV infection: 

        § Italy has reported 46, 

        § Greece 21, 

        § North Macedonia five, 

        § Romania five, 

        § Spain three and 

        § France one case.

    ° This week, nine areas are reported as affected for the first time this season. The affected areas identified as at 22 July 2026 are listed in Table 1 and shown in Map 1 below.

(...)

Table 1. Areas affected by West Nile virus during the 2026 transmission season at 22 July, by country and NUTS3 or GAUL1 area

{Click on Images to Enlarge}

(...)

Source: 

Link: https://www.ecdc.europa.eu/en/west-nile-fever/surveillance-and-disease-data/disease-data-ecdc

____

#WNV in #humans, the European Region, Weekly #Report (ECDC, July 17 '26): #Italy (21), #Greece (7), North #Macedonia (2), #Romania (2) & #Spain (2) cases so far

 

{Excerpt}

Week 29, 2026 | Produced on 17 July 2026 at 08:30, based on data submitted up until and including 15 July 2026.

Current situation

    ° Since the beginning of the 2026 transmission season, and as at 15 July, 28 areas affected by West Nile virus (WNV) have been identified in five countries across Europe {1}.

    ° These areas are located in: 

        § Italy (17), 

        § Greece (five), 

        § North Macedonia (two), 

       § Romania (two) and 

        § Spain (two).

    ° The five countries have reported 34 locally acquired {2} human cases of WNV infection: 

        § Italy has reported 21, 

        § Greece seven,     

        § North Macedonia two, 

        § Romania two and 

        § Spain two cases.

    ° This week, 17 areas are reported as affected for the first time this season. The affected areas identified as at 15 July 2026 are listed in Table 1 and shown in Map 1 below.

(...)

Table 1. Areas affected by West Nile virus during the 2026 transmission season at 15 July, by country and NUTS3 or GAUL1 area

{Click on Images to Enlarge}

__

* ‘First reported this week’ indicates that the affected area was not included in the previous weekly overview.

(...)

Source: 

Link: https://wnv-weekly.ecdc.europa.eu/

____

Seasonal #surveillance in #humans in 2026 for #WNV - Update (ECDC, July 10 '26): #Italy reported 6 cases, #Macedonia 2, #Romania 2, #Greece 1, #Spain 1

 

Week 28, 2026 | Produced on 9 July 2026 at 08:45, based on data submitted up to 8 July 2026.

Current situation

    ° Since the beginning of the 2026 transmission season, and as of 8 July, 11 areas affected by West Nile virus (WNV) have been identified in five countries across Europe {1}.

    ° These areas are located in: 

        - Italy (five), 

        - North Macedonia (two), 

        - Romania (two), 

        - Greece (one) and 

        - Spain (one).

    ° The five countries have reported 12 locally acquired {2} human cases of WNV infection: 

        - Italy has reported six, 

        - North Macedonia two, 

        - Romania two, 

        - Greece one and 

        - Spain one case.

    ° This week, five areas are reported as affected for the first time this season. 

(...)

Table 1. Areas affected by West Nile virus during the 2026 transmission season as of 8 July, by country and NUTS3 or GAUL1 area

{Click on Image to Enlarge}

(...)

__

{*} ‘First reported this week’ indicates that the affected area was not included in the previous weekly overview.

{1} European Union/European Economic Area countries and selected EU-neighbouring countries (Albania, Bosnia and Herzegovina, Kosovo**, Montenegro, North Macedonia, Serbia and Türkiye).

{**} This designation is without prejudice to positions on status and is in line with UNSCR 1244/1999 and the ICJ Opinion on the Kosovo declaration of independence.↩︎

{2} Cases acquired within the reporting country.↩︎

(...)

Source: 

Link: https://www.ecdc.europa.eu/en/west-nile-fever/surveillance-and-disease-data/disease-data-ecdc

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Seasonal #surveillance in #humans in 2026 for #WNV - Weekly Report (ECDC, Week 27, 2026, July 4 '26): Six cases reportes so far in total {#Italy, #Romania, N. #Macedonia}

 

Week 27, 2026

Produced on 2 July 2026 at 12:00 based on data submitted up to 1 July 2026

Epidemiological summary

    Since the beginning of 2026, and as of 1 July, three countries in Europe reported six human cases{1} of West Nile virus (WNV) infection: Italy (three cases), Romania (two cases) and North Macedonia (one case).

