Around 1,000 people were in quarantine in Germany's most populous state Friday, as the number of confirmed cases of novel coronavirus in Europe's biggest economy rose above 50.
The district of Heinsberg in North Rhine-Westphalia said it had to take the step of keeping around 1,000 home as an infected couple had participated in carnival celebrations in mid-February.
Schools and kindergartens were also shut in the district until Monday as the number of cases linked to the cluster reached 20.
In Hamburg, parents and children who were in contact with an infected employee at a university clinic have also been ordered to stay home for 14 days.
With cases now detected across several further German states including Hesse, Baden-Wuerttemberg and Bavaria, Health Minister Jens Spahn said this week that Europe's biggest country was "at the beginning of a coronavirus epidemic".
The government has ordered local authorities in the country's 16 states to update their pandemic readiness plans.
It also from Thursday began requiring travellers arriving from China, South Korea, Japan, Iran and Italy to provide contact details in case their movements had to be traced over possible infections.
Authorities are also poised to decide if international travel fair ITB is to be cancelled days before its scheduled opening in Berlin.