Second-generation Enzyme Immunoassay Research Articles

Anti-mumps IgM antibody positive rate with sudden sensorineural hearing loss using second-generation enzyme immunoassay: A retrospective, multi-institutional investigation in Hokkaido, Japan

Anti-mumps IgM antibody positive rate with sudden sensorineural hearing loss using second-generation enzyme immunoassay: A retrospective, multi-institutional investigation in Hokkaido, Japan

Anti-mumps IgM antibody positive rate with sudden sensorineural hearing loss using second-generation enzyme immunoassay: A retrospective, multi-institutional investigation in Hokkaido, Japan

ObjectiveAlthough elevated anti-mumps IgM antibody levels were reported in 5.7%–7.2% of Japanese patients with sudden sensorineural hearing loss (SSNHL), there were several reports of false-positive cases, such as the continually IgM positive case and the IgM positive case in normal adults. To improve specificity, the new enzyme immuno assay (EIA) anti-mumps IgM antibody measurement kit was introduced in December 2009. This study re-examined the frequency of anti-mumps IgM antibody test positivity with SSNHL using the new measurement kit and compared the results with those from a previous report that used old kit. MethodsThis is a retrospective multi-institutional study involving patients diagnosed with SSNHL who exhibited the anti-mumps IgM antibody. We compared the positive rate of anti-mumps IgM antibody and the annual average number of mumps cases per sentinel in Hokkaido between the patients in the present study and patients previously evaluated. ResultsOverall, 100 patients with SSNHL were enrolled. One case (1.0%) was positive for anti-mumps IgM antibody. Of the 69 patients evaluated in the previous study, 5 cases (7.2%) were positive for anti-mumps IgM antibody. The positive rate of the anti-mumps IgM antibody in the present cases was significantly lower than that previously reported (p=0.042). The annual average number of mumps cases per sentinel in Hokkaido of the present and previous surveillance period was 34.47 and 42.77, respectively; no significant difference was seen in these data (p=0.4519). ConclusionThe present study revealed that 1.0% of SSNHL was positive for the anti-mumps IgM antibody using the new EIA-IgM measurement kit. After the introduction of the new EIA-IgM measurement kit, anti-mumps IgM antibody positive rate with SSNHL significantly decreased, indicating that the proportion of asymptomatic mumps among etiology of SSNHL may be lower than those previously reported.

HIV Testing in a High‐Incidence Population: Is Antibody Testing Alone Good Enough?

The Centers for Disease Control and Prevention recently recommended the expansion of human immunodeficiency virus (HIV) antibody testing. However, antibody tests have longer "window periods" after HIV acquisition than do nucleic acid amplification tests (NAATs). Public Health-Seattle & King County offered HIV antibody testing to men who have sex with men (MSM) using the OraQuick Advance Rapid HIV-1/2 Antibody Test (OraQuick; OraSure Technologies) on oral fluid or finger-stick blood specimens or using a first- or second-generation enzyme immunoassay. The enzyme immunoassay was also used to confirm reactive rapid test results and to screen specimens from OraQuick-negative MSM prior to pooling for HIV NAAT. Serum specimens obtained from subsets of HIV-infected persons were retrospectively evaluated by use of other HIV tests, including a fourth-generation antigen-antibody combination assay. From September 2003 through June 2008, a total of 328 (2.3%) of 14,005 specimens were HIV antibody positive, and 36 (0.3%) of 13,677 antibody-negative specimens were NAAT positive (indicating acute HIV infection). Among 6811 specimens obtained from MSM who were initially screened by rapid testing, OraQuick detected only 153 (91%) of 169 antibody-positive MSM and 80% of the 192 HIV-infected MSM detected by the HIV NAAT program. HIV was detected in serum samples obtained from 15 of 16 MSM with acute HIV infection that were retrospectively tested using the antigen-antibody combination assay. OraQuick may be less sensitive than enzyme immunoassays during early HIV infection. NAAT should be integrated into HIV testing programs that serve populations that undergo frequent testing and that have high rates of HIV acquisition, particularly if rapid HIV antibody testing is employed. Antigen-antibody combination assays may be a reasonably sensitive alternative to HIV NAAT.

