Incidence and prevalence of Parkinson's disease among Navajo people living in the Navajo nation.

Parkinson's disease (PD) is largely unstudied among American Indians. Unique populations might harbor clues to elusive causes. We describe the incidence and prevalence of PD among Navajo people residing in the Navajo Nation, home to the largest American Indian tribe in the United States. We analyzed 2001-2011 inpatient and outpatient visit data for Navajo people obtained from the Indian Health Service, which provides health care to American Indian people living on the Navajo Reservation. Cases were defined by at least two inpatient or outpatient visits with the diagnosis of PD. Crude and age-adjusted incidence and prevalence rates were calculated overall as well as by age, sex, region of residence, and time period. Five hundred twenty-four Navajo people with median age-at-onset of 74.0 years were diagnosed with PD during the study period, yielding an average annual crude incidence rate of 22.5/100,000. Age-specific incidence was 232.0 for patients 65 years of age or older and 302.0 for 80 years of age or older. Age-adjusted incidence was 35.9 overall (238.1 for ≥65 years), was higher in men than in women (47.5 vs. 27.7; P<0.001), varied by region (P=0.03), and was similar between time periods (2002-2004 vs. 2009-2011). The age-adjusted point prevalence rate was 261.0. The rate of PD among Navajo People appears to be as high as or higher than rates reported in many other populations. Rates increased to the highest age group, consistent with population-based studies. Further investigation is warranted to examine risk factors for PD in this remote population.

Pneumonia and influenza mortality among American Indian and Alaska Native people, 1990-2009.

OBJECTIVES: We compared pneumonia and influenza death rates among American Indian/Alaska Native (AI/AN) people with rates among Whites and examined geographic differences in pneumonia and influenza death rates for AI/AN persons. METHODS: We adjusted National Vital Statistics Surveillance mortality data for racial misclassification of AI/AN people through linkages with Indian Health Service (IHS) registration records. Pneumonia and influenza deaths were defined as those who died from 1990 through 1998 and 1999 through 2009 according to codes for pneumonia and influenza from the International Classification of Diseases, 9th and 10th Revision, respectively. We limited the analysis to IHS Contract Health Service Delivery Area counties, and compared pneumonia and influenza death rates between AI/ANs and Whites by calculating rate ratios for the 2 periods. RESULTS: Compared with Whites, the pneumonia and influenza death rate for AI/AN persons in both periods was significantly higher. AI/AN populations in the Alaska, Northern Plains, and Southwest regions had rates more than 2 times higher than those of Whites. The pneumonia and influenza death rate for AI/AN populations decreased from 39.6 in 1999 to 2003 to 33.9 in 2004 to 2009. CONCLUSIONS: Although progress has been made in reducing pneumonia and influenza mortality, disparities between AI/AN persons and Whites persist. Strategies to improve vaccination coverage and address risk factors that contribute to pneumonia and influenza mortality are needed.

Infectious disease mortality among American Indians and Alaska Natives, 1999-2009.

OBJECTIVES: We described death rates and leading causes of death caused by infectious diseases (IDs) in American Indian/Alaska Native (AI/AN) persons. Methods. We analyzed national mortality data, adjusted for AI/AN race by linkage with Indian Health Service registration records, for all US counties and Contract Health Service Delivery Area (CHSDA) counties. The average annual 1999 to 2009 ID death rates per 100,000 persons for AI/AN persons were compared with corresponding rates for Whites. RESULTS: The ID death rate in AI/AN populations was significantly higher than that of Whites. A reported 8429 ID deaths (rate 86.2) in CHSDA counties occurred among AI/AN persons; the rate was significantly higher than the rate in Whites (44.0; rate ratio [RR] = 1.96; 95% confidence interval [CI] = 1.91, 2.00). The rates for the top 10 ID underlying causes of death were significantly higher for AI/AN persons than those for Whites. Lower respiratory tract infection and septicemia were the top-ranked causes. The greatest relative rate disparity was for tuberculosis (RR = 13.51; 95% CI = 11.36, 15.93). CONCLUSIONS: Health equity might be furthered by expansion of interventions to reduce IDs among AI/AN communities.

Death rates from human immunodeficiency virus and tuberculosis among American Indians/Alaska Natives in the United States, 1990-2009.

