Screening and diagnostic performance of enzyme immunoassay for antibody to lymphadenopathy-associated virus.

In a multicenter cooperative study, an enzyme immunoassay (EIA) using purified antigen of lymphadenopathy-associated virus was compared with radioimmune precipitation (RIP) for detection of antibody to human immunodeficiency virus (HIV) in 634 patients with acquired immunodeficiency syndrome or related conditions, 687 apparently healthy persons at risk for HIV infection, 93 controls with cancer or autoimmune diseases, and 10,038 blood or plasma donors. Excluding the donors, the EIA was reactive in 875 (61.9%) of 1,414 subjects; compared with RIP, the sensitivity and specificity of EIA both were 99.8%. There was one false-positive EIA among 148 intravenous drug abusers and two false-negative EIAs among 472 apparently healthy homosexual men; no other discordant results between EIA and RIP occurred in these subjects. The EIA was repeatably reactive in 20 donors (0.2%), among whom 13 (65%) were positive by RIP; none of 529 randomly selected EIA-negative donors was RIP positive. In addition to its utility as a screening test in low-risk populations, the EIA for antibody to lymphadenopathy-associated virus is useful as a diagnostic test in persons with clinical evidence of or at risk for HIV infection.     

Prevalence of hepatitis C virus antibody among Korean adults.

To estimate the prevalence of hepatitis C virus (HCV) infection among Korean adults and to present the putative route of HCV transmission among them, serum samples from 4917 adults older than 20 years of age were tested for antibody to HCV (anti-HCV), and histories of blood transfusion and other pertinent information were obtained by self-administered questionnaires. The overall prevalence of anti-HCV was 1.7%; prevalence was 1.4% in subjects with normal levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), 3.3% in those with slightly elevated and 5.9% in those with markedly elevated levels of the enzymes. The prevalence of anti-HCV increased with increasing age (P < 0.01), but was not associated with blood transfusion. The present study suggests that the prevalence of HCV infection was 1.4% and that the major routes of HCV transmission may be other than blood transfusion in healthy Korean adults.     

Prevalence of antibodies to hepatitis E virus among hemodialysis patients in Sweden

In order to study the prevalence of antibody to hepatitis E virus (HEV) among hemodialysis patients and to evaluate whether chronic hemodialysis is associated with an increased risk of exposure to HEV in developed countries, the IgG anti-HEV was determined in serum samples obtained from 182 patients on chronic hemodialysis and 349 statistically selected, healthy Swedish control subjects. Serum specimens from 11 of the 182 (6.0%) hemodialysis patients and from 18 of the 349 (5.2%) control subjects were repeatedly positive for HEV antibodies (the difference was not significant: P= .67). Analysis of serial serum samples obtained at the initiation of hemodialysis and consecutively during follow-up periods of several years demonstrated no IgG anti-HEV seroconversion during chronic hemodialysis. The seroprevalence of anti-HEV antibody in the adult Swedish population was associated significantly with age. In persons younger than 40 years, the percentage of seropositive individuals was 2.5%, whereas the seroprevalence rate of anti-HEV was 7.4% in subjects older than 40 years (P< .05). This study indicates that nosocomial transmission of HEV to patients on maintenance hemodialysis was non-existent in three dialysis centers in Sweden (a developed country) and that chronic hemodialysis is not associated with an increased risk of exposure to HEV infection in this region. J. Med. Virol. 54:38–43, 1998. © 1998 Wiley-Liss,Inc.     