Recent Canadian experience with targeted hepatitis C virus lookback

Targeted hepatitis C virus (HCV) lookback studies have been performed in Canada since 1995. The yield of HCV lookback has not been reassessed since the introduction of improved HCV screening tests. Data were combined from the two Canadian blood suppliers to determine the yield of targeted HCV lookback performed on donors found to be HCV-positive by antibody screening and/or nucleic acid testing (NAT) from the introduction of NAT in 1999 until January 1, 2005. Lookback was performed on 498 donations from 176 HCV-seropositive and two NAT-only-positive donors; 494 components had been transfused, and 160 components were traced to living recipients who underwent HCV testing. Seventy-two percent of recipients of components derived from donations given before the introduction of second-generation enzyme immunoassay (EIA) testing were HCV-seropositive. Four recipients of components derived from donations tested by second- or third-generation EIA, with or without NAT, were HCV-seropositive. Two of these recipients tested HCV-seropositive before transfusion, and a third was probably infected by transfusions before the introduction of HCV testing. The fourth recipient likely received a noninfectious transfusion, since five other recipients of components from subsequent donations made by this donor were seronegative. When previous donations had been tested by second- or third-generation EIA, the yield of HCV lookback was likely zero. Because HCV infection is relatively common in the general population and patients in Canada do not undergo pretransfusion testing, coincident infections in recipients may be erroneously attributed to transfusion. The regulatory requirement for HCV lookback should be reassessed.

Seroreversion in Subjects Receiving Antiretroviral Therapy during Acute/Early HIV Infection

We assessed human immunodeficiency virus (HIV) antibody seroreversion among individuals initiating antiretroviral therapy (ART) during acute/early HIV infection and determined whether seroreversion was associated with loss of cytotoxic T lymphocyte responses. Subjects in a cohort with acute/early HIV infection (<12 months into infection) who initiated ART within 28 days after study entry and maintained HIV type 1 ribonucleic acid levels of < or =500 copies/mL for >24 weeks were selected. Two clinically available second-generation enzyme immunoassays (EIAs) and a confirmatory Western blot were used to screen subjects for antibody reversion. Those with negative screening test results underwent additional antibody testing, including a third-generation EIA, and were assessed for cytotoxic T lymphocyte responses. Of 87 subjects identified, 12 (14%) had negative antibody test results at the start of ART; all 12 had seroconversion, although 1 had seroconversion only on a third-generation EIA. Of the 87 subjects, 6 (7%) had seroreversion on at least 1 EIA antibody assay while receiving ART during a median follow-up of 90 weeks. The only clinical predictor of seroreversion was a low baseline "detuned" (less sensitive) antibody. Cytotoxic T lymphocyte responses to HIV Gag peptides were detected in 4 of 5 subjects with seroreversion who could be tested. All 5 who had seroreversion who stopped ART experienced virologic rebound and antibody evolution. HIV antibody seroconversion on second-generation EIA antibody tests may fail to occur when ART is initiated early. Seroreversion was not uncommon among subjects treated early, although cytotoxic T lymphocyte responses to HIV antigens remained detectable in most subjects. Antibody seroreversion did not indicate viral eradication. A third-generation EIA was the most sensitive test for HIV antibodies.

Hepatitis C virus transmission and its risk factors within families of patients infected with hepatitis C virus in southern Iran: Khuzestan

To determine whether hepatitis C virus (HCV) infection of index cases increases intrafamilial transmission (sexual and nonsexual contacts) of HCV. In a case-control descriptive study we enrolled 300-household contacts of 60 index cases (40 males and 20 females) of HCV infection and 360 pair-matched controls in Ahwaz JundiShapour University Hospitals from August 1, 1998 to September 1, 2003. The control group consisted of first time blood donors referred to the Regional Blood Transfusion Organization. Serum samples and demographic data and a medical history including the existence of risk factors for HCV (after a questionnaire on the risk factors for parenteral exposure) were obtained from each subject. Antibodies to HCV were detected employing a commercially available second-generation enzyme immunoassay (EIA, Abbott II). Positive serum specimens were retested using a second-generation recombinant immunoblot assay (RIBA-2) and a polymerase chain reaction for HCV RNA. Data analysis was carried out for intra-household clustering. Only 4 of 300 (1.33%) cases of household contacts without percutaneous risk factors were positive for HCV Ab while the remaining 296 family contacts were negative for anti-HCV. The mean age of the index cases was 28.4 (Std 15.22) years. The anti-HCV prevalences in parents, spouses, children of the index cases were 0.87% (1/115), 3.39% (2/59)) and 0.79% (1/126), respectively. Among couple partners negative for anti-HCV antibodies, the mean duration of the sexual relationship was 6 years. The two-couple partners positive for anti-HCV antibodies married the index cases for longer than 15 years. The prevalence of positive HCV Ab among household contacts (1.33%) was not significantly higher than that in the controls (1%) (P > 0.06). Intrafamilial transmission of HCV is not the significant transmission route and sexual transmission does not seem to play a role in the intrafamilial spread of HCV infection. Intrafamilial transmission of HCV is possible but occurs at a low rate.

