Trends in diarrhea-associated hospitalizations among American Indian and Alaska native children, 1980-1995

Water quality, availability, and acute gastroenteritis on the Navajo Nation - a pilot case-control study

The Navajo Nation includes approximately 250,000 American Indians living in a remote high desert environment with limited access to public water systems. We conducted a pilot case-control study to assess associations between acute gastroenteritis (AGE) and water availability, use patterns, and quality. Case patients with AGE and non-AGE controls who presented for care to two Indian Health Service hospitals were recruited. Data on demographics and water use practices were collected using a standard questionnaire. Household drinking water was tested for presence of pathogens, coliforms, and residual chlorine. Sixty-one subjects (32 cases and 29 controls) participated in the study. Cases and controls were not significantly different with respect to water sources, quality, or patterns of use. Twenty-one percent (n = 12) of study participants resided in dwellings not connected to a community water system. Eleven percent (n = 7) of subjects reported drinking hauled water from unregulated sources. Coliform bacteria were present in 44% (n = 27) of household water samples, and 68% (n = 40) of samples contained residual chlorine concentrations of <0.2 mg/L. This study highlights issues with water availability, quality, and use patterns within the Navajo Nation, including sub-optimal access to community water systems, and use of water hauled from unregulated sources.

Norovirus and Sapovirus Epidemiology and Strain Characteristics among Navajo and Apache Infants

Norovirus and sapovirus are important causes of acute gastroenteritis (AGE) among American Indian infants. We investigated the prevalence and molecular epidemiology of norovirus and sapovirus in American Indian infants who have historically experienced a high burden of AGE compared to other US populations. Stool samples were collected from 241 children with AGE (cases) and from 343 infants without AGE (controls) ≤9 months of age from 2002-2004. Cases experienced forceful vomiting and/or 3 or more watery or looser-than-normal stools in 24 hours. Stools were tested by real-time RT-PCR for norovirus GI, GII and GIV and sapovirus GI, GII, GIV and GV. Positive samples were genotyped after sequencing conventional RT-PCR products. Norovirus was identified in 76 (31.5%) of the cases and 70 (20.4%) of the controls (p<0.001). GII.3 and GII.4 Farmington Hills were the most frequently identified genotypes in 14.5% and 30.3% of cases and 17.1% and 27.1% of controls, respectively. Sapovirus GI and GII genotypes were identified in 8 (3.3%) of cases and 8 (2.3%) of controls and a single GIV virus was detected in a control. The same norovirus and sapovirus genotypes were circulating in the general U.S. population in the same time period. The high detection rate of norovirus in healthy controls suggests significant asymptomatic transmission in young infants in these communities.

Impact of providing in-home water service on the rates of infectious diseases: results from four communities in Western Alaska

Approximately 20% of rural Alaskan homes lack in-home piped water; residents haul water to their homes. The limited quantity of water impacts the ability to meet basic hygiene needs. We assessed rates of infections impacted by water quality (waterborne, e.g. gastrointestinal infections) and quantity (water-washed, e.g. skin and respiratory infections) in communities transitioning to in-home piped water. Residents of four communities consented to a review of medical records 3 years before and after their community received piped water. We selected health encounters with ICD-9CM codes for respiratory, skin and gastrointestinal infections. We calculated annual illness episodes for each infection category after adjusting for age. We obtained 5,477 person-years of observation from 1032 individuals. There were 9,840 illness episodes with at least one ICD-9CM code of interest; 8,155 (83%) respiratory, 1,666 (17%) skin, 241 (2%) gastrointestinal. Water use increased from an average 1.5 gallons/capita/day (g/c/d) to 25.7 g/c/d. There were significant (P-value < 0.05) declines in respiratory (16, 95% confidence interval (CI): 11-21%), skin (20, 95%CI: 10-30%), and gastrointestinal infections (38, 95%CI: 13-55%). We demonstrated significant declines in respiratory, skin and gastrointestinal infections among individuals who received in-home piped water. This study reinforces the importance of adequate quantities of water for health.

Epidemiologic Association Between FUT2 Secretor Status and Severe Rotavirus Gastroenteritis in Children in the United States

IMPORTANCE

A genetic polymorphism affecting FUT2 secretor status in approximately one-quarter of humans of European descent affects the expression of histo-blood group antigens on the mucosal epithelia of human respiratory, genitourinary, and digestive tracts. These histo-blood group antigens serve as host receptor sites necessary for attachment and infection of some pathogens, including norovirus.

OBJECTIVE

We investigated whether an association exists between FUT2 secretor status and laboratory-confirmed rotavirus infections in US children.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter case-control observational study involving active surveillance at 6 US pediatric medical institutions in the inpatient and emergency department clinical settings. We enrolled 1564 children younger than 5 years with acute gastroenteritis (diarrhea and/or vomiting) and 818 healthy controls frequency matched by age and month, from December 1, 2011, through March 31, 2013.

