Cutaneous Larva Migrans Within the United States Military Health System-Clinical Presentation and Association With Autochthonous Spread or International Travel.

Background: The epidemiology of cutaneous larva migrans (CLM) within the US population is not well described. We seek to describe the epidemiology of CLM, its association with international travel, and its clinical presentation within the US Military Health System. Methods: We performed a retrospective cohort study within the Military Health System between October 2012 and September 2018. Cases were identified by a billing data diagnosis code of "hookworm." Demographic data were collected, individual record review verified the diagnosis of CLM and identified risk factors, clinical presentation, and management. Comparative statistical analysis was performed. Results: Of the initial 272 cases with the diagnosis of hookworm, 72 (26.4%) were confirmed CLM. Only 30.6% of CLM cases had documented preceding international travel, primarily to the Latin America and Caribbean region (68.2%). Most CLM cases (69.4%) were diagnosed within the United States without documented preceding international travel within 3 months of diagnosis. Of these autochthonous cases, 80% occurred within the South region of the United States. The most common exposures were spending time on the beach, exposure to pet dogs, or walking barefoot outdoors, symptom onset usually occurred within 2 weeks after suspected exposure, and CLM most frequently involved the foot. More than 90% of cases were treated for CLM, but 36.7% of cases received ineffective antihelminthic medication. Conclusions: Our findings are useful in providing nationwide data on the epidemiology of CLM and allowing for informed preventive counseling to travelers and nontravelers within the United States. Treatment for CLM should include antihelminthic therapy that is both appropriately dosed and systemically absorbed.