Trends in hospitalizations associated with gastroenteritis among adults in the United States, 1979-1995

Gastroenteritis (GE) is among the most common illnesses of humans but the burden of disease, its epidemiology, and the distribution of pathogens in adults have not been fully examined. This information is needed to plan prevention strategies particularly for high-risk groups. This study is a retrospective analysis of data from the National Hospital Discharge Survey for the years 1979 through 1995 which describes the disease burden and epidemiology of hospitalizations associated with GE among adults in the United States. Diarrhoea was listed as a diagnosis on an average of 452,000 hospital discharges per year representing 1.5% of all hospitalizations among adults. The annual number of GE hospitalizations has decreased by 20% from approximately 500,000 in 1979 to 400,000 in 1995. The aetiology of 78% of cases coded as GE was undetermined. Until the aetiology of disease can be better established, specific strategies for prevention cannot be developed.

Effects of trans-pyridine ligands on the interactions of RuII and RuIII ammine complexes N7-coordinated to purine nucleosides and DNA

DNA binding by trans-[(H2O)(Pyr)(NH3)4RuII]2+ (Pyr = py, 3-phpy, 4-phpy, 3-bnpy, 4-bnpy) is highly selective for G7 with KG = 1.1 x 10(4) to 2.8 x 10(4), with the more hydrophobic Pyr ligands exhibiting slightly higher binding. A strong dependence on ionic strength indicates that ion-pairing with DNA occurs prior to binding. At mu = 0.05, d[RuII-DNA]/dt = k[RuII][DNA], where k = 0.17-0.21 M-1 s-1 with the various Pyr ligands. The air oxidation of [(py)(NH3)4RuII]n-DNA to [(py)(NH3)4RuIII]n-DNA at pH 6 occurs with a pseudo-first-order rate constant of kobs = 5.6 x 10(-4) s-1 at mu = 0.1, T = 25 degrees C. Strand cleavage of plasmid DNA appears to occur by both Fenton/Haber-Weiss chemistry and by base-catalyzed routes, some of which are independent of oxygen. Base-catalyzed cleavage is more efficient than O2 activation at neutral pH and involves the disproportionation of covalently bound RuIII and, in the presence of O2, Ru-facilitated autoxidation to 8-oxoguanine. Disproportionation of [py(NH3)4RuIII]n,-DNA occurs according to the rate law: d[RuII-GDNA]/dt = k0[RuIII-GDNA] + k1[RuIII-GDNA][OH-], where k0 = 5.4 x 10(-4) s-1 and k1 = 8.8 M-1 s-1 at 25 degrees C, mu = 0.1. The appearance of [(Gua)(py)(NH3)4RuIII] under argon, which occurs according to the rate law: d[RuIII-G]/dt = k0[RuIII-GDNA] + k1[OH-][RuIII-GDNA] (k0 = 5.74 x 10(-5) s-1, k1 = 1.93 x 10(-2) M-1 s-1 at T = 25 degrees C, mu = 0.1), is consistent with lysis of the N-glycosidic bond by RuIV-induced general acid hydrolysis. In air, the ratio of [Ru-8-OG]/[Ru-G] and their net rates of appearance are 1.7 at pH 11, 25 degrees C. Small amounts of phosphate glycolate indicate a minor oxidative pathway involving C4' of the sugar. In air, a dynamic steady-state system arises in which reduction of RuIV produces additional RuII.

Trans-pyridine tetraammine complexes of RuII and RuIII with N7-coordinated purine nucleosides

The synthesis, spectroscopic, and electrochemical properties of trans-[L(Pyr)(NH3)4RuII/III] (Pyr = py, 3-phpy, 4-phpy, 3-pnpy, or 4-bnpy; L = H2O, Guo, dGuo, 1MeGuo, Gua, Ino, or G7-DNA) are reported. As expected, the Pyr ligand slows DNA binding by trans-[(H2O)(Pyr)(NH3)4RuII]2+ relative to [(H2O)(NH3)5RuII]2+ and favors reduction of RuIII by about 150 mV. The pyridine ligand also promotes the disproportionation of RuIII to afford the corresponding complexes of RuII and, presumably, RuIV. For L = Ino, disproportionation follows the rate law: d[RuII]/dt = k0[RuIII] + k1[OH-][RuIII], k0 = (2.7 +/- 0.7) x 10(-4) s-1 and k1 = 70 +/- 1 M-1 s-1.

