Evaluation of seasonal patterns of Kawasaki syndrome- and rotavirus-associated hospitalizations in California and New York, 2000-2005.

BACKGROUND: Kawasaki Syndrome (KS) is an uncommon childhood disease with unknown etiology. It has been suggested that rotavirus infection may play a causative role in the development of KS. METHODS: To examine potential temporal associations between KS and rotavirus infection, seasonal patterns of KS- and rotavirus-associated hospitalizations among children in California and New York during 2000-2005 were compared. RESULTS: Rotavirus hospital admissions were markedly winter seasonal, with very few summer hospitalizations. KS hospitalizations occurred year-round but also peaked slightly during winter and spring. CONCLUSION: The strong winter seasonal pattern of rotavirus clearly differed from the year-round pattern of KS hospitalizations. While the present study cannot completely rule out rotavirus as having a role in the development of KS, other agents must be involved in the etiology of KS.

A method for statistically comparing spatial distribution maps.

BACKGROUND: Ecological niche modeling is a method for estimation of species distributions based on certain ecological parameters. Thus far, empirical determination of significant differences between independently generated distribution maps for a single species (maps which are created through equivalent processes, but with different ecological input parameters), has been challenging. RESULTS: We describe a method for comparing model outcomes, which allows a statistical evaluation of whether the strength of prediction and breadth of predicted areas is measurably different between projected distributions. To create ecological niche models for statistical comparison, we utilized GARP (Genetic Algorithm for Rule-Set Production) software to generate ecological niche models of human monkeypox in Africa. We created several models, keeping constant the case location input records for each model but varying the ecological input data. In order to assess the relative importance of each ecological parameter included in the development of the individual predicted distributions, we performed pixel-to-pixel comparisons between model outcomes and calculated the mean difference in pixel scores. We used a two sample Student's t-test, (assuming as null hypothesis that both maps were identical to each other regardless of which input parameters were used) to examine whether the mean difference in corresponding pixel scores from one map to another was greater than would be expected by chance alone. We also utilized weighted kappa statistics, frequency distributions, and percent difference to look at the disparities in pixel scores. Multiple independent statistical tests indicated precipitation as the single most important independent ecological parameter in the niche model for human monkeypox disease. CONCLUSION: In addition to improving our understanding of the natural factors influencing the distribution of human monkeypox disease, such pixel-to-pixel comparison tests afford users the ability to empirically distinguish the significance of each of the diverse environmental parameters included in the modeling process. This method will be particularly useful in situations where the outcomes (maps) appear similar upon visual inspection (as are generated with other modeling programs such as MAXENT), as it allows an investigator the capacity to explore subtle differences among ecological parameters and to demonstrate the individual importance of these factors within an overall model.

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.

Epidemiology of hospitalizations associated with ulcers, gastric cancers, and Helicobacter pylori infection among American Indian and Alaska Native persons.

To describe the epidemiology of ulcers, gastric cancer, and Helicobacter pylori infection among American Indian (AI) and Alaska Native (AN) persons, we analyzed hospitalization discharge records with physician discharge diagnoses coded as ulcer, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma during 1980 to 2005, and H. pylori during 1996 to 2005 from the Indian Health Service Inpatient Dataset. The average annual age-adjusted rate of hospitalizations that included an ulcer-associated condition was 232.4 per 100,000 AI/AN persons. The age-adjusted rate for gastric cancer was 14.2 per 100,000 persons. MALT lymphoma was listed as a discharge diagnosis at an age-adjusted rate of 6.1 per 100,000, and the age-adjusted rate of H. pylori discharge diagnoses was 28.2 per 100,000. The AI/AN persons living in the Alaska region and those >or= 65 years old had the highest rates of hospitalizations that listed ulcer-associated conditions, gastric cancers, MALT lymphoma, and H. pylori as a discharge diagnosis.

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.

Infectious disease hospitalizations among infants in the United States.

