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Biomedical subjects

Beth P Bell

Publications and source records attributed to Beth P Bell.

At least 19 recordsLinked to original sources

The economics of routine childhood hepatitis A immunization in the United States: the impact of herd immunity.

OBJECTIVES: Because of the herd-immunity phenomenon, the benefits of immunization against hepatitis A extend beyond those received by those who are vaccinated. This analysis estimates the impact of herd immunity on the cost-effectiveness of routine hepatitis A immunization among US children. PATIENTS AND METHODS: In an economic model, the costs and benefits of hepatitis A immunization were estimated for immunizing all US children at age 1 year over a 10-year period starting in 2005. The future burden of disease from hepatitis A was also estimated with this model, and the fraction that would be prevented by herd immunity was modeled by using a previously published analysis of the relationship between hepatitis A vaccination coverage and declines in hepatitis A incidence. RESULTS: Without accounting for herd-immunity effects, the costs of routine immunization would average 32,000 dollars per quality-adjusted life-year gained for the first 10 cohorts immunized starting with the 2005 birth cohort. Herd-immunity effects would be expected to produce substantial additional benefits, lowering the cost of the immunization program to 1000 dollars per quality-adjusted life-year gained for the first 10 cohorts. Herd-immunity benefits would be greatest for the first few cohorts, more than doubling the benefits of immunization, and would decline over time. In a univariate sensitivity analysis, estimates were most sensitive to vaccination costs but remained below 20,000 dollars per quality-adjusted life-year under all of the assumptions. CONCLUSIONS: Herd-immunity effects more than double the savings from hepatitis A immunization during the first 10 years of the program. After accounting for these effects, immunization is close to cost-neutral on a cost-per-quality-adjusted-life-year basis.

Child, Preschool↗

Cost-effectiveness of routine childhood vaccination for hepatitis A in the United States.

OBJECTIVES: Economic analysis is an important component in formulating national policy. We evaluated the economic impact of hepatitis A vaccination of all US children ages 12 to 23 months as compared with no vaccination and with current implementation of the preexisting (issued in 1999), regional policy. METHODS: We developed a Markov model of hepatitis A that followed a single cohort from birth in 2005 through death or age 95 years. From the societal perspective, the model compared the outcomes that resulted from routine vaccination at age 1 year to 2 scenarios: no hepatitis A vaccination and hepatitis A vaccination at levels observed in 2003 under the preexisting policy. We evaluated the economic impact of vaccination nationwide, in areas where vaccination was already recommended, and in areas where no previous recommendation existed. RESULTS: Without childhood vaccination, the approximately 4 million children in the 2005 birth cohort would be expected over their lifetimes to have 199,000 hepatitis A virus infections, including 74,000 cases of acute hepatitis A and 82 deaths, resulting in 134 million dollars in hepatitis A-related medical costs and productivity losses. Compared with no vaccination, routine vaccination at age 1 year would prevent 172,000 infections, at a cost of 28,000 dollars per quality-adjusted life year saved. Compared with maintaining the levels of hepatitis A vaccination under the preexisting regional policy, routine vaccination at age 1 year would prevent an additional 112,000 infections, at a cost of 45,000 dollars per quality-adjusted life year saved. CONCLUSIONS: The cost-effectiveness of nationwide hepatitis A vaccination compared with no vaccination, and the incremental cost-effectiveness of this recommendation compared with preexisting recommendations, is similar to that of other accepted public health interventions. In October 2005, the Advisory Committee on Immunization Practices recommended extending hepatitis A immunization to all US children ages 12 to 23 months.

Adult↗

A comprehensive immunization strategy to eliminate transmission of hepatitis B virus infection in the United States: recommendations of the Advisory Committee on Immunization Practices (ACIP) Part II: immunization of adults.

