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Biomedical subjects

H S Margolis

Publications and source records attributed to H S Margolis.

At least 19 recordsLinked to original sources
PubMed2001

Control of hepatitis A through routine vaccination of children.

CONTEXT: The impact of routine hepatitis A vaccination of children living in large communities with elevated disease rates has not been evaluated. OBJECTIVE: To determine the effect of routine vaccination of children on disease incidence in a community with recurrent hepatitis A epidemics. DESIGN, SETTING, AND PARTICIPANTS: Community-based demonstration project conducted from January 12, 1995, through December 31, 2000, in Butte County, California, among children aged 2 to 17 years. INTERVENTION: In 1995, vaccination was offered to children aged 2 to 12 years during vaccination clinics conducted on 2 occasions 6 to 12 months apart at most schools in the county. In 1996-2000, vaccine was distributed to community health care clinicians, who vaccinated eligible children without charge. Vaccine was also available at health department clinics, selected child care centers, and other sites. MAIN OUTCOME MEASURES: Hepatitis A vaccination coverage, hepatitis A incidence, and vaccine effectiveness. RESULTS: During the study period, 29 789 (66.2%) of an estimated 44 982 eligible children received at least 1 vaccine dose; 17 681 (39.3%) received a second dose. The number of hepatitis A cases among the entire county population declined 93.5% during the study period, from 57 cases in 1995 to 4 in 2000, the lowest number of cases reported in the county since hepatitis A surveillance began in 1966. The 2000 incidence rate of 1.9 per 100 000 population was the lowest of any county in the state. Of the 245 cases reported during the 6-year period, 40 (16.3%) occurred among children 17 years of age or younger, of which 16 (40%) occurred in 1995 and only 1 in 2000. One of the 27 case patients eligible for vaccination had been vaccinated, having received the first dose 3 days before symptom onset. The estimated protective vaccine efficacy was 98% (95% confidence interval, 86%-100%). CONCLUSIONS: In this population, hepatitis A vaccine was highly effective in preventing disease among recipients. Childhood vaccination appears to have decreased hepatitis A incidence among children and adults and controlled the disease in a community with recurrent epidemics.

Adolescent↗
PubMed2001

Hepatitis E virus antibody prevalence among persons who work with swine.

Prevalence of antibody and risk factors to hepatitis E virus (HEV) infection were determined in a cross-sectional study of 2 group-matched populations: swine farmers (n=264) and persons without occupational exposure to swine (n=255) in Moldova, a country without reported cases of hepatitis E. The prevalence of HEV infection was higher among swine farmers than among the comparison group (51.1% vs. 24.7%; prevalence ratio, 2.07; 95% confidence interval [CI], 1.62-2.64). In multivariate analysis, HEV infection was associated with an occupational history of cleaning barns or assisting sows at birth (odds ratio [OR], 2.46; 95% CI, 1.52-4.01), years of occupational exposure (OR, 1.04 per year; 95% CI, 1.01-1.07), and a history of drinking raw milk (OR, 1.61; 95% CI, 1.08-2.40). HEV infection was not associated with civilian travel abroad or having piped water in the household. The increased prevalence of HEV infection among persons with occupational exposure to swine suggests animal-to-human transmission of this infection.

Agricultural Workers' Diseases↗
PubMed2001

Evaluation of the response to a booster dose of hepatitis B vaccine in previously immunized healthcare workers.

INTRODUCTION: Hepatitis B vaccination is recommended for all healthcare workers (HCW) at risk of exposure to infectious body fluids. However, the absolute duration of protection from immunization is unknown. The purpose of this randomized comparison trial was to determine how previously immunized HCW respond to different booster doses of hepatitis B vaccine. METHOD: Adult HCW (n=59) were classified by level of hepatitis B surface antigen (anti-HBs), either <10 milli-International Units per milliliter (mIU/ml) or 10-50 mIU/ml. Participants were then randomized to receive a 2.5 or 10 microg dose of hepatitis B vaccine. Evaluation of anti-HBs levels were conducted 10 to 14 days, one month and one year postbooster. RESULTS AND DISCUSSION: All participants responded to the booster dose with increased anti-HBs levels. At 14 days, mean anti-HBs levels were significantly higher for those with higher levels at baseline (P=0.004) and those receiving the 10 microg dose (P=0.016). At one month, those with higher anti-HBs levels at baseline and those receiving the 10 microg dose were significantly higher (P<0.01 for both). At one year, the increase for the higher dose was no longer statistically significant when examined by itself (P=0.081); statistical significance (P=0.021) was achieved after adjusting for anti-HBs level at baseline. For all participants, the geometric mean anti-HBs level was 2618 mIU/ml at 14 days, 2175 mIU/ml at one month and 88.9 mIU/ml at one year. At all time points the increase in anti-HBs levels represented an increase over the geometric mean baseline level of anti-HBs (7.4 mIU/ml). Hepatitis B immunized adults responded to a booster dose of hepatitis B vaccine from 3 to 13 yr postvaccination series. Data support current recommendations that immunized HCW do not require periodic antibody testing or vaccine boosters.