Prevalence of antibody to current influenza virus strains in adolescents

During the Spring of 1986, 118 pupils aged 15-18 years were surveyed for the presence of humoral antibodies to five influenza strains. Prevalence of humoral immunity (HI) antibodies and immunity was found to be related to the year of the strain's emergence and to length of circulation time in the community. A high percentage of the adolescents were not immune to one or more of the tested strains. More than 40% of the studied group were not immune to the old A strains A/Philipines 2/82 (H3N2) and A/Chile 1/83 (H1N1), nearly 70% were not immune to the two B strains (B/USSR 100/83 and B/Ann Arbor 1/86), and almost the entire group (96%) was unprotected against the recent strain A/Singapore 6/86. Only one pupil was immune to all five strains; 35.6%, 22.2%, 17.8%, and 9.2% were immune to one, two, three, or four of the strains, respectively; and 14.4% were not immune to even one strain.     

Prevalence of antibody to hepatitis E virus among wild sika deer, Cervus nippon, in Japan

Summary We examined 976 sika deer serum samples, 159 liver tissue samples and 88 stool samples collected from 16 prefectures in Japan, and performed ELISA and RT-PCR assays to detect antibodies to HEV and HEV RNA, respectively. Although 25 (2.6%) of 976 samples were positive for anti-HEV IgG, the antibody titers were very low. The OD values ranged between 0.018 and 0.486, forming a single distribution rather than a bimodal distribution, suggesting that the antibody detected in this study was not induced by HEV infection, or that deer have low sensitivity to HEV. HEV RNA was not detected in these samples, also suggesting that deer may not play a role as an HEV reservoir.     

Prevalence of antibody to the Norwalk virus in various countries.

Serum samples from children and adults from several countries were tested by radioimmunoassay for antibody to the Norwalk virus. Antibody was commonly found in adults from all the countries tested. Antibody appears to be acquired more rapidly in children from underdeveloped countries than in children from the United States.     

Prevalence of antibody to delta antigen among HBV carriers in Japan

Of 280 hepatitis B virus (HBV) carriers in Kure, Hiroshima Prefecture, Japan, 14 (5.0%) were seropositive for antibody to delta antigen (anti-HD by radioimmunoassay. HBV carriers with chronic liver disease had a greater frequency of seropositivity of anti-HD than asymptomatic HBV carriers (7% vs. 0%, P less than 0.05). Among the various geographic regions of Kure, the east suburban area had a significantly higher prevalence of anti-HD when compared with all other regions combined (9.8% vs. 2.7%, P less than 0.025). It is suggested that hepatitis delta virus (HDV) infection exists in Japan and HDV may be an etiologic agent of chronic liver disease.     

Prevalence of human T-cell leukemia virus antibody among heterosexuals living in Amsterdam, The Netherlands

To determine the heterosexual spread of human T-cell leukemia virus (HTLV-I) infections, a cohort of 472 individuals with more than 5 heterosexual partners in the 6 months before entry was studied. They were recruited from visitors to the Clinic for Sexually Transmitted Diseases of the Municipal Health Service. Half of the study group was born in the Netherlands, 13% in Surinam or the Dutch Antilles, and 8% in Turkey or Morocco. Seventy percent were involved in commercial sex. Three persons were positive for HTLV-I, with serum antibodies against p19, p24, p28, gp46, and gp61 in Western immunoblot (WIB) and radio-immunoprecipitation assay (RIPA). Two of them originated from Surinam and the third was a Dutch woman. Two other individuals were HIV-positive, 19% had hepatitis B virus (HBV)-markers and 6% Treponema pallidum reacted in the hemagglutination assay (TPHA). It is concluded that HTLV-I circulates in the Surinamese population in Amsterdam and there was no evidence of appreciable heterosexual transmission.     

Hepatitis C virus infection among noninjecting drug users in New York City

The prevalence of hepatitis C virus (HCV) infection among noninjecting drug users has been reported to be higher than in the general population, but the reasons for this observation remain unclear. Noninjecting drug users aged 15-40 years and who used drugs for no longer than 10 years were enrolled in the study. The participants were interviewed about risk behaviors and had specimens drawn for serological testing. Of 276 enrolled, 4.7% were infected with HCV. Drug users who had ever sniffed or snorted heroin in combination with cocaine were significantly more likely to be infected with HCV compared with those who never sniffed or snorted heroin with cocaine. No other drug use or sexual risk behaviors were found to be associated with HCV infection. These findings suggest that sniffing or snorting heroin with cocaine may explain the increase frequently found in HCV infection among noninjectors, but further studies are necessary.     

