The Hawaii Department of Health’s COVID-19 cluster report this week focuses on outbreaks in places of worship due to two clusters under investigation on Oahu and Kauai.

This month, health officials said they investigated a cluster of 13 cases associated with a faith-based retreat and large gathering on the U.S. mainland.

Eight out of 17 attendees from Hawaii tested positive for COVID-19, while five secondary household cases have been identified. Four were hospitalized, including one person in hospice care.

Only six out of the 17 reported having been fully vaccinated for COVID-19.

Masks were not required during the retreat or gathering, officials said. Several attendees also confirmed their symptoms started before travel or during the trip, including before their return to Oahu.

The Centers for Disease Control and Prevention recommends that unvaccinated individuals continue to wear masks indoors, maintain 6 feet from non-household members, and not congregate in common areas.

Additionally, CDC recommends not attending services or events, and delaying travel if sick with a fever or symptoms consistent with COVID-19 to prevent exposing other people, officials said in the report. CDC also recommends that people postpone travel until they are fully vaccinated.

The state Health Department is also investigating another cluster of 11 cases associated with a place of worship on Kauai.

In this cluster, two unrelated visitors from the mainland in early June tested positive for SARS-CoV-2. They had attended services on the island the same day and location, with overlapping service times.

The services took place indoors, with singing, which increases the risk of COVID-19 transmission, and inconsistent mask use.

There have since been nine more cases identified among those who attended services on the same day, bringing the total to 11. Seven cases were symptomatic, and one was hospitalized.

Fortunately, no secondary cases have been identified, so far. All individuals who contracted the coronavirus in the cluster were not vaccinated for COVID-19.

The Kauai District Health Office worked closely with the faith-based organization’s leaders to notify approximately 300 families of their potential exposure, plus offer information on free community testing.

Health officials said requiring mask use indoors and encouraging vaccination have proven effective in slowing the spread of COVID-19.

Services and events at places of worship are safest when everyone is vaccinated, officials said.

The report, published Thursday, reflects clusters under investigation for the past two weeks. The state Health Department said it generally does not disclose the exact location or identity of entities involved in clusters unless they pose an “imminent health threat.”

Health officials are currently investigating nine clusters across four counties:

>> On Oahu, officials are investigating a cluster at a restaurant with seven cases, two clusters resulting from social gatherings that resulted in 20 cases, and a cluster in the “other” category that resulted in three cases. The “other category can include offices, retail establishments and first responders.

>> On Maui County, officials are investigating a cluster at an educational setting with five cases and a cluster at a shelter with 10 cases.

>> On Hawaii County, officials are investigating a cluster at a correctional facility that resulted in 270 cases. The number of cases at the Hilo Community Correctional Center, as previously reported, continues to grow, with staff and inmates reporting deplorable and overcrowded conditions.

>> On Kauai County, officials are now investigating one cluster from a restaurant with eight cases, and the cluster at a place of worship with 11 cases.