Sensitivity of second-generation enzyme immunoassay for detection of hepatitis C virus infection among oncology patients

Background The second-generation hepatitis C virus (HCV) enzyme immunoassay (EIA 2), an antibody-detection test, has high sensitivity and is one of the recommended screening tests for detecting HCV infection in the United States. However, its sensitivity among oncology patients is unknown. Objective Assess the EIA 2 sensitivity among a group of oncology patients at a Nebraska clinic where an HCV outbreak occurred during 2000–2001 using nucleic acid testing (NAT) and recombinant immunoblot assay (RIBA) as the gold standards. Study design Serum specimens were collected from patients 16 months after transmission had stopped. We tested the specimens using EIA 2 (Abbott HCV EIA 2.0), a NAT assay based on transcription-mediated amplification (TMA) (Gen-Probe TMA assay) and RIBA (Chiron RIBA ® HCV 3.0 SIA). HCV infection was defined as a positive RIBA or TMA test in an oncology patient. Alanine aminotransferase (ALT) levels were determined in EIA 2-negative/TMA-positive samples. Results A total of 264 samples were included in the study. We identified 92 HCV infections, 76 of which were Abbott EIA 2 positive. Abbott EIA 2 sensitivity was 83% (76/92), lower than that reported among healthy adults (90%) ( p = 0.01) and poor sensitivity was associated with receipt of chemotherapy during the outbreak period ( p = 0.02). Only 1 (6%) of the 16 EIA 2-negative cases had elevated ALT. Conclusions In this study, EIA 2 sensitivity among oncology patients was lower than that previously reported among immunocompetent persons. Impaired antibody production related to cancer and/or chemotherapy might explain the reduced sensitivity. These findings indicate that, when assessing HCV status in oncology patients, a NAT test should be routinely considered in addition to EIA.

Contribution of metabolic factors to alanine aminotransferase activity in persons with other causes of liver disease

Nonalcoholic fatty liver disease has been defined by the presence of hepatic steatosis in the absence of other chronic liver diseases. We sought to determine whether obesity, insulin resistance, and the metabolic syndrome, which are the main risk factors for nonalcoholic fatty liver disease, are associated with similar elevations in serum alanine aminotransferase activity in persons with and those without other causes of chronic liver disease. Adult participants of the third National Health and Nutrition Examination Survey were divided into those with causes of chronic liver disease (n = 1037), defined as viral hepatitis, excessive alcohol consumption, or increased transferrin-iron saturation, and those without (n = 8004). Among persons with other causes of chronic liver disease, obesity (adjusted odds ratio, 4.9; 95% confidence interval, 2.5-9.4), insulin resistance (adjusted odds ratio, 6.8; 95% confidence interval, 3.0-15.5, comparing the highest and the lowest quartile), and the metabolic syndrome (adjusted odds ratio, 3.3; 95% confidence interval, 1.4-8.0) were all strongly associated with increased alanine aminotransferase activity (>43 IU/L). Among persons without other causes of chronic liver disease, statistically similar associations were identified. Obesity, insulin resistance, and the metabolic syndrome are strong predictors of increased alanine aminotransferase activity in the US population, both in persons with and in persons without other causes of chronic livers disease. We hypothesize that metabolic fatty liver disease related to these conditions is the cause of the increased alanine aminotransferase activity and may be underrecognized in persons with other causes of chronic liver disease.