    The current report in Table 1 includes the number of probable and confirmed cases of WNV infections per NUTS3 region. However, these figures are preliminary and should be interpreted with caution as they may be revised by the countries as more information becomes available. 

    For further details on case numbers, please refer to the joint monthly report, which offers a more detailed analysis.

    Please note: The table and map in this report contain countries and areas where human West Nile virus infection cases were reported to EpiPulse Cases.

(...)

Overview of West Nile virus cases in EU/EEA and EU-neighbouring countries

Table 1. Countries and regions with locally acquired human cases of West Nile virus infections in 2026 as of 1 July.

{Click on Image to Enlarge}

* An ‘affected area’ or ‘risk area’ is defined as ‘a risk area with ongoing transmission of WNV to humans’. This means that at least one autochthonous human case of WNV has been reported as a result of local transmission in the area according to the agreed, standardised and disease-specific case definition. In exceptional circumstances, a probable case can be used to determine transmission, however, this should only apply in specific and agreed situations when a case cannot be confirmed within a reasonable time.

** Compared to the previous weekly report.

(...)

Source: 

Link: https://www.ecdc.europa.eu/en/west-nile-fever/surveillance-and-disease-data/disease-data-ecdc

____

Seasonal #surveillance in #humans and #animals in 2026 for West Nile virus (#WNV) (ECDC, Monthly Report, Summary)

 

June 2026 | Produced on 30 June 2026 at 07:15 based on data submitted up to 24 June 2026

Epidemiological summary

    As of 24 June, two countries in Europe reported three locally acquired1 human cases of WNV infection: 

        ° Italy reported two cases and 

        ° North Macedonia one case. 

    Dates of onset ranged from 12 to 27 May 2026. 

    No deaths have been reported.

    The cases were reported from three regions across the two countries. Although no cases had been reported by this time in 2025, some cases with onset dates in May and June were subsequently notified with a delay. Therefore, the current situation remains consistent with the early phase of the seasonal reporting pattern observed in previous years.

    This year, human cases of WNV infection were reported for the first time ever in one affected area: North Macedonia in Vardarski (MK001).

    Among the three cases reported this year, one person was aged 65 years or older, one was aged under 65 years, and the age of one person was unknown. All three cases were hospitalised. 

    Neurological manifestations were reported in two individuals; information on clinical presentation was unavailable for the remaining case. 

    As only three cases have been reported to date, comparisons with demographic or severity patterns observed over the previous decade are not yet meaningful. Further updates will be provided in subsequent monthly reports.

    From the veterinary perspective, five WNV outbreaks have been reported in Europe in 2026: one among equids and four among birds. 

    The equid outbreak was reported by France and started on 30 March 2026. The four bird outbreaks were reported by Italy, with start dates ranging from 31 March to 4 May 2026.

    No information was available on the equid species involved in the outbreak reported in France in the Animal Disease Information System (ADIS). For birds, species information indicated that the four outbreaks reported in Italy involved hooded crows (three outbreaks) and a golden eagle (one outbreak).

    Outbreaks in birds and/or equids have been reported in three regions across two countries. Both countries that reported outbreaks in 2026 had previously reported WNV outbreaks in birds and/or equids in the same regions, indicating that WNV is endemic in these areas.

    The number of outbreaks in birds and equids reported during this first period of 2026 is similar to the mean monthly outbreak count for the same time of year, calculated for 2022–2025 for birds and for 2016–2025 for equids.

    Italy reported both locally acquired human WNV cases and WNV outbreaks in birds; however, the human cases and bird outbreaks were reported from different regions.

    Owing to delays in diagnosis and reporting, and because most WNV infections are asymptomatic or subclinical, the reported case numbers likely underestimate the true number of infections. Seasonal surveillance in humans primarily captures laboratory-confirmed cases, which may further contribute to reporting delays.

    Given the favourable weather conditions for WNV transmission in Europe, ECDC and EFSA expect further human cases and outbreaks in equids and birds to be reported in the coming weeks and months. In previous years, transmission has typically peaked in August and September.

    ECDC and EFSA will continue to closely monitor the situation in Europe.

(...)

