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Biomedical subjects

J R Livengood

Publications and source records attributed to J R Livengood.

At least 19 recordsLinked to original sources

Intussusception among infants given an oral rotavirus vaccine.

BACKGROUND: Intussusception is a form of intestinal obstruction in which a segment of the bowel prolapses into a more distal segment. Our investigation began on May 27, 1999, after nine cases of infants who had intussusception after receiving the tetravalent rhesus-human reassortant rotavirus vaccine (RRV-TV) were reported to the Vaccine Adverse Event Reporting System. METHODS: In 19 states, we assessed the potential association between RRV-TV and intussusception among infants at least 1 but less than 12 months old. Infants hospitalized between November 1, 1998, and June 30, 1999, were identified by systematic reviews of medical and radiologic records. Each infant with intussusception was matched according to age with four healthy control infants who had been born at the same hospital as the infant with intussusception. Information on vaccinations was verified by the provider. RESULTS: Data were analyzed for 429 infants with intussusception and 1763 matched controls in a case-control analysis as well as for 432 infants with intussusception in a case-series analysis. Seventy-four of the 429 infants with intussusception (17.2 percent) and 226 of the 1763 controls (12.8 percent) had received RRV-TV (P=0.02). An increased risk of intussusception 3 to 14 days after the first dose of RRV-TV was found in the case-control analysis (adjusted odds ratio, 21.7; 95 percent confidence interval, 9.6 to 48.9). In the case-series analysis, the incidence-rate ratio was 29.4 (95 percent confidence interval, 16.1 to 53.6) for days 3 through 14 after a first dose. There was also an increase in the risk of intussusception after the second dose of the vaccine, but it was smaller than the increase in risk after the first dose. Assuming full implementation of a national program of vaccination with RRV-TV, we estimated that 1 case of intussusception attributable to the vaccine would occur for every 4670 to 9474 infants vaccinated. CONCLUSIONS: The strong association between vaccination with RRV-TV and intussusception among otherwise healthy infants supports the existence of a causal relation. Rotavirus vaccines with an improved safety profile are urgently needed.

Case-Control Studies↗

Economic evaluation of use of diphtheria, tetanus, and acellular pertussis vaccine or diphtheria, tetanus, and whole-cell pertussis vaccine in the United States, 1997.

OBJECTIVE: To compare the economic costs and benefits associated with using either diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) or diphtheria and tetanus toxoids and whole-cell pertussis vaccine (DTwP) in the United States in 1997. DESIGN: Standard cost-benefit analysis, from both the societal and health care system perspectives, was performed for each combination vaccine as well as for the pertussis components singly. SETTING: A simulated cohort of 4.1 million children from birth to age 15 years. MAIN OUTCOME MEASURES: Net costs (savings) and benefit-cost ratios (BCRs) RESULTS: Without a vaccination program, diphtheria, tetanus, and pertussis disease caused more than 3 million cases and more than 28,000 deaths, at a cost of $23.6 billion. From the societal perspective, net savings because of the use of DTaP and DTwP were $22.510 million and $22.623 million, respectively. The net savings from the acellular pertussis component and the whole-cell pertussis component only were $4.362 million and $4.474 million, respectively. Benefit-cost ratios for DTaP from a societal and health care system perspective were 27:1 and 9:1, respectively. Sensitivity analyses of key variables did not result in appreciable changes in results. CONCLUSIONS: Compared with no program, vaccination with DTaP or DTwP resulted in substantial savings, regardless of the perspective taken and for all sensitivity analyses conducted. Compared with DTwP, use of DTaP generated a small cost increase that might be offset by the value of other factors, such as increased confidence in pertussis vaccination resulting from reduced adverse events. Arch Pediatr Adolesc Med. 2000;154:797-803

Adolescent↗

Changing epidemiology of pertussis in the United States: increasing reported incidence among adolescents and adults, 1990-1996.