Hepatitis B vaccination is the most effective measure to prevent hepatitis B virus (HBV) infection and its consequences, including cirrhosis of the liver, liver cancer, liver failure, and death. In adults, ongoing HBV transmission occurs primarily among unvaccinated persons with behavioral risks for HBV transmission (e.g., heterosexuals with multiple sex partners, injection-drug users [IDUs], and men who have sex with men [MSM]) and among household contacts and sex partners of persons with chronic HBV infection. This report, the second of a two-part statement from the Advisory Committee on Immunization Practices (ACIP), provides updated recommendations to increase hepatitis B vaccination of adults at risk for HBV infection. The first part of the ACIP statement, which provided recommendations for immunization of infants, children, and adolescents, was published previously (CDC. A comprehensive immunization strategy to eliminate transmission of hepatitis B virus infection in the United States: recommendations of the Advisory Committee on Immunization Practices [ACIP]. Part 1: immunization of infants, children, and adolescents. MMWR 2005;54[No. RR-16]:1-33). In settings in which a high proportion of adults have risks for HBV infection (e.g., sexually transmitted disease/human immunodeficiency virus testing and treatment facilities, drug-abuse treatment and prevention settings, health-care settings targeting services to IDUs, health-care settings targeting services to MSM, and correctional facilities), ACIP recommends universal hepatitis B vaccination for all unvaccinated adults. In other primary care and specialty medical settings in which adults at risk for HBV infection receive care, health-care providers should inform all patients about the health benefits of vaccination, including risks for HBV infection and persons for whom vaccination is recommended, and vaccinate adults who report risks for HBV infection and any adults requesting protection from HBV infection. To promote vaccination in all settings, health-care providers should implement standing orders to identify adults recommended for hepatitis B vaccination and administer vaccination as part of routine clinical services, not require acknowledgment of an HBV infection risk factor for adults to receive vaccine, and use available reimbursement mechanisms to remove financial barriers to hepatitis B vaccination.

Adult↗

The contributions of hepatitis B virus and hepatitis C virus infections to cirrhosis and primary liver cancer worldwide.

BACKGROUND/AIMS: End-stage liver disease accounts for one in forty deaths worldwide. Chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) are well-recognized risk factors for cirrhosis and liver cancer, but estimates of their contributions to worldwide disease burden have been lacking. METHODS: The prevalence of serologic markers of HBV and HCV infections among patients diagnosed with cirrhosis or hepatocellular carcinoma (HCC) was obtained from representative samples of published reports. Attributable fractions of cirrhosis and HCC due to these infections were estimated for 11 WHO-based regions. RESULTS: Globally, 57% of cirrhosis was attributable to either HBV (30%) or HCV (27%) and 78% of HCC was attributable to HBV (53%) or HCV (25%). Regionally, these infections usually accounted for >50% of HCC and cirrhosis. Applied to 2002 worldwide mortality estimates, these fractions represent 929,000 deaths due to chronic HBV and HCV infections, including 446,000 cirrhosis deaths (HBV: n=235,000; HCV: n=211,000) and 483,000 liver cancer deaths (HBV: n=328,000; HCV: n=155,000). CONCLUSIONS: HBV and HCV infections account for the majority of cirrhosis and primary liver cancer throughout most of the world, highlighting the need for programs to prevent new infections and provide medical management and treatment for those already infected.

Adult↗

Hepatitis A in the era of vaccination.

The World Health Organization estimates an annual total of 1.5 million clinical cases of hepatitis A worldwide, but seroprevalence data indicate that tens of millions of hepatitis A virus infections occur each year. In the United States in the 1980s-1990s, an average of 26,000 acute hepatitis A cases were reported per year, representing approximately 270,000 infections annually. Since licensure of effective hepatitis A vaccines in the mid-1990s, US hepatitis A rates have fallen precipitously-particularly since 1999, when routine childhood vaccination was recommended in states with consistently elevated rates. By 2004, the overall rate had declined to 1.9/100,000 population, the lowest rate ever recorded and 79% lower than any previously recorded nadir. These marked declines occurred with relatively modest vaccination coverage, suggesting that strong herd immunity accompanies the initiation of routine vaccination programs. Routine childhood vaccination has produced similar results in Israel and selected regions of Italy, Spain, and Australia. Hepatitis A vaccination will probably remain a low priority for some time in the poorest countries, where most persons are infected as young children. However, shifts in the epidemiologic patterns of disease associated with declining hepatitis A virus transmission are occurring in many regions of the world. These shifts are likely to create circumstances where strategically targeted vaccination of children could produce substantial public health benefits.

Child, Preschool↗

Hepatitis B virus infection: epidemiology and vaccination.