MAIN OUTCOMES AND MEASURES

Paired fecal-saliva specimens were tested for rotavirus and for secretor status. Comparisons were made between rotavirus test-positive cases and healthy controls stratified by ethnicity and vaccination status. Adjusted multivariable analyses assessed the preventive association of secretor status against severe rotavirus gastroenteritis.

RESULTS

One (0.5%) of 189 rotavirus test-positive cases was a nonsecretor, compared with 188 (23%) of 818 healthy control participants (P < .001). Healthy control participants of Hispanic ethnicity were significantly less likely to be nonsecretors (13%) compared with healthy children who were not of Hispanic ethnicity (25%) (P < .001). After controlling for vaccination and other factors, children with the nonsecretor FUT2 polymorphism appeared statistically protected (98% [95% CI, 84%-100%]) against severe rotavirus gastroenteritis.

CONCLUSIONS AND RELEVANCE

Severe rotavirus gastroenteritis was virtually absent among US children who had a genetic polymorphism that inactivates FUT2 expression on the intestinal epithelium. We observed a strong epidemiologic association among children with rotavirus gastroenteritis compared with healthy control participants. The exact cellular mechanism behind this epidemiologic association remains unclear, but evidence suggests that it may be rotavirus genotype specific. The lower prevalence of nonsecretors among Hispanic children may translate to an enhanced burden of rotavirus gastroenteritis among this group. Our findings may have bearing on our full understanding of rotavirus infections and the effects of vaccination in diverse populations.

Rotavirus genotypes and the indigenous children of Brazilian midwest in the vaccine era, 2008-2012: Footprints of animal genome

World group A rotavirus (RVA) surveillance data provides useful estimates of the disease burden, however, indigenous population might require special consideration. The aim of this study was to describe the results of G- and P-types from Brazilian native children ≤ 3 years. Furthermore, selected strains have been analyzed for the VP7, VP6, VP4, and NSP4 encoding genes in order to gain insight into genetic variability of Brazilian strains. A total of 149 samples, collected during 2008-2012, were tested for RVA using ELISA and PAGE, following by RT-PCR and sequencing. RVA infection was detected in 8.7% of samples (13/149). Genotype G2P[4] was detected in 2008 and 2010, G8P[6] in 2009, and G3P[8] in 2011. The phylogenetic analysis of the VP7 and VP4 genes grouped the Brazilian G2P[4] and G3P[8] strains within the lineages currently circulating in humans worldwide. However, the phylogenetic analysis of the VP6 and NSP4 from the Brazilian G2P[4] strains, and the VP7 and NSP4 from the Brazilian G3P[8] strains suggest a distant common ancestor with different animal strains (bovine, caprine, and porcine). The epidemiological and genetic information obtained in the present study is expected to provide an updated understanding of RVA genotypes circulating in the native infant population, and to formulate policies for the use of RVA vaccines in indigenous Brazilian people. Moreover, these results highlight the great diversity of human RVA strains circulating in Brazil, and an in-depth surveillance of human and animal RVA will lead to a better understanding of the complex dynamics of RVA evolution.

Breastfeeding as a means to prevent infant morbidity and mortality in Aboriginal Canadians: A population prevented fraction analysis

OBJECTIVES

Canadian Aboriginal infants experience poor health compared with other Canadian infants. Breastfeeding protects against many infant infections that Canadian Aboriginals disproportionately experience. The objective of our research was to estimate the proportion of select infant infection and mortality outcomes that could be prevented if all Canadian Aboriginal infants were breastfed.

METHODS

We used Levin's formula to estimate the proportion of three infectious outcomes and one mortality outcome that could be prevented in infancy by breastfeeding. Estimates were calculated for First Nations (both on- and off-reserve), Métis and Inuit as well as all Canadian infants for comparison. We extracted prevalence estimates of breastfeeding practices from national population-based surveys. We extracted relative risk estimates from published meta-analyses.

RESULTS

Between 5.1% and 10.6% of otitis media, 24.3% and 41.4% of gastrointestinal infection, 13.8% and 26.1% of hospitalizations from lower respiratory tract infections, and 12.9% and 24.6% of sudden infant death could be prevented in Aboriginal infants if they received any breastfeeding.

CONCLUSION

Interventions that promote, protect and support breastfeeding may prevent a substantial proportion of infection and mortality in Canadian Aboriginal infants.