Source: 

Link: https://www.ecdc.europa.eu/en/infectious-disease-topics/west-nile-virus-infection/surveillance-and-disease-data/monthly-updates

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Surveillance for West NileVirus Infections in Humans in Europe, Weekly Report: Week 26, 2026 (ECDC, summary)

 

{Excerpt}

Epidemiological summary

    Since the beginning of 2026, and as of 24 June, two countries in Europe reported three human cases{1} of West Nile virus (WNV) infection: Italy (two cases) and North Macedonia (one case).

    The current report in Table 1 includes the number of probable and confirmed cases of WNV infections per NUTS3 region. However, these figures are preliminary and should be interpreted with caution as they may be revised by the countries as more information becomes available. For further details on case numbers, please refer to the joint monthly report, which offers a more detailed analysis.

    Please note: The table and map in this report contain countries and areas where human West Nile virus infection cases were reported to EpiPulse Cases.

(...)

#) Country

    ° Affected area*

        § Newly affected area**

            - Number of probable cases - Number of confirmed cases - Total cases 

1) Italy

    ° Caserta

        § No

            - 0 / 1 /1 

    ° Firenze

         § No

            - 0 / 1 /1 

2) North Macedonia

    ° Vardarski

        § No

            - 0 / 1 / 1

__

{*} An ‘affected area’ or ‘risk area’ is defined as ‘a risk area with ongoing transmission of WNV to humans’. This means that at least one autochthonous human case of WNV has been reported as a result of local transmission in the area according to the agreed, standardised and disease-specific case definition. In exceptional circumstances, a probable case can be used to determine transmission, however, this should only apply in specific and agreed situations when a case cannot be confirmed within a reasonable time.

{**} Compared to the previous weekly report.

(...)

Source: 

Link: https://wnv-weekly.ecdc.europa.eu/

____

#Surveillance of West Nile Virus {#WNV} #Human #Infections in #Europe, Weekly Report (ECDC, Jun. 18 '26): First two cases reported in #Italy

 

Epidemiological summary

    Since the beginning of 2026, and as of 17 June, 2 countries in Europe reported 3 human cases of West Nile virus infection: Italy and North Macedonia.

    The current report in Table 1 includes the number of probable and confirmed cases of WNV infections per NUTS region. 

    However, these figures are preliminary and should be interpreted with caution as they may be revised by the countries as more information becomes available. 

    Consequently, no totals are provided. 

    For further details on case numbers, please refer to the joint monthly report, which offers a more detailed analysis.

    Please note: The table and map in this report contain countries and areas where human West Nile virus infection cases were reported to EpiPulse Cases.

Introduction

    The European Centre for Disease Prevention and Control (ECDC) provides a weekly overview of human cases of West Nile virus (WNV) infection to support the competent authorities responsible for blood safety. 

    This overview can aid decisions on the deferral or testing of blood donors who may have been exposed to the virus, in accordance with Commission Directives 2004/33/EC and 2014/110/EU.

    West Nile virus infection in humans is a notifiable disease at the EU level and cases are reported in accordance with the EU case definition. 

    The table and map in this report show the countries and areas where human cases of WNV infection have been reported to the European surveillance portal for infectious diseases (EpiPulse Cases).

    More information on the occurrence of WNV infection among humans in Europe, as well as WNV outbreaks among equids and birds, is available in the joint monthly report produced by ECDC and the European Food Safety Authority (EFSA).

    Here we present the weekly report as of 17 June 2026.

Overview of West Nile virus cases in EU/EEA and EU-neighbouring countries

Table 1. Countries and regions with locally acquired human cases of West Nile virus infections in 2026 as of 17 June.

[Country

    ° Affected Region

        § Newly Affected Region

           * No. of Probable / Confirmed / Total Cases]

Italy

    ° Caserta

        § Yes

            * 0 / 1 / 1

    ° Firenze

        § Yes

            * 0 / 1 / 1

Macedonia

    ° Vardarski

        § No

            * 0 / 1 / 1

(...)

Source: 

 Link: https://wnv-weekly.ecdc.europa.eu/

____

#Surveillance of West Nile Virus #WNV #infections in #human in #Europe, Weekly Report (ECDC, June 12 '26)

 

Week 24, 2026

Produced on 11 June 2026 at 08:15 based on data submitted up to 10 June 2026

Epidemiological summary

    Since the beginning of 2026, and as of 10 June, 1 country in Europe reported 1 human case of West Nile virus infection: North Macedonia.