Worldwide, two billion people have been infected with hepatitis B virus (HBV), 360 million have chronic infection, and 600,000 die each year from HBV-related liver disease or hepatocellular carcinoma. This comprehensive review of hepatitis B epidemiology and vaccines focuses on definitive and influential studies and highlights current trends, policies, and directions. HBV can be transmitted vertically, through sexual or household contact, or by unsafe injections, but chronic infections acquired during infancy or childhood account for a disproportionately large share of worldwide morbidity and mortality. Vaccination against HBV infection can be started at birth and provides long-term protection against infection in more than 90% of healthy people. In the 1990s, many industrialized countries and a few less-developed countries implemented universal hepatitis B immunization and experienced measurable reductions in HBV-related disease. For example, in Taiwan, the prevalence of chronic infection in children declined by more than 90%. Many resource-poor nations have recently initiated universal hepatitis B immunization programs with assistance from the Global Alliance for Vaccines and Immunization. Further progress towards the elimination of HBV transmission will require sustainable vaccination programs with improved vaccination coverage, practical methods of measuring the impact of vaccination programs, and targeted vaccination efforts for communities at high risk of infection.

Child Health Services↗

Prevention of hepatitis A through active or passive immunization: recommendations of the Advisory Committee on Immunization Practices (ACIP).

Routine vaccination of children is an effective way to reduce hepatitis A incidence in the United States. Since licensure of hepatitis A vaccine during 1995-1996, the hepatitis A childhood immunization strategy has been implemented incrementally, starting with the recommendation of the Advisory Committee on Immunization Practices (ACIP) in 1996 to vaccinate children living in communities with the highest disease rates and continuing in 1999 with ACIP's recommendations for vaccination of children living in states, counties, and communities with consistently elevated hepatitis A rates. These updated recommendations represent the final step in the childhood hepatitis A immunization strategy, routine hepatitis A vaccination of children nationwide. Implementation of these recommendations will reinforce existing vaccination programs, extend the benefits associated with hepatitis A vaccination to the rest of the country, and create the foundation for eventual consideration of elimination of indigenous hepatitis A virus transmission. This report updates ACIP's 1999 recommendations concerning the prevention of hepatitis A through immunization (CDC. Prevention of hepatitis A through active or passive immunization: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 1999:48[No. RR-12]:1-37) and includes 1) new data on the epidemiology of hepatitis A in the era of hepatitis A vaccination of children in selected U.S. areas, 2) results of analyses of the economics of nationwide routine vaccination of children, and 3) recommendations for the routine vaccination of children in the United States. Previous recommendations for vaccination of persons in groups at increased risk for hepatitis A or its adverse consequences and recommendations regarding the use of immune globulin for protection against hepatitis A are unchanged from the 1999 recommendations.

Adult↗

Locally acquired hepatitis E virus infection, El Paso, Texas.

Hepatitis E virus (HEV) is an enterically transmitted RNA virus that causes both epidemic and sporadic cases of acute hepatitis. Despite sero-surveys showing antibody to HEV in up to 36% of the US population, acute hepatitis E has been reported among individuals with no history of international travel only three times in the United States. We report a case of apparently locally-acquired hepatitis E that occurred in El Paso, Texas that was 98% similar to a previously isolated HEV found in swine in the United States. Like the three previous cases, a thorough investigation found no conclusive sources of infection. Active case surveillance found no additional cases.

Aged↗

Changes in hepatitis C virus (HCV) viral load and interferon-alpha levels in HIV/HCV-coinfected patients treated with highly active antiretroviral therapy.

BACKGROUND: Reports are mixed as to whether highly active antiretroviral therapy (HAART) increases liver transaminase levels or hepatitis C virus (HCV) titers in HIV/HCV-coinfected individuals. It is hypothesized that increases in HCV RNA titers may result from changes in endogenous interferon-alpha (IFN-alpha) production. METHODS: HIV/HCV-coinfected patients receiving HAART were tested at baseline, 1, 2, 3, 6, and 9 months for liver transaminase levels, HIV and HCV viral loads, and IFN-alpha. Linear regression analysis was used to determine the effect of HAART on liver transaminase levels, HCV viral load, and IFN-alpha. RESULTS: Initiating HAART did not increase liver transaminase levels in majority of cases. In patients (n = 30) with baseline HIV titer >10,000 copies/mL, HCV titers increased 0.69 log10 and IFN-alpha decreased -0.96 log10 during HAART, in association with a > or =0.5 log10 decrease in HIV titer. As HIV titers reached their nadir approximately 4 months after initiation of HAART, HCV titers remained 0.54 log10 and IFN-alpha -0.71 log10 above and below baseline levels, respectively. HCV titers and IFN-alpha levels did not change from baseline in patients with baseline HIV titer < or =10,000 copies/mL. CONCLUSIONS: Coinfected patients did not have evidence of hepatoxicity HAART. In patients with baseline HIV titer >10,000 copies/mL, suppression of HIV replication by HAART was associated with an increase in HCV titer and a decrease in endogenous IFN-alpha levels.

