|World Athletics Championships on the BBC|
|Venue: London Stadium Dates: 4-13 August|
|Coverage: Live across BBC One and Two, BBC Radio 5 live, BBC Radio 5 live sports extra, the BBC Sport website and app. Click for times|
Four cases of norovirus have been confirmed at the World Championships, with 50 people affected by illness.
The virus has affected athletes and officials at the London event.
Dr Deborah Turbitt of Public Health England (PHE) said: "PHE has been working to provide infection control advice to limit the spread of illness."
Botswana's Isaac Makwala was denied entry in Tuesday's 400m final and placed under quarantine for 48 hours as officials tried to contain the virus.