Since 1990, the reported incidence of pertussis has increased in the United States with peaks occurring every 3-4 years. On the basis of analysis of pertussis cases reported to the Centers for Disease Control and Prevention, the incidence remained stable among children aged younger than 5 years, most of whom were protected by vaccination. In contrast to 1990-1993, during 1994-1996, the average incidence among persons aged 5-9 years, 10-19 years, and 20 years or older increased 40%, 106%, and 93%, respectively. Since 1990, 14 states reported pertussis incidences of > or =2 cases per 100,000 population during at least 4 years between 1990 and 1996; seven of these states also reported that a high proportion of cases occurred in persons aged 10 years or older. Analysis of national data on pertussis did not provide sufficient information to fully elucidate the relative importance of multiple possible explanations for the increase in the incidence of pertussis in adolescents and adults. Improvement in diagnosis and reporting of pertussis in this age group, particularly in some states, is an important factor contributing to the overall increase.

Adolescent↗

Addressing the challenges to immunization practice with an economic algorithm for vaccine selection.

The biotechnology revolution is producing a growing bounty of new vaccines which pose difficult choices in selecting among many products. Some major public and private purchasers of vaccine may offer individual physicians and clinics their choice in assembling vaccine inventories. Others might purchase only a limited stock of products that would satisfactorily immunize a typical child. In either case, current vaccine selection decisions are based principally on purchase price alone without systematic consideration of other factors of fiscal consequence. As a potential tool for decision making, we developed an economic algorithm for vaccine selection that would minimize the overall costs of disease control through immunization by considering: (1) purchase price, (2) number of doses needed, (3) preparation time, (4) route of administration, (5) cold storage needs, (6) shelf life, (7) earliest age of full immunity, (8) adverse events frequency, and (9) efficacy of protection. To demonstrate the algorithm, variables (1) to (4) above were incorporated into a pilot binary-integer linear programming model that satisfied the recommended immunization schedule for diphtheria, tetanus, pertussis, Haemophilus influenzae b, and hepatitis B, using eleven vaccines (DTaP, DTaP-Hib, Hib, HepB and Hib-HepB) from four manufacturers. Five (or six) opportunities to vaccinate were modeled at (1), 2, 4, 6, 12-18, and 60 months of life, assuming US$40 per clinic visit, $15 per injection, and $0.50 per minute of nurse preparation time. Vaccine costs were varied using actual March and September 1997 US Federal vaccine prices, as well as estimates for unpriced new vaccines. Over 16,000 distinct vaccine stocking lists by vaccine type and brand were possible. Including a 1-month visit, the lowest-cost 'solution' of the algorithm was $529.41 per child in the March cost-assumption case, and $490.32 in the September one (both included four doses of DTaP-Hib, three HepB, and one DTaP). Without a 1-month visit, the lowest-cost solution in the March case cost $486.67 (four DTaP, two Hib-HepB, one DTaP-Hib, and one HepB), while the September case cost $450.32 (four DTaP-Hib, three HepB, and one DTaP). Ensuring at least one product was selected from each of the four manufacturers increased costs about $13.00, and the needed injections rose from eight to nine. The most economical selection of vaccines to use cannot be intuitively predicted, as permutations are large and solutions are sensitive to minor changes in costs and constraints. A transparent, objective selection method that weighs the economic value of distinguishing features among competing vaccines might offer the 'best value' to vaccine purchasers, while also creating strong market incentives for continuing innovation and competition in the vaccine industry.

Adolescent↗

A large community outbreak of salmonellosis caused by intentional contamination of restaurant salad bars.