Burden of rotavirus hospitalisations in young children in three paediatric hospitals in the United States determined by active surveillance compared to standard indirect methods

AIM

  The number of rotavirus hospitalisations is usually estimated from assigned diagnosis codes for gastroenteritis despite lack of validation for these indirect methods. Reliable estimates before and after introduction of vaccines are needed to quantify the absolute impact of new immunisation programs.

METHODS

  This 2-year study conducted at three hospitals prior to the licensure of the rotavirus vaccines in the USA compared two indirect methods for estimating hospitalisations for rotavirus gastroenteritis with estimates derived from prospective recruitment of children presenting with diarrhoea, vomiting or fever. For active surveillance, rotavirus gastroenteritis was confirmed by demonstration of stool antigen. The indirect residual and proportional methods assumed rotavirus to have caused a proportion of hospitalisations coded as acute gastroenteritis identified from computerised records.

RESULTS

  There were 447 rotavirus hospitalisations among inpatients 31 days through 4 years of age admitted with vomiting and/or diarrhoea, compared with 306 and 228 hospitalisations identified by the two indirect methods. Only 52% of children hospitalised with gastroenteritis received a qualifying diagnosis code at discharge. Relative to active surveillance, the sensitivity and specificity (95% confidence interval (CI)) in identifying rotavirus-attributable hospitalisations was 45% (95% CI: 43-48%) and 89% (88-90%) for the residual method and 34% (30-39%) and 92% (90-94%) for the proportional method.

CONCLUSIONS

  Many children admitted to the hospital with diarrhoea, vomiting or fever were not assigned discharge codes for acute gastroenteritis. Consequently, standard indirect methods missed a substantial number of rotavirus-associated hospitalisations, thereby underestimating the absolute number of children who could potentially benefit from vaccination.

Epidemiologic and clinical features of other enteric viruses associated with acute gastroenteritis in American Indian infants

OBJECTIVE

To investigate the viral etiology, through the use of molecular methods, of acute gastroenteritis (AGE), which is a considerable public health burden in Native American infants.

STUDY DESIGN

From March 2002 through February 2004, AGE and non-diarrheal stools were collected from Navajo and White Mountain Apache infants who received placebo during a rotavirus vaccine trial. Case (n=247) and control (n=344) specimens were tested for enteric adenovirus, astrovirus, norovirus, rotavirus, and sapovirus with real-time polymerase chain reaction. The odds of AGE were compared with population-averaged logistic regression models.

RESULTS

In 65% of the cases of AGE (161/247), at least one virus was detected; norovirus (n=80, 32%) and rotavirus (n=70, 28%) were the most common. A virus was detected in 38% of control specimens (132/344). Detection of "any virus" was associated with AGE (OR=3.22; 95% CI, 2.11-4.91), as was detection of norovirus (OR=2.00; 95% CI, 1.22-3.26) and rotavirus (OR=2.69; 95% CI, 1.52-4.79).

CONCLUSION

This study highlights the significant burden of viral AGE in American Indian infants and identifies pathogen targets for future prevention efforts in this population.

Impact of rotavirus vaccine on diarrhea-associated disease burden among American Indian and Alaska Native children

OBJECTIVE

Beginning in 2006, the Indian Health Service (IHS) began rotavirus vaccination of American Indian and Alaska Native (AI/AN) infants. To assess vaccine impact, we examined trends in IHS diarrhea-associated hospitalization and outpatient visits among AI/AN children in the pre- and postrotavirus vaccine era.

METHODS

Diarrhea-associated hospitalizations and outpatient visits among AI/AN children <5 years of age during 2001 through 2010 were examined by gender, age group, and region for prevaccine years 2001-2006 and postvaccine years 2008, 2009, and 2010. To account for secular declining trends observed in prevaccine years, expected diarrhea-associated hospitalization and outpatient rates for postvaccine years were generated by using Poisson regression analysis of the 2001-2006 annual rates.

RESULTS

Coverage with at least 1 dose of rotavirus vaccine among AI/AN infants aged 3 to 5 months in the first half of 2008, 2009, and 2010 ranged from 48% to 80% in various IHS regions. The prevaccine average annual diarrhea-associated hospitalization rates among AI/AN children <5 years of age was 63 per 10 000 persons (range: 57-75 per 10 000), and declined to 39, 31, and 27 per 10 000 in 2008, 2009, and 2010, respectively. Observed 2008, 2009, and 2010 rates were 24%, 37%, and 44% lower than expected rates, respectively. Decreases in diarrhea-associated hospitalizations and outpatient visits were observed in all IHS regions.

CONCLUSIONS

Diarrhea-associated hospitalization and outpatient visit rates among AI/AN children have declined after implementation of rotavirus vaccination in AI/AN populations.

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.

