Optimizing and evaluating PCR-based pooled screening during COVID-19 pandemics.

Area of Science:

• Epidemiology
• Public Health
• Infectious Disease Modeling

Background:

• Population screening was crucial for safely reopening economies and preventing COVID-19 outbreaks.
• Pooled PCR screening enables widespread testing with limited resources by combining samples.
• Various screening methods, including pooled PCR, individual PCR, and antigen tests, were evaluated as interventions.

Purpose of the Study:

• To compare the effectiveness, accuracy, and cost of different population-wide COVID-19 screening methods.
• To model the impact of testing and isolation protocols on test sensitivity during an epidemic.
• To assess the efficiency of screening strategies in controlling viral transmission.

Main Methods:

• Developed an epidemic model incorporating testing-isolation processes and individual viral load.
• Compared pooled PCR, individual PCR, and antigen screening methods.
• Analyzed cost-effectiveness, accuracy, and efficiency of each screening approach.

Main Results:

• The testing-isolation process maintained stable test sensitivity by removing infected individuals, particularly during epidemic decline.
• PCR-based pooled screening proved cost-effective for reversing pandemics at low prevalence.
• High-prevalence outbreaks may not be halted by pooled PCR; frequent antigen screening can be effective despite costs and false positives.

Conclusions:

• Pooled PCR screening is an efficient and cost-effective strategy for managing COVID-19 at low prevalence.
• Antigen screening, when performed frequently, can effectively control epidemics, though it incurs higher costs and false positives.
• The choice of screening method should consider prevalence levels, resource availability, and desired epidemic control outcomes.