Adult↗

Factors associated with hepatitis a vaccination among children 24 to 35 months of age: United States, 2003.

OBJECTIVES: In 1999, the Advisory Committee on Immunization Practices made recommendations for hepatitis A vaccination of children according to historic rates of hepatitis A incidence in different regions of the country. The objective of this study was to examine hepatitis A vaccination coverage rates among children living in states with different vaccination recommendations and to examine individual characteristics associated with vaccination. METHODS: Hepatitis A vaccination status data were collected for children 24 to 35 months of age through the National Immunization Survey, a telephone survey with health care provider-verified vaccination results. Vaccination status data were collected from children in each of the 50 states and 28 selected urban areas. RESULTS: In 2003, 50.9% (95% confidence interval [CI]: 47.6-54.2%) of children living in 11 states where routine hepatitis A vaccination is recommended had received > or =1 dose, compared with 25.0% (95% CI: 21.8-28.2%) of children in 6 states where vaccination is suggested and 1.4% (95% CI: 1.0-1.8%) of children in 33 states without a recommendation. Coverage was higher among children who lived in urban areas, were Hispanic or American Indian/Alaska Native, or were born to women with less education. CONCLUSIONS: Hepatitis A vaccination is being targeted successfully to children at higher risk of infection; however, overall vaccination coverage remains lower for hepatitis A vaccination, compared with other routine childhood vaccinations.

Child, Preschool↗

Hepatitis A virus infection in the United States: serologic results from the Third National Health and Nutrition Examination Survey.

To determine the prevalence of hepatitis A virus (HAV) infection in the general U.S. population, sera from participants in the Third National Health and Nutrition Examination Survey (NHANES III) conducted in 1988-1994 were tested for antibody to HAV (anti-HAV). Among 21,260 participants aged > or = 6 years tested, the overall prevalence of infection was 31.3%, and increased markedly with age. The age-adjusted prevalence was significantly higher among foreign- compared to U.S.-born participants, and was highest among Mexican-Americans and lowest among non-Hispanic whites. Among U.S.-born children, only Mexican-American ethnicity and income below the poverty level were associated with HAV infection in a multivariate model. During this period before hepatitis A vaccination, age, ethnicity and birthplace were the most important determinants of HAV infection in the United States.

Female↗

A comprehensive immunization strategy to eliminate transmission of hepatitis B virus infection in the United States: recommendations of the Advisory Committee on Immunization Practices (ACIP) part 1: immunization of infants, children, and adolescents.

This report is the first of a two-part statement from the Advisory Committee on Immunization Practices (ACIP) that updates the strategy to eliminate hepatitis B virus (HBV) transmission in the United States. The report provides updated recommendations to improve prevention of perinatal and early childhood HBV transmission, including implementation of universal infant vaccination beginning at birth, and to increase vaccine coverage among previously unvaccinated children and adolescents. Strategies to enhance implementation of the recommendations include 1) establishing standing orders for administration of hepatitis B vaccination beginning at birth; 2) instituting delivery hospital policies and procedures and case management programs to improve identification of and administration of immunoprophylaxis to infants born to mothers who are hepatitis B surface antigen (HBsAg) positive and to mothers with unknown HBsAg status at the time of delivery; and 3) implementing vaccination record reviews for all children aged 11-12 years and children and adolescents aged <19 years who were born in countries with intermediate and high levels of HBV endemicity, adopting hepatitis B vaccine requirements for school entry, and integrating hepatitis B vaccination services into settings that serve adolescents. The second part of the ACIP statement, which will include updated recommendations and strategies to increase hepatitis B vaccination of adults, will be published separately.