Hidden mortality attributable to Rocky Mountain spotted fever: immunohistochemical detection of fatal, serologically unconfirmed disease

Rocky Mountain spotted fever (RMSF) is the most severe tickborne infection in the United States and is a nationally notifiable disease. Since 1981, the annual case-fatality ratio for RMSF has been determined from laboratory-confirmed cases reported to the Centers for Disease Control and Prevention (CDC). Herein, a description is given of patients with fatal, serologically unconfirmed RMSF for whom a diagnosis of RMSF was established by immunohistochemical (IHC) staining of tissues obtained at autopsy. During 1996-1997, acute-phase serum and tissue samples from patients with fatal disease compatible with RMSF were tested at the CDC. As determined by indirect immunofluorescence assay, no patient serum demonstrated IgG or IgM antibodies reactive with Rickettsia rickettsii at a diagnostic titer (i.e., >/=64); however, IHC staining confirmed diagnosis of RMSF in all patients. Polymerase chain reaction validated the IHC findings for 2 patients for whom appropriate samples were available for testing. These findings suggest that dependence on serologic assays and limited use of IHC staining for confirmation of fatal RMSF results in underestimates of mortality and of case-fatality ratios for this disease.

Kawasaki syndrome among American Indian and Alaska Native children, 1980 through 1995

BACKGROUND

Kawasaki syndrome (KS) is a leading cause of acquired heart disease among US children, but the epidemiologic features of KS among American Indian and Alaska Native (AI/AN) children have not been described.

METHODS

We examined Indian Health Service computerized records of hospital discharges for AI/AN children <18 years of age with KS during 1980 through 1995.

RESULTS

During 1980 through 1995, 85 AI/AN children were reported with a hospitalization for KS; 10 of the children had an additional KS hospitalization record within 5 months. The average annual KS hospitalization rate for children <5 years of age, based on first KS hospitalization only, was 4.3 cases per 100000 children; the rate for children age <1 year (n = 21) was 8.6 per 100000 and for children ages 1 to 4 years was 3.6 per 100000. The annual rates for children < 5 years of age ranged from 0 to 8.5 per 100000 children. KS hospitalizations for children peaked in January and February; 50.6% of the children were hospitalized during January through April. The overall median length of hospital stay was 4 days (range, 1 to 29 days); the median duration decreased from 8 days from 1980 through 1982 to 4 days from 1993 through 1995.

CONCLUSIONS

The overall annual hospitalization rate of KS among AI/AN children <5 years of age was slightly lower than rates for several majority white populations in the United States. (4.6 to 15.2 cases per 100000) and much lower than rates for blacks and Asians/Pacific Islanders.

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

OBJECTIVE

To describe trends in diarrhea- associated hospitalizations among American Indian and Alaska Native (AI/AN) children and to estimate the morbidity from rotavirus.

DESIGN

Retrospective analysis of Indian Health Service hospital discharge records.

PATIENTS

AI/AN children 1 month through 4 years of age with a diarrhea-associated diagnosis listed on the hospital discharge record.

SETTING

Hospitals on or near US Indian reservations from 1980 through 1995.

RESULTS

During 1980 through 1995, 21 669 diarrhea-associated hospitalizations were reported among AI/AN children. The annual incidence of diarrhea-associated hospitalizations declined by 76% from 276 per 10 000 in 1980 to 65 per 10 000 in 1995. The median length of hospital stay decreased from 4 days during 1980-1982 to 2 days during 1993-1995. Diarrhea-associated hospitalizations peaked during the winter months (October through March), especially among children 4-35 months of age, with the peaks appearing first in the Southwest during October and moving to the East in March. In the early years of the study (1980-1982), the rate of diarrhea-associated hospitalizations among AI/AN children (236 per 10 000) was greater than the national rate (136 per 10 000). By the end of the study period (1993-1995), the rate for AI/AN children (71 per 10 000) was similar to the national rate (89 per 10 000), although the rate for AI/AN infants remained higher than the national rate for infants.