Tendências da internação e da mortalidade infantil por diarréia: Brasil, 1995 a 2005

OBJETIVO: Analisar a tendência das internações e da mortalidade por diarréia em crianças menores de um ano. MÉTODOS: Foi realizado um estudo ecológico de séries temporais entre 1995 e 2005, para o Brasil e para as capitais dos estados. Foram utilizados dados secundários do Ministério da Saúde, obtidos do Sistema de Informação Hospitalar e do Sistema de Informação sobre Mortalidade. Durante o período de estudo foram registradas 1.505.800 internações e 39.421 mortes por diarréia de crianças menores de um ano de idade. Para as análises das tendências da taxa de internação e de mortalidade foram utilizados modelos de regressão polinomial. RESULTADOS: Houve redução tanto nas internações por diarréia quanto na mortalidade infantil por diarréia no País e em 13 capitais. Oito capitais tiveram queda somente na mortalidade por diarréia, enquanto três apresentaram decréscimo somente nas taxas de internação por diarréia. Na análise conjunta dos indicadores de diarréia e dos indicadores gerais, observou-se que houve decréscimo em todas as séries históricas somente no Brasil e em quatro capitais. CONCLUSÕES: A redução nas taxas de internações e mortalidade por diarréia observada pelas séries temporais podem ser resultado das medidas de prevenção e controle empregadas.

Acute and persistent diarrhea

Socially disadvantaged Indigenous infants and children living in western industrialized countries experience high rates of infectious diarrhea, no more so than Aboriginal children from remote and rural regions of Northern Australia. Diarrheal disease, poor nutrition, and intestinal enteropathy reflect household crowding, inadequate water and poor sanitation and hygiene. Acute episodes of watery diarrhea are often best managed by oral glucose-electrolyte solutions with continuation of breastfeeding and early reintroduction of feeding. Selective use of lactose-free milk formula, short-term zinc supplementation and antibiotics may be necessary for ill children with poor nutrition, persistent symptoms, or dysentery. Education, high standards of environmental hygiene, breastfeeding, and immunization with newly licensed rotavirus vaccines are all needed to reduce the unacceptably high burden of diarrheal disease encountered in young children from Indigenous communities.

Vaccine preventable diseases and vaccination policy for indigenous populations

There are many similarities regarding the health status of Indigenous people in the 4 English-speaking developed countries of North America and the Pacific (United States, Canada, Australia, New Zealand), where they are all now minority populations. Although vaccines have contributed to the reduction or elimination of disease disparities for many infections, Indigenous people continue to have higher morbidity and mortality from many chronic and infectious diseases compared with the general populations in their countries. This review summarizes the available data on the epidemiology of vaccine-preventable diseases in Indigenous populations in these 4 countries in the context of the vaccination strategies used and their impact, with the aim of identifying successful strategies with the potential for wider implementation.

Trends in healthcare usage attributable to diarrhea, 1995-2004

OBJECTIVE

To determine current diarrhea-associated healthcare usage rates and associated sociodemographic factors. These data can be used to determine the impact of the rotavirus vaccine.

STUDY DESIGN

Using discharge diagnosis codes, we determined diarrhea-associated visit rates for children aged 0 to 18 years enrolled in Tennessee Medicaid, 1995-2004. Poisson regression compared data across time and within strata. The winter residual excess method estimated the rotavirus burden.

RESULTS

Analyzing approximately 500 000 person-years annually, outpatient and hospitalization rates remained stable from 1995 to 2004; emergency department (ED) rates approximately doubled, incidence rate ratio (IRR): 1.92 (1.81-2.04). White children used healthcare at greater rates than black children: outpatient IRR 1.90: (1.85-1.95), ED IRR: 1.69 (1.64-1.74), and inpatient IRR: 1.82 (1.73-1.92); and rural children greater than urban: outpatient IRR 1.66 (1.62-1.70), ED IRR 1.14 (1.11-1.17), inpatient IRR 1.88 (1.80-1.97). Children aged 0 to 35 months experienced 1627 outpatient and 792 ED visits, and 148 hospitalizations per 10 000 child-years; rotavirus may have affected up to 40% of these hospitalizations.

CONCLUSIONS

Diarrhea-associated ED visit rates nearly doubled from 1995 to 2004. Future studies could explore factors resulting in increased healthcare usage by white children and those living in rural areas and document the rotavirus vaccine's impact after its release.

The relationship between in-home water service and the risk of respiratory tract, skin, and gastrointestinal tract infections among rural Alaska natives

OBJECTIVES

We investigated the relationship between the presence of in-home piped water and wastewater services and hospitalization rates for respiratory tract, skin, and gastrointestinal tract infections in rural Alaska.

METHODS

We determined in-home water service and hospitalizations for selected infectious diseases among Alaska Natives by region during 2000 to 2004. Within 1 region, infant respiratory hospitalizations and skin infections for all ages were compared by village-level water services.