Adult↗
PubMed2001

Screening for chronic hepatitis B and C virus infections in an urban sexually transmitted disease clinic: rationale for integrating services.

BACKGROUND AND OBJECTIVES: Clients attending sexually transmitted disease (STD) clinics are at risk for multiple infections (e.g., STDs, HIV, and infectious viral hepatitis). Risk assessment and serosurveys can document the need for hepatitis screening and vaccination services. GOAL: To determine hepatitis C and B virus seroprevalence, identify predictive risk factors, and provide a rationale for integrating hepatitis services in an STD clinic. METHODS: During various periods in 1998, consecutive clients completed a self-administered risk assessment and were offered screening for markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection (HBV core antibody and anti-HCV [enzyme-linked immunosorbent assay 3.0, confirmed by recombinant immunoblot assay 2.0]). RESULTS: Sixteen percent of 300 clients tested for an anti-HBV core were positive, with injecting-drug users (IDUs) and men who have sex with men (MSM) having higher prevalences (50% and 37%, respectively). Of 615 clients tested for anti-HCV, 21 (3.4%) were positive. Injecting-drug users (n = 34) had a 38% anti-HCV prevalence compared with 1.1% for non-IDUs. Of 66 non-IDU MSM tested, none was HCV infected. IDUs had a high prevalence of past STDs (> 50%) and unsafe sexual behavior. CONCLUSIONS: Injecting drug users and MSM are at high risk for STDs, HIV, and hepatitis infections and could benefit from a "one-stop" STD clinic that included hepatitis prevention services.

Adult↗
PubMed2001

Childhood hepatitis B virus infections in the United States before hepatitis B immunization.

OBJECTIVE: To estimate the number of hepatitis B virus (HBV) infections among US children younger than 10 years before implementation of routine childhood hepatitis B immunization. METHODS: Incidence of HBV infection in children was modeled from existing prevalence data by means of regression analysis. Sources of data for the models included published and unpublished surveys that determined the prevalence of HBV infection in US-born children. The number of nonperinatal HBV infections in children younger than 10 years was estimated by applying these infection rates to 1991 population data according to maternal race, ethnicity, and birthplace. RESULTS: Estimated annual rates of infection ranged from 24 per 100 000 in non-Asian children to 2580 per 100 000 in children of Southeast Asian immigrant mothers. These rates indicate that by the early 1990s, HBV was infecting 16 000 children who were younger than 10 years (8700 non-Asian children and 7300 Asian-American children) annually. The total estimate, not including perinatal infections, ranged from 12 000 (95% confidence interval: 5500-27 700) to 24 900 (95% confidence interval: 16 700-42 300) infections and depended on how the estimated rates were applied to the population data. CONCLUSION: Thousands of US children were infected each year with HBV before routine infant hepatitis B immunization, placing them at high risk of death from cirrhosis or hepatocellular carcinoma later in life.

Biomarkers↗
PubMed2001

[Prevalence of mutants in the determinant region of hepatitis B surface antigen among Chinese carriers after receiving only active postexposure immunoprophylaxis].

OBJECTIVE: To determine the frequency of hepatitis B surface antigen (HBsAg) mutations in the alpha determinant region among children who developed chronic hepatitis B virus (HBV) infection after receiving only active postexposure immunoprophylaxis. METHODS: HBsAg mutations were determined by PCR-directed nucleotide sequencing and sequence-specific solid-phase PCR analysis(SS-SPPCR) for 97 Chinese carrier cases after hepatitis B vaccination, for 88 children born aged women controls, and for 95 population based children controls. RESULTS: Prevalence of amino acid substitutions as detected by direct sequencing among carrier cases, women controls, and children controls were 30.9%, 10.2%, and 5.3%, respectively. The most frequent amino acid substitutions observed were at residues 145, 126, and 133. However, there was no difference in the prevalence of 145 and 126 amino acid mutants as detected by a sensitive SS-SPPCR method between carrier cases and controls. The prevalence of 145 Arg and 145 Ala mutants that were detected by SS-SPPCR was 39.2%, 33.0% and 32.6% among carrier cases, women controls, and children controls, respectively. The total odds ratio was 5.41 for mutants detected by direct sequencing. Odds ratio were 34.55 and 33.39 among adw2 subtype and genotype B subjects for mutants detected by direct sequencing, respectively. CONCLUSIONS: The results show that hepatitis B virus mutants in the determinant are fairly consistent observed but without immune selective pressures; HBV variant strains may pre-existent as minor quasispecies. The prevalence of mutants is related to HBV subtypes and genotypes.