CONCLUSIONS

Diarrhea-associated hospitalization rates for AI/AN children have declined to a level similar to that of the national population. Rotavirus may be an important contributor to diarrheal morbidity among AI/AN children, underscoring the need for vaccines against this pathogen.

Pandemic versus epidemic influenza mortality: a pattern of changing age distribution

Almost all deaths related to current influenza epidemics occur among the elderly. However, mortality was greatest among the young during the 1918-1919 pandemic. This study compared the age distribution of influenza-related deaths in the United States during this century's three influenza A pandemics with that of the following epidemics. Half of influenza-related deaths during the 1968-1969 influenza A (H3N2) pandemic and large proportions of influenza-related deaths during the 1957-1958 influenza A (H2N2) and the 1918-1919 influenza A (H1N1) pandemics occurred among persons <65 years old. However, this group accounted for decrementally smaller proportions of deaths during the first decade following each pandemic. A model suggested that this mortality pattern may be explained by selective acquisition of protection against fatal illness among younger persons. The large proportion of influenza-related deaths during each pandemic and the following decade among persons <65 years old should be considered in planning for pandemics.

Epidemiology of diarrheal disease among children enrolled in four West Coast health maintenance organizations. Vaccine Safety Datalink Team

BACKGROUND

We used information from the Vaccine Safety Datalink (VSD) about approximately 1 million children enrolled in four health maintenance organizations to assess the morbidity from diarrhea and estimate the disease burden of rotavirus.

METHODS

We examined trends of diarrhea-associated hospitalizations and emergency room (ER) visits among VSD children ages 1 month through 4 years during October, 1992, through September, 1994 (two rotavirus seasons) and estimated the morbidity from rotavirus on the basis of characteristic patterns of age and seasonality.

RESULTS

Overall diarrhea was associated with 6.3% of hospitalizations and 4% of ER visits. During a child's first 5 years of life, we estimated that 1 in 57 was hospitalized and 1 in 21 required an ER visit because of diarrhea. Each year the number of diarrhea-associated hospitalizations and ER visits was greatest in winter among children ages 4 to 23 months and peaked in November in California and during February in Oregon and Washington. The winter seasonality of diarrhea-associated hospitalizations reflected the trends for diarrhea of presumed noninfectious and viral etiologies, which together accounted for most (92.9%) hospitalizations.

CONCLUSIONS

Diarrhea is an important cause of morbidity among VSD children. The epidemiologic patterns of diarrhea-associated hospitalizations and ER visits resembled those reported previously for rotavirus diarrhea, suggesting that rotavirus may be a major contributor to the overall morbidity from diarrhea. Enhanced surveillance by screening for rotavirus in a sample of children with diarrhea will permit a more accurate assessment of the disease burden of this pathogen and the cost effectiveness of a rotavirus immunization program.

Influence of more extensive radiotherapy and adjuvant chemotherapy on long-term outcome of early-stage Hodgkin's disease: a meta-analysis of 23 randomized trials involving 3,888 patients. International Hodgkin's Disease Collaborative Group

PURPOSE

To assess the effect of more extensive radiotherapy and of adjuvant combination chemotherapy on long-term outcome of early-stage Hodgkin's disease.

METHODS

In a collaborative worldwide systematic overview, individual patient data were centrally reviewed on 1,974 patients in eight randomized trials of more versus less extensive radiotherapy and on 1,688 patients in 13 trials of radiotherapy plus chemotherapy versus radiotherapy alone. Crude mortality data on 226 patients in two other trials of chemotherapy were also reviewed.

RESULTS

More extensive radiotherapy reduced the risk of treatment failure (resistant or recurrent disease) at 10 years by more than one third (31.3% v 43.4% failures; P < .00001), but there was no apparent improvement in overall 10-year survival (77.1 % v 77.0% alive). The addition of chemotherapy to radiotherapy halved the 10-year risk of failure (15.8% v 32.7%; P < .00001), with a small, nonsignificant improvement in survival (79.4% v 76.5% alive). This involved a reduction of borderline significance for deaths from Hodgkin's disease (12.3% v 15.4% dead at 10 years; P = .07), which was partly counterbalanced by a nonsignificant excess of deaths from other causes (12.4% v 10.0% 10-year risk).