Adolescent↗

Transmission of hepatitis C virus to several organ and tissue recipients from an antibody-negative donor.

BACKGROUND: Although hepatitis C virus (HCV) transmission through tissue transplantation has been rarely reported, a donor with undetected viremia may infect several recipients. A patient developed acute hepatitis C shortly after tissue transplantation. Ninety-one tissues or organs had been recovered from the donor. OBJECTIVE: To determine whether the donor was the source of infection and the extent of transmission to other organ and tissue recipients. DESIGN: Descriptive epidemiologic study; serum testing for HCV infection. SETTING: Recipients were located in 16 states and 2 other countries. PARTICIPANTS: Donor and graft recipients. MEASUREMENTS: Hepatitis C virus infection was defined as the presence of anti-HCV or HCV RNA. The authors determined the genetic relatedness of viral isolates from the donor and recipients by genotype comparison and quasi-species analysis. RESULTS: The donor was anti-HCV-negative but was HCV RNA-positive (genotype 1a). Forty persons received transplants during 22 months. Five persons were HCV-infected before transplantation or had a genotype other than 1a, and 5 persons had no post-transplantation serum specimens available. Of the remaining 30 recipients, HCV infection occurred in 8 recipients: 3 of 3 organ recipients, 1 of 2 saphenous vein recipients, 1 of 3 tendon recipients, and 3 of 3 tendon with bone recipients. These 8 recipients had viral isolates genetically related to those of the donor. No cases occurred in recipients of skin (n = 2), cornea (n = 1), or irradiated bone (n = 16). LIMITATIONS: Post-transplantation serum specimens were unavailable for 5 recipients. CONCLUSIONS: An anti-HCV-negative donor was the source of HCV infection for 8 recipients of organs or tissues. Although HCV transmission from anti-HCV-negative donors is probably uncommon, changes in donor screening to include routine testing for HCV RNA merit further consideration to improve the safety of transplantation.

Female↗

A mathematical model to estimate global hepatitis B disease burden and vaccination impact.

BACKGROUND: Limited data are available regarding global hepatitis B virus (HBV)-related morbidity and mortality and potential reduction in disease burden from hepatitis B vaccination. METHODS: A model was developed to calculate the age-specific risk of acquiring HBV infection, acute hepatitis B (illness and death), and progression to chronic HBV infection. HBV-related deaths among chronically infected persons were determined from HBV-related cirrhosis and hepatocellular carcinoma (HCC) mortality curves, adjusted for background mortality. The effect of hepatitis B vaccination was calculated from vaccine efficacy and vaccination series coverage, with and without administration of the first dose of vaccine within 24 h of birth (i.e. birth dose) to prevent perinatal HBV infection. RESULTS: For the year 2000, the model estimated 620,000 persons died worldwide from HBV-related causes: 580,000 (94%) from chronic infection-related cirrhosis and HCC and 40,000 (6%) from acute hepatitis B. In the surviving birth cohort for the year 2000, the model estimated that without vaccination, 64.8 million would become HBV-infected and 1.4 million would die from HBV-related disease. Infections acquired during the perinatal period, in early childhood (<5 years old), and > or = 5 years of age accounted for 21, 48, and 31% of deaths, respectively. Routine infant hepatitis B vaccination, with 90% coverage and the first dose administered at birth would prevent 84% of global HBV-related deaths. CONCLUSION: Globally, most HBV-related deaths result from the chronic sequelae of infection acquired in the perinatal and early childhood periods. Inclusion of hepatitis B vaccine into national infant immunization programs could prevent >80% of HBV-related deaths.

Adolescent↗

Molecular epidemiology of foodborne hepatitis a outbreaks in the United States, 2003.

