BACKGROUND: International travel poses a risk of destination-specific illness and may contribute to the global spread of infectious diseases. Despite this, little is known about the health characteristics and pretravel healthcare of US international travelers, particularly those at higher risk of travel-associated illness. METHODS: We formed a national consortium (Global TravEpiNet) of 18 US clinics registered to administer yellow fever vaccination. We collected data regarding demographic and health characteristics, destinations, purpose of travel, and pretravel healthcare from 13235 international travelers who sought pretravel consultation at these sites from January 2009 through January 2011. RESULTS: The destinations and itineraries of Global TravEpiNet travelers differed from those of the overall population of US international travelers. The majority of Global TravEpiNet travelers were visiting low- or lower-middle-income countries, and Africa was the most frequently visited region. Seventy-five percent of travelers were visiting malaria-endemic countries, and 38% were visiting countries endemic for yellow fever. Fifty-nine percent of travelers reported >/=1 medical condition. Atovaquone/proguanil was the most commonly prescribed antimalarial drug, and most travelers received an antibiotic for self-treatment of travelers' diarrhea. Hepatitis A and typhoid were the most frequently administered vaccines. CONCLUSIONS: Data from Global TravEpiNet provide insight into the characteristics and pretravel healthcare of US international travelers who are at increased risk of travel-associated illness due to itinerary, purpose of travel, or existing medical conditions. Improved understanding of this epidemiologically significant population may help target risk-reduction strategies and interventions to limit the spread of infections related to global travel.

BACKGROUND: The relationship between serum 25-hydroxyvitamin D [25(OH) vitamin D] concentration and hip fractures is unclear. OBJECTIVE: To see whether low serum 25(OH) vitamin D concentrations are associated with hip fractures in community-dwelling women. DESIGN: Nested case-control study. SETTING: 40 clinical centers in the United States. PARTICIPANTS: 400 case-patients with incident hip fracture and 400 control participants matched on the basis of age, race or ethnicity, and date of blood draw. Both groups were selected from 39 795 postmenopausal women who were not using estrogens or other bone-active therapies and who had not had a previous hip fracture. MEASUREMENTS: Serum 25(OH) vitamin D was measured and patients were followed for a median of 7.1 years (range, 0.7 to 9.3 years) to assess fractures. RESULTS: Mean serum 25(OH) vitamin D concentrations were lower in case-patients than in control participants (55.95 nmol/L [SD, 20.28] vs. 59.60 nmol/L [SD, 18.05]; P = 0.007), and lower serum 25(OH) vitamin D concentrations increased hip fracture risk (adjusted odds ratio for each 25-nmol/L decrease, 1.33 [95% CI, 1.06 to 1.68]). Women with the lowest 25(OH) vitamin D concentrations (< or =47.5 nmol/L) had a higher fracture risk than did those with the highest concentrations (> or =70.7 nmol/L) (adjusted odds ratio, 1.71 [CI, 1.05 to 2.79]), and the risk increased statistically significantly across quartiles of serum 25(OH) vitamin D concentration (P for trend = 0.016). This association was independent of number of falls, physical function, frailty, renal function, and sex-steroid hormone levels and seemed to be partially mediated by bone resorption. LIMITATIONS: Few case-patients were nonwhite women. Bone mineral density and parathyroid hormone levels were not accounted for in the analysis. CONCLUSION: Low serum 25(OH) vitamin D concentrations are associated with a higher risk for hip fracture.