CONCLUSION

More extensive radiotherapy fields or the addition of chemotherapy to radiotherapy in the initial treatment of early-stage Hodgkin's disease had a large effect on disease control, but only a small effect on overall survival. Recurrences could be prevented by more extensive radiotherapy or by additional chemotherapy. However, if chemotherapy had not been given initially, recurrences were generally salvageable by re-treatment with chemotherapy. Hence, less intensive primary treatment--particularly a reduction in radiotherapy fields--appears to achieve similar survival rates as more intensive treatment, although more randomized evidence is needed to confirm this.

Hospitalizations associated with rotavirus diarrhea in the United States, 1993 through 1995: surveillance based on the new ICD-9-CM rotavirus-specific diagnostic code

The introduction of a specific International Classification of Diseases code for rotavirus diarrhea in 1992 prompted examination of the National Hospital Discharge Survey (NHDS) for trends in rotavirus-associated hospitalizations among US children aged 1 month through 4 years. During 1993-1995, 13.5% of hospitalizations were associated with diarrhea (n = 162,478/year). Rotavirus was the most common pathogen identified, coded in 16.5% of diarrhea cases (n = 26,798/year), and increased from 13.3% in 1993 to 18.9% in 1995. The age distribution and seasonality of hospitalizations of presumed noninfectious and viral etiology resembled those associated with rotavirus. Rotavirus was reported as a cause of diarrhea more frequently by hospitals that were large (> or =100 beds), proprietary-owned, or in the West/Midwest. Although these findings suggest incomplete detection of rotavirus diarrhea cases, the large number of rotavirus-associated hospitalizations underscores the need for vaccines and indicates that NHDS data could be used to monitor the impact of a US rotavirus immunization program.

Diarrheal mortality in US infants. Influence of birth weight on risk factors for death

OBJECTIVES

To examine diarrhea-associated deaths among very low-birth-weight (VLBW) (< 1500 g) infants and low- and normal-birth-weight (LNBW) (> or = 1500 g) infants at birth and to identify specific interventions to prevent these deaths.

DESIGN

Retrospective analyses of linked infant and birth death data on diarrhea of all causes compiled by the National Center for Health Statistics, Centers for Disease Control and Prevention, Atlanta, Ga.

PATIENTS

Infants aged 27 days through 11 months who died with diarrhea.

SETTING

United States, 1991.

RESULTS

A majority (56%, n = 143) of the 257 diarrhea-associated deaths reported among US infants in 1991 occurred among VLBW infants. Compared with LNBW infants, VLBW infants had a 100-fold greater diarrheal mortality (269 deaths per 100,000 live births for VLBW infants vs 2.8 deaths per 100,000 live births for LNBW infants), died at a younger age, and more often died in the hospital. Diarrhea-associated deaths among VLBW infants were strongly associated with prematurity and a low 1-minute Apgar score whereas African American race, less maternal education, and a low 1-minute Apgar score were associated with increased diarrheal mortality among LNBW infants.

CONCLUSIONS

Infants of VLBW are at an increased risk for diarrheal deaths and new efforts are required to understand and improve the diagnosis of and therapy for diarrhea among these infants. For LNBW infants, diarrheal deaths remain a social problem and efforts need to focus on improved education and home-based rehydration therapy for children whose mothers fit the high-risk profile and who may lack adequate access to health care.

Pediatric hospitalizations for croup (laryngotracheobronchitis): biennial increases associated with human parainfluenza virus 1 epidemics

Croup is a common manifestation of respiratory tract infection in children, and human parainfluenza virus 1 (HPIV-1) is the agent most commonly associated with croup. In the United States, HPIV-1 produces a distinctive pattern of biennial epidemics of respiratory illness during the autumn months of odd-numbered years. National Hospital Discharge Survey data for croup hospitalizations among patients <15 years old between 1979 and 1993 were examined along with laboratory-based surveillance data on HPIV-1 activity in the United States. The mean annual number of croup hospitalizations was 41,000 (range, 27,000-62,000/year). Ninety-one percent of hospitalizations occurred among children <5 years of age. Minor peaks in croup hospitalizations occurred each year in February, and major peaks occurred in October of odd-numbered years, coincident with peak HPIV-1 activity. Each biennial epidemic of HPIV-1 was associated with 18,000 excess croup hospitalizations nationwide.

