Long-term serologic follow-up of hepatitis C virus-seropositive homosexual men.

Hepatitis C virus (HCV) infection may go undiagnosed and continue to present a source of community-acquired or transfusion-associated infection because of shortcomings in sensitivity, specificity, and reproducibility of serologic tests. This project was designed to longitudinally study persons who were HCV seropositive or were at risk for seroconversion to characterize the course of infection. Sequential serum samples obtained semiannually from 617 homosexual male volunteers were available for study from the Pittsburgh site of the Multicenter AIDS Cohort Study. Testing by anti-HCV enzyme immunoassay (EIA) was performed on baseline (1984 to 1985) and most-recent (censor date, August 1992) samples. Selected samples were also assayed for alanine aminotransferase and by recombinant immunoblot (RIBA II) and nested PCR. A total of 17 of 617 (2.8%) men were HCV seropositive at entry. Of the 600 seronegative men, 9 converted to HCV seropositive during the study interval. Parenteral sources of exposure could be identified in 6 of these 26 HCV-seropositive men. Four men were HCV seropositive at baseline and seronegative at their most recent visit. Of the 26 HCV-seropositive men, 12 were also seropositive for human immunodeficiency virus. EIA analysis of 298 longitudinal samples from the 26 men revealed three patterns of HCV seropositivity: persistent, intermittent, and rare. Nine men (35%) showed intermittent or rare seropositivity with periods of over 1 year between some seropositive samples. PCR was positive in 76% of the HCV EIA-positive and 84% of the RIBA-positive samples. Thus, a low but significant number of homosexual men were HCV seropositive with variable positivity over several years of follow-up. A portion of these men become HCV seronegative. Individuals who exhibit intermittent or rare seropositivity are a challenge to diagnosis.     

Syphilis,hepatitis A and hepatitis B seromarkers in homosexual men

Summary Two hundred homosexual men were investigated for prevalence rates of syphilis, hepatitis A (HAV) and hepatitis B (HBV). A reactive Treponema pallidum haemagglutination test (TPHA) was found in 56.3% of the participants. In 81.7% HBV scromarkers were detected. Hepatitis B surface antigen (HBsAg) was present in 6.6%. Anti-HAV was found in 51.0%. Risk factors for acquisition of these infections are discussed.     

Long-term immunogenicity and efficacy of hepatitis B vaccine in homosexual men

To study the duration of antibody persistence and protection provided by the hepatitis B vaccine, we followed 773 homosexual men for five years after completion of vaccination. Among the 635 participants in whom antibody levels above 9.9 sample ratio units (SRU) developed after vaccination, 15 percent lost antibody altogether, and in another 27 percent, antibody levels declined below 10 SRU within five years. The extent of the maximal antibody response strongly predicted the persistence of protective antibody. Hepatitis B infection occurred in 55 men; 8 of these infections were clinically important (characterized by the presence of the hepatitis B surface antigen and elevation of liver-enzyme levels), and two of the patients became hepatitis B virus carriers. The long-term risk of hepatitis B infection was inversely related to the maximal antibody response to vaccine. Most severe infections occurred among those who responded poorly or had no response to the vaccination. The risk of late infection with hepatitis B in those with an initially adequate vaccine response increased markedly when antibody levels decreased below 10 SRU, but only 1 of 34 late infections resulted in viremia and liver inflammation. A second series of vaccinations induced a moderate antibody response in 50 percent of the subjects who initially had no response or a poor response; however, the persistence of antibody was poor. Both antibody loss and the risk of severe disease should be considered when booster-dose strategies for the hepatitis B vaccine are being designed.     

Sexual transmission of hepatitis A in homosexual men: incidence and mechanism

We performed monthly examinations and serologic tests for antibody to hepatitis virus A (anti-HA) in a study of 57 heterosexual men and 102 homosexual men followed prospectively for a mean of 8.9 months and 6.1 months, respectively. The initial prevalence of anti-HA was 30 per cent in homosexual men and 12 per cent in heterosexual men P less than 0.01). The annual incidence of hepatitis A in susceptible (seronegative) homosexual men was 22 per cent, whereas no heterosexual men acquired hepatitis A. Diaries concerning sexual behavior kept by homosexual men showed that the acquisition of hepatitis A virus infection contact. Hepatitis A should be considered one of the enteric infections that appear to be sexually transmitted among homosexual men.     

Active immunization of homosexual men using a recombinant hepatitis B vaccine

Twenty homosexual men [13 anti-human immunodeficiency virus (HIV)-positive, seven anti-HIV negative] without HBsAg, anti-HBs, and anti-HBc were vaccinated with three 20 micrograms doses of a recombinant hepatitis B vaccine. All anti-HIV-positive homosexuals were nonresponders independent of the initial number of CD4-positive cells. Among seven anti-HIV-negative individuals, five responded. After three doses of the vaccine, CD4-positive cells fell in anti-HIV positive individuals by 22.4%. A similar fall in CD4-positive cells of an average 24.9% was noted in 17 matching, but nonvaccinated, anti-HIV-positive homosexuals. The study indicates that the efficacy of vaccination in anti-HIV-positive individuals is questionable. There is, however, no evidence that vaccination against hepatitis B might be harmful to anti-HIV-positive subjects.     

Risk and clearance of GB virus C/hepatitis G virus infection in homosexual men: A longitudinal study.