    The current report in Table 1 includes the number of probable and confirmed cases of WNV infections per NUTS3 region. However, these figures are preliminary and should be interpreted with caution as they may be revised by the countries as more information becomes available. Consequently, no totals are provided. For further details on case numbers, please refer to the joint monthly report, which offers a more detailed analysis.

    Please note: The table and map in this report contain countries and areas where human West Nile virus infection cases were reported to EpiPulse Cases.

Introduction

    The European Centre for Disease Prevention and Control (ECDC) provides a weekly overview of human cases of West Nile virus (WNV) infection to support the competent authorities responsible for blood safety. This overview can aid decisions on the deferral or testing of blood donors who may have been exposed to the virus, in accordance with Commission Directives 2004/33/EC and 2014/110/EU.

    West Nile virus infection in humans is a notifiable disease at the EU level and cases are reported in accordance with the EU case definition. The table and map in this report show the countries and areas where human cases of WNV infection have been reported to the European surveillance portal for infectious diseases (EpiPulse Cases).

    More information on the occurrence of WNV infection among humans in Europe, as well as WNV outbreaks among equids and birds, is available in the joint monthly report produced by ECDC and the European Food Safety Authority (EFSA).

    Here we present the weekly report as of 10 June 2026.

Overview of West Nile virus cases in EU/EEA and EU-neighbouring countries

{Country - Affected Region - Probable - Confirmed - Total Cases}

    ° North Macedonia - Vardarski - 0 - 1 - 1

(...)

Source: 

Link: https://wnv-weekly.ecdc.europa.eu/

____

#Italy, #WNV & #USUV Integrated #Surveillance - Weekly Bulletin No. 16 - 30 October 2025 (Summary)

 

{Summary}

-- During current epidemiological week (from 23 to 29 Oct. 2025), two new human cases of infection with West Nile Virus have been reported. 

-- The cumulative number of confirmed cases this season so far rose to 773 (they were 771 last week), of these: 

- 367 were West Nile Neuroinvasive Disease (WNND): 17 in Piedmont, 56 Lombardy, 35 Veneto, 4 Friuli-Venezia Giulia, 1 Liguria, 30 Emilia-Romagna, 11 Tuscany, 1 Marche, 87 Latium, 2 Molise, 83 Campania, 2 Apulia, 2 Basilicata, 5 Calabria, 3 Sicily, 28 Sardinia, 

- 56 were asymptomatic cases detected in blood donors, 

- 339 were West Nile Fever cases (of which: 1 imported from Kenya, 1  from Egypt and 1 from Maldives), 

- 3 asymptomatic cases, 

- 8 unspecified cases. 

-- Among confirmed cases, 72 fatalities have been recorded: 7 in Piedmont, 9 Lombardy, 1 Veneto, 2 Emilia-Romagna, 1 Marche, 19 Latium, 29 Campania, 2 Calabria, 1 Sicily, 1 Sardinia. 

- The Case-Fatality Rate in WNND cases is 19.6% (it was 20% in 2018, 14% in 2024). 

-- Since the start of the epidemic season, 11 confirmed human cases of Usutu virus infection were reported: 2 in Piedmont, 3 Lombardy, 2 Veneto, 1 Tuscany, 3 Latium.

(...)

Source: High Institute of Health, https://www.epicentro.iss.it/westnile/bollettino/Bollettino_WND_2025_16.pdf

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Detection of #WNV, #USUV and #Insect-Specific #Bunyaviruses in #Culex spp. Mosquitoes, #Greece, 2024

 

Abstract

Greece is one of the countries in Europe most affected by West Nile virus (WNV), and since 2010, when the virus caused a large outbreak with 197 human neuroinvasive cases, outbreaks occur almost every year. Mosquito surveillance is an indirect sign of virus circulation; therefore, the purpose of the study was the molecular detection of WNV in 45,988 C. pipiens s.l. mosquitoes collected during 2024 in four Regions of Greece and the genetic characterization of the virus strains. WNV was detected in 41 of 1316 (3.12%) Culex spp. mosquito pools. Next-generation sequencing was applied to the WNV-positive samples that had a high viral load. All WNV sequences belong to Cluster B of the sub-lineage Europe WNV-2A presenting a temporal clustering. The WNV infection rates varied highly across the Regions, regional units and months, being higher in Thessaly and Central Macedonia Regions, especially in July and September. All mosquito pools were also tested for Usutu virus (USUV), and one pool was found positive, with sequence clustering into the EU-2 lineage. A subset of mosquitoes (737 pools) was tested for additional viruses, and bunya-like viruses were detected in 6 pools with sequences clustering into four distinct subclades. The prompt detection of pathogenic viruses is helpful for the design of control measures, while the detection of insect-specific viruses provides insights into viral diversity and evolution.