The impact of influenza epidemics on mortality: introducing a severity index

OBJECTIVES

The purpose of this study was to assess the impact of recent influenza epidemics on mortality in the United States and to develop an index for comparing the severity of individual epidemics.

METHODS

A cyclical regression model was applied to weekly national vital statistics from 1972 through 1992 to estimate excesses in pneumonia and influenza mortality and all-cause mortality for each influenza season. Each season was categorized on the basis of increments of 2000 pneumonia and influenza excess deaths, and each of these severity categories was correlated with a range of all-cause excess mortality.

RESULTS

Each of the 20 influenza seasons studied was associated with an average of 5600 pneumonia and influenza excess deaths (range, 0-11,800) and 21,300 all-cause excess deaths (range, 0-47,200). Most influenza A(H3N2) seasons fell into severity categories 4 to 6 (23,000-45,000 all-cause excess deaths), whereas most A(H1N1) and B seasons were ranked in categories 1 to 3 (0-23,000 such deaths).

CONCLUSIONS

From 1972 through 1992, influenza epidemics accounted for a total of 426,000 deaths in the United States, many times more than those associated with recent pandemics. The influenza epidemic severity index was useful for categorizing severity and provided improved seasonal estimates of the total number of influenza-related deaths.

The epidemiology of necrotizing enterocolitis infant mortality in the United States

OBJECTIVES

This study examined trends and risk factors for infant mortality associated with necrotizing enterocolitis in the United States.

METHODS

Necrotizing enterocolitis-associated deaths and infant mortality rates from 1979 through 1992 were determined by means of US multiple cause-of-death and linked birth/infant death data.

RESULTS

Annual necrotizing enterocolitis infant mortality rates decreased from 1979 through 1986 but increased thereafter and were lower during the 3-year period before (1983 through 1985;11.5 per 100,000 live births) the introduction of surfactants than after (1990 through 1992; 12.3 per 100,000). Low-birthweight singleton infants who were Black male, or born to mothers younger than 17 had increased risk for necrotizing enterocolitis-associated death.

CONCLUSIONS

As mortality among low-birth weight infants continues to decline and smaller newborns survive early causes of death, necrotizing enterocolitis-associated infant mortality may increase.

Visualizing geographic and temporal trends in rotavirus activity in the United States, 1991 to 1996. National Respiratory and Enteric Virus Surveillance System Collaborating Laboratories

BACKGROUND

Rotavirus is the leading cause of severe pediatric gastroenteritis worldwide. A vaccine may soon be licensed for use in the United States to prevent this disease. To characterize US geographic and temporal trends in rotavirus activity, we made contour maps showing the timing of peak rotavirus activity.

METHODS

From July, 1991, through June, 1996, 79 laboratories participating in the National Respiratory and Enteric Virus Surveillance System reported on a weekly basis the number of stool specimens that tested positive for rotavirus. The peak weeks in rotavirus detections from each laboratory were mapped using kriging, a modeling technique originally developed for geostatistics.

RESULTS

During the 5-year period 118,716 fecal specimens were examined, of which 27,616 (23%) were positive for rotavirus. Timing of rotavirus activity varied by geographic location in a characteristic pattern in which peak activity occurred first in the Southwest from October through December and last in the Northeast in April or May. The Northwest exhibited considerable year-to-year variability (range, December to May) in the timing of peak activity, whereas the temporal pattern in the remainder of the contiguous 48 states was relatively constant.

CONCLUSION

Kriging is a useful method for visualizing geographic and temporal trends in rotavirus activity in the United States. This analysis confirmed trends reported in previous years, and it also identified unexpected variability in the timing of peak rotavirus activity in the Northwest. The causes of the seasonal differences in rotavirus activity by region are unknown. Tracking of laboratory detections of rotavirus may provide an effective surveillance tool to assess the impact of a rotavirus vaccination campaign in the United States.

Meta-analyses using individual patient data

Systematic reviews of randomized controlled trials often provide the most reliable information on which to base treatment policy. However, to be reliable, such reviews need to contain a high proportion of all the relevant randomized evidence. This relates both to the need to find all trials and the need to analyse data on all participants. One way to achieve this is through a collaboration in which those responsible for the trials supply data on each randomized patient for an individual patient data meta-analysis. However, such projects require more time and resources than more conventional reviews and are still rare. This paper illustrates how they can help to achieve the aim of using complete data in a systematic review.

