anti-HAV Positivity Research Articles

Should Brazilian patients with chronic hepatitis C virus infection be vaccinated against hepatitis A virus?

Hepatitis A virus (HAV) superinfection is associated with a high risk of liver failure and death in patients with hepatitis C virus (HCV) infection. The aim of this study was to investigate the presence of serological and molecular HAV markers in a population of HCV-infected patients in order to determine a cost-effective strategy to vaccinate against HAV. The presence of total and immunoglobulin (Ig)M anti-HAV antibodies was investigated in 399 patients (median age, 50 years; range, 4-81) referred to the Public Health Central Laboratory of Pernambuco State who tested positive for anti-HCV antibodies and HCV RNA. HAV RNA was investigated by reverse transcription-nested polymerase chain reaction in these patients. Three hundred and eighty-four (96%) patients were positive for anti-HAV total and negative for IgM anti-HAV antibodies (immune patients). Three patients had IgM (and total) anti-HAV antibodies, showing an acute infection, and two of them had HAV RNA detected in serum samples. HAV RNA was also found in another patient in the absence of detectable anti-HAV antibodies. By nucleotide sequencing, it was demonstrated that the HAV isolates infecting these patients belonged to subgenotype 1B. This study provides valuable new data on anti-HAV prevalence among HCV carriers in Brazil. In the present study, we found a high proportion of patients with anti-HAV positivity, indicating that anti-HAV testing of HCV-infected patients is a cost-effective strategy and should be carried out before vaccination against HAV in these patients, particularly in regions such as our geographical area with high total anti-HAV prevalence.

Prevalence of anti-HAV antibodies in multitransfused patients with beta-thalassemia

To detect the prevalence of anti-HAV IgG antibodies in adult multitransfused beta-thalassemic patients. We studied 182 adult beta-thalassemic patients and 209 controls matched for age and sex from the same geographic area, at the same time. Anti-HAV IgG antibodies, viral markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection were evaluated. Anti-HAV IgG antibodies were detected more frequently in thalassemic patients (133/182; 73.1%) than in healthy controls (38/209; 18.2%, P < 0.0005). When we retrospectively evaluated the prevalence of anti-HAV IgG antibodies in 176/182 (96.7%) thalassemic patients, whose medical history was available for the previous ten years, it was found that 83 (47.2%) of them were continuously anti-HAV IgG positive, 16 (9.1%) acquired anti-HAV IgG antibody during the previous ten years, 49 (27.8%) presented anti-HAV positivity intermittently and 28 (15.9%) were anti-HAV negative continuously. Multitransfused adult beta-thalassemic patients present higher frequency of anti-HAV IgG antibodies than normal population of the same geographic area. This difference is difficult to explain, but it can be attributed to the higher vulnerability of thalassemics to HAV infection and to passive transfer of anti-HAV antibodies by blood transfusions.

Seroepidemiology of hepatitis A in voluntary blood donors from Pune, western India (2002 and 2004-2005).

Recently, a changing pattern of hepatitis A epidemiology has been reported in the Indian population indicating a rise in the rate of hepatitis A infection among adults. The study's objective was to assess anti-HAV prevalence in voluntary blood donors from middle and high socioeconomic strata. Serum samples collected from voluntary blood donors from Pune city and its suburbs in the years 2002 and 2004-2005 were tested for anti-HAV IgG antibodies. Serum samples collected during 2004-2005 were examined for anti-HAV IgM antibodies. Positive samples were tested for HAV-RNA. Agewise anti-HAV positivity was significantly low in adults aged 18-25 years (90.4%) compared to those aged >25 years (97.4%) (P<0.01). A decline in anti-HAV prevalence was significant in 2004-2005 compared to that in 2002 (96.5% vs. 92.1%) (P<0.01). Overall, in both adult age groups, the proportion of anti-HAV positivity was remarkably low in the high socioeconomic group (HSG) (88.96%) compared to that of the middle socioeconomic group (MSG) (95.86%) (P<0.01). Anti-HAV IgM positivity was not significant (~1%), however, presence of HAV-RNA in one of the samples indicated the possibility of horizontal transmission of HAV. Increase in seronegativity to HAV in HSG implicates a rise in the susceptible pool and indicates the need for vaccination against hepatitis A.

