COVID-19 cases and hospitalizations are on the rise across Washington, according to a Washington State Department of Health.

Case counts and hospitalizations flattened at the end of June only to increase starting in the first week of July, according to the department’s July 27 media release. Beginning July 8, hospitalizations increased among people ages 40-49 and ages 70-79. More recent reports show an increase in hospitalizations across all age groups, according to the department. Case counts in King and Pierce counties have increased since July 8.

Cases among people ages 20-39 are increasing, while cases among other age groups are flattening, according to the Department of Health.

The transmission rate also increased sharply around the end of June and beginning of July. This is likely due to the delta variant, which is more transmissible than the original COVID-19 virus and is now the dominant strain among people who have contracted the virus.

Projections suggest that on July 19, around 90% of all cases were attributed to the delta variant, according to the Department of Health.

On July 2, the estimated reproductive number of the virus was 1.46, and in order for cases to decline, the reproductive rate has to be below 1.0 for a substantial period of time. The reproductive number determines how many people will likely contract the virus from a single case, according to the Department of Health.

This announcement comes one day after several counties across Washington recommended that masks be worn at indoor public spaces by all people regardless of vaccination status due to the spread of the delta variant.