OBJECTIVES: We used race-corrected data and comprehensive diagnostic codes to better compare HIV and tuberculosis (TB) mortality from 1999 to 2009 between American Indian/Alaska Natives (AI/ANs) and Whites. METHODS: National Vital Statistics Surveillance System mortality data were adjusted for AI/AN racial misclassification through linkage with Indian Health Service registration records. We compared average annual 1990 to 2009 HIV and TB death rates (per 100,000 people) for AI/AN persons with those for Whites; Hispanics were excluded. RESULTS: Although death rates from HIV in AI/AN persons were significantly lower than those in Whites from 1990 to 1998 (4.2 vs 7.0), they were significantly higher than those in Whites from 1999 to 2009 (3.6 vs 2.0). Death rates from TB in AI/AN persons were significantly higher than those in Whites, with a significant disparity during both 1990 to 1998 (3.3 vs 0.3) and 1999 to 2009 (1.5 vs 0.1). CONCLUSIONS: The decrease in death rates from HIV and TB was greater among Whites, and death rates remained significantly higher among AI/AN individuals. Public health interventions need to be prioritized to reduce the TB and HIV burden and mortality in AI/AN populations.

American Indian and Alaska Native infant and pediatric mortality, United States, 1999-2009.

OBJECTIVES: We described American Indian/Alaska Native (AI/AN) infant and pediatric death rates and leading causes of death. METHODS: We adjusted National Vital Statistics System mortality data for AI/AN racial misclassification by linkage with Indian Health Service (IHS) registration records. We determined average annual death rates and leading causes of death for 1999 to 2009 for AI/AN versus White infants and children. We limited the analysis to IHS Contract Health Service Delivery Area counties. RESULTS: The AI/AN infant death rate was 914 (rate ratio [RR] = 1.61; 95% confidence interval [CI] = 1.55, 1.67). Sudden infant death syndrome, unintentional injuries, and influenza or pneumonia were more common in AI/AN versus White infants. The overall AI/AN pediatric death rates were 69.6 for ages 1 to 4 years (RR = 2.56; 95% CI = 2.38, 2.75), 28.9 for ages 5 to 9 years (RR = 2.12; 95% CI = 1.92, 2.34), 37.3 for ages 10 to 14 years (RR = 2.22; 95% CI = 2.04, 2.40), and 158.4 for ages 15 to 19 years (RR = 2.71; 95% CI = 2.60, 2.82). Unintentional injuries and suicide occurred at higher rates among AI/AN youths versus White youths. CONCLUSIONS: Death rates for AI/AN infants and children were higher than for Whites, with regional disparities. Several leading causes of death in the AI/AN pediatric population are potentially preventable.

Dog bite injuries among American Indian and Alaska Native children.

OBJECTIVE: To examine dog bites among American Indian (AI) and Alaska Native (AN) children visiting Indian Health Service and tribal health facilities. STUDY DESIGN: We retrospectively analyzed hospitalizations and outpatient visits with a diagnosis of dog bite between 2001 and 2008 in AI/AN children aged <20 years. Rates of dog bite hospitalizations and outpatient visits were estimated by age group, sex, region, and number and location of open wounds using Indian Health Service data. Analyses of hospitalizations for the general US population aged<20 years used the Nationwide Inpatient Sample. RESULTS: The average annual dog bite hospitalization rate was higher among AI/AN children in Alaska (6.1/100,000 population) and the Southwest region (5.3/100,000) compared with the general US child population (3.1/100,000; 95% CI, 2.9-3.3/100,000). The average annual outpatient visit rate in AI/AN children was highest in the Alaska (596.4/100,000), Southwest (540.0/100,000), and Northern Plains West (537.6/100,000) regions. The hospitalization rate was highest in both AI/AN and US males aged<5 years, and outpatient visit rates were highest in AI/AN males aged 5-9 years. Open wounds diagnoses were most commonly seen on the head, neck, and face in hospitalized children (45.5% of open wounds in AI/AN children, 59.3% in US children; SE, 1.0%) and on the leg in AI/AN outpatients (35.6%). CONCLUSION: Dog bites represent a significant public health threat in AI/AN children in the Alaska, the Southwest, and Northern Plains West regions of the US. Enhanced animal control and education efforts should reduce dog bite injuries and associated problems with pets and stray dogs, such as emerging infectious diseases.

Changing socioeconomic indicators of human plague, New Mexico, USA.

Socioeconomic indicators associated with temporal changes in the distribution of human plague cases in New Mexico were investigated for 1976-2007. In the 1980s, cases were more likely in census block groups with poor housing conditions, but by the 2000s, cases were associated with affluent areas concentrated in the Santa Fe-Albuquerque region.