CONTEXT: This large outbreak of foodborne disease highlights the challenge of investigating outbreaks caused by intentional contamination and demonstrates the vulnerability of self-service foods to intentional contamination. OBJECTIVE: To investigate a large community outbreak of Salmonella Typhimurium infections. DESIGN: Epidemiologic investigation of patients with Salmonella gastroenteritis and possible exposures in The Dalles, Oregon. Cohort and case-control investigations were conducted among groups of restaurant patrons and employees to identify exposures associated with illness. SETTING: A community in Oregon. Outbreak period was September and October 1984. PATIENTS: A total of 751 persons with Salmonella gastroenteritis associated with eating or working at area restaurants. Most patients were identified through passive surveillance; active surveillance was conducted for selected groups. A case was defined either by clinical criteria or by a stool culture yielding S Typhimurium. RESULTS: The outbreak occurred in 2 waves, September 9 through 18 and September 19 through October 10. Most cases were associated with 10 restaurants, and epidemiologic studies of customers at 4 restaurants and of employees at all 10 restaurants implicated eating from salad bars as the major risk factor for infection. Eight (80%) of 10 affected restaurants compared with only 3 (11%) of the 28 other restaurants in The Dalles operated salad bars (relative risk, 7.5; 95% confidence interval, 2.4-22.7; P<.001). The implicated food items on the salad bars differed from one restaurant to another. The investigation did not identify any water supply, food item, supplier, or distributor common to all affected restaurants, nor were employees exposed to any single common source. In some instances, infected employees may have contributed to the spread of illness by inadvertently contaminating foods. However, no evidence was found linking ill employees to initiation of the outbreak. Errors in food rotation and inadequate refrigeration on ice-chilled salad bars may have facilitated growth of the S Typhimurium but could not have caused the outbreak. A subsequent criminal investigation revealed that members of a religious commune had deliberately contaminated the salad bars. An S Typhimurium strain found in a laboratory at the commune was indistinguishable from the outbreak strain. CONCLUSIONS: This outbreak of salmonellosis was caused by intentional contamination of restaurant salad bars by members of a religious commune.

Contact Tracing↗

National trends in the initial hospitalization for heart failure.

OBJECTIVES: Heart failure is a major health care burden among older adults, but information on recent trends has not been available. We compare rates, sociodemographic characteristics, and discharge outcomes of the initial hospitalization for heart failure in the Medicare populations of 1986 and 1993. DESIGN: Information reported on the Medicare hospital claims record during initial hospitalization for heart failure was compared for patients aged 65 and older hospitalized in 1986 (N = 631,306) and those aged 65 and older hospitalized in 1993 (N = 803,506). RESULTS: Age-standardized hospitalization rates (per 1000 person-years) for any diagnosis of heart failure were higher in 1993 than in 1986 (white: 24.6 vs 22.4, black: 26.1 vs 22.4, respectively). Age-specific results suggested an earlier onset of heart failure in black adults. In 1993, compared with 1986, higher proportions of heart failure patients were discharged to another care facility (white: 23.9% vs 16.8%, black: 17.6% vs 10.5%, respectively) or to health service care at home (white: 11.3% vs 6.0%, black: 12.4% vs 6.5%, respectively). In contrast, in-hospital mortality was lower in 1993 than in 1986 (white: 10.4% vs 13.3%, black: 8.9% vs 11.1%, respectively). CONCLUSION: The increased numbers of hospitalizations for heart failure and the likelihood that these patients will require advanced nursing care after discharge have important implications for future national health care expenditures and resources.

Age Distribution↗

Pharmacologic management of heart failure among older adults by office-based physicians in the United States.

