More than half a million people tested positive for Covid-19 in the last week, with positive tests now accounting for more than half the total.

The RIVM’s latest weekly update also showed the number of patients admitted to hospital was at its highest level for four weeks, while intensive care admissions increased for the first time since November.

The infection rate is highest among school-age children, with 8.5% of 10 to 14-year-olds testing positive in the last week. However, the biggest increase was among people aged between 65 and 80, where the number of positive tests was almost 60% higher.

More than a million tests were taken in the last week of January, 56.1% of which were positive. The total number of 530,015 cases is 45% higher than last week.

The RIVM is also working through a backlog of around 81,000 tests that have still not been processed by local health boards.

In the last seven days 1,056 people with coronavirus were admitted to hospital, 11% more than last week, while the number taken into intensive care went up from 66 to 78, an increase of 18%.

The RIVM also published figures showing how many people in each age group were admitted primarily because of Covid-19, as distinct from those who tested positive but were being treated for other conditions.

Altogether 59% of patients with a coronavirus infection were in hospital as a direct result, while another 17% were being treated for a combination of coronavirus and other conditions.

In younger age groups fewer than half of patients with coronavirus infections were in hospital as a result of Covid-19, but 75% of infected patients over 80 were hospitalised by the virus.

The total number of coronavirus patients in hospital has gone up by 15% in the last week to 1,343, but in intensive care the number is still declining.

On Tuesday there were 206 intensive care patients with Covid-19, 18% fewer than a week ago. The RIVM’s figures show 76% of people in intensive care with coronavirus are being treated specifically for the virus.