Something to Declare: Calais; Aachen and Cologne; american diseases

The column that gives the global picture

Destination of the week: Calais

Twenty-seven million visitors a year can't be wrong – unless they turn up at the Channel port on an average Sunday, when hypermarkets are closed under strict French shopping laws. Some of the Calais stores have obtained a dérogation spéciale that allows them to open on a limited number of Sundays.

The Carrefour and Auchan hypermarkets will open on 2, 9, 16 and 23 December. Continent opens only 2, 23 and 30 December. Starting tomorrow, Sainsbury's Wine Store and many other shops will be open on Sundays, continuing until 16 December. The port's Christmas market takes place on Saturday 1 and Sunday 2 December.

A day return for a car plus five people with P&O Stena Line (0870 600 0600) costs £42, or £2 less if you register at www.POSL.com. With Eurotunnel from Folkestone, you pay £49 for a car plus nine people booking on 08705 353535, or £42 if you register for "Points Plus" at www.eurotunnel.com.

Lower fares are available for afternoon-only trips.

Bargain of the week: Aachen or Cologne before Christmas

People who need a short break, but prefer not to fly, can take advantage of a deal from German Rail (08702 43 53 63, www.deutsche-bahn. co.uk): London Waterloo via Brussels to Cologne or Aachen for £84 return. You can travel between next Friday, 23 November and Christmas Eve. Perhaps unfairly, single travellers pay a supplement of £5.

Warning of the week: diseases borne in the USA

An outbreak of whooping cough has been reported in Arkansas, according to the travellers' health service, MASTA (09068 224100). If travelling with children, ensure they have had a pertussis vaccination.

Dengue fever has returned to Hawaii after an absence of half a century. It is spread by mosquitoes that bite during the day. Seventy-four cases have been reported in Oahu (where Honolulu airport is located), Maui and Kauai. One suspected case has also been reported from Molokai.

The only effective precaution is avoiding bites.