SBGT: Scaling Bayesian-based Group Testing for Disease Surveillance.

The COVID-19 pandemic underscored the necessity for disease surveillance using group testing. Novel Bayesian methods using lattice models were proposed, which offer substantial improvements in group testing efficiency by precisely quantifying uncertainty in diagnoses, acknowledging varying individual risk and dilution effects, and guiding optimally convergent sequential pooled test selections using a Bayesian Halving Algorithm. Computationally, however, Bayesian group testing poses considerable challenges as computational complexity grows exponentially with sample size. This can lead to shortcomings in reaching a desirable scale without practical limitations. We propose a new framework for scaling Bayesian group testing based on Spark: SBGT. We show that SBGT is lightning fast and highly scalable. In particular, SBGT is up to 376x, 1733x, and 1523x faster than the state-of-the-art framework in manipulating lattice models, performing test selections, and conducting statistical analyses, respectively, while achieving up to 97.9% scaling efficiency up to 4096 CPU cores. More importantly, SBGT fulfills our mission towards reaching applicable scale for guiding pooling decisions in wide-scale disease surveillance, and other large scale group testing applications.