OBJECTIVE: This study describes the burden and epidemiologic features of infectious disease hospitalizations among infants in the United States. METHODS: Hospitalizations with an infectious disease listed as a primary diagnosis for infants (<1 year of age) in the United States during 2003 were examined by using the Kids' Inpatient Database. National estimates of infectious disease hospitalizations, hospitalization rates, and various hospital parameters were examined. RESULTS: During 2003, an estimated 286,739 infectious disease hospitalizations occurred among infants in the United States and accounted for 42.8% of all infant hospitalizations. The national infectious disease hospitalization rate was 7010.8 hospitalizations per 100,000 live births, or approximately 1 infectious disease hospitalization for every 14 infants. The median length of stay was 3 days, and stays totaled >1 million hospital days for infants. Infectious disease hospitalization rates were highest among boys and nonwhite infants. The most commonly listed diagnoses among the infant infectious disease hospitalizations included lower respiratory tract infections (59.0%), kidney, urinary tract, and bladder infections (7.6%), upper respiratory tract infections (6.5%), and septicemia (6.5%). The median cost of an infectious disease hospitalization was $2235, with total annual hospital costs of approximately $690 million, among infants in the United States. CONCLUSIONS: Infectious disease hospitalizations among infants account for substantial health care expenditures and hospital time in the United States, with respiratory disease hospitalizations constituting more than one half of all hospitalizations. Younger infants, boys, and nonwhite infants were at increased risk for infectious disease hospitalization. Measures to reduce racial disparities and the occurrence of respiratory tract infections should substantially decrease the infectious disease burden among infants.

Severe bronchiolitis and respiratory syncytial virus among young children in Hawaii.

BACKGROUND: Lower respiratory tract infections are a leading cause of hospitalization and mortality among children worldwide. Our objective was to describe the incidence and epidemiology of severe bronchiolitis, respiratory syncytial virus (RSV), and pneumonia among children in Hawaii. METHODS: Retrospective analysis of the patient-linked hospital discharge data associated with bronchiolitis, RSV, and pneumonia among Hawaii residents younger than 5 years of age during 1997 through 2004 using the Hawaii State Inpatient Database. RESULTS: During 1997 through 2004, the average annual incidence rates for bronchiolitis, RSV, and pneumonia were 3.8, 2.7, and 6.8 per 1000 children younger than 5 years, respectively. The incidence of each condition was higher for infants younger than 1 year (15.1, 9.8, and 15.9 per 1000 infants, respectively) than the incidence for children 1-4 years of age, and higher for boys compared with girls. The incidence of each condition was highest among Native Hawaiian and other Pacific Islander children compared with children of other race groups living in Hawaii. Most hospitalizations occurred during the months of October through February. Estimated median hospital charges were $4806 (bronchiolitis), $5465 (RSV) and $5240 (pneumonia), with overall average annual charges of $11.5 million. CONCLUSION: The incidence and hospitalization rates for bronchiolitis, RSV, and pneumonia among children younger than 5 years of age in Hawaii were low; the corresponding hospitalization rates were lower than those for the general U.S. population. However, the hospitalization rates for each condition among Hawaiian and other Pacific Islander children were much higher than those for other race groups or for the U.S. population.

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.

Kawasaki syndrome in Denmark.

