Elevated West Nile virus activity in mosquitoes—1,284 positive pools across all boroughs, nearly double last year’s pace—combined with just one confirmed neuroinvasive case among New York City residents as of late August is the main driver behind closely matched market-implied odds favoring under 20 or 20–34 cases for 2026. Recent annual averages of 25–31 neuroinvasive cases (2021–2025) reflect the roughly 1-in-150 infection rate that produces severe central-nervous-system illness, yet only a fraction of infections are detected. Peak transmission typically occurs through September, and intensified surveillance plus larviciding may limit further human cases despite widespread vector positivity. Trader consensus therefore hinges on whether current conditions produce a below-average or typical season before mosquito activity declines in October.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedHow many West Nile neuroinvasive disease cases will be reported among New York City residents in 2026?
How many West Nile neuroinvasive disease cases will be reported among New York City residents in 2026?
Fewer than 20 43%
20 to 34 40%
35 to 49 16%
50 or more 7%
NEW
NEW
Mar 31, 2027
Fewer than 20
43%
20 to 34
40%
35 to 49
16%
50 or more
7%
Fewer than 20 43%
20 to 34 40%
35 to 49 16%
50 or more 7%
NEW
NEW
Mar 31, 2027
Fewer than 20
$801 Vol.
43%
20 to 34
$699 Vol.
40%
35 to 49
$1,458 Vol.
16%
50 or more
$282 Vol.
7%
This market resolves based on the total number of West Nile neuroinvasive disease cases (encephalitis, meningitis, and acute flaccid paralysis) reported among New York City residents in 2026, as published by the New York City Department of Health and Mental Hygiene on its West Nile Virus Reports page at nyc.gov/site/doh/health/health-topics/west-nile-virus-reports.page.
Cases are counted as whole numbers, so each outcome covers a distinct range with no overlap or gap.
The 2026 count shown on the source as of January 1, 2027 is the starting figure.
If the DOHMH publishes or revises the 2026 count on or after January 1, 2027, this market will resolve based on the count shown on the source at 11:59 PM ET on the 14th day after the first such update, or on March 31, 2027, 11:59 PM ET, whichever comes first. If no such update occurs, this market will resolve on March 31, 2027, 11:59 PM ET, based on the 2026 count shown on the source at that time.
If no 2026 count has been published on the source by March 31, 2027, 11:59 PM ET, this market will resolve based on the sum of 2026 West Nile neuroinvasive disease case counts reported by CDC ArboNET for the five New York City counties (Bronx, Kings, New York, Queens, and Richmond). Revisions published after this market resolves will not be considered. If the DOHMH changes its reporting format or URL structure, the closest equivalent NYC Health Department publication of 2026 West Nile neuroinvasive case data will be used.Elevated West Nile virus activity in mosquitoes—1,284 positive pools across all boroughs, nearly double last year’s pace—combined with just one confirmed neuroinvasive case among New York City residents as of late August is the main driver behind closely matched market-implied odds favoring under 20 or 20–34 cases for 2026. Recent annual averages of 25–31 neuroinvasive cases (2021–2025) reflect the roughly 1-in-150 infection rate that produces severe central-nervous-system illness, yet only a fraction of infections are detected. Peak transmission typically occurs through September, and intensified surveillance plus larviciding may limit further human cases despite widespread vector positivity. Trader consensus therefore hinges on whether current conditions produce a below-average or typical season before mosquito activity declines in October.
This market resolves based on the total number of West Nile neuroinvasive disease cases (encephalitis, meningitis, and acute flaccid paralysis) reported among New York City residents in 2026, as published by the New York City Department of Health and Mental Hygiene on its West Nile Virus Reports page at nyc.gov/site/doh/health/health-topics/west-nile-virus-reports.page.
Cases are counted as whole numbers, so each outcome covers a distinct range with no overlap or gap.
The 2026 count shown on the source as of January 1, 2027 is the starting figure.
If the DOHMH publishes or revises the 2026 count on or after January 1, 2027, this market will resolve based on the count shown on the source at 11:59 PM ET on the 14th day after the first such update, or on March 31, 2027, 11:59 PM ET, whichever comes first. If no such update occurs, this market will resolve on March 31, 2027, 11:59 PM ET, based on the 2026 count shown on the source at that time.
If no 2026 count has been published on the source by March 31, 2027, 11:59 PM ET, this market will resolve based on the sum of 2026 West Nile neuroinvasive disease case counts reported by CDC ArboNET for the five New York City counties (Bronx, Kings, New York, Queens, and Richmond). Revisions published after this market resolves will not be considered. If the DOHMH changes its reporting format or URL structure, the closest equivalent NYC Health Department publication of 2026 West Nile neuroinvasive case data will be used.
Cases are counted as whole numbers, so each outcome covers a distinct range with no overlap or gap.
The 2026 count shown on the source as of January 1, 2027 is the starting figure.
If the DOHMH publishes or revises the 2026 count on or after January 1, 2027, this market will resolve based on the count shown on the source at 11:59 PM ET on the 14th day after the first such update, or on March 31, 2027, 11:59 PM ET, whichever comes first. If no such update occurs, this market will resolve on March 31, 2027, 11:59 PM ET, based on the 2026 count shown on the source at that time.
If no 2026 count has been published on the source by March 31, 2027, 11:59 PM ET, this market will resolve based on the sum of 2026 West Nile neuroinvasive disease case counts reported by CDC ArboNET for the five New York City counties (Bronx, Kings, New York, Queens, and Richmond). Revisions published after this market resolves will not be considered. If the DOHMH changes its reporting format or URL structure, the closest equivalent NYC Health Department publication of 2026 West Nile neuroinvasive case data will be used.
