With the London 2012 Olympics set to begin in five days time, if you’re a Londoner, now might be a good time to check your vaccination records. The Olympic games represents one of the largest gatherings of humanity from all corners of the globe. Such large events, be they sporting, artistic, religious, political or musical in nature, can lead to breakouts of infectious disease, although these are relatively rare: a report that analysed records spanning 1964 to 1993 turned up only 38 outbreaks associated with sports events. More recently, the Special Olympics in Minneapolis in 1994, the Vancouver Winter Olympics in 2010 and a Superbowl event in Indiana in February this year have all been associated with infectious disease outbreaks. With several million visitors expected in London over the 16 days that the Olympic games will be held, public health officials are working hard to make sure that people are aware of the risks.

And it’s not just for human competitors: spare a thought for the horses in the equestrian events. Even though horses must pass a strict health test before travelling, outbreaks can still occur: equine influenza was detected at a horse trials event in Queensland, Australia in 2007, while equine herpesvirus was identified following a national equine championship event in Utah in 2011.

The American Centers for Disease Control and Prevention (CDC), the European Centre for Disease Prevention and Control (ECDC) and the World Health Organisation (WHO) have all issued warnings that spectators at the London 2012 Olympics should make sure that their vaccines are up-to-date, especially for measles, which is currently undergoing a resurgence in several countries, including the United Kingdom.

Before you travel, make sure your routine vaccinations are up-to-date. The main travel risks are food- and waterbourne illness, airbourne disease and sexually-transmitted disease. Simple measures, such as hand sanitisation, drinking bottled water and the use of prophylactics during sexual intercourse, can help to protect you against these risks.