Parkinson's disease among American Indians and Alaska natives: a nationwide prevalence study.

BACKGROUND: The objective of this study was to determine the prevalence of Parkinson's disease (PD) among American Indian and Alaska Native (AI/AN) people. METHODS: We analyzed records for AI/AN people between 2002 and 2009 using inpatient and outpatient visit data from the Indian Health Service. Crude and age-adjusted prevalence, using the 2000 projected US population as the standard, was determined overall and by age group, sex, period, and region. RESULTS: An estimated 2613 AI/AN people carried the diagnosis of PD (crude prevalence, 143.8/100,000). Prevalence increased with age through 84 years. The age-adjusted rate was 355.7 and was higher among men than women (P < .0001). Rates differed by region (P < .0001). CONCLUSIONS: Parkinson's disease is prevalent among AI/AN people. The prevalence increases with age, varies by geographic region, and is higher among men than women. Community-based studies are needed to define incidence, examine risk factors, and determine reasons for sex and regional differences in PD among AI/AN people.

2009 Pandemic influenza A H1N1 in Alaska: temporal and geographic characteristics of spread and increased risk of hospitalization among Alaska Native and Asian/Pacific Islander people.

Alaska Native people have suffered disproportionately from previous influenza pandemics. We evaluated 3 separate syndromic data sources to determine temporal and geographic patterns of spread of 2009 pandemic influenza A H1N1 (pH1N1) in Alaska, and reviewed records from persons hospitalized with pH1N1 disease in 3 areas in Alaska to characterize clinical and epidemiologic features of disease in Alaskans. A wave of pH1N1 disease swept through Alaska beginning in most areas in August or early September. In rural regions, where Alaska Native people comprise a substantial proportion of the population, disease occurred earlier than in other regions. Alaska Native people and Asian/Pacific Islanders (A/PI) were 2-4 times more likely to be hospitalized than whites. Alaska Native people and other minorities remain at high risk for early and substantial morbidity from pandemic influenza episodes. These findings should be integrated into plans for distribution and use of vaccine and antiviral agents.

Epidemic assistance from the Centers for Disease Control and Prevention involving American Indians and Alaska Natives, 1946-2005.

The authors describe 169 Centers for Disease Control and Prevention epidemic-assistance investigations involving American Indians and Alaska Natives that occurred during 1946-2005. The unique relation between the US federal government and American Indian and Alaska Native tribes is described in the context of transfer in the 1950s of responsibility for Indian health to the US Public Health Service, which at the time included the Communicable Disease Center, the Centers for Disease Control and Prevention's precursor. The vast majority of epidemic-assistance investigations were for infectious disease outbreaks (86%), with a relatively limited number, since 1980 only, involving environmental exposures and chronic disease. Although outbreaks investigated were often widespread geographically, the majority were limited in scope, typically involving fewer than 100 patients. Epidemic-assistance investigations for hepatitis A, gastrointestinal and foodborne infectious diseases, vaccine-preventable diseases, zoonotic and vectorborne diseases, acute respiratory tract infections, environmental exposures, and chronic diseases are described chronologically in more detail.

Changing trends in viral hepatitis-associated hospitalizations in the American Indian/Alaska Native population, 1995-2007.

OBJECTIVE: We described the changing epidemiology of viral hepatitis among the American Indian/Alaska Native (AI/AN) population that uses Indian Health Service (IHS) health care. METHODS: We used hospital discharge data from the IHS National Patient Information Reporting System to determine rates of hepatitis A-, B-, and C-associated hospitalization among AI/ANs using IHS health care from 1995-2007 and summary periods 1995-1997 and 2005-2007. RESULTS: Hepatitis A-associated hospitalization rates among AI/AN people decreased from 4.9 per 100,000 population during 1995-1997 to 0.8 per 100,000 population during 2005-2007 (risk ratio [RR] = 0.2, 95% confidence interval [CI] 0.1, 0.2). While there was no significant change in the overall hepatitis B-associated hospitalization rate between time periods, the average annual rate in people aged 45-64 years increased by 109% (RR=2.1, 95% CI 1.4, 3.2). Between the two time periods, the hepatitis C-associated hospitalization rate rose from 13.0 to 55.0 per 100,000 population (RR=4.2, 95% CI 3.8, 4.7), an increase of 323%. The hepatitis C-associated hospitalization rate was highest among people aged 45-64 years, males, and those in the Alaska region. CONCLUSIONS: Hepatitis A has decreased to near-eradication levels among the AI/AN population using IHS health care. Hepatitis C-associated hospitalizations increased significantly; however, there was no significant change in hepatitis B-associated hospitalizations. Emphasis should be placed on continued universal childhood and adolescent hepatitis B vaccination and improved vaccination of high-risk adults. Prevention and education efforts should focus on decreasing hepatitis C risk behaviors and identifying people with hepatitis C infection so they may be referred for treatment.

