This week’s cluster report from the Hawaii Department of Health focuses on COVID-19 outbreaks at a restaurant chain, as well as one caused by a food supply delivery by an infected person, and a gathering at a karaoke bar.

Health officials say the risk among food service and restaurant workers has grown due to the highly transmissible delta variant — which now accounts for almost all COVID cases in Hawaii – combined with work environments that tend to be small and poorly ventilated and low vaccination rates among employees.

In July and August, health officials investigated two clusters with 40 coronavirus cases at a large restaurant chain on Oahu — with one location in a tourist area and the other in a community with low vaccination rates.