The risk and clearance of GB virus type C (GBV-C)/hepatitis G virus (HGV) infection was investigated in a cohort of homosexual men (n=180; median follow-up time, 7 years). The interaction between GBV-C/HGV RNA and antibodies against the E2 region of the virus, and the clinical impact of chronic GBV-C/HGV infection were studied. GBV-C/HGV RNA was detected by RT-PCR, and E2 antibodies were assessed by an immunoassay. At baseline, 63% of the participants had evidence of previous or current GBV-C/HGV infection. The GBV-C/HGV incidence rate was 2 per 100 person-years (95% confidence interval 0. 9-3.8) and was similar to the HIV incidence. The incidence of GBV-C/HGV infection was significantly higher in those reporting unprotected anal intercourse (3.6 per 100 person-years compared to 0 in the group without such sexual contacts). The occurrence of E2 antibodies was strongly associated with GBV-C/HGV RNA clearance. A loss of E2 antibodies was observed at a rate of 1.5 per 100 person-years. It was higher among HIV-infected individuals. Chronic GBV-C/HGV infection was not associated with clinical or biochemical evidence of liver disease.     

Epidemiology of hepatitis B and C in Croatia

The incidence of HBV and HCV infection is hard to determine because of the high number of asymptomatic infections. According to data of the Croatian Institute of Public Health, there are 200 newly infected persons with hepatitis B and approximately the same number of newly identified HBsAg carriers occur each year. Accordingly, Croatia is among the countries with less than 2% of HBsAg carriers in the general population. In these circumstances, HBV infection is most often spread among adolescents and younger adults. The route of transmission is most often sexual (semen) or through the skin in high-risk groups. An increased risk of infection is found in newborns of HBsAg positive mothers, i.v. addicts, promiscuous individuals, male homosexuals, person in close contact with acutely ill or chronic HBsAg carriers, persons that come in contact with blood and other potentially contaminated body fluids, dialysis patients, patients with multiple blood transfusions, patients with transplanted organ or tissue, patients treated for hematologic malignancies and hemophilia, and persons who undergo acupuncture, tattooing or piercing, or travel to areas with a high prevalence of HBV infection. The estimated prevalence of HCV infection marker (anti-HCV) in the Croatian general population is more than 1% and the number of yearly infected with hepatitis C reported to the Croatian Institute of Public Health is around 200 cases. The highest incidence is found in the 20-40 age groups at a high risk of infection by the use of drug injection. At risk are persons who received transfusion of blood or blood products prior to the availability of blood screening of voluntary blood donors.     

Protozoal enteric infections in homosexual men

Summary The prevalence of enteric protozoal infections was examined in a group of 200 homosexual men. Entamoeba histolytica (E. histolyt.) was found in 22.8%, apathogen amoeba in 54.5% and Giardia lamblia (G. lamblia) in 9.1% of the participants. Antibodies against E. histolyt. were significantly higher in subjects carrying E. histolyt. than in the group with apathogen amoeba and in uninfected participants. Clinical symptoms were not associated with protozoal infection. The analysis of a number of variables showed that oral-anal sex and promiscuity were the two most important risk factors for protozoal infection. The clinical significance of protozoal enteric infections and their possible relation to the acquired immune deficiency syndrome (AIDS) is discussed.     

Epidemiology of hepatitis C virus infection in Pakistan.

Since the discovery of hepatitis C virus (HCV) in 1989 as the causative agent of post-transfusion non-A non-B hepatitis, the epidemiology, pattern of transmission, different genotypes and clinical consequences of the disease have been studied worldwide, but little is known about the epidemiology of HCV infection in Pakistan. This paper reviews the available evidence on the epidemiology of HCV infection in Pakistan obtained via MEDLINE search (1970-2005) of published articles with key words hepatitis C and Pakistan, and other sources including ongoing discussions within the medical community. Approximately 10 million people have been infected with HCV in Pakistan. The majority of patients have acquired their infection through unsafe injections, reuse of syringes and needles and community barber shops used for face and armpit shaving. More than two-thirds of HCV patients were 40 to 50 years old. Although at present a small proportion of those with chronic HCV infection develop liver failure or hepatocellular carcinoma, it is estimated that the incidence of these advanced disease complications will increase over the coming years.     

Epidemiology of hepatitis C virus infection in Australia.

BACKGROUND: Since the discovery in 1989 of hepatitis C virus (HCV) as the infectious agent responsible for the vast majority of post-transfusion non-A non-B hepatitis the patterns of transmission and clinical consequences of this highly prevalent flavivirus have been widely studied. OBJECTIVE: This paper reviews available evidence on the epidemiology of HCV infection in Australia, including HCV notification data obtained through public health surveillance systems, HCV seroprevalence surveys among high risk populations, and models for estimating and projecting HCV transmission and long-term consequences of chronic HCV infection. RESULTS: Over the period 1990-2000 approximately 160,000 notifications of HCV infection were received by State and Territory health jurisdictions making it the most commonly notified communicable disease in Australia. Approximately 210,000 people are estimated to be living with HCV infection in Australia, with an estimated 80% having acquired their infection through injecting drug use. Less than 500 cases of newly acquired HCV infection are notified each year, however, an estimated 16,000 new infections occur annually. Despite the widespread introduction of needle and syringe programmes in the late 1980s, HCV transmission continues at high levels among current injecting drug users (IDUs) with incidence and prevalence estimates of 10-20/100 person years and 50-55%, respectively. Levels of HCV transmission are particularly high in both younger and incarcerated IDUs. In contrast to HCV infection, prevalence of HIV among current IDUs has remained below 2% since 1995. Although a small minority of people with chronic HCV infection will develop liver failure or hepatocellular carcinoma, the incidence of these advanced disease complications is estimated to double over the next decade. CONCLUSION: The epidemic of HCV infection continues to escalate in Australia, predominantly through transmission related to injecting drug use. As the population of people with chronic HCV infection and progressive liver disease expands the public health burden of advanced disease complications will be considerable.