RESULTS

Regions with a lower proportion of home water service had significantly higher hospitalization rates for pneumonia and influenza (rate ratio [RR] = 2.5), skin or soft tissue infection (RR = 1.9), and respiratory syncytial virus (RR = 3.4 among those younger than 5 years) than did higher-service regions. Within 1 region, infants from villages with less than 10% of homes served had higher hospitalization rates for pneumonia (RR = 1.3) and respiratory syncytial virus (RR = 1.2) than did infants from villages with more than 80% served. Outpatient Staphylococcus aureus infections (RR = 5.1, all ages) and skin infection hospitalizations (RR = 2.7, all ages) were higher in low-service than in high-service villages.

CONCLUSIONS

Higher respiratory and skin infection rates were associated with a lack of in-home water service. This disparity should be addressed through sanitation infrastructure improvements.

Diarrhea-associated hospitalizations and outpatient visits among American Indian and Alaska Native children younger than five years of age, 2000-2004

BACKGROUND

Diarrhea accounts for many hospitalizations and outpatient clinic visits among children. American Indian and Alaska Native (AI/AN) children have experienced a greater infectious disease burden compared with the general U.S. population of children, although diarrhea-associated hospitalization rates have declined among AI/AN children.

METHODS

Hospital discharge and outpatient visit records with a diagnosis indicating a diarrhea-associated diagnosis were evaluated for AI/AN children <5 years of age, using the 2000-2004 Indian Health Service Direct and Contract Health Service Inpatient Data and outpatient visit data from the Indian Health Service National Patient Information Reporting System, and for the general U.S. population of children <5 years of age using the Kids' Inpatient Database for 2003 and National Ambulatory data for 2000-2004.

RESULTS

For 2000-2004, the diarrhea-associated hospitalization rate was similar for AI/AN children and U.S. children <5 years of age (65.9 and 79.3 of 10,000, respectively), but the rate among AI/AN infants was nearly twice the rate among U.S. infants (262.6 and 154.7 of 10,000, respectively). The rate of diarrhea-associated outpatient visits among AI/AN children was higher than for U.S. children (2255.4 versus 1647.9 of 10,000, respectively), as a result of the high rate among AI/AN infants compared with U.S. infants (6103.5 and 2956.3 of 10,000, respectively).

CONCLUSIONS

Although the diarrhea-associated hospitalization rate in AI/AN children <5 years old has declined to levels comparable with that of all U.S. children, the rate for AI/AN in infants remains higher than for U.S. infants. The diarrhea-associated outpatient visit rate for AI/AN children was higher than for U.S. children. Ongoing evaluation of hospitalization and outpatient data is important to understand the impact of rotavirus vaccine among AI/AN children.

Infection is the major component of the disease burden in aboriginal and non-aboriginal Australian children: a population-based study

BACKGROUND

Infection accounts for the majority of pediatric mortality and morbidity in developing countries, but there are limited data on the infectious diseases burden in children from developed countries. We investigated reasons for hospitalization before age 2 years in a birth cohort of Western Australian Aboriginal and non-Aboriginal children.

METHODS

Data on live births between January 1990 and December 2000, and corresponding deaths and hospitalizations in the first 2 years of life, were obtained through linked population-based data.

RESULTS

Almost half the cohort of 270,068 children were hospitalized at least once. Aboriginal children had significantly higher admission rates (2196 vs. 779 per 1000 live births), stayed longer and were more likely to die in hospital than non-Aboriginal children. Infections (mainly respiratory and gastrointestinal) were the most common reason for hospitalization, accounting for 34% of all admissions, with higher rates in Aboriginal (1114 per 1000 live births) than non-Aboriginal children (242 per 1000) (P < 0.001). Over time, admission rates for infections declined in Aboriginal children but increased in non-Aboriginal children. Aboriginal children were admitted 14 times more often for pneumonia than non-Aboriginal children.

CONCLUSIONS

Infections are the leading cause of hospitalization in children under 2 years of age. The continuing heavy burden of serious infections, borne disproportionately by Aboriginal children, needs to be alleviated. Public health interventions such as the development and universal implementation of vaccines for respiratory syncytial virus, rotavirus and influenza are needed, while adequate funding must be committed to Indigenous health services and training.

Lower respiratory tract infections among american Indian and Alaska Native children and the general population of U.S. Children

BACKGROUND AND OBJECTIVE

Lower respiratory tract infections (LRTIs) cause substantial childhood morbidity. This study characterizes and compares LRTI-associated morbidity among American Indian/Alaska Native (AI/AN) children and the general population of U.S. children.

METHODS

Hospitalization and outpatient records with a diagnosis indicating LRTIs were evaluated for children aged younger than 5 years during 1990-2001.

