threat of transmission to the general population. Cultural and socioeconomic issues may affect case detection and long-term disease management in this population, including adherence to and completion of therapy. The objective of this report is to describe, on the basis of secondary analysis of existing program data, the epidemiology of HD among Marshallese and Micronesian persons residing in the United States. The intent is to assist in providing resources to address a health disparity that disproportionately affects a group of a particular national origin, while at the same time avoiding worsening of ethnic and disease-related stigma. Materials and Methods Demographic and disease-related data were abstracted for January 1990–October 2009 NHDP surveillance and clinical records of cases that identiﬁed patients’ place of birth as the former Trust Territory (Marshall Islands or Micronesia). To facilitate global comparison, US cases (reported by using the Ridley-Jopling classiﬁcation system [11]) were reclassiﬁed into the WHO multibacillary/ paucibacillary system (12). Country-of-origin HD data (case numbers or rates and age/sex/disease classiﬁcation) were abstracted from WHO reports (1,2,13). Country-of- origin demographic data, US Census reports, and published reports relevant to migration patterns were abstracted to obtain denominator estimates where possible (14–17). Data were analyzed by using the SPSS version 16.0 statistical analysis program (SPSS Inc., Chicago, IL, USA). The study was approved by the Tulane University Institutional Review Board and exempted from review by the University of Arkansas for Health Sciences Institutional Review Board. Results The number of HD case-patients of Micronesian or Marshallese origin as a proportion of all US cases has risen over the past decade, with Micronesian and Marshallese patients constituting 90 (13%) of all 686 cases in the United States during 2004–2008 (Figure 1); the total source population of these 2 countries is only ≈170,000. Data are summarized in Table 1. During January 2000–October 2009, 72 (55%) of US HD cases in Micronesian or Marshallese patients were reported in Hawaii. Of 29 Micronesian patients, 22 (76%) had multibacillary HD, 5 were female, and 3 were children. Of 43 Marshallese patients, 31 (72%) had multibacillary HD, 17 (17%) were female, and 1 was a child. Cases in Hawaii were not consistently reported to NHDP until the late 1990s; however, Bomgaars et al. reported that HD cases in 15 Micronesian and 23 Marshallese patients were noted there from 1990 through mid-1998, including the Marshallese cluster summarized in Table 2 (6). Hansen Disease, United States Figure 1. New patients of Marshallese or Micronesian origin with Hansen disease, compared with total new US patients with Hansen disease, 2000–2008. White bars, total US patients; black bars, total patients of Marshallese or Micronesian origin; red line, patients of Marshallese or Micronesian origin as percentage of total US patients. Since 1990, 88 cases have been reported in 26 states of the US mainland (Figures 2, 3), 66 of these since 2000. Cases are increasingly being reported in inland locations. In all groups, the majority of patients were young men with multibacillary disease. Among Micronesians, 55 cases occurred in 22 states of the US mainland (Table 1), 41 of these since 2000. All but 2 patients were <40 years of age, 42 (76%) had multibacillary disease, 10 (18%) were female, and 6 (10%) were children. Six patients reported having a previous HD diagnosis in the Federated States of Micronesia; 4 of these patients reported having completed the WHO- recommended 1 year of multidrug therapy (MDT) there. Of these patients, 14 (25%) originated in Chuuk State and 13 (24%) in Pohnpei State; for 28 (51%), the speciﬁc Federated State was not documented. During the 1990s, 11 of 14 US-mainland HD cases were reported in the western coastal states of California, Washington, and Oregon. Since 2000, a total of 28 of 41 cases were reported in midwestern and southern states (e.g., 6 in Iowa, 5 each in Texas and Florida, 3 in Missouri). Before moving to the reporting state, 21 patients had resided in other mainland states (often in multiple locations), 5 in Hawaii, and 8 in Guam. Of the 33 patients for whom clinical data were available, 25 (76%) had >1 complication, including 15 patients with erythema nodosum leprosum (ENL) and 3 with severe facial involvement (lagophthalmos, blindness, nasopalatal destruction). One patient was pregnant when her HD was diagnosed. Of the 24 patients for whom pharmacy data were available (excluding 8 who had recently begun treatment), the complete US-recommended MDT course had been dispensed to 10 (42%) (Table 1). Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 17, No. 7, July 2011 1203