Adolescent↗
PubMed2000

Duration of viremia in hepatitis A virus infection.

The duration of viremia and time course for development of IgM antibodies were determined prospectively in natural and experimental hepatitis A virus (HAV) infection. Serial serum samples from HAV-infected men (n=13) and experimentally infected chimpanzees (n=5) were examined by nested reverse-transcriptase polymerase chain reaction analysis to detect HAV RNA and by ELISA to detect IgM antibodies to HAV. Among infected humans, HAV RNA was detected an average of 17 days before the alanine aminotransferase peak, and viremia persisted for an average of 79 days after the liver enzyme peak. The average duration of viremia was 95 days (range, 36-391 days). Results were similar in chimpanzees. In addition, HAV RNA was detected in serum of humans and chimpanzees several days before IgM antibodies to HAV were detected. These results indicate that adults with HAV infection are viremic for as long as 30 days before the onset of symptoms and that the duration of viremia may be longer than previously described.

Animals↗
PubMed2000

Identification of hepatitis B virus indigenous to chimpanzees.

Hepatitis B viruses (HBV) and related viruses, classified in the Hepadnaviridae family, are found in a wide variety of mammals and birds. Although the chimpanzee has been the primary experimental model of HBV infection, this species has not been considered a natural host for the virus. Retrospective analysis of 13 predominantly wild-caught chimpanzees with chronic HBV infection identified a unique chimpanzee HBV strain in 11 animals. Nucleotide and derived amino acid analysis of the complete HBV genome and the gene coding for the hepatitis B surface antigen (S gene) identified sequence patterns that could be used to reliably identify chimpanzee HBV. This analysis indicated that chimpanzee HBV is distinct from known human HBV genotypes and is closely related to HBVs previously isolated from a chimpanzee, gibbons, gorillas, and orangutans.

Amino Acid Sequence↗
PubMed2000

The cost-effectiveness of adolescent hepatitis A vaccination in states with the highest disease rates.

BACKGROUND: The Advisory Committee on Immunization Practices has recommended routine childhood hepatitis A vaccination in states and communities where the incidence of disease exceeds the national average, but most adolescents are currently unprotected from infection. OBJECTIVE: To estimate clinical and economic consequences of vaccinating adolescents against hepatitis A in the 10 states with the highest disease rates. DESIGN: Decision analysis was used to assess cost-effectiveness from societal and health system perspectives. Parameter estimates were obtained from national surveillance data, a study of hepatitis A cases, and an expert panel. MAIN OUTCOME MEASURES: Reduction in disease incidence; costs of vaccination, treatment, and work loss; years of life saved (YOLS); and costs per YOLS. RESULTS: In states with the highest disease rates, vaccination of adolescents against hepatitis A would reduce the lifetime risk of symptomatic infection from 3.3% to 0.7% and prevent loss of 2117 years of life. Vaccination of a single birth cohort would cost $30.9 million, yet treatment and work loss costs would decline $14.2 million and $23.8 million, respectively. Hepatitis A vaccination would cost the health system $7902 per YOLS or $13,722 per discounted YOLS. Results are most sensitive to variation in the discount rate and assumptions regarding long-term vaccine protective efficacy. CONCLUSIONS: Hepatitis A vaccination of adolescents in states with high disease rates would reduce costs to society. Although health system costs would increase, cost-effectiveness is comparable to other recommended vaccines and superior to many commonly used medical interventions. Arch Pediatr Adolesc Med. 2000;154:763-770

Adolescent↗
PubMed2000

The past incidence of hepatitis C virus infection: implications for the future burden of chronic liver disease in the United States.