RESULTS

For 1999-2001, the LRTI-associated hospitalization rate was significantly higher for AI/AN children than for U.S. children (116.1 versus 63.2/1000, respectively), with the disparity being greater for infants than for 1- to 4-year-old children. Also the rate of LRTI-associated outpatient visits among AI/AN infants was higher than that for all U.S. infants (737.7 versus 207.2/1000, respectively). LRTI hospitalization and outpatient visit rates were highest in the Alaska and Southwest Indian Health Service regions. During 1990-2001, the LRTI hospitalization rate among AI/AN infants in the Alaska region and among the general U.S. infant population increased. Bronchiolitis-associated hospitalization rates increased for AI/AN and U.S. infants, whereas the pneumonia-associated hospitalization rate decreased among AI/AN infants and remained stable among U.S. infants.

CONCLUSIONS

LRTIs continue to be an important cause of morbidity in children, especially among AI/AN infants in the Alaska and Southwest regions. Strategies to reduce LRTI hospitalizations and outpatient visits are warranted for all infants, but the greatest potential impact would be among AI/AN infants.

Respiratory syncytial virus hospitalizations among American Indian and Alaska Native infants and the general United States infant population

OBJECTIVE

To determine the burden of respiratory syncytial virus (RSV) disease among American Indian (AI) and Alaska Native (AN) infants, by examining RSV-associated hospitalizations.

METHODS

Infant hospitalizations from 1997 through 2001 with RSV listed as a diagnosis were selected by using Indian Health Service/tribal hospital discharge data for AIs/ANs and National Hospital Discharge Survey data for the general US population.

RESULTS

In 2000-2001, RSV disease was listed as a diagnosis for 14.4% of all AI/AN infant hospitalizations, with bronchiolitis attributable to RSV infection (12.2%) being among the top 5 listed diagnoses. The rate of RSV-specific hospitalizations was 34.4 hospitalizations per 1000 infants for AI/AN infants and 27.4 hospitalizations per 1000 births for the general US infant population. The hospitalization rates for AI/AN infants living in the Alaska and Southwest regions (70.9 and 48.2 hospitalizations per 1000 infants, respectively) were much higher than the overall rate for US infants.

CONCLUSIONS

RSV infection is one of the leading causes of hospitalization among all infants in the United States, and AI/AN infants living in the Southwest and Alaska regions are at especially high risk for hospitalizations associated with RSV infection. Development of vaccines, antiviral agents, and other strategies to prevent RSV disease could yield substantial public health benefits.

Laboratory-Confirmed Shigellosis in the United States, 1989-2002: Epidemiologic Trends and Patterns

During 1989-2002, a total of 208,368 laboratory-confirmed Shigella infections were reported to the Centers for Disease Control and Prevention. Shigella sonnei accounted for 71.7%, Shigella flexneri accounted for 18.4%, Shigella boydii accounted for 1.6%, and Shigella dysenteriae accounted for 0.7% of infections; for 7.6%, no serogroup was reported. National incidence rates ranged from 7.6 cases per 100,000 persons in 1993 to 3.7 cases per 100,000 persons in 1999. Incidence rates for S. boydii, S. dysenteriae, and S. flexneri decreased over the 14-year period by 81%, 83%, and 64%, respectively; S. sonnei rates only decreased by 8%. The highest rates were reported from western states (10.0 cases per 100,000 persons) and among children 1-4 years of age (20.6 cases per 100,000 persons). The female-male S. sonnei incidence rate ratio among 20-39-year-old adults decreased from 2.3 during 1989-1999 to 1.4 during 2000-2002. Approximately 1% of isolates were from extraenteric sources; 0.25% were from blood. S. sonnei remains an important cause of diarrhea in the United States. Prevention efforts that target high-risk groups are needed.

Disparities in hospitalizations of rural American Indians

BACKGROUND

Disparities in hospitalization rates, particularly rates for avoidable hospitalizations, are indicators of potentially unmet health needs and inefficient use of health resources. Hospitalization rates that the Indian Health Service (IHS) can report underestimate disparities for American Indians (AIs) and Alaska Natives (ANs) relative to other Americans, because the IHS cannot track all hospitalizations of AIs/ANs in their user population.

OBJECTIVES

To compare hospitalization and avoidable hospitalization rates for a rural AI/AN user population with those of non-Indians living in the same counties where both groups use the same hospital system, regardless of the expected source of payment.

RESEARCH DESIGN

Retrospective analysis of California hospital discharge data for 1996 linked to rural IHS user data for 1995 and 1996 (3920 hospitalizations) compared with a random sample of discharge data for the rest of the non-Indian population in the 37 counties of the IHS Contract Health Service delivery area (7840 hospitalizations).

