Fairfield County, Connecticut

CDC NNDSS 2022-2023, averaged. These counts are a floor: they are what was reported to CDC and carried a county code, not an estimate of infections.

Most of this state's cases carry a county code, so county comparisons within the state are meaningful.

This county appears in only one of the two years CDC county-coded. Appearing in the data for the first time is a reporting event, not a measured increase, so no county change is computed.

A change between years reflects reporting as well as transmission. County-coding coverage moved over this period, so a rise may be a rise in what was recorded.

No county-resolved environmental layer ships with this build. NOAA climate and USGS land-cover data inform the platform's environmental pages but are not joined to counties here, so this brief does not report an environmental value it cannot source.

June sits at 1.00 on the Ixodes scapularis activity curve, which peaks in June with the nymph stage.

A national curve applied uniformly. Tick phenology shifts with latitude and with the year’s weather; this curve does not.

Observed emergency-department visits for tick bites peaked in May (MMWR Morb Mortal Wkly Rep 2021;70(17):612–616 (NSSP, ED visits for tick bites per 100k ED visits)):

2017–2019 baseline, emergency departments only (≈71% of US ED visits covered by NSSP by 2019). Most people bitten by ticks never visit an ED, so this is a floor for bite exposure.

Modeled, not observed. This is a weighted index over four published components, not a CDC statistic and not a probability that anyone is infected.

1. 1.Seasonal vector activityIxodes scapularis activity curve — June20.0 pts
2. 2.Historical incidenceCDC county-coded Lyme surveillance5.3 pts
3. 3.Current exposure geographyCDC county-coded Lyme surveillance5.3 pts

Evidence retrieval runs in the ML service and requires a session. Open the Evidence section for cited findings; each carries its DOI and a source-strength rating, and uncited reference text is labelled as such.

• —Whether any individual has Lyme disease. The index describes a place, a month and a symptom pattern, not a person.
• —That reported cases equal actual cases. CDC surveillance counts what was reported and county-coded; the figures here are floors.
• —That a county with no data has no risk. Absence of county coding is absence of measurement.
• —That a change between 2022 and 2023 reflects a change in transmission. Reporting practice, testing, and county-coding coverage all moved over the same period.
• —Anything about co-infections, chronic presentations, or treatment response. None of those are in the data behind this brief.

• —Bring the symptom timeline and exposure history in this brief to a clinician; the timeline matters more to diagnosis than any single figure here.
• —If tick exposure occurred in the last 30 days, note the date — serology is frequently negative early and a negative test in that window does not rule Lyme out.
• —Check the completeness figure before comparing this county against another state's county.
• —Use the evidence section's citations directly rather than this summary when discussing findings with a clinician.

Information for clinician review. This brief is not a diagnosis and does not recommend treatment.

Data lineage