VANCOUVER -- The vast majority of B.C.'s COVID-19 cases continue to be located in the Lower Mainland, but the latest map of infection data from the B.C. Centre for Disease Control shows transmission increasing in some parts of the region and declining in others.

The map shows coronavirus cases detected during the week of April 11 to 17, and includes both the number of infections recorded in each local health area as well as an approximation of the daily number per 100,000 residents.

As always, Surrey leads the way. The local health area that makes up most of the City of Surrey saw 1,698 people test positive for COVID-19 during the week shown on the map. That's up from 1,573 the week prior.

Some neighbouring health regions south of the Fraser River also saw more new cases last week than they did the previous one. That includes Langley - where 340 cases were recorded during the week shown on the map, compared to 210 the week before - and Abbotsford, which saw 492 new infections last week, compared to 313 during the previous one.

The local health area that includes South Surrey and White Rock trended slightly downward during the week in question, from 159 new cases to 144 in the most recent week.

Delta saw a similarly small decrease, from 262 new cases to 241.

These patterns come as B.C.'s overall transmission of COVID-19 begins to trend downward. The rolling seven-day average for daily new cases dropped below 1,000 for the first time in two weeks on Wednesday. 

Modelling presented by provincial health officer Dr. Bonnie Henry earlier this month suggested that, without a reduction in the number of contacts people had, the province was on pace to see more than 2,000 infections per day.

While that scenario hasn't yet come to pass, more restrictions are on the way to help bend the infection curve further down. Part of the goal of new orders limiting travel between health authorities is to keep people from visiting - or straying too far from - hotspots like Surrey and the broader Lower Mainland.

"We know that right now with the transmission rates we are having, travel will spread the virus further," said Henry during a news conference Thursday. "Staying in our local communities, we are not going to and from COVID hotspots and inadvertently bringing the virus with us."

One of those hotspots - the Howe Sound local health area, which includes Whistler - saw a significant decline in new COVID-19 infections during the week that ended April 17.

The region recorded 131 new cases during the week shown on the map. That total is still more than 20 per 100,000 residents per day, but it's much lower than the 337 the region saw the previous week.

Because of the ongoing transmission in Whistler, all adults living or working in the municipality were offered COVID-19 vaccines beginning on April 12. 

A similar program put in place for the northern B.C. city of Prince Rupert in March has been credited with dramatically reducing the spread of the coronavirus there. 

On the most recent map, the Prince Rupert local health area recorded just three new cases of COVID-19. That's down from 27 the week before.

Henry said last week that infections in the province's north had shifted from the coast, where Prince Rupert is, to the Interior.

The latest case map shows 61 infections in the Peace River North region and 76 in Peace River South during the week in question. Both of those totals equate to more than 20 cases per 100,000 residents.

The full-size version of the latest map can be found on the BCCDC website.