Anti-cyclic citrullinated peptide autoantibodies in IgM rheumatoid factor-positive patients

Background Antibodies to citrullinated proteins have been described in patients with RA and these appear to be the most specific markers of the disease. The objective of this study was to analyse the improvement in diagnostic accuracy of anti-cyclic citrullinated peptide autoantibodies and IgA rheumatoid factor in patients with clinical suspicion of RA and who were IgM rheumatoid factor-positive. Anti-CCP antibodies were measured with three different second-generation enzyme immunoassays. Methods We chose 133 serum samples with IgM RF levels greater than 20 IU/mL sent to our Laboratory from Specialized Care Units. Subsequently, patients were classified according to their clinical records. Eighty-seven had rheumatoid arthritis and 46 had other diseases. In all samples anti-CCP and IgA RF were measured by the corresponding ELISAs. Results Comparison of the three anti-CCP second-generation ELISAs revealed differences between them. Likewise, clinical performances in terms of sensitivity, specificity, and positive and negative likelihood ratios were different. In patients with IgM RF higher than 20 IU/mL, anti-CCP antibodies increased the clinical efficiency of IgM RF and offered better performance as compared with IgA RF. Conclusions The use of anti-CCP antibodies affords good clinical efficiency and modifies the pre-test probability of the occurrence of RA in patients with IgM rheumatoid factor higher than 20 IU/mL.

Helicobacter pylori and gastrointestinal symptoms in school children in Russia.

Helicobacter pylori is considered to be the major cause of chronic gastritis and duodenal ulcer disease recurrence in childhood. However, the association between H. pylori and recurrent abdominal pain (RAP) syndrome is still controversial. Therefore, the spectrum of clinical variants of gastrointestinal symptoms associated with H. pylori-positive status was studied in consecutive symptomatic children who were undergoing diagnostic endoscopy. A consecutive series of 225 school children from the Ural area of Russia (mean age 11.1 + 1.4 years, age range 7-15 years) who presented with RAP were investigated using esophagogastroduodenoscopy, including three antral biopsies for histology and polymerase chain reaction. Helicobacter pylori immunoglobulin G antibodies were found using a second-generation enzyme immunoassay. Information about the clinical symptoms was collected using a special questionnaire. The authors found a high incidence of H. pylori infection (80%) and peptic ulcers (16%) in 225 school children from the Ural area of Russia who were referred for upper gastrointestinal (UGI) endoscopy for chronic abdominal pain. Of the overall 225 symptomatic children who underwent endoscopy, 182 (80,8%) were found to be H. pylori-positive. Duodenal ulcers were detected in 36 H. pylori-positive children. A family history of peptic ulcers was significantly more frequent in the children infected with H. pylori (P < 0.001). Symptom score and duration of symptoms were similar, but night-time pain (P < 0.0001) and fasting pain relieved by food (P < 0.001) were more frequent in the H. pylori-positive children as compared with the H. pylori-negative children. The present results provide further evidence for a significant association between H. pylori and some patterns of gastrointestinal symptoms in children who underwent UGI endoscopy in order to exclude an organic cause of severe chronic gastrointestinal disorders.

The epidemiology of chronic hepatitis C infection in survivors of childhood cancer: an update of the St Jude Children's Research Hospital hepatitis C seropositive cohort

AbstractChildhood cancer survivors transfused before 1992 are at risk for chronic hepatitis C (HCV) infection. In 1995, St Jude Children's Research Hospital initiated an epidemiologic study of childhood cancer survivors with transfusion-acquired HCV. Of the 148 survivors with HCV confirmed by second-generation enzyme immunoassay, 122 consented to participate in the study. Their current median age is 29 years (range, 9 to 47 years). At enrollment, polymerase chain reaction (PCR) testing indicated chronic infection in 81.1%; genotype 1 was the most common viral genotype. Liver biopsy in 60 patients at a median of 12.4 years from the diagnosis of malignancy showed mild (28.8%) or moderate (35.6%) fibrosis; 13.6% had cirrhosis. Elevated body mass index was associated with histologic findings of increased steatosis (P= .008). Antimetabolite chemotherapy exposure was associated with early progression of fibrosis. Significant quality-of-life deficits were observed in noncirrhotic adult survivors. Antiviral therapy resulted in clearance of infection in 17 (44%) of 38 patients to date. Six patients have died; 1 patient with decompensated cirrhosis died of variceal bleeding. Despite a young age at HCV infection, the progression of liver disease in childhood cancer survivors is comparable to that seen in adults.

