UK role 4 military infection services: past, present and future.

NATO describes 'Role 4' military medical services as those provided for the definitive care of patients who cannot be treated within a theatre of operations and these are usually located in a military force's country of origin and may include the involvement of civilian medical services. The UK Defence Medical Services have a proud history of developing and providing clinical services in infectious diseases and tropical medicine, sexual health and HIV medicine, and medical microbiology and virology. These UK Role 4 Military Infection Services have adapted well to recent overseas deployments, but new challenges will arise due to current military cutbacks and a greater diversity of contingency operations in the future. Further evidence-based development of these services will require leadership by military clinicians and improved communication and support for 'reach-back' services.