Elevated Ambient Temperature Associated With Reduced Infectious Disease Test Positivity Rates: Retrospective...

Area of Science:

• Environmental Health
• Epidemiology
• Public Health

Background:

• External factors like medication and time of day influence human body temperature (BT).
• Ambient temperature is an emerging factor affecting BT, though its real-world impact on healthcare is unclear.
• Clinical interpretation of BT often considers demographic factors, such as age-related fever thresholds.

Purpose of the Study:

• To assess the relationship between ambient temperatures and COVID-19 test positivity rates.
• To determine if environmentally mediated increases in BT affect COVID-19 diagnostic testing.
• To investigate the impact of environmental conditions on public health screening accuracy.

Main Methods:

• Utilized daily statewide COVID-19 polymerase chain reaction testing data from California.
• Combined testing data with ambient temperature data for 133 days.
• Employed a mixed-effects beta-regression model to analyze the association between temperature and test positivity rates, controlling for population and prevalence.

Main Results:

• A significant negative association was found between daily ambient temperature and COVID-19 test positivity rate (P<.001).
• Over 19 million tests across 45 counties were analyzed, demonstrating a robust relationship.
• A sensitivity analysis using random temperatures showed no significant relationship, strengthening the findings.

Conclusions:

• Environmental factors, specifically ambient temperature, significantly impact body temperature (BT) and can influence public health screening outcomes.
• The study supports the hypothesis that higher ambient temperatures correlate with decreased COVID-19 test positivity.
• Integrating environmental context into the interpretation of patient data, like BT, is crucial for improving healthcare practices and public health strategies.