Laboratory evaluation of a fully automated chemiluminescence immunoassay for rapid detection of HBsAg, antibodies to HBsAg, and antibodies to hepatitis C virus.

The performance of a fully automated, random access, enhanced chemiluminescence immunoassay (Ortho/ECi) for the detection of antibody to hepatitis C virus (HCV) (anti-HCV), HBsAg, and antibody to HBsAg (anti-HBsAg), in human serum was compared to a Abbott second-generation enzyme immunoassay (EIA 2.0). The Ortho/ECi assays employ an immunometric technique with enhanced chemiluminescence for optimal assay performance. With regard to the study of clinical laboratory performance, six groups of sera prescreened with Abbott EIAs were assayed: anti-HCV-negative samples (n = 318), anti-HCV-positive samples (n = 177), anti-HBsAg-negative samples (n = 241), anti-HBsAg-positive samples (n = 239), HBsAg-positive samples (n = 158), and HBsAg-negative samples (n = 312). Sera with discrepant results in the two serological assays were resolved by confirmatory tests. Sera with indeterminate results by one or more confirmatory tests were evaluated by reviewing medical records. The overall concordance between the Ortho/ECi assay and the Abbott EIA were 97.78, 93.54, and 97.66% for anti-HCV antibodies, anti-HBsAg antibodies, and HBsAg, respectively. After resolving the discrepancies, the specificities of the new assay for anti-HCV and anti-HBsAg antibodies and HBsAg were 98.1, 92.8, and 100%, respectively. The sensitivities of the new assay for anti-HCV, anti-HBsAg, and HBsAg were 100, 98.8, and 97.4%, respectively. In conclusion, The Ortho/ECi assays for diagnosis of HCV and hepatitis B virus (HBV) infections are highly specific and sensitive assays. The rapid turnaround time, random access, full automation, and high throughput make it an effective assay system for clinical laboratory diagnosis of HCV and HBV infections.

Hepatitis C virus: prevalence and routes of infection among blood donors of West Mexico

In Latin America few studies have explored frequency and risk factors predicting hepatitis C virus (HCV) infection in blood donors. In this study we determined the prevalence of HCV infection in blood donors from West Mexico. Potential risk factors, clinical, histological and virologic characteristics presented in this group were also evaluated. Methods: HCV antibodies were evaluated in 57 108 blood donors with commercial second-generation enzyme immunoassays. Positive results were confirmed by a recombinant immunoblot assay. Repeatedly seropositive donors were further studied for risk factors, history for hepatitis, hepatic enzymes (aspartate aminotransferase and alanine aminotransferase (AST and ALT)), liver histology and hepatitis C virus–ribonucleic acid (HCV–RNA) detection. Results: A total of 499 blood donors were initially tested positive doubtful for antibodies to HCV Ab (0.8%). While there was no difference in HCV prevalence with respect to age or gender, the most frequent risk factors identified were transfusion (42%), household exposure (14.8%), multiple sex partner (6.8%) and intranasal cocaine use (2.3%). Also, we found that from a subgroup of donors tested for histological analysis, 19% presented abnormal ALT levels and 90% showed abnormal liver histology. No correlation was found between abnormal ALT levels and the presence of HCV–RNA in serum. Conclusion: These results demonstrate a low prevalence (0.8%) of HCV infection among Western Mexican blood donors, which was comparable to those established for Western countries, but in contrast in our study the most frequent risk factor continues being transfusion followed by household exposure.

Lack of seronegative hepatitis C virus infections in patients with chronic renal failure.

