Fewer than 10,000 coronavirus cases were reported by the public health agency RIVM in the last week for the first time since mid-September.

The latest weekly report shows infections were down by 37.6%, the second week in a row that the number has fallen by more than 30%.

In total there were 8981 confirmed cases, while 5.3% of all tests were positive compared to 7.2% a week ago. The latest calculation of the R number is 0.78 on May 31, meaning every 100 infected people transmitted the virus to 78 others.

The infection rate fell to 53 per 100,000 people per week, with more than half of all cases in people under 30. The smallest decline was among teenagers aged 15 to 19, where cases were down by 8.2%. The same age group had the highest weekly infection rate of 141 per 100,000.

The RIVM urged young people returning from post-exam trips to book tests even if they had no symptoms, after a spate of infections in people who have recently travelled to Spain and Portugal.

‘In the past week we have seen an increase in young people testing positive for coronavirus after a holiday abroad,’ said a spokesman.

Visitors to the Iberian peninsula accounted for 63% of the 514 cases where people had travelled abroad in the previous 14 days and 3.6% of all infections last week.

Portugal and the Spanish islands are classed as yellow risk by the Dutch foreign ministry, meaning people returning from those countries are not required to show a negative test before they fly home or quarantine on their return. Mainland Spain is code orange.

The number of people admitted to hospital with Covid-19 fell by 44% in the last seven days from 414 to 232, while intensive care admissions declined from 53 to 43.

Another 21 deaths were recorded compared to 63 in the previous week.

Around the 25 safety board regions the infection rate ranged from 27.5 per 100,000 in Groningen to 77.3 in Gelderland-Zuid. Five regions have an infection rate of 35 or less, which is the upper limit for level 1 on the government’s four-stage risk scale.