Source: Viruses, https://www.mdpi.com/1999-4915/17/11/1414

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#Italy, #WNV & #USUV Integrated #Surveillance - Weekly Bulletin No. 14, 15 Ocotber 2025 (ISS, edited)

 

{Summary}

-- New human cases of West Nile Virus infection continue to be reported albeit with reduced intensity. 

-- During current epidemiological week (from 9 to 15 October 2025) 26 new confirmed cases have been reported. 

-- The total number of cases so far is 767 (they were 740 last week), of these: 

- 366 were West Nile Neuroinvasive Disease (WNND): 17 in Piedmont, 56 Lombardy, 34 Veneto, 4 Friuli-Venezia Giulia, 1 Liguria, 32 Emilia-Romagna, 10 Tuscany, 1 Marche, 86 Latium, 2 Molise, 83 Campania, 2 Apulia, 2 Basilicata, 5 Calabria, 3 Sicily, 28 Sardinia, 

- 57 were asymptomatic cases among blood donors, 

- 333 were West Nile Fever cases (of which 1 imported from Kenya, 1 from Egypt and 1 from Maldive), 

- 3 asymptomatic cases, 

- eight unspecified cases. 

-- Among confirmed cases, 69 fatalities have been reported: 7 in Piedmont, 9 Lombardy, 2 Emilia-Romagna, 18 Latium, 29 Campania, 2 Calabria, 1 Sicily, 1 Sardinia. 

-- The case-fatality rate in WNND cases stands at 18.8% (in 2018 it was 20%, in 2024 it was 14%). 

-- So far this season, 10 cases of Usutu virus infection have been recorded: 2 in Piedmont, 3 Lombardy, 2 Veneto, 3 Latium.

(...)

Source: High Institute of Health, https://www.epicentro.iss.it/westnile/bollettino/Bollettino_WND_2025_14.pdf

____

#Italy, Integrated #WNV & #USUV #Surveillance - Weekly Bulletin No. 13, 9 October 2025 (Summary): 22 new confirmed cases

{Summary}

-- During current epidemiological week, a rise in the West Nile Virus human cases has been observed although with reduced intensity compared most recent weeks. 

-- Twenty-two new confirmed human cases have been reported during surveillance week from 2 to 8 October 2025. 

-- The cumulative number of cases rose to 740 (they were 718 last week), of these: 

- 354 were West Nile Neuroinvasive Disease (WNND): 16 in Piedmont, 53 Lombardy, 33 Veneto, 4 Friuli-Venezia Giulia, 1 Liguria, 30 Emilia-Romagna, 11 Tuscany, 1 Marche, 84 Latium, 2 Molise, 81 Campania, 2 Apulia, 2 Basilicata, 5 Calabria, 3 Sicily, 26 Sardinia,

- 57 were asymptomatic cases in blood donors, 

- 318 were West Nile Fever cases, of which 1 imported from Kenya, 1 from Egypt and 1 from Maldives, 

- 4 asymptomatic cases, 

- 7 unspecified cases. 

-- Among confirmed cases there were 68 fatalities: 7 in Piedmont, 9 Lombardy, 2 Emilia-Romagna, 18 Latium, 28 Campania, 2 Calabria, 1 Sicily, 1 Sardinia. 

- The Case-Fatality Rate in WNND cases is now at 19.2% (it was 20% in 2018 and 14% in 2024). 

-- During current epidemic season, ten Usutu Virus human cases have been confirmed: 2 in Piedmont, 3 Lombardy, 2 Veneto, 3 Latium.

(...)

Source: High Institute of Health, https://www.epicentro.iss.it/westnile/bollettino/Bollettino_WND_2025_13.pdf

____

#Italy, Integrated #WNV & #USUV #Surveillance - Weekly Bulletin No. 12, 2 October 2025: 38 new confirmed cases (Summary)

 

{Summary}

-- During current epidemiological week (from 25 September to 1rst October 2025), 38 new confirmed human infection with West Nile Virus have been reported. 