A method for timely assessment of influenza-associated mortality in the United States

Influenza-associated mortality has traditionally been estimated as the excess mortality above a baseline of deaths during influenza epidemic periods. Excess mortality estimates are not timely, because national vital statistics data become available after a period of 2-3 years. To develop a method for timely reporting, we used the 121 Cities Surveillance System (121 Cities), maintained at the Centers for Disease Control and Prevention, as an alternative data source. We fit a cyclical regression model to time series of weekly 121 Cities pneumonia and influenza deaths for 1972-1996 to estimate the excess pneumonia and influenza mortality and to compare these figures with national vital statistics estimates for 20 influenza seasons during 1972-1992. Seasonal excess mortality based on 121 Cities correlated well with the national data: for 18 (90%) of 20 seasons, our influenza epidemic severity index category approximated the result based on national vital statistics. We generated preliminary severity categories for the four recent seasons during 1992-1996. We conclude that the 121 Cities Surveillance System can be used for the timely assessment of the severity of future influenza epidemics and pandemics. Timely pneumonia and influenza mortality reporting systems established in sentinel countries worldwide would help alert public health officials and allow prompt prevention and intervention strategies during future influenza epidemics and pandemics.

1H and (31)P NMR and EPR of Pentaammineruthenium(III) Complexes of Endocyclically Coordinated Nucleotides, Nucleosides, and Related Heterocyclic Bases. Autoxidation of [(Guokappa(N7))(NH(3))(5)Ru(III)] (Guo = Guanosine). Crystal Structure of [7MeGuakappa(N9)(NH(3))(5)Ru]Cl(3).3H(2)O

The (1)H-NMR spectra of complexes involving the paramagnetic metal center [(NH(3))(5)Ru(III)] coordinated at ring nitrogens have been examined with pyridine, purine, nucleoside, and nucleotide ligands along with (31)P-NMR of the nucleotide complexes and EPR of representative complexes. Variations in the spectra have been investigated as a function of the coordination site and pH. Pseudocontact and contact shifts have been calculated for various protons, and an attempt has been made to correlate sugar conformations in coordinated 5'GMP, 5'IMP, Guo, and Ino with paramagnetically induced shifts. The compound [(7MeGuakappa(N9))(NH(3))(5)Ru]Cl(3).3H(2)O crystallizes in the orthorhombic space group Pna2(1) with cell parameters a = 25.375(4) Å, b = 11.803(4) Å, c = 6.958(2) Å, Z = 4, and R = 0.042. The autoxidation of [L(NH(3))(5)Ru(III)], where L = Guo, dGuo, and 1MeGuo, to the corresponding 8-oxo complexes under atmospheric oxygen is first order in the complex and [OH(-)]. For L = Guo, k = 6.6 x 10(-5) M(-1) s(-1), DeltaH = 58 kJ/mol, and DeltaS = -124 J/(mol K).

1H and (31)P NMR of Pentaammineruthenium(III) Complexes of Exocyclically-Coordinated Adenine and Cytosine Ligands. Evidence for Rotamers with Distinct Acidities

1H NMR spectra of the paramagnetic complexes [L(NH(3))(5)Ru(III)], where L = derivatives of cytosine-kappa(N4) and adenine-kappa(N6), reveal rotameric isomers with distinct acid-base equilibria. (31)P NMR spectra of the 5'CMPkappa(N4) and 5'AMPkappa(N6) complexes indicate little interaction between the metal and phosphate centers. Differences between the (1)H and (31)P NMR of endo- and exocyclically-coordinated nucleosides and nucleotides are discussed and provide a means of distinguishing exocyclic from endocyclic nitrogen coordination.

