Simple Questionnaires to Improve Pooling Strategies for SARS-CoV-2 Laboratory Testing

Area of Science:

• Virology
• Public Health
• Laboratory Medicine

Background:

• Liberal PCR testing for SARS-CoV-2 (COVID-19) is crucial for pandemic containment.
• Multi-sample pooled testing can enhance laboratory capacity and reduce costs, particularly in low- and middle-income countries.

Purpose of the Study:

• To evaluate a simple questionnaire for guiding SARS-CoV-2 pooled testing strategies.
• To improve the efficiency and cost-effectiveness of COVID-19 laboratory diagnostics.

Main Methods:

• A questionnaire assessed pre-test probability of COVID-19 based on symptoms, travel, and contact history.
• Samples were individually or pooled tested based on questionnaire responses.
• Questionnaire-guided pooling was compared against random pooling for positivity rates and tests required.

Main Results:

• Over 25,000 samples were processed; questionnaire-guided pooling covered 76.9%.
• Pool positivity and individual prevalence were higher in random pooling.
• Questionnaire-based pooling required 0.09 tests per participant vs. 0.27 in random pooling, increasing capacity by 73-91%.

Conclusions:

• Combining pooled testing with questionnaire-based risk stratification boosts COVID-19 testing capacity.
• This approach is particularly valuable in resource-constrained settings.
• Optimized pooling strategies enhance laboratory efficiency for infectious disease surveillance.