-- Since the beginning of the epidemic season, 718 confirmed cases have been recorded in Italy (they were 680 in the last bulletin), of these: 

- 341 were West Nile Neuroinvasive Disease (WNND): 15 in Piedmont, 51 Lombardy, 30 Veneto, 4 Friuli-Venezia Giulia, 1 Liguria, 27 Emilia-Romagna, 11 Tuscany, 1 Marche, 84 Latium, 2 Molise, 79 Campania, 2 Apulia, 2 Basilicata, 5 Calabria, 2 Sicily, 25 Sardinia, 

- 57 were asymptomatic cases in blood donors, 

- 309 were West Nile Fever cases (1 imported from Kenya, 1 Egypt, and one Maldives), 

- 4 asymptomatic cases, 

- 7 unspecified cases. 

-- Among confirmed cases, there have been 49 fatalities: 7 in Piedmont, 5 Lombardy, 2 Emilia-Romagna, 18 Latium, 14 Campania, 2 Calabria, 1 Sardinia. 

- The Case-Fatality Rate in WNND cases was 14.4% (it was 20% in 2018 and 14% in 2024. 

-- This season 10 confirmed Usutu virus human infections have been recorded: 2 in Piedmont, 3 Lombardy, 2 Veneto, 3 Latium.

(...)

Source: High Institute of Health, https://www.epicentro.iss.it/westnile/bollettino/Bollettino_WND_2025_12.pdf

____

#Italy, Integrated #WNV & #USUV #Surveillance - Weekly Bulletin No. 11, September 25 '25 (ISS, Summary)

 

{Summary}

-- During current surveillance week (from 18 to 24 Sept. '25), 33 new confirmed human cases of West Nile Virus have been detected. 

-- Since the beginning of the epidemic season, there have been 680 cases in total, (they were 647 last week); of these: 

- 321 were West Nile Neuroinvasive Disease (WNND): 15 in Piedmont, 44 Lombardy, 27 Veneto, 2 Friuli-Venezia Giulia, 1 Liguria, 25 Emilia-Romagna, 8 Tuscany, 1 Marche, 83 Latium, 2 Molise, 79 Campania, 2 Apulia, 2 Basilicata, 5 Calabria, 1 Sicily, 24 Sardinia), 

- 54 were asymptomatic cases in blood donors, 

- 296 were West Nile Fever cases (1 imported from Kenya, 1 Egypt and 1 Maldives), 

- 3 asymptomatic cases,  

- 6 unspecified cases. 

-- Among confirmed cases, there were 48 deaths: 7 in Piedmont, 5 Lombardy, 2 Emilia-Romagna, 17 Latium, 14 Campania, 2 Calabria, 1 Sardinia. 

- The Case-Fatality Rate among WNND cases was 14.9% (it was 20% in 2018 and 14% in 2024). 

-- During current surveillance week, nine new confirmed human cases of Usutu virus have been confirmed: 2 in Piedmont, 2 Lombardy, 2 Veneto, 3 Latium).

(...)

Source: High Institute of Health, https://www.epicentro.iss.it/westnile/bollettino/Bollettino_WND_2025_11.pdf

____

#Italy, Integrated #Surveillance for #WNV & #USUV - Weekly Bulletin No. 10, 18 September '25 (Summary)

 

{Summary}

-- During current epidemiological week (11– 17 September 2025), 65 new confirmed human cases of infection with West Nile Virus have been reported. 

-- The total number of confirmed cases, since the beginning of the epidemic season, has thus risen to 647 (it was 582 last week), of these: 

- 300 were West Nile Neuroinvasive Disease (WNND): 15 in Piedmont, 39 Lombardy, 24 Veneto, 2 Friuli-Venezia Giulia, 1 Liguria, 23 Emilia-Romagna, 5 Tuscany, 83 Latium, 2 Molise, 77 Campania, 2 Apulia, 2 Basilicata, 5 Calabria, 1 Sicily, 19 Sardinia, 

- 54 were asymptomatic cases detected among blood donors, 

- 284 were West Nile Fever cases (one imported from Kenya), 

- 3 asymptomatic cases and 

- 6 unspecified casese. 

-- Among confirmed cases, there were 47 death cases: 7 in Piedmont, 5 Lombardy, 1 Emilia-Romagna, 16 Latium, 15 Campania, 2 Calabria, 1 Sardinia. 