The epidemiology of rotavirus diarrhea in the United States: surveillance and estimates of disease burden

The decision to develop rotavirus vaccines was predicated on the extensive burden of rotavirus disease among children worldwide. US reports on nationwide hospitalizations (1979-1992) and deaths (1968-1991) due to diarrhea and weekly reports of rotavirus infection by 74 laboratories were reviewed to estimate the burden of rotavirus disease, identify epidemiologic trends, and consider methods for evaluating an immunization program when a vaccine becomes available. From 1968 to 1985, diarrhea-related deaths among US children <5 years old declined from 1100 to 300/year. This decline was associated with the disappearance of winter peaks for diarrhea-related deaths previously associated with rotavirus infection among children 4-23 months old. From 1979 to 1992, however, hospitalizations for diarrhea averaged 186,000/year and retained their winter peaks, which have been linked to rotavirus infections. Each year an estimated 54,000-55,000 US children are hospitalized for diarrhea, but <40 die with rotavirus. A rotavirus vaccine program will require improved surveillance, including the timely collection of data from sentinel hospitals, in which a diagnosis of rotavirus can be established or ruled out for all children hospitalized for diarrhea.

1H NMR, EPR, UV-Vis, and Electrochemical Studies of Imidazole Complexes of Ru(III). Crystal Structures of cis-[(Im)(2)(NH(3))(4)Ru(III)]Br(3) and [(1MeIm)(6)Ru(II)]Cl(2).2H(2)O

Comparisons of the spectroscopic properties of a number of Ru(III) complexes of imidazole ligands provide methods of distinguishing between various types of bonding that can occur in proteins and nucleic acids. In particular, EPR and (1)H NMR parameters arising from the paramagnetism of Ru(III) should aid in determining binding sites of Ru(III) drugs in macromolecules. Electrochemical studies on several imidazole complexes of ruthenium suggest that imidazole may serve as a significant pi-acceptor ligand in the presence of anionic ligands. Crystal structures are reported on two active immunosuppressant complexes. cis-[(Im)(2)(NH(3))(4)Ru(III)]Br(3) crystallizes in the triclinic space group P&onemacr; (No. 2) with the cell parameters a = 8.961(2) Å, b = 12.677(3) Å, c = 7.630(2) Å, alpha = 98.03(2) degrees, beta = 100.68(2) degrees, gamma = 81.59(2) degrees, and Z = 2 (R = 0.044). [(1MeIm)(6)Ru(II)]Cl(2).2H(2)O crystallizes in the monoclinic space group P2(1)/n (No. 14) with the cell parameters a = 7.994(2) Å, b = 13.173(4) Å, c = 14.904(2) Å, beta = 97.89(1) degrees, and Z = 2 (R = 0.052). The average Ru(II)-N bond distance is 2.106(8) Å.

Trends in hospitalizations for diarrhea in United States children from 1979 through 1992: estimates of the morbidity associated with rotavirus

OBJECTIVES

To examine trends in the hospitalizations of children for diarrheal disease in the U.S. and to provide estimates for the burden of disease associated with rotavirus diarrhea.

METHODS

Data for diarrheal hospitalizations among U.S. children ages 1 month through 4 years were compiled from the National Hospital Discharge Survey for the years 1979 through 1992. Between 1979 and 1992, 12% of all hospitalizations of U.S. children 1 month through 4 years of age had an International Classification of Diseases code for diarrhea listed in one of the top three positions on the discharge diagnosis.

RESULTS

The annual rate of diarrheal hospitalizations, 97 per 10 000 persons (average, 185 742 per year), did not change substantially during the 14-year study period and accounted annually for 724 394 inpatient days (3.9 days per hospitalization). For most diarrheal hospitalizations (75.9%) no causative agent was specified in the National Hospital Discharge Survey records; of the remaining 24.8%, viruses were most commonly reported (19.3%), followed by bacteria (5.1%) and parasites (0.7%). The proportion of hospitalizations associated with viral diarrheas rose from 13% to 27% during the 14-year study period, whereas the proportion of hospitalizations for noninfectious diarrhea declined from 79% to 60%. Every year the number of hospitalizations peaked from November through April, the "winter" months, among children ages 4 through 35 months; this peak began in the West during November and December and reached the Northeast by March.

CONCLUSIONS

Diarrhea continues to be a common cause of hospitalization among children in the United States and the winter seasonality estimated to be caused in large part by rotavirus would be expected to decrease if rotavirus vaccines currently being developed were introduced. Our analysis of temporal trends in diarrheal hospitalizations provides a unique surrogate with which to estimate the disease burden associated with rotavirus diarrhea.