Prevalence and significance of antibodies to hepatitis C virus among Saudi haemodialysis patients.

Seventy-four patients who were maintained on chronic haemodialysis in King Khalid University Hospital, Riyadh, Saudi Arabia were tested using the recently available ELISA to determine the prevalence of antibodies to hepatitis C virus (anti-HCV) in a haemodialysis unit. The prevalence rate of anti-HCV antibodies of 41.9% in the haemodialysis patients was significantly higher than the rate of 3.9% detected in 488 asymptomatic blood donors who were similarly tested. In the haemodialysis patients, anti-HCV positivity was related to previous blood transfusion (greater than 5 units of blood) and to the duration of haemodialysis (greater than 4 years); but was unrelated to sex, age, positive HBV markers or to past or current elevation of serum ALT. The results indicate a relatively higher prevalence of anti-HCV antibodies in our patients compared to rates of 1-20% reported from Europe and the U.S.A. An effective control strategy for HCV infection in this high risk group is urgently indicated.     

Prevalence of hepatitis C virus antibodies among patients infected with human immunodeficiency virus.

A study was undertaken to determine the prevalence and risk factors for serological evidence of hepatitis C virus (HCV) infection in patients infected with the human immunodeficiency virus (HIV). Tests for anti-HCV antibody were carried out by enzyme-linked immunoassay (EIA) on 101 HIV-infected patients from two university-based outpatient clinics. Anti-HCV antibody reactive samples were tested by using a recombinant immunoblot assay (RIBA) for HCV antibodies. Fourteen of 101 (13.9%) HIV-infected patients were anti-HCV reactive by EIA. Of these 14, only seven were reactive by RIBA: four were intravenous drug users as a sole risk factor for HIV infection; and the remaining three acquired HIV by blood transfusion, contaminated instrument exposure or IV drug use and sexual contact. Acquisition of HIV by sexual activity alone was not associated with HCV infection. It is concluded that HCV infection is found in approximately 7% of a university HIV clinic population. False-positive anti-HCV antibody serology may lead to overestimation of the prevalence of HCV infection. Female sex and intravenous drug use are significantly associated with HCV infection among HIV-infected individuals.     

Prevalence of SEN virus among children in Japan

Recently, a novel deoxyribonucleic acid (DNA) virus, designated SEN virus (SENV), was discovered and strong associations between the two SENV variants (SENV-D and SENV-H) and non-A to E hepatitis were reported. To clarify the character of SENV infection in children, we investigated the detection rates of serum SENV DNA by polymerase chain reaction (PCR) among children with non-A to C hepatitis, with histories of transfusions, with neither histories of transfusions nor liver diseases (control), and among pregnant women. SENV-D was detected in 60% of fulminant hepatitis, 5% of acute hepatitis, 11% of chronic hepatitis, 13% of controls, and 15% of pregnant women. SENV-H was detected in none of fulminant hepatitis, 5% of acute hepatitis, none of chronic hepatitis, 2% of controls, and 12% of pregnant women. No significant difference was found for SENV-D between acute or chronic hepatitis and controls, however SENV-D detection rate in fulminant hepatitis was significantly higher than that in controls (P<0.05). No significant difference was found for SENV-H between any hepatitis and controls, however SENV-H detection rate in pregnant women was significantly higher than that in controls (P<0.05). Neither SENV-D nor SENV-H was associated with acute or chronic hepatitis; however, SENV-D might be a risk factor of fulminant hepatitis.     