OBJECTIVE: To describe the epidemiologic characteristics of Kawasaki syndrome (KS) and to estimate national KS incidence rates among children in Denmark. METHODS: A retrospective population-based study using hospital discharge records with a KS diagnosis for children younger than 15 years selected from the Danish National Hospital Register for 1981-2004. Incidence rates were calculated using the number of KS patients and corresponding census data. RESULTS: During 1981-2004, 360 children younger than 15 years were hospitalized with KS in Denmark, with 73% younger than 5 years. In this age group, the average annual incidence of KS gradually increased from 1981 to 1999 and thereafter stabilized at 4.5 to 5.0 per 100,000 person-years. The incidence was greater for boys than for girls (RR = 1.6, 95% CI = 1.2-2.0) and was highest among infants younger than 1 year (4.5), declining with increasing age (P = 0.03). However, the age-specific decline in incidence was only observed for boys, whereas the incidence for girls remained unchanged by age. The median length of hospital stay was 12 days, and the incidence peaked in the winter months. CONCLUSIONS: Major epidemiologic characteristics identified among Danish childhood KS are consistent with those described in previous studies, such as highest incidence among young children and winter-seasonality. The KS incidence rate among children younger than 5 years in Denmark increased steadily during the early study period (coinciding with global recognition of KS) and seems to have stabilized from 1998-1999 onwards. Although the incidence among Danish children was lower than that reported for several other European countries, differences in methodology challenge definite comparisons.

Ecological niche and geographic distribution of human monkeypox in Africa.

Monkeypox virus, a zoonotic member of the genus Orthopoxviridae, can cause a severe, smallpox-like illness in humans. Monkeypox virus is thought to be endemic to forested areas of western and Central Africa. Considerably more is known about human monkeypox disease occurrence than about natural sylvatic cycles of this virus in non-human animal hosts. We use human monkeypox case data from Africa for 1970-2003 in an ecological niche modeling framework to construct predictive models of the ecological requirements and geographic distribution of monkeypox virus across West and Central Africa. Tests of internal predictive ability using different subsets of input data show the model to be highly robust and suggest that the distinct phylogenetic lineages of monkeypox in West Africa and Central Africa occupy similar ecological niches. High mean annual precipitation and low elevations were shown to be highly correlated with human monkeypox disease occurrence. The synthetic picture of the potential geographic distribution of human monkeypox in Africa resulting from this study should support ongoing epidemiologic and ecological studies, as well as help to guide public health intervention strategies to areas at highest risk for human monkeypox.

Human tissue oversight in hospitals: an AABB survey.

BACKGROUND: Reports of human tissue allograft-transmitted infections have underscored the need for better accounting of allografts in health-care facilities. The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) implemented new storage and issuance tissue standards for hospital oversight as of July 1, 2005. This study sought to survey hospital tissue responsibilities. STUDY DESIGN AND METHODS: The AABB Tissue Task Force conducted a Web-based survey distributed to all 904 hospital institutional members in January 2005. The survey asked about tissue type used, breadth of responsibility, hospital department involvement, and views on AABB involvement. Data from 402 of 904 (45%) respondents were tabulated and analyzed. RESULTS: Among the 402 respondents, 325 (81%) used allogeneic and/or autologous human tissue. The most frequently used tissues were musculoskeletal (n = 240, 74%) and skin (n = 169, 52%) allografts. The department of surgery (e.g., operating room; n = 245, 76%) most often had responsibility for tissue use, followed by the blood bank (i.e., transfusion service; n = 164, 51%); surgery most frequently had responsibility for all tissue types except peripheral blood progenitor cells. Only 32 of 402 (8%) respondents had plans for increased oversight in the next 12 months; 129 of 178 (72%) thought there was a role for AABB in developing guidance on hospital tissue responsibilities. CONCLUSIONS: In this survey, most AABB member hospital respondents indicated facility use of allogeneic and/or autologous tissues. Although tissue allograft responsibility by surgery was extensive, hospital blood banks also had significant involvement. Few blood banks, however, plan increased oversight in the near future. Given JCAHO standards, blood banks have an opportunity to assist their hospital in planning for assigned tissue responsibilities and oversight to ensure patient safety.

Necrotising enterocolitis hospitalisations among neonates in the United States.