- The Case-Fatality Rate in WNND cases was 15.8% (it was 20% in 2018 and  14% in 2024). 

-- This week nine confirmed cases of Usutu Virus infection have been reported: 2 in Piedmont, 2 Lombardy, 2 Veneto, 3 Latium.

(...)

Source: High Institute of Health, https://www.epicentro.iss.it/westnile/bollettino/Bollettino_WND_2025_10.pdf

____

#Italy, Integrated #Surveillance for #WNV & #USUV - Weekly Bulletin No. 9, 11 September '25 (summary): 80 new cases

{Summary}

-- During current epidemiological week (4 to 10 September), eighty new confirmed human cases of West Nile Virus infection have been reported in Italy.

-- Since the beginning of the epidemic season, there have been a total of 582 confirmed cases (they were 502 last week), of these: 

- 260 were West Nile Neuroinvasive Disease (WNND): 14 in Piedmont, 24 Lombardy, 22 Veneto, 1 Friuli-Venezia Giulia, 1 Liguria, 20 Emilia-Romagna, 3 Tuscany, 77 Latium, 2 Molise, 74 Campania, 1 Apulia, 2 Basilicata, 5 Calabria, 1 Sicily, 13 Sardinia, 

- 48 asymptomatic cases among blood donors, 

- 262 cases of West Nile Fever (1 imported from Kenya), 

- 4 asymptomatic cases, 

- 8 unspecified cases. 

-- A total of 39 fatal cases have been reported so far this season: 5 in Piedmont, 2 Lombardy, 1 Emilia-Romagna, 15 Latium, 14 Campania, 2 Calabria. 

- The Case-Fatality Rate among WNND cases is thus far at 15% (during 2018 season it was 20%, in 2024 14%). 

-- During current surveillance week there were 7 new confirmed Usutu Virus infection cases: 2 in Piedmont, 2 Lombardy, 1 Veneto, 2 Latium.

(...)

Source: High Institute of Health, https://www.epicentro.iss.it/westnile/bollettino/Bollettino_WND_2025_09.pdf

____

Shared viral burdens: Evidence of active #Usutu virus circulation and multi- #arbovirus exposure in migrant and resident #birds at wintering locations in #Nigeria

 

Abstract

Background: 

West Nile (WNV), Usutu (USUV), and Sindbis (SINV) virus were initially detected in the African region, and subsequently across temperate regions where they were absent. Wild birds are primary reservoirs for these arboviruses and are considered major contributors to their global spread through seasonal migration. To understand the transmission dynamics of arboviruses in wild birds and the potential of migratory birds to spread the viruses at an intercontinental scale, we investigated arboviral infections and exposures in African resident and Palearctic migratory birds at wintering locations in Nigeria. 

Methodology/Principal Findings: 

Oropharyngeal- and cloacal swabs, feathers and blood were collected from resident and migratory birds at two wintering locations (Amurum and Ngel-Nyaki Forest Reserves). Swabs and feathers were tested using RT-PCR for WNV, USUV and SINV, and blood with ELISA and FRNT90 or PRNT80 for antibodies. 573 birds were sampled between 2021 to 2024 across months coinciding with arrival and departure of migratory birds. USUV RNA was detected in 2.6% of feathers including a positive Icterine warbler and a garden warbler sampled prior to spring migration. None of the swabs was positive for viral RNA but neutralizing antibodies to WNV and USUV were detected in 4.5% of birds. SINV antibodies were also found in 34.1% of birds sampled across the wintering locations. 

Conclusions/Significance: 

Our findings showed that migratory birds can become infected with USUV, and potentially with WNV and SINV during their overwintering periods in Africa and highlighted a wider arbovirus risk in Nigeria. In addition, detections of viral RNA in feathers, but not swabs, suggest feathers may be a suitable matrix for surveillance in the absence of a reliable cold chain. The overall detections in wild birds at these locations highlight the need for further surveillance to define the epidemiology and public health risks of these arboviruses in the region.

Competing Interest Statement

The authors have declared no competing interest.

Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2025.09.08.674803v1

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#Italy, Integrated #WNV & #USUV Viruses #Surveillance - Weekly #Bulletin No. 8, September 4 2025 (summary)

{Summary}

-- During current surveillance week (28 August - 3 September 2025): 

- 72 new confirmed human cases of West Nile Virus infection have been confirmed; 

-- The total number of cases since the beginning of epidemic season has risen to 502 (they were 430 in the last bulletin); of these: 

- 226 were West Nile Neuroinvasive Disease (WNND): 11 in Piedmont, 16 in Lombardy, 17 Veneto, 1 Friuli-Venezia Giulia, 1 Liguria, 15 Emilia-Romagna, 3 Tuscany, 71 Latium, 2 Molise, 72 Campania, 1 Apulia, 2 Basilicata, 5 Calabria, 1 Sicily, 8 Sardinia, 

- 40 were asymptomatic cases detected in blood donors, 

- 226 were West Nile Fever cases (one of them imported from Kenya),

- 5 asymptomatic cases, 

- 5 unspecified. 

-- So far there have been 33 fatal cases: 3 in Piedmont, 1 Lombardy, 1 Emilia-Romagna, 14 Latium, 12 Campania, 2 Calabria. 

- The Case-Fatality rate among WNND cases is thus far at 14.6% (in 2018 it was 20%, in 2024 14%). 

-- During current surveillance week, there have been 4 confirmed Usutu virus human infections: 2 in Piedmont, 1 Veneto, 1 Latium).

(...)

Source: High Institute of Health, https://www.epicentro.iss.it/westnile/bollettino/Bollettino_WND_2025_08.pdf

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The paradoxical #impact of #drought on #WNV #risk: insights from long-term ecological data

 

Abstract

Mosquito-borne diseases are deeply embedded within ecological communities, with environmental changes—particularly climate change—shaping their dynamics. Increasingly intense droughts across the globe have profound implications for the transmission of these diseases, as drought conditions can alter mosquito breeding habitats, host-seeking behaviours and mosquito–host contact rates. To quantify the effect of drought on disease transmission, we use West Nile virus as a model system and leverage a robust mosquito and virus dataset consisting of over 500 000 trap nights collected from 2010 to 2023, spanning a historic drought period followed by atmospheric rivers. We pair this surveillance dataset with a novel modelling approach that incorporates monthly changes in bird host community competence, along with drought conditions, to estimate the effect of drought severity on West Nile virus risk using panel regression models. Our results show that while drought decreases mosquito abundances, it paradoxically increases West Nile virus infection rates. This counterintuitive pattern probably stems from reduced water availability, which concentrates mosquitoes and pathogen-amplifying bird hosts around limited water sources, thereby increasing disease transmission risk. However, the magnitude of the effect depends critically on mosquito species, suggesting species-specific behavioural traits are key to understanding the effect of drought on mosquito-borne disease risk across real landscapes.

Source: Proceedings of the Royal Society B Biological Sciences, https://royalsocietypublishing.org/doi/full/10.1098/rspb.2025.1365?af=R

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#Vectors on the Move: How #Climate Change Fuels the Spread of #Arboviruses in #Europe

 

Abstract

Climate change is increasingly recognized as a major driver of emerging infectious diseases, particularly vector-borne diseases (VBDs), which are expanding in range and intensity worldwide. Europe, traditionally considered low-risk for many arboviral infections, is now experiencing autochthonous transmission of pathogens such as dengue, chikungunya, Zika virus, West Nile virus, malaria, and leishmaniasis. Rising temperatures, altered precipitation patterns, and milder winters have facilitated the establishment and spread of competent vectors, including Aedes, Anopheles, Phlebotomus, and Culex species, in previously non-endemic areas. These climatic shifts not only impact vector survival and distribution but also influence vector competence and pathogen development, ultimately increasing transmission potential. This narrative review explores the complex relationship between climate change and VBDs, with a particular focus on pediatric populations. It highlights how children may experience distinct clinical manifestations and complications, and how current data on pediatric burden remain limited for several emerging infections. Through an analysis of existing literature and reported outbreaks in Europe, this review underscores the urgent need for enhanced surveillance, integrated vector control strategies, and climate-adapted public health policies. Finally, it outlines research priorities to better anticipate and mitigate future disease emergence in the context of global warming. Understanding and addressing this evolving risk is essential to safeguard public health and to protect vulnerable populations, particularly children, in a rapidly changing climate.

Source: Microorganisms, https://www.mdpi.com/2076-2607/13/9/2034

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