Recent reports have indicated that serologic testing for hepatitis C virus (HCV) in patients with chronic renal failure may be inadequate to detect infections in this patient population. We prospectively tested 258 patients with end-stage renal disease who were referred for evaluation for renal transplantation for anti-HCV using a second-generation enzyme immunoassay (EIA) and a second-generation qualitative reverse-transcriptase polymerase chain reaction (RT-PCR). We confirmed all positive EIAs with a third-generation recombinant immunoblot assay and genotyped RT-PCR-positive specimens. We found that 22 patients (8.5%) had serological evidence of HCV infection. Nineteen (86%) of the antibody-positive patients were viremic (HCV RNA positive). All but 1 of the patients was infected with HCV genotype 1. None of the 233 HCV antibody-negative patients were shown to be viremic by RT-PCR. No additional HCV cases were detected by screening all patients for HCV RNA by RT-PCR. However, RT-PCR is a valuable adjunct to serology in antibody-positive patients to distinguish resolved from active infections.

Advances in the Molecular Diagnosis of Hepatitis C and Their Clinical Implications

Advances in the Molecular Diagnosis of Hepatitis C and Their Clinical Implications

Persistent hyperendemicity of hepatitis C virus infection in Taiwan: The important role of iatrogenic risk factors

The purpose of this study was to investigate determinants of endemic hepatitis C virus (HCV) infection within communities in Taiwan. A two-phase study, including a seroprevalence survey and a prevalent case-control study at the first phase, which has been published previously, and a follow-up seroconversion determination and an incident case-control study during the second phase, was carried out to evaluate correlates of persistent endemic HCV infection. At the first phase, a total of 12,021 men and 1,819 women who were 30-64 years old and living in seven townships in Taiwan were tested for the seroprevalence of antibodies to HCV (anti-HCV). In addition, a prevalent case-control study involving 272 HCV-positive cases and 282 seronegative controls identified from the anti-HCV testing was conducted to investigate risk factors associated with HCV prevalence. During the second phase, a total of 2,728 men and 834 women who were seronegative at recruitment participated in the 1-year prospective study on anti-HCV seroconversion. Subsequently, an incident case-control study based on 39 seroconverters and 81 persistently seronegative controls were carried out to elucidate determinants of HCV seroconvertion. Antibodies to HCV were tested by the second-generation enzyme immunoassay. Information on risk factors of HCV infection was collected from subject interviews. The prevalence of anti-HCV consistently increased with age (range 2.9-5.4%), whereas no apparent age trend was observed for anti-HCV seroconversion rate (range 0.9-1.7%). A striking geographical variation in seroprevalence and seroconversion rates of anti-HCV was observed in the study townships. Furthermore, a significant geographical correlation between HCV seroprevalence and seroconversion rates was noted (r = 0.962, P = 0.001). From the results of both prevalent and incident case-control comparisons, medical injections were found to be the main mode to sustain the persistent endemic state of HCV infection within a community (odds ratios for prevalent and incident case-control studies were 2.5 (95% CI = 1.7-3.6) and 3.1 (95% CI = 1.4-7.1), respectively. The data indicate that the basis for HCV transmission has already been existed in study areas and the iatrogenic risk factor tended to be the major determinant for sustaining persistent endemicity within a community.

Acute-phase-specific heptapeptide epitope for diagnosis of parvovirus B19 infection.

The major capsid protein VP2 of human parvovirus B19, when studied in a denatured form exhibiting linear epitopes, is recognized exclusively by immunoglobulin G (IgG) antibodies of patients with acute or recent B19 infection. By contrast, conformational epitopes of VP2 are recognized both by IgG of the acute phase and by IgG of past immunity. In order to localize the VP2 linear epitope(s) specific for acute-phase IgG, the entire B19 capsid protein sequence was mapped by peptide scanning using well-characterized acute-phase and control sera. A unique heptapeptide epitope showing strong and selective reactivity with the acute-phase IgG was detected and characterized. By using this linear epitope (VP2 amino acids 344 to 350) and virus-like particles exhibiting conformational VP2 epitopes, an innovative approach, second-generation epitope-typing enzyme immunoassay, was set up for improved diagnosis of primary infections by human parvovirus B19.