The objective of this study was to estimate the rate and describe the epidemiology of necrotising enterocolitis (NEC) among neonates (infants <1 month of age) hospitalised in the United States. Hospital discharge records for neonates with an NEC diagnosis and an in-hospital death or routine discharge were selected for analysis from the 2000 Kids' Inpatient Database. An estimated 4463 (SE = 219) hospitalisations associated with NEC occurred among neonates in the United States during the year 2000, resulting in a hospitalisation rate of 109.9 [95% CI 97.2, 122.6] per 100 000 livebirths. The rate of NEC hospitalisations was highest among non-Hispanic Black neonates. The median hospital length of stay was 49 days. The in-hospital fatality rate was 15.2% (SE = 1.0%). Neonates who underwent a surgical procedure during hospitalisation were more likely to have a longer length of stay and to die than were those who did not have surgical intervention. Low-birthweight (LBW) neonates with NEC were more likely than LBW neonates hospitalised with other diagnoses to be very LBW (VLBW), non-Hispanic Black and male. In addition, compared with LBW neonates hospitalised with other diagnoses, LBW neonates with NEC had higher hospital charges and longer lengths of stay, and were more likely to die during hospitalisation. This study provides the first national estimate of the rate of hospitalisation for NEC among neonates in the United States. During 2000, there was one NEC hospitalisation per 1000 livebirths, with approximately 1 in 7 NEC hospitalisations ending in death. NEC accounts for substantial morbidity; thus, the development of prevention strategies and effective therapies continues to be an important issue.

Clinical manifestations of human monkeypox influenced by route of infection.

BACKGROUND: In April 2003, an outbreak of monkeypox occurred in the United States following the importation of monkeypox virus (MPXV)-infected animals in a consignment of exotic pets from West Africa. Transmission of the virus to non-African captive species, including prairie dogs, preceded human disease. METHODS: We evaluated the influence of the route of infection on clinical illness for persons with confirmed and probable cases of human monkeypox. Exposures were categorized as being "noninvasive" (e.g., the person touched an infected animal, cleaned an infected animal's cage, and/or stood within 6 feet of an infected animal) or "complex" (e.g., invasive bite or scratch from an ill prairie dog plus potential noninvasive exposure), and associations between exposure, illness manifestation, and illness progression (i.e., elapsed time from first exposure to an ill prairie dog through various benchmarks of illness) were assessed. RESULTS: Patients with complex exposures were more likely than patients with noninvasive exposures to have experienced pronounced signs of systemic illness (49.1% vs. 16.7%; P=.041) and to have been hospitalized during illness (68.8% vs. 10.3%; P<.001). Complex exposures were also associated with shorter incubation periods (9 days for complex exposures vs. 13 days for noninvasive exposures) and the absence of a distinct febrile prodrome. CONCLUSIONS: The findings of this study indicate that route of infection can influence monkeypox illness manifestations.

Kawasaki syndrome in Hawaii.

OBJECTIVE: To describe the incidence and epidemiology of Kawasaki syndrome (KS) in Hawaii. METHODS: Retrospective analysis of the State Inpatient Database for Hawaii residents hospitalized with KS during 1996 through 2001. RESULTS: During 1996 through 2001, 267 persons younger than 18 years of age living in Hawaii were hospitalized with KS; 226 (84.6%) were younger than 5 years of age. The average annual incidence for KS was 45.2 per 100,000 children younger than 5 years of age. The incidence was higher for children younger than 1 year of age than for those 1-4 years of age (74.3 and 37.5 per 100,000). The KS incidence for Asian and Pacific Islander children and for White children was 70.9 and 35.3 per 100,000, respectively. Incidence was highest among Japanese American children living in Hawaii (197.7 per 100,000). Honolulu County had the most KS patients (85.0%) and the highest incidence (53.1 per 100,000) among Hawaii counties. For children younger than 5 years of age hospitalized with KS, the median length of stay was 2 days, and the median hospital charge was $9379. CONCLUSION: During 1996 through 2001, the annual incidence rate for KS among children younger than 5 years of age in Hawaii was the highest in the United States. The incidence among Japanese American children in Hawaii was higher than that among other racial groups in the state and when compared with children living in Japan.