Chronic illnesses in travelers to developing countries.

BACKGROUND: Data regarding travelers with chronic illnesses (TCI) traveling to developing countries is limited. METHODS: A retrospective cohort study of travelers. We analyzed demographics, travel destinations, travel dates and duration, as well as the medical history (chronic illnesses, chronic medications, and allergies) of the travelers. RESULTS: Of 16,681 travelers evaluated, 3046 (18%) were TCI, of who, 2221 (13%) were taking chronic medications. The percentage of TCI ranged from 4% in the first decade of life to 65% in the 8th decade. The highest number of TCI (1085) was among the 20­30 years age group. The median age (IQR) of TCI was 39.0 (23.1­58.2), compared to 24.2 (22.0­32.1) years, of healthy travelers (p < 0.001). The major pre-existing medical conditions among TCI were endocrine/metabolic (38%), cardiovascular (26%) and pulmonary illnesses (16%). Within age groups, no difference was found in itinerary and other travel characteristics. However, 20­30 years old TCI, who were using chronic medications had significantly shorter travel duration (P < 0.001). CONCLUSIONS: TCI form a significant proportion of travelers among all age groups and travel destinations. Chronic illnesses appear to have little impact on travel itinerary and characteristics, but chronic medication use is associated with shorter travel duration to developing countries.

Potential drug interactions in travelers with chronic illnesses: a large retrospective cohort study.

BACKGROUND: Data regarding the prevalence of potential interactions between travel-related medications (TRM) and chronic medications in use, or medical conditions of travelers to developing countries are limited. METHODS: A retrospective cohort study of travelers to low income countries. We extracted data on demographics, travel destinations, use of chronic medications, drug allergies, and relevant medical conditions. The following TRM were evaluated: mefloquine, primaquine, doxycycline, atovaquone/proguanil, fluoroquinolone antibiotics, rifaximin, azithromycin, and acetazolamide. RESULTS: A total of 16,263 travelers were included in the analysis, of whom 3299(20%) suffered from chronic illnesses and 2316(14%) reported chronic medication use. A potential drug-drug interaction with TRM was identified in 1047(45%) of travelers using chronic medication. Fluoroquinolones and azithromycin were the most commonly implicated TRMs. A potential medical condition interaction with TRM was identified in 717(22%) of travelers having chronic illnesses. acetazolamide, primaquine and mefloquine, were the most commonly TRMs implicated. Drug allergies, which can pose a relative contraindication for use of acetazolamide, were reported by 1323(8.1%) of all travelers. CONCLUSIONS: Potential drug-drug and drug-disease interactions involving TRM might occur in a significant proportion of travelers with chronic medical conditions. Education of health practitioners regarding such potential drug interactions and caution when in prescribing travel-related medications is warranted.