Tuberculosis in indigenous peoples in the U.S., 2003-2008.

OBJECTIVES: We examined trends and epidemiology of tuberculosis (TB) across racial/ethnic groups to better understand TB disparities in the United States, with particular focus on American Indians/Alaska Natives (AI/ANs) and Native Hawaiians/other Pacific Islanders (NH/PIs). METHODS: We analyzed cases in the U.S. National Tuberculosis Surveillance System and calculated TB case rates among all racial/ethnic groups from 2003 to 2008. Socioeconomic and health indicators for counties in which TB cases were reported came from the Health Resources and Services Administration Area Resource File. RESULTS: Among the 82,836 TB cases, 914 (1.1%) were in AI/ANs and 362 (0.4%) were in NH/PIs. In 2008, TB case rates for AI/ANs and NH/PIs were 5.9 and 14.7 per 100,000 population, respectively, rates that were more than five and 13 times greater than for non-Hispanic white people (1.1 per 100,000 population). From 2003 to 2008, AI/ANs had the largest percentage decline in TB case rates (-27.4%) for any racial/ethnic group, but NH/PIs had the smallest percentage decline (-3.5%). AI/ANs were more likely than other racial/ethnic groups to be homeless, excessively use alcohol, receive totally directly observed therapy, and come from counties with a greater proportion of people living in poverty and without health insurance. A greater proportion of NH/PIs had extrapulmonary disease and came from counties with a higher proportion of people with a high school diploma. CONCLUSIONS: There is a need to develop flexible TB-control strategies that address the social determinants of health and that are tailored to the specific needs of AI/ANs and NH/PIs in the U.S.

Disparities in infectious disease hospitalizations for American Indian/ Alaska Native people.

OBJECTIVES: We described disparities in infectious disease (ID) hospitalizations for American Indian/Alaska Native (AI/AN) people. METHODS: We analyzed hospitalizations with an ID listed as the first discharge diagnosis in 1998-2006 for AI/AN people from the Indian Health Service National Patient Information Reporting System and compared them with records for the general U.S. population from the Nationwide Inpatient Survey. RESULTS: The ID hospitalization rate for AI/AN people declined during the study period. The 2004-2006 mean annual age-adjusted ID hospitalization rate for AI/AN people (1,708 per 100,000 populiation) was slightly higher than that for the U.S. population (1,610 per 100,000 population). The rate for AI/AN people was highest in the Southwest (2,314 per 100,000 population), Alaska (2,063 per 100,000 population), and Northern Plains West (1,957 per 100,000 population) regions, and among infants (9,315 per 100,000 population). ID hospitalizations accounted for approximately 22% of all AI/AN hospitalizations. Lower-respiratory-tract infections accounted for the largest proportion of ID hospitalizations among AI/AN people (35%) followed by skin and soft tissue infections (19%), and infections of the kidney, urinary tract, and bladder (11%). CONCLUSIONS: Although the ID hospitalization rate for AI/AN people has declined, it remains higher than that for the U.S. general population, and is highest in the Southwest, Northern Plains West, and Alaska regions. Lower-respiratory-tract infections; skin and soft tissue infections; and kidney, urinary tract, and bladder infections contributed most to these health disparities. Future prevention strategies should focus on high-risk regions and age groups, along with illnesses contributing to health disparities.

A review of missed opportunities for prenatal HIV screening in a nationwide sample of health facilities in the Indian Health Service.