Market Opened: Aug 20, 2026, 5:18 PM ET
Volume
$3,240End Date
Mar 31, 2027Market Opened
Aug 20, 2026, 5:18 PM ETResolver
0x69c47De9D...This market resolves based on the total number of West Nile neuroinvasive disease cases (encephalitis, meningitis, and acute flaccid paralysis) reported among New York City residents in 2026, as published by the New York City Department of Health and Mental Hygiene on its West Nile Virus Reports page at nyc.gov/site/doh/health/health-topics/west-nile-virus-reports.page.
Cases are counted as whole numbers, so each outcome covers a distinct range with no overlap or gap.
The 2026 count shown on the source as of January 1, 2027 is the starting figure.
If the DOHMH publishes or revises the 2026 count on or after January 1, 2027, this market will resolve based on the count shown on the source at 11:59 PM ET on the 14th day after the first such update, or on March 31, 2027, 11:59 PM ET, whichever comes first. If no such update occurs, this market will resolve on March 31, 2027, 11:59 PM ET, based on the 2026 count shown on the source at that time.
If no 2026 count has been published on the source by March 31, 2027, 11:59 PM ET, this market will resolve based on the sum of 2026 West Nile neuroinvasive disease case counts reported by CDC ArboNET for the five New York City counties (Bronx, Kings, New York, Queens, and Richmond). Revisions published after this market resolves will not be considered. If the DOHMH changes its reporting format or URL structure, the closest equivalent NYC Health Department publication of 2026 West Nile neuroinvasive case data will be used.Elevated West Nile virus activity in mosquitoes—1,284 positive pools across all boroughs, nearly double last year’s pace—combined with just one confirmed neuroinvasive case among New York City residents as of late August is the main driver behind closely matched market-implied odds favoring under 20 or 20–34 cases for 2026. Recent annual averages of 25–31 neuroinvasive cases (2021–2025) reflect the roughly 1-in-150 infection rate that produces severe central-nervous-system illness, yet only a fraction of infections are detected. Peak transmission typically occurs through September, and intensified surveillance plus larviciding may limit further human cases despite widespread vector positivity. Trader consensus therefore hinges on whether current conditions produce a below-average or typical season before mosquito activity declines in October.
This market resolves based on the total number of West Nile neuroinvasive disease cases (encephalitis, meningitis, and acute flaccid paralysis) reported among New York City residents in 2026, as published by the New York City Department of Health and Mental Hygiene on its West Nile Virus Reports page at nyc.gov/site/doh/health/health-topics/west-nile-virus-reports.page.
Cases are counted as whole numbers, so each outcome covers a distinct range with no overlap or gap.
The 2026 count shown on the source as of January 1, 2027 is the starting figure.
If the DOHMH publishes or revises the 2026 count on or after January 1, 2027, this market will resolve based on the count shown on the source at 11:59 PM ET on the 14th day after the first such update, or on March 31, 2027, 11:59 PM ET, whichever comes first. If no such update occurs, this market will resolve on March 31, 2027, 11:59 PM ET, based on the 2026 count shown on the source at that time.
If no 2026 count has been published on the source by March 31, 2027, 11:59 PM ET, this market will resolve based on the sum of 2026 West Nile neuroinvasive disease case counts reported by CDC ArboNET for the five New York City counties (Bronx, Kings, New York, Queens, and Richmond). Revisions published after this market resolves will not be considered. If the DOHMH changes its reporting format or URL structure, the closest equivalent NYC Health Department publication of 2026 West Nile neuroinvasive case data will be used.
Cases are counted as whole numbers, so each outcome covers a distinct range with no overlap or gap.
The 2026 count shown on the source as of January 1, 2027 is the starting figure.
If the DOHMH publishes or revises the 2026 count on or after January 1, 2027, this market will resolve based on the count shown on the source at 11:59 PM ET on the 14th day after the first such update, or on March 31, 2027, 11:59 PM ET, whichever comes first. If no such update occurs, this market will resolve on March 31, 2027, 11:59 PM ET, based on the 2026 count shown on the source at that time.
If no 2026 count has been published on the source by March 31, 2027, 11:59 PM ET, this market will resolve based on the sum of 2026 West Nile neuroinvasive disease case counts reported by CDC ArboNET for the five New York City counties (Bronx, Kings, New York, Queens, and Richmond). Revisions published after this market resolves will not be considered. If the DOHMH changes its reporting format or URL structure, the closest equivalent NYC Health Department publication of 2026 West Nile neuroinvasive case data will be used.
Volume
$3,240End Date
Mar 31, 2027Market Opened
Aug 20, 2026, 5:18 PM ETResolver
0x69c47De9D...Elevated West Nile virus activity in mosquitoes—1,284 positive pools across all boroughs, nearly double last year’s pace—combined with just one confirmed neuroinvasive case among New York City residents as of late August is the main driver behind closely matched market-implied odds favoring under 20 or 20–34 cases for 2026. Recent annual averages of 25–31 neuroinvasive cases (2021–2025) reflect the roughly 1-in-150 infection rate that produces severe central-nervous-system illness, yet only a fraction of infections are detected. Peak transmission typically occurs through September, and intensified surveillance plus larviciding may limit further human cases despite widespread vector positivity. Trader consensus therefore hinges on whether current conditions produce a below-average or typical season before mosquito activity declines in October.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated
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