Because chronic liver disease may develop many years after acute hepatitis C virus (HCV) infection, the past incidence of acute infections is a major determinant of the future burden of HCV-associated complications. We estimated past incidence of acute HCV infection using national seroprevalence data and relative age-specific incidence data from a sentinel counties surveillance system. Projections of the future prevalence of HCV-infected patients were derived from models that included an 85% drop in HCV infection incidence as observed for reported cases in the early 1990s. The models showed a large increase in the incidence of HCV infections from the late 1960s to the early 1980s. The degree of increase was dependent on the assumed rate of antibody loss; a model with 2.5% annual antibody loss showed annual incidence increasing from 45,000 infections (95% confidence interval [95% CI]: 0-110,000) in the early 1960s to 380,000 infections (95% CI: 250,000 to 500, 000) in the 1980s. Projections showed that although the prevalence of HCV infection may be declining currently because of the decline in incidence in the 1990s, the number of persons infected for >/=20 years could increase substantially before peaking in 2015. If the incidence of new HCV infections does not increase in the future, persons born between 1940 and 1965 will be at highest lifetime risk of acquiring the infection.

Adolescent↗
PubMed2000

Evaluation of office-based intervention to improve prevention counseling for patients at risk for sexually acquired hepatitis B virus infection. Hepatitis B-WARE Study Group.

The aim of this study was to determine the effectiveness of tools to identify and counsel patients at risk for sexually transmitted hepatitis B virus infection. Physicians were randomly assigned to either an intervention group or a control group. The intervention group was provided with materials intended to encourage patients to return for counseling and to guide counseling concerning prevention of hepatitis B virus infection. Baseline data on 457 patients at risk for hepatitis B virus infection showed that 7% had received prevention counseling and 2% had begun hepatitis B vaccination. Counseling was least likely to occur in obstetric-gynecologic practices, among uninsured patients, and among patients whose only risk factor was a diagnosis of a sexually transmitted disease. After a 6-month intervention period 26% of the intervention group patients and 7% of the control group patients had been counseled (P <.01). Vaccination was more likely among intervention group patients (8% vs <1%; P <.001). The use of tools to identify and counsel patients at risk for sexually transmitted hepatitis B virus infection resulted in increased office-based prevention activities.

Adolescent↗
PubMed2000

Evaluation of the effectiveness of targeted lookback for HCV infection in the United States-interim results.

BACKGROUND: As part of a nationwide program to identify persons at increased risk for HCV infection, persons who received blood from donors who later tested positive for anti-HCV are being directly notified. STUDY DESIGN AND METHODS: In December 1999, all 198 blood collection establishments (BCEs) and 5442 hospital transfusion services (TSs) in the United States were surveyed by mailed questionnaire to evaluate their progress in carrying out this notification. RESULTS: Eighty-one percent of the BCEs and 64 percent of the TSs responded. After correcting for nonresponse, an estimated 98,484 components at potential risk for transmitting HCV, according to previous testing of multiantigen-screened donors, were identified nationwide, of which 85 percent had been transfused to recipients. Lookback for these recipients was completed for 80 percent, of whom 69 percent had died. Of those living, 78 percent were successfully notified. An estimated 49.5 percent of those notified were tested; 18.9 percent of those tested were anti-HCV positive, and 32 percent of that group knew they were positive before notification. On the basis of an 85.5 percent reported completion rate for component notifications back through 1988, an estimated 1520 persons will have been newly identified as anti-HCV-positive when lookback related to multiantigen screening of donors is completed. CONCLUSION: Targeted lookback related to previous multiantigen screening of donors will identify <1 percent of the estimated 300,000 HCV-positive persons in the United States who may have acquired their infection via blood transfusion.

DNA, Viral↗
PubMed2000

Elimination of new chronic hepatitis B virus infections: results of the Alaska immunization program.

An immunization assessment and a serologic survey were conducted to evaluate the effectiveness of a hepatitis B immunization program in eliminating hepatitis B virus (HBV) transmission among Alaska Natives in a region in which HBV infection is endemic. Hepatitis B vaccine coverage was 93% among 567 children </=10 years old residing in the study villages, and catch-up vaccine coverage among 582 susceptible persons 11-30 years old was 62%. None of 271 tested children </=10 years old were chronically infected with HBV, and just 4 (1.5%) had evidence of resolved infection. In contrast, 16% of 332 persons 11-30 years old (those born before implementation of routine infant hepatitis B vaccination) were chronically infected. A hepatitis B immunization program that includes prevention of perinatal HBV infection, routine infant vaccination, and catch-up vaccination of older children and adults can eliminate new chronic HBV infections in a population with a high rate of chronic infection.

Adolescent↗
PubMed2000

Prevalence of antibody to hepatitis E virus among rodents in the United States.

