The general approach to the travel requirements of special groups also includes (5) consider any concerns regarding underlying conditions and possible drug interactions; (6) consult experts in travel medicine or specialty areas as necessary; (7) educate the traveler, understanding that this aspect may need considerable reinforcement, including written information; and (8) indicate to the traveler that vaccination, self-treatment and chemoprophylaxis are not 100% protective and they should seek medical advice if they become sick.

Ericsson CD. Travellers with pre-existing medical conditions. Int J Antimicrobial Agents 2003; 21: 181-188.