MEASURES

Hospitalization and avoidable hospitalization rates and risk ratios (RRs).

RESULTS

Hospitalization and avoidable hospitalization rates were both higher for the AI/AN user population than for the non-Indian general population. The age-adjusted hospitalization ratios were 72% higher for men (RR 1.72, confidence interval [CI] 1.40-2.12) and 52% higher for women (RR 1.52, CI 1.36-1.92). The comparable ratios for avoidable hospitalizations were 136% higher for men (RR 2.36, CI 1.52-3.29) and 106% higher for women (RR 2.06, CI 1.32-3.50).

CONCLUSIONS

Disparities in both hospitalization and avoidable hospitalization rates of rural AIs/ANs in California were previously undetected by either federal IHS or state hospital discharge data alone. At least some of the disparities are likely reducible with improved access to care.

Infectious disease hospitalizations among American Indian and Alaska native infants

OBJECTIVE

To describe the burden and trends in hospitalizations associated with infectious diseases among American Indian and Alaska Native (AI/AN) infants.

METHODS

First-listed infectious disease hospitalizations and hospitalization rates among AI/AN infants and infants in the general US population from 1988-1999 were analyzed by using Indian Health Service/tribal hospital discharge data and the National Hospital Discharge Survey data, respectively.

RESULTS

Infectious disease hospitalizations accounted for 53% of all AI/AN infant hospitalizations and approximately 43% of all US infant hospitalizations during 1988-1999. The annual hospitalization rate for infectious diseases among AI/AN infants declined from 27,486 per 100,000 infants in 1988 to 14,178 per 100,000 infants in 1999. However, the rates for AI/AN infants within the Alaska, Southwest, and Northern Plains regions remained higher than that for the general US infant population at the end of the study period. Lower respiratory tract infection hospitalizations accounted for almost 75% of AI/AN infant infectious disease hospitalizations, and the lower respiratory tract infection hospitalization rate for AI/AN infants was twice that for US infants.

CONCLUSIONS

Although infectious disease hospitalization rates for AI/AN infants have declined, AI/AN infants continue to have a higher infectious disease burden than the general US infant population.

Hospitalizações por diarréia infecciosa no Estado do Rio de Janeiro

A diarréia é causa de hospitalização importante entre os menores de um ano, sendo influenciada por múltiplos e complexos fatores, tais como, sociais, econômicos, culturais, além de necessidades médicas e seu tipo de financiamento. O objetivo deste trabalho foi o de medir a taxa de hospitalização de diarréia infantil no Rio de Janeiro, em 1996, e a associação com informações demográficas, geográficas e clínicas, cotejando diferenças entre hospitais públicos/universitários e contratados/filantrópicos do Sistema Único de Saúde (SUS). Os dados do estudo foram provenientes do Sistema de Informação Hospitalar. Os estabelecimentos contratados/filantrópicos admitem cerca de quatro vezes mais crianças do que os públicos/universitários. As variações observadas quanto à idade das crianças internadas, o tempo e custos médios de internação e a utilização da Unidade de Tratamento Intensivo podem refletir diferenças na conduta médica, e por conseguinte, na capacidade do serviço em evitar o óbito por diarréia das crianças internadas. Conclui-se que é necessário monitorar, de forma contínua, a utilização dos recursos hospitalares, para atuar diretamente nos custos e na qualidade da assistência prestada.

Outpatient and hospital visits associated with otitis media among American Indian and Alaska native children younger than 5 years

OBJECTIVE

To describe the burden of otitis media (OM) among American Indian and Alaska Native (AI/AN) children.

METHODS

OM morbidity among AI/AN younger than 5 years was evaluated using OM-associated outpatient visit and hospitalization rates. These rates were compared with outpatient and hospitalization rates for the general US population of children younger than 5 years. AI/AN children who were younger than 5 years and receiving care through the Indian Health Service or tribally operated facilities and US children younger than 5 years of age were studied.

RESULTS

From 1994--1996, the average annual rate of AI/AN OM-associated outpatient visits was 138 per 100 children younger than 5 years. Among AI/AN children younger than 1 year (infants), these rates were almost 3 times greater than those for US infants (318 vs 110 visits per 100 infants, respectively). AI/AN children 1 to 4 years of age had rates 1.5 times greater than US children of the same age (107 vs 65 visits per 100 children, respectively). AI/AN children also experienced higher rates of OM-associated hospitalization than did US children (5643 vs 2440 per 100 000 infants, 823 vs 665 per 100 000 1- to 4-year-olds).

CONCLUSION

We found that AI/AN children, especially AI/AN infants, have higher OM-associated outpatient and hospitalization rates than those for the general US population of children. The disparity in rates suggests that additional prevention programs and continued resources are needed to reduce OM morbidity among AI/AN children.