The recent identification of antibody to hepatitis E virus (HEV) in pigs, sheep, and cattle and characterization of an HEV isolated from domestic pigs suggest animal reservoirs for this virus. To investigate whether rodents might be a natural reservoir of HEV, the prevalence of anti-HEV was determined among a variety of species throughout the United States. Serum samples were obtained from 806 rodents of 26 species in 15 genera. Anti-HEV prevalence was assessed by 2 EIAs (mosaic protein- and 55-kDa protein-based), which gave concordant results. The highest prevalence of antibody was found in the genus Rattus (59.7%; 166/278). Overall, rodents from urban habitats had a significantly higher prevalence of anti-HEV than did animals captured from rural areas. A high prevalence of anti-HEV was found in animals captured on mainland versus barrier islands. The results from this study provide convincing evidence of widespread HEV or HEV-like infection in rodents of the United States.

Animals↗
PubMed2000

Genetic relatedness of hepatitis A virus isolates during a community-wide outbreak.

In 1993-94, a community-wide outbreak of hepatitis A occurred in Stanislaus County, California. Stool specimens collected from a sample of 33 case patients were used to evaluate the duration of hepatitis A virus (HAV) excretion and the genetic relatedness of HAV isolates. Twenty-four percent of the patients had a stool sample positive for HAV antigen by enzyme immunoassay, whereas 91% had at least one stool positive for HAV RNA by RT-PCR amplification. Children were found to excrete low levels of HAV RNA for up to 10 weeks after the onset of symptoms. Analysis of the HAV VP1 amino terminus and VP1/P2A regions showed that a limited number of HAV isolates circulated during the epidemic and the majority of the cases were infected with the same strain.

Adolescent↗
PubMed1999

The prevalence of hepatitis C virus infection in the United States, 1988 through 1994.

BACKGROUND: Because many persons with chronic hepatitis C virus (HCV) infection are asymptomatic, population-based serologic studies are needed to estimate the prevalence of the infection and to develop and evaluate prevention efforts. METHODS: We performed tests for antibody to HCV (anti-HCV) on serum samples from 21,241 persons six years old or older who participated in the third National Health and Nutrition Examination Survey, conducted during 1988 through 1994. We determined the prevalence of HCV RNA by means of nucleic acid amplification and the genotype by means of sequencing. RESULTS: The overall prevalence of anti-HCV was 1.8 percent, corresponding to an estimated 3.9 million persons nationwide (95 percent confidence interval, 3.1 million to 4.8 million) with HCV infection. Sixty-five percent of the persons with HCV infection were 30 to 49 years old. Seventy-four percent were positive for HCV RNA, indicating that an estimated 2.7 million persons in the United States (95 percent confidence interval, 2.4 million to 3.0 million) were chronically infected, of whom 73.7 percent were infected with genotype 1 (56.7 percent with genotype 1a, and 17.0 percent with genotype 1b). Among subjects 17 to 59 years of age, the strongest factors independently associated with HCV infection were illegal drug use and high-risk sexual behavior. Other factors independently associated with infection included poverty, having had 12 or fewer years of education, and having been divorced or separated. Neither sex nor racial-ethnic group was independently associated with HCV infection. CONCLUSIONS: In the United States, about 2.7 million persons are chronically infected with HCV. People who use illegal drugs or engage in high-risk sexual behavior account for most persons with HCV infection.

Adolescent↗
PubMed1999

Antigenic epitopes of the hepatitis A virus polyprotein.

Forty-two antigenic domains were identified across the hepatitis A virus (HAV) polyprotein by using a set of 237 overlapping 20-mer synthetic peptides spanning the entire HAV polyprotein and a panel of serum samples from acutely HAV-infected patients. The term "antigenic domain" is used in this study to define a protein region spanned with consecutive overlapping immunoreactive peptides. Nineteen antigenic domains were found within the structural proteins, and 22 were found within the nonstructural proteins, with 1 domain spanning the junction of VP1 and P2A proteins. Five of these domains were considered immunodominant, as judged by both the breadth and the strength of their immunoreactivity. One domain is located within the VP2 protein at position 57-90 aa. A second domain, located at position 767-842 aa, contains the C-terminal part of the VP1 protein and the entire P2A protein. A third domain, located at position 1403-1456 aa, comprises the C-terminal part of the P2C protein and the N-terminal half of the P3A protein. The fourth domain, located at position 1500-1519 aa, includes almost the entire P3B, and the last domain, located at position 1719-1764 aa, contains the C-terminal region of the P3C protein and the N-terminal region of the P3D protein. It is interesting to note that four of the five most immunoreactive domains are derived from small HAV proteins and/or encompass protein cleavage sites separating different HAV proteins. The HAV-specific immunoreactivity of each antigenically reactive peptide was confirmed by using seven HAV seroconversion panels. Collectively, these data demonstrate that HAV structural and nonstructural proteins contain antigenic epitopes that can be efficiently modeled with short synthetic peptides.

Amino Acid Sequence↗