BACKGROUND: Despite the recent availability of new classes of heart failure medications, little is known about national patterns in the actual physician utilization of these drugs. METHODS: In the National Ambulatory Medical Care Survey, 2912 US physicians reported on 16,968 office visits in 1991-1992 with patients aged > or = 65 years. National estimates were obtained from weighted results that accounted for the complex sampling design. RESULTS: An estimated 8.3 million (2.6%) office visits with older adults involved heart failure. This included 9.3% of visits to cardiologists, 4.3% to internists, 3.5% to general and family physicians, and 0.6% to other physicians. The most frequently prescribed medications during visits with these patients were diuretics (69%), digitalis compounds (46%), angiotensin-converting enzyme inhibitors (30%), and nitrates (19%). Internists and general and family physicians prescribed angiotensin-converting enzyme inhibitors, digitalis compounds, and loop diuretics for patients with heart failure less often than did cardiologists. CONCLUSIONS: These are the first national surveillance estimates of physician practices in the management of heart failure. These data were collected during the same period in which heart failure clinical trial results were initially published, and they provide a baseline for monitoring the influence of recent clinical practice guidelines and professional education on changes in the management of heart failure by primary care physicians.

Aged↗

Monitoring Babesia bovis infections in cattle by using PCR-based tests.

The sensitivity and specificity of PCR tests based on the small-subunit rRNA gene sequence of Babesia bovis were compared in a blind study of experimentally infected cattle with the corresponding parameters of the complement fixation (CF) test currently used in the United States to screen for bovine babesiosis. Cattle were experimentally infected with a single inoculum of a cloned laboratory strain of B. bovis. Blood samples were collected and tested over a period covering from the day of infection to 10 months postinfection. The level of parasitemia (percent infected erythrocytes) present in each sample was estimated from test results and was plotted as a function of time postinfection. These data are the first describing the course of infection by methods capable of detecting parasitemias in the range of 10(-7)%, which frequently occur in the carrier state. Parasitemias in the samples tested strongly influenced the sensitivity and negative predictive value of the PCR-based tests which varied with time postinfection. The average sensitivities of the three PCR-based tests for B. bovis ranged from 58 to 70% for a single determination, while the sensitivity of the CF test was only 6%. Both PCR-based and CF tests for B. bovis had high specificity values ranging from 96 to 100%.

Animals↗

Surveillance of pharyngeal colonization: detection and control of serious bacterial illness in low birth weight infants.

Routine surveillance for bacterial colonization has been used for the past three decades as a tool for the prediction of nosocomial infection in low birth weight infants; however, its usefulness has never been proven. A prospective cohort study was conducted to examine the utility of surveillance for pharyngeal colonization in detection and control of serious bacterial illness in low birth weight infants. One hundred fifty-four infants who weighed less than 1750 g and who were admitted to the Neonatal Intensive Care Unit were enrolled and followed for a total of 5620 infant-days. Pharyngeal cultures were collected at the time of enrollment and then weekly. All infants had bacterial pharyngeal colonization by the third day of life. Coagulase-negative staphylococci were the most common organisms cultured from the pharynx, followed by viridans streptococci and Staphylococcus aureus. More than 90% of the pharyngeal cultures grew multiple isolates. Gram-positive organisms, particularly coagulase-negative staphylococci, were the most prevalent organism recovered from blood and cerebrospinal fluid cultures. Fifty-two episodes of bacteremia and 6 episodes of cerebrospinal fluid infection occurred in 42 infants. Among infants with viridans streptococci in pharyngeal cultures, the subsequent risk of serious bacterial illness was significantly reduced (odds ratio = 0.16). However, pharyngeal cultures were poor predictors of the causative organism in an episode of serious bacterial illness. Pharyngeal and blood/cerebrospinal fluid cultures were concordant in only 11% of invasive infections. We conclude that pharyngeal surveillance cultures provide little clinically meaningful information and have no apparent utility in the Neonatal Intensive Care Unit setting.

Analysis of Variance↗

Academic centers for prevention research. Making prevention a practical reality.

The Prevention Centers Grant Program attempts to bridge the gap between the development and the implementation of research findings in public health practice. The program funds practical research on health issues of national and international importance. Grants can be awarded to schools of medicine, schools of osteopathy, or schools of public health. Ongoing programs at the University of North Carolina, the University of Washington, the University of Texas, and the University of Hawaii, as well as programs funded in 1990 at the University of Arizona, the University of Illinois, and Columbia University, are discussed.