To better serve our patients, we sought to identify missed opportunities for prenatal HIV screening across Indian Health Service and potential ways to increase screening. Twenty-seven of 161 Federal or Tribal IHS health facilities were randomly selected. Each facility received a standardized set of commands to identify the charts of prenatal patients who were not screened for HIV according to the national Health Information Technology (HIT) platform. We reviewed 598 records at 27 sites of prenatal patients who were identified as not screened for HIV during their pregnancy. According to on-site chart review, nearly half (267/598, 45%) had been screened for HIV, and a slight majority (331/598, 55%) had not been screened. Among the 331 pregnant women not screened for HIV, about half had no HIV screening despite having had ≥2 prenatal care encounters and no screening exclusions (167/331, 50%). A majority of missed opportunities (118/167, 71%) had prenatal testing for other infectious diseases. Based on these results, the National HIV/AIDS program has encouraged increased bundling of HIV with infectious disease tests in prenatal laboratory panels. Improvements in documentation of HIV screening are expected with the IHS transition to electronic health records.

Physician and nurse perspectives on implementation of universal adult HIV screening guidelines in the Indian health service: results of a randomized survey.

OBJECTIVES: We sought to determine attitudes and needs among health care providers in the Indian Health Service toward implementing routine human immunodeficiency virus (HIV) screening among 13- to 64-year-olds as per Centers for Disease Control and Prevention (CDC) guidelines. METHODS: We surveyed a random sample of Indian Health Service physicians and nurses by e-mail and telephone interview. A total of 205 eligible respondents (response rate = 70%) completed the survey. RESULTS: A majority (58%) of respondents were familiar or somewhat familiar with the 2006 CDC guidelines on HIV screening for 13- to 64-year-olds. A proportion of respondents (43%) felt that community HIV prevalence was below the 0.1% threshold the CDC recommends to initiate screening. Respondents supported routine, rather than solely risk-based HIV testing (70%) and stated that HIV screening would be realistic in their health facility (51%). Respondents felt that they needed special qualification to offer an HIV test (49%) or to notify a patient of a "reactive" HIV test result (67%). CONCLUSIONS: A majority of Indian Health Service physicians and nurses support the CDC HIV screening guidelines. Providers need more information and training on HIV screening guidelines, implementation strategies, and relevant state HIV regulations.

Methicillin-resistant Staphylococcus aureus-associated hospitalizations among the American Indian and Alaska native population.

BACKGROUND: American Indians and Alaska Natives (AI/ANs) have had documented outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) infection but, to our knowledge, no studies have examined MRSA infection among this population nationally. We describe MRSA-associated hospitalizations among the approximately 1.6 million AI/ANs who receive care at Indian Health Service health care facilities nationwide. METHODS: We used hospital discharge data from the Indian Health Service National Patient Information Reporting System to determine the rate of MRSA-associated hospitalizations among AI/ANs who used Indian Health Service health care in 1996-2005 and in the comparison periods 1996-1998 and 2003-2005. Hospitalization rates among AI/ANs were examined by year, age group, sex, and region. MRSA-associated diagnoses were also examined. Rate comparisons were performed using Poisson regression analysis. Comparison of rates to those of the general United States population was made for 2003-2005 by means of the Nationwide Inpatient Sample. RESULTS: Between comparison periods, the rate of MRSA-associated hospitalization increased from 4.6 to 50.6 hospitalizations per 100,000 AI/ANs (P<.01), with increases in both sexes, all age groups, and all regions. By 2005, MRSA was the causative organism for the majority (52%) of all S. aureus-associated hospitalizations. The most common associated diagnosis was skin and soft-tissue infection, which accounted for 59% of MRSA-associated diagnoses. In 2003-2005, the age-adjusted rate among AI/ANs was 58.8 hospitalizations per 100,000 persons, compared with 84.7 hospitalizations per 100,000 persons in the general US population. CONCLUSIONS: MRSA-associated hospitalizations have increased significantly among AI/ANs served by Indian Health Service health care facilities. Clinicians should have a high index of suspicion for MRSA infection in AI/ANs, especially in those with a diagnosis of skin and soft-tissue infection.

Trends in otitis media and myringtomy with tube placement among American Indian/Alaska native children and the US general population of children.