Transmission of hepatitis C virus in Taiwan: Prevalence and risk factors based on a nationwide survey

A nationwide community-based survey on hepatitis C virus (HCV) was carried out in seven townships in Taiwan. A total of 11,904 men aged 30-64 years were recruited for testing for antibodies against HCV (anti-HCV) by second-generation enzyme immunoassay. A total of 272 seropositive cases and 282 seronegative controls were interviewed to explore risk factors for HCV infection in the study areas. Spouses of 214 seropositive cases were identified to assess the concordance of seropositivity of anti-HCV between spouses; genotypes of HCV were also tested in 26 couples who were both seropositive. A significant geographic variation in seroprevalence of anti-HCV was observed in the study townships (1.6-19.6%). Blood transfusions, medical injections, acupuncture and tattooing were related to an increased anti-HCV seroprevalence showing multivariate-adjusted odds ratios of 8.6, 2.5, 3.1, and 2.2, respectively, with corresponding population attributable risk percentages of 25%, 57%, 16%, and 3%, respectively. The anti-HCV prevalence in spouses of index cases (24%) was significantly higher than that observed in the general population of the study areas (4%). However, a striking interspousal discrepancy in HCV genotypes (20/26 = 77%) was observed among both seropositive couples. Common exposures to medical injections and acupuncture were reported by 15 (58%) of these couples. This study identified some endemic areas of HCV infection in Taiwan. Iatrogenic factors were common vehicles for HCV infection, and a concordance of anti-HCV seropositivity between spouses may primarily be due to extrafamilial iatrogenic infectious sources in study areas.

A novel biochemical approach to congestive heart failure: Cardiac troponin T

Background The major structural characteristic of congestive heart failure is myocardial cell death. The aim of our study was to determine whether the level of cardiac troponin T, a protein specific for cardiac necrosis, was increased in patients with congestive heart failure. Methods and results Plasma samples were obtained from 33 patients and 47 healthy control subjects. Quantitative determination of cardiac troponin T was achieved with a second-generation enzyme immunoassay without cross-reactivity with the skeletal muscle troponin T. The mean circulating level of cardiac troponin T was 0.140 ± 0.439 ng/mL in patients with heart failure and 0.0002 ± 0.001 ng/mL in the healthy controls ( P = .0001). To evaluate the relation between structural degradation and functional impairment, patients in heart failure were categorized according to their radionuclide left ventricular ejection fraction (LVEF). In the 23 patients with LVEF ≤45%, cardiac troponin T was 0.163 ± 0.50 ng/mL, a level significantly higher than that in patients with LVEF >45% ( P = .04). There was also a negative correlation between cardiac troponin T and LVEF ( R = –0.41, P = .01). Conclusions These data show that cardiac troponin T is increased in patients with congestive heart failure and that the level parallels the severity of the disease. We conclude that cardiac troponin T is a suitable candidate-marker molecule to monitor congestive heart failure from a structural perspective. (Am Heart J 1999;138:95-9.)

Prevalence of anti-hepatitis A antibodies, hepatitis B viral markers, and anti-hepatitis C antibodies among immigrants from the former USSR who arrived in Israel during 1990-1991.

The goal of this study was to assess the susceptibility of the sub-population of over 500,000 immigrants from the former USSR who came to Israel during 1989-94 to HAV infection, and to provide military physicians with estimates of the prevalence of HBV and HCV carriage in this sub-population. 987 males aged 17-49 and 195 females aged 17-19, reporting to military recruitment offices between December 1991 and March 1992 were tested. Anti-HAV, anti-HBV antibodies and hepatitis B surface antigen (HBsAg) were detected by using standard enzyme immunoassay (EIA) tests, and anti-HCV antibodies by a second-generation EIA and confirmed by a third-generation INNO-LIA test. It was found that in the 17-19-year age-group the prevalence of anti-HAV antibodies was 37%, anti-HBV was 12.8%, HBsAg was 3.0% and anti-HCV 1.3%. All markers were higher among males. The prevalence of anti-HAV and anti-HBs antibodies increased with age among males. That of HBsAg and anti-HCV antibodies increased with age overall. In the multiple logistic regression analysis, HAV and HBV seropositivity were significantly associated with the mother's education and republic of origin. It was concluded that the prevalence of anti-HAV antibodies is similar to that among the local population, which should not be considered at a higher risk of infection during military service. On the other hand, the higher prevalence of HBsAg and anti-HCV antibodies in this sub-population should heighten the awareness of the possibility of chronic liver pathology.