Prevalence and risk factors of Hepatitis D virus antibody among asymptomatic carriers of Hepatitis B virus: a community survey

BackgroundHepatitis D virus (HDV) can cause a chronic infection in the presence of hepatitis B surface antigen and contribute to the burden of chronic liver disease especially in regions where chronic hepatitis B virus (HBV) infection is endemic.AimTo determine the prevalence and risk factors of HDV among asymptomatic carriers of HBsAg in Cross River State, Nigeria.MethodsThis was a cross-sectional study conducted among apparently healthy adults resident in Cross River State, Nigeria. A structured questionnaire was used to collect socio-demograhic data and risk factors for HBV/HDV infection. Participants blood samples were screened for HBsAg. Samples that were HBsAg positive were further screened for anti-HDVIgM. Statistical analysis was performed using statistical package for social sciences (SPSS) version 20.ResultsA total of 90 HBsAg positive samples were assayed. The prevalence of anti-HDV IgM was 5.6% (95% CI 1.1–10.1). The HDV positive subjects were mostly females (80%), reported family size of >5 members (80%), had female circumcision (75%) and took injections from Non-certified health care practitioners (NCHCPs). None of the assessed risk factors were significantly associated with HDV infection (p >0.05).ConclusionHepatitis D virus is moderately prevalent amongst asymptomatic HBsAg carriers in Cross River State, Nigeria.     

Prevalence of antibody to hepatitis C virus (HCV) in HIV-1-infected patients (nice seroco cohort)

The prevalence of antibody to hepatitis C virus (HCV) in a cohort of 272 HIV-infected patients was assessed by means of 4 anti-HCV assays: a 1st generation and a neutralization test, a 2nd generation test, and a confirmatory test, the dot-blot Matrix HCV? immunoassay. The cohort included, as a single risk factor, 35.7% intravenous drug users (IVDUs), 25% homosexual men, 30.1% heterosexual individuals, 5.9% transfused patients, 0.7% occupational infections, and 2.6% patients with unknown infection source, and was studied on entry and in samples collected for up to 36 months. Results showed that on entry (i) sera of 83 out of 272 members of the cohort were positive by the HCV 1st generation EIA (30.5%); 70 were confirmed by the neutralization test (84.3%); (ii) 115 of the cohort were reactive with the 2nd generation HCV EIA (41.3%); (iii) with the dot-blot immunoassay 99 (86.1%) of the cohort were confirmed and 16 remained indeterminate. The overall confirmed HCV antibody-positive rate in these 272 patients was 36.4%. Antibody to HCV was detected in 78.3% of IVDUs, 18.3% of heterosexual individuals, 31.2% of transfused patients, and only 2.9% of homosexual men. The 36-month follow-up of this cohort revealed that 4/145 patients became anti-HCV positive by second generation assay. Hepatitis B markers were frequently associated with HCV in IVDUs (71.1%) but infrequently in heterosexual (8.5%) or homosexual (1.5%) individuals. Our results suggest that HCV 2nd generation EIA used in combination with the semiautomated dot-blot assay as a confirmatory test improves the specificity and sensitivity for HCV antibody detection. Homosexual males are at low risk of HCV infection among HIV risk groups. © 1994 Wiiey-Liss, Inc.     

Prevalence of hepatitis B virus infection among alcoholic patients with liver disease.

The aim of this investigation was to elucidate a possible role of hepatitis B virus (HBV) in the pathogenesis of liver diseases in alcoholics. Two hundred and fifty-three alcoholics with liver disease were admitted to two medical departments in Copenhagen during a 15 months period. Seventy-nine patients (31%) showed serological signs (HBsAg, anti-HBs) of previous or active HBV infection. This is a significantly higher prevalence than found in an age-matched control population. Among the 79 patients with HBV markers, a total of 11 was found to be HBsAg-positive. From these 11 patients liver specimens were available for re-evaluation in nine cases. In only three of these liver biopsies, morphological changes indicating alcohol as the aetiological cause were found. In conclusion, different or concomitant aetiology must be considered in alcoholics with liver disease.