BACKGROUND: Otitis media (OM) morbidity in American Indian and Alaska Native (AI/AN) children is historically higher than that in other US children. METHODS: Outpatient visits and hospitalizations listing OM as a diagnosis and outpatient visits listing myringotomy with insertion of tubes as a procedure among AI/AN children <5 years of age from the Indian Health Service National Patient Information Reporting system for 2003-2005 were analyzed. Outpatient visits and hospitalizations with OM for the general US child population were analyzed using the National Hospital Ambulatory Medical Care and National Ambulatory Medical Care Surveys for 2003-2005, and the 2003 Kids' Inpatient Database, respectively. RESULTS: The OM-associated outpatient visit rate for AI/AN children <5 years of age (89 per 100 children/yr) for 2003-2005 was less than that reported for 1994-1996 (138); however, the rate increased for Alaska region (158 to 181). The OM outpatient visit and myringotomy with insertion of tubes rates (181 and 2.6 per 100 children/yr, respectively) for AI/AN children in Alaska were higher than rates for children in each of the other IHS regions and rates for US children (63 and 1.8 per 100 children/yr, respectively). The OM outpatient visit rates for AI/AN infants (184), especially in the Alaska region (334), were higher than the rate for US infants (84). CONCLUSIONS: The OM-associated outpatient visit rate in AI/AN children <5 years of age has decreased but remains higher than that of the US general child population; however, the rate increased in the Alaska region, where a limited decline in invasive pneumococcal disease has been demonstrated. The ongoing disparity in OM outpatient visit rates among AI/AN children, especially Alaska Native children, indicates a need for new prevention measures, including expanded-valency pneumococcal conjugate vaccines, to reduce OM morbidity.

Rocky Mountain spotted fever from an unexpected tick vector in Arizona.

BACKGROUND: Rocky Mountain spotted fever is a life-threatening, tick-borne disease caused by Rickettsia rickettsii. This disease is rarely reported in Arizona, and the principal vectors, Dermacentor species ticks, are uncommon in the state. From 2002 through 2004, a focus of Rocky Mountain spotted fever was investigated in rural eastern Arizona. METHODS: We obtained blood and tissue specimens from patients with suspected Rocky Mountain spotted fever and ticks from patients' homesites. Serologic, molecular, immunohistochemical, and culture assays were performed to identify the causative agent. On the basis of specific laboratory criteria, patients were classified as having confirmed or probable Rocky Mountain spotted fever infection. RESULTS: A total of 16 patients with Rocky Mountain spotted fever infection (11 with confirmed and 5 with probable infection) were identified. Of these patients, 13 (81 percent) were children 12 years of age or younger, 15 (94 percent) were hospitalized, and 2 (12 percent) died. Dense populations of Rhipicephalus sanguineus ticks were found on dogs and in the yards of patients' homesites. All patients with confirmed Rocky Mountain spotted fever had contact with tick-infested dogs, and four had a reported history of tick bite preceding the illness. R. rickettsii DNA was detected in nonengorged R. sanguineus ticks collected at one home, and R. rickettsii isolates were cultured from these ticks. CONCLUSIONS: This investigation documents the presence of Rocky Mountain spotted fever in eastern Arizona, with common brown dog ticks (R. sanguineus) implicated as a vector of R. rickettsii. The broad distribution of this common tick raises concern about its potential to transmit R. rickettsii in other settings.

Pertussis-associated hospitalizations in American Indian and Alaska Native infants.

OBJECTIVE: To investigate the burden of pertussis in American Indian and Alaska Native (AI/AN) infants. STUDY DESIGN: AI/AN pertussis-associated hospitalizations between 1980 and 2004 were evaluated using Indian Health Service (IHS)/tribal inpatient data, which include all reported hospitalizations within the IHS/tribal health care system. RESULTS: Between 1980 and 2004, 483 pertussis-associated hospitalizations in AI/AN infants were documented; 88% of cases involved infants age < 6 months. For this entire period, the average annual hospitalization rate was 132.7 per 100,000 AI/AN infants (95% confidence interval [CI] = 121.3 to 145.2), and 234.5 per 100,000 AI/AN infants age < 6 months (95% CI = 213.1 to 258.1). Between 2000 and 2004, the annual hospitalization rate was 100.5 per 100,000 AI/AN infants (95% CI = 81.6 to 123.7), which exceeds the estimated 2003 pertussis hospitalization rate of 67.7 per 100,000 in the general US infant population (95% CI = 61.9 to 73.5). The highest pertussis hospitalization rates in 2000 to 2004 were in AI/AN infants in the Alaska and Southwestern IHS regions of the United States. CONCLUSIONS: The burden of pertussis in AI/AN infants is high, particularly so in infants age < 6 months in the Alaska and the Southwestern IHS regions of the United States. Ensuring implementation of vaccination strategies to reduce the incidence of pertussis in AI/AN, infants, adolescents, and adults alike is warranted to reduce the burden of pertussis in AI/AN infants.