Infectious diarrhea in children

Infectious diarrhea in children remains an important cause of morbidity in North America with rotavirus, nontyphoidal salmonella, Campylobacter and Giardia being the predominant pathogens in children younger than 5 years. Knowledge of the epidemiology of the diarrheal illness in a community together with the clinical information are necessary when determining the extent of investigation. Oral rehydration remains the mainstay of therapy and antibiotics are reserved for specific clinical situations and infections.

Trends in infectious disease hospitalizations among American Indians and Alaska Natives

OBJECTIVES

This study sought to describe trends in hospitalizations associated with infectious diseases among American Indians and Alaska Natives.

METHODS

Infectious disease hospitalizations and rates among American Indians and Alaska Natives from 1980 through 1994 were examined via Indian Health Service hospital discharge data and compared with published trends for the general US population.

RESULTS

Annual hospitalization rates for infectious diseases among American Indians and Alaska Natives decreased by 31.0% between 1980 and 1994. Infectious disease hospitalizations accounted for 16.3% of all hospitalizations in 1980 and 21.2% in 1994, an increase of 30.1%. In 1994, the age-adjusted infectious disease hospitalization rate for American Indians and Alaska Natives was 1863 per 100,000 population, approximately 21% greater than that for the general US population.

CONCLUSIONS

Hospitalization trends for infectious diseases show that there has been improvement in the health status of American Indians and Alaska Natives but also indicate that this population has a higher infectious disease burden than the general US population.

Cost of diarrhea-associated hospitalizations and outpatient visits in an insured population of young children in the United States

OBJECTIVE

To assess the financial and clinical burden of diarrhea- and rotavirus-associated disease among a population of privately insured US children.

METHODS

For the period 1993 through 1996, we analyzed medical claims data from a large, administrative database containing information on approximately 300,000 children <5 years of age to examine trends in, and costs associated, with hospitalizations and outpatient visits for diarrhea.

RESULTS

An annual average of 1,186 diarrhea-associated hospitalizations (35 per 10,000 children <5 years) and 33 386 outpatient visits (943 per 10,000 children <5 years) were reported, accounting for 4% of all hospitalizations and 2% of all outpatient visits among children <5 years of age. Diarrhea-associated hospitalizations and outpatient visits showed a distinct winter-spring peak consistent with that of rotavirus infection. The excess of diarrhea-associated events occurring during the winter-spring peak accounted for an average of 50% of all diarrhea-associated hospitalizations and 18% of all diarrhea-associated outpatient visits. The median cost (in 1998 constant dollars) of a diarrhea-associated hospitalization was $2,307, and that for a rotavirus-associated hospitalization was $2,303. Median costs of diarrhea- and rotavirus-associated outpatient visits were $47 and $57, respectively.

CONCLUSIONS

Diarrhea is an important cause of morbidity in this insured population of young children. The epidemiologic features of diarrhea-associated events suggest that rotavirus is an important contributor to the overall morbidity from diarrhea. These disease burden and cost estimates should provide useful information with which to assess the costs and benefits of future interventions for rotavirus-associated illness.

Bronchiolitis-associated hospitalizations among American Indian and Alaska Native children

BACKGROUND

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract illness among infants and young children. Respiratory system diseases account for a large proportion of hospitalizations in American Indian and Alaska Native (AI/AN) children; however, aggregate estimates of RSV-associated hospitalizations among AI/AN children have not been made.

METHODS

We used Indian Health Service hospitalization data from 1990 through 1995 to describe hospitalizations associated with bronchiolitis, the most characteristic clinical manifestation of RSV infection, among AI/AN children <5 years old.

RESULTS

The overall bronchiolitis-associated hospitalization rate among AI/AN infants < 1 year old was considerably higher (61.8 per 1,000) than the 1995 estimated bronchiolitis hospitalization rate among all US infants (34.2 per 1,000). Hospitalization rates were higher among male infants (72.2 per 1,000) than among females infants (51.1 per 1,000). The highest infant hospitalization rate was noted in the Navajo Area (96.3 per 1,000). Hospitalizations peaked annually in January or February, consistent with national peaks for RSV detection. Bronchiolitis hospitalizations accounted for an increasing proportion of hospitalizations for lower respiratory tract illnesses.

CONCLUSIONS

Bronchiolitis-associated hospitalization rates are substantially greater for AI/AN infants than those for all US infants. This difference may reflect an increased likelihood of severe RSV-associated disease or a decreased threshold for hospitalization among AI/AN infants with bronchiolitis compared with all US infants. AI/AN children would receive considerable benefit from lower respiratory tract illness prevention programs, including an RSV vaccine, if and when one becomes available.