How should I assess a patient's risk for yellow fever before travel to endemic areas?

To assess a patient's risk for yellow fever before travel to endemic areas, start by identifying whether the destination is within a yellow fever endemic zone as defined by the World Health Organization's updated risk maps, which highlight specific tropical regions in Africa and South America where transmission occurs Jentes et al. 2011. Evaluate the duration and nature of travel, including urban versus rural exposure, as rural and forested areas carry higher risk due to increased mosquito vector presence Monath & Cetron 2002. Consider the patient's vaccination history and any contraindications to yellow fever vaccine, such as severe immunosuppression or age extremes, since vaccination is the primary preventive measure but carries risks in certain populations Monath 2012. Assess underlying health conditions that may increase vaccine risk or complicate yellow fever infection, including immunodeficiency or thymus disorders Monath 2012. Additionally, review the patient's itinerary for potential transit through or extended stays in endemic areas, as even brief exposure can pose risk Jentes et al. 2011. Finally, incorporate UK travel health guidelines which recommend vaccination for travelers to endemic areas unless contraindicated, and advise on mosquito bite prevention measures as adjunct protection (CKS - Travel immunizations) NICE CKS.

In summary: Risk assessment integrates geographic exposure, travel details, vaccination status, and individual health factors to guide yellow fever vaccination and preventive advice NICE CKS Monath & Cetron 2002Jentes et al. 2011Monath 2012.