Academic Medical Centers↗

[Estimation of vital statistics in rural areas of northern Haiti using a simplified sampling method].

In September 1983, we selected 30 villages in four rural counties of northern Haiti for a partial census and malaria prevalence survey. A cohort of 1,577 persons was enumerated in this census. Survey teams revisited the same houses in these villages in September 1984 and updated the previous census, inquiring about all listed family members. We administered an additional questionnaire to each household concerning the occurrence over the past year of deaths, births, pregnancies, and migration. Among the 1,218 persons who had been followed for one year, there were 21 deaths (crude mortality rate: 17 per 1,000 population; 95% confidence interval [95% CI]: 12 per 1,000, 25 per 1,000) and 35 births (birth rate: 29 per 1,000 population year; 95% CI: 19 per 1,000, 38 per 1,000). The infant mortality rate was 171 per 1,000 live births (95% CI: 81 per 1,000, 315 per 1,000), and the mortality rate for children less than 5 years old was 36 per 1,000 (95% CI: 24 per 1,000, 56 per 1,000). Although small sample surveys are subject to limitations of precision dependent on sample size, they can be a simple method by which researchers may estimate vital statistics for rural areas of less-developed countries.

Epidemiologic Methods↗

Family history of convulsions and use of pertussis vaccine.

To evaluate the risk of neurologic events after vaccination with diphtheria-tetanus-pertussis (DTP) vaccine, we used data from the Centers for Disease Control Monitoring System for Adverse Events Following Immunization to compare the family history of convulsions in persons reporting neurologic events with that in persons reporting nonneurologic events; these events have an onset within 3 days of immunization with DTP vaccine, given either alone or with oral poliovirus vaccine. Persons reporting neurologic events were 6.4 times more likely to report a prior personal history of convulsions than those reporting nonneurologic events (95% confidence interval 4.7 to 8.8), and were 2.4 times more likely to report a history of convulsions in first-degree family members, that is, siblings or parents (95% confidence interval 1.7 to 3.4). Similar risks were noted for subgroup analyses controlling for type of event (febrile vs nonfebrile convulsion), age at immunization, source of report, number of previous doses of DTP vaccine, and day of onset. Because the Centers for Disease Control monitoring system receives reports on a nonrandom sample of all adverse events after immunization, selection bias could not be ruled out. On the basis of these data, we conclude that children with a family history of seizures are at increased risk of neurologic events, primarily febrile convulsions, after DTP vaccination. However, this increase in risk may reflect a nonspecific familial tendency for convulsions rather than a specific vaccine effect. Considering the rare occurrence of neurologic events after DTP vaccination, the generally benign outcome of febrile convulsions (which make up the majority of these neurologic events), and the possible increased risk of pertussis in the general population if the estimated 5% to 7% of persons with a first-degree family history of convulsions were exempted from pertussis vaccination, we further conclude that a history of convulsions in siblings or parents should not be a contraindication to pertussis vaccination. Special care in the prevention of postvaccination fever may be warranted in children with a family history of seizures.

Centers for Disease Control and Prevention, U.S.↗

Risk of sudden infant death syndrome after immunization with the diphtheria-tetanus-pertussis vaccine.