BACKGROUND: Molecular epidemiologic investigations can link geographically separate foodborne hepatitis A outbreaks but have not been used while field investigations are in progress. In 2003, outbreaks of foodborne hepatitis A were reported in multiple states. METHODS: Case-control studies were conducted in 3 states. Hepatitis A virus was sequenced from serologic specimens from individuals associated with outbreaks and from individuals concurrently ill with hepatitis A in non-outbreak settings in the United States and Mexico. RESULTS: Case-control studies in Tennessee (TN), North Carolina (NC), and Georgia (GA) found green onions to be associated with illness among restaurant patrons (TN: odds ratio [OR], 65.5 [95% confidence interval {CI}, 8.9-482.5; NC: OR, 2.4 [95% CI, 0.3-21.9]; GA: OR, 20.9 [95% CI, 3.9-110.3]). Viral sequences from TN case patients differed by 2 nt, compared with those from case patients in NC and GA. A third sequence, differing from the TN and GA/NC sequences by 1 nt, was identified among case patients in a subsequent outbreak in Pennsylvania. Each outbreak sequence was identical to > or =1 sequence isolated from northern Mexican resident(s) with hepatitis A. The sources of green onions served in restaurants in TN and GA were 3 farms in northern Mexico. CONCLUSIONS: Ongoing viral strain surveillance facilitated the rapid implementation of control measures. Incorporation of molecular epidemiologic methods into routine hepatitis A surveillance would improve the detection of hepatitis A outbreaks and increase our understanding of hepatitis A epidemiology in the United States.

Case-Control Studies↗

An outbreak of hepatitis A associated with green onions.

BACKGROUND: In November 2003, a large hepatitis A outbreak was identified among patrons of a single Pennsylvania restaurant. We investigated the cause of the outbreak and factors that contributed to its unprecedented size. METHODS: Demographic and clinical outcome data were collected from patients with laboratory confirmation of hepatitis A, and restaurant workers were tested for hepatitis A. A case-control study was conducted among patrons who dined at the restaurant between October 3 and October 6, 2003. Sequence analysis was performed on a 315-nucleotide region of viral RNA extracted from serum specimens. RESULTS: Of 601 patients identified, 3 died; at least 124 were hospitalized. Of 425 patients who recalled a single dining date at the restaurant, 356 (84 percent) had dined there between October 3 and October 6. Among 240 patients in the case-control study, 218 had eaten mild salsa (91 percent), as compared with 45 of 130 controls (35 percent) (odds ratio, 19.6; 95 percent confidence interval, 11.0 to 34.9) for whom data were available. A total of 98 percent of patients and 58 percent of controls reported having eaten a menu item containing green onions (odds ratio, 33.3; 95 percent confidence interval, 12.8 to 86.2). All restaurant workers were tested, but none were identified who could have been the source of the outbreak. Sequences of hepatitis A virus from all 170 patients who were tested were identical. Mild salsa, which contained green onions grown in Mexico, was prepared in large batches at the restaurant and provided to all patrons. CONCLUSIONS: Green onions that were apparently contaminated before arrival at the restaurant caused this unusually large foodborne outbreak of hepatitis A. The inclusion of contaminated green onions in large batches that were served to all customers contributed to the size of the outbreak.

Adolescent↗

Risk factors for hepatitis B in an outbreak of hepatitis B and D among injection drug users.

During January-April, 2000, 12 cases of acute hepatitis B were reported in Pierce County, Washington, compared with seven in all of 1999. Seven (58.3%) case patients were injection drug users (IDUs), three of whom were coinfected with hepatitis D virus (HDV) and died of fulminant hepatitis. Vaccination clinics were implemented at the local health department and needle exchange program to control the outbreak. We investigated this outbreak to determine risk factors for hepatitis B virus (HBV) transmission among IDUs. Hepatitis B cases were ascertained through routine surveillance and prevaccination testing at vaccination clinics. We conducted a case-control study comparing IDU case patients with HBV-susceptible IDUs identified at the vaccination clinics. Fifty-eight case patients were identified during January-December, 2000, 20 (34.5%) of whom were coinfected with HDV. Thirty-eight case patients (65.5%) reported current IDU. In the case-control study, the 17 case patients were more likely than the 141 controls to report having more than one sex partner [odds ratio (OR) =4.8, 95% confidence interval (CI) =1.5-15.0], injecting more than four times a day (OR = 4.5, 95% CI =1.2-15.6) and sharing drug cookers with more than two people (58.8% vs. 14.0%, OR =14.0, 95% CI =2.4-81.5). Results were similar after controlling for syringe sharing in multivariable analysis. IDUs should be vaccinated against hepatitis B and should be advised against sharing drug injection equipment.

Acute Disease↗