To evaluate recent immunization against diphtheria, tetanus, and pertussis (DTP) as a possible risk factor for sudden infant death syndrome (SIDS), we studied the rates of SIDS after the administration of DTP vaccine in a cohort of 129,834 children who were born in four urban Tennessee counties during the period from 1974 through 1984. All the children received at least one DTP immunization in the first year of life at county health-department clinics or from Medicaid providers. Computerized immunization records from these sources were linked with Tennessee birth and death certificates to establish the cohort, ascertain the timing of immunization, and identify cases of SIDS. These children represented 42 percent of the births in the four counties. Among these children, 204 deaths occurred at the ages of 29 to 365 days; 109 deaths were classified as due to SIDS. We estimated the risk of SIDS according to the length of time, up to 30 days, since DTP immunization and compared it with the risk 31 days or more after immunization to calculate the relative risk. With control for age, the relative risk from 0 to 3 days after DTP immunization was 0.18 (95 percent confidence interval, 0.04 to 0.8); from 4 to 7 days, 0.17 (95 percent confidence interval, 0.04 to 0.7); from 8 to 14 days, 0.75 (95 percent confidence interval, 0.4 to 1.5); and from 15 to 30 days, 1.0 (95 percent confidence interval, 0.6 to 1.6). A multivariate analysis in which we controlled for age, sex, race, year, birth weight, and Medicaid enrollment, produced similar results. We conclude that in this large population of children there was no increase in the risk of SIDS after immunization with the DTP vaccine.

Analysis of Variance↗

Monitoring system for adverse events following immunization.

The Monitoring System for Adverse Events Following Immunization (MSAEFI) has collected data from the public sector nationwide on adverse events occurring during the 4-week period following administration of vaccine. From 1979 to 1984, 6483 reports were received. Although rates of reporting have increased throughout the 6-year period, increases were larger for less serious events (209%) than for more serious events (53%). The MSAEFI data have been used to evaluate risk factors for adverse events following immunization, will continue to provide information on the safety of both current and future vaccines and may identify other factors that increase the risks of adverse events following immunization.

Centers for Disease Control and Prevention, U.S.↗

Isoniazid-resistant tuberculosis. A community outbreak and report of a rifampin prophylaxis failure.

The choice of effective preventive treatment for persons exposed to Mycobacterium tuberculosis resistant to isoniazid is uncertain. Although no data document the efficacy of any drug other than isoniazid for preventive treatment of tuberculosis, rifampin, with or without ethambutol, has been used for prophylaxis in contacts of cases with known isoniazid-resistant organisms. This report describes a community outbreak of isoniazid-resistant tuberculosis infection and a case of rifampin prophylaxis failure with acquired rifampin resistance. This raises concern about the efficacy of rifampin for the preventive treatment of contacts exposed to isoniazid-resistant tuberculosis.

Adult↗

Adverse events following immunization: assessing probability of causation.

The Monitoring System for Adverse Events Following Immunization of the Centers for Disease Control collects data on events temporally related to immunization. Occasionally, reports are received of neurologic disturbances temporally related to receipt of vaccine. Most of these disturbances are events that regularly occur in the absence of immunization. It is then difficult to determine whether the relationship between the immunization and illness is causal or coincidental. We developed a method to assess causation of serious neurologic events by probability theory. By combining epidemiologic information on disease incidence with specific elements of the patient history, an estimate of the odds of vaccine causation can be derived, based on rational assumptions rather than observer bias. The result is not a diagnosis but an estimate of probability.

Brain Diseases↗

Hepatitis B and workers in institutions for the mentally retarded: risk of infection for staff in patient care.

In the fall of 1982, we conducted a serosurvey of 920 of 933 employees in a large residential institution for the mentally retarded in Salem, Oregon. This survey demonstrated an overall prevalence of 10% for antibody to hepatitis B core antigen (anti-HBc), a marker of present or previous hepatitis B virus infection. Antibody positivity was significantly associated with a history of ever having worked in a position involving direct patient care (adjusted odds ratio = 3.1, 95% confidence interval 2.6-4.2). The length of time employed at the institution was significantly associated with an increasing prevalence of anti-HBc positivity among those persons who had ever worked in direct patient care (chi 2 for linear trend = 19.3, P less than .00001, one tail), but not among those employees who had never worked in patient contact. This evidence supports the Immunization Practices Advisory Committee (ACIP) recommendation of hepatitis B virus screening and, where appropriate, vaccinations for those workers in institutions for the mentally retarded who work closely with patients.

Adolescent↗