Consumption of uncooked deer meat as a risk factor for hepatitis E virus infection: an age- and sex-matched case-control study.

It was reported previously food-borne transmission of hepatitis E virus (HEV) to humans from deer meat. The present study attempted to clarify whether eating uncooked deer meat is a major epidemiological risk factor for HEV infection in Kasai, a city in western Japan. In total, 45 volunteer subjects with experience of eating raw deer meat were enrolled. An equivalent number of people from the same area who had never eaten raw deer meat served as controls. The subjects and controls had comparable age and sex distributions. Serum anti-HEV IgG and anti-hepatitis A virus (HAV) IgG levels were measured in all 90 volunteers. There was no significant difference in age, overseas travel history, or rate of anti-HAV antibody positivity between the subjects and controls. Eight (17.7%) of the subjects but only one (2.2%) of the controls had measurable serum anti-HEV IgG levels (P = 0.014). Anti-HAV prevalence did not differ between the anti-HEV-positive and negative groups. The results suggest that eating uncooked deer meat is an epidemiological risk factor for HEV infection in the studied area. In countries such as Japan where deer meat is sometimes eaten raw, attention must be paid to this route of HEV infection.

Epidemiology of hepatitis A and hepatitis E infection and their determinants in adult Chinese community in Hong Kong.

Current epidemiology of hepatitis A virus (HAV) and hepatitis E virus (HEV) in Hong Kong was evaluated in 936 adult Chinese subjects recruited through a telephone interview in 2001. Some 15% of the subjects had IgG antibodies to both HAV and HEV while 665 (71.0%) and 176 (18.8%) had anti-HAV and anti-HEV, respectively. Age was the most significant independent factor. Six hundred thirty-eight (79.8%) and 165 (20.7%) subjects aged > or =30 had anti-HAV and anti-HEV, respectively, as compared with 27 (19.7%) and 11 (8.0%) in people aged <30. The corresponding adjusted Odds ratio (OR) was 14.94 (95% CI: 9.13-24.44; P<0.001) for anti-HAV positivity and 2.99 (95% CI: 1.58-5.67; P=0.001) for anti-HEV positivity. Subjects born outside Hong Kong were more likely to have anti-HAV (adjusted OR: 3.41; 95% CI: 2.21-5.26; P<0.001) but not anti-HEV. Non-labour work people were less likely to have anti-HAV-adjusted OR, 0.40 (95% CI: 0.26-0.62; P<0.001). Age-specific HAV prevalence right shifted in the last 20 years. Anti-HAV positivity was less frequent, across all age groups, in subjects >21-years-old in the present study than another study done in 1987-89 (P<0.001). HAV prevalence only increased slightly in every 10-year age groups of people aged 21-50 when compared with their corresponding 10-year-younger age groups (P=0.11), suggesting an ageing cohort effect with no major infections in the last decade. For HEV, both the overall and age-specific prevalence decreased over the last decade (P<0.001). The increasing proportion of susceptible population to enterically transmitted viral hepatitis has implications to future prevention and control programmes, including vaccination strategies.

Viral hepatitis in the Canadian Inuit and First Nations populations.

To review published prevalence data regarding hepatitis A (HAV), B (HBV) and C (HCV) in Canadian Inuit and First Nations populations. PubMed database search and review of all papers describing data derived from seroepidemiological surveys. The prevalence of anti-HAV positivity in Canadian Inuit and First Nations populations reported to date is high (range 75% to 95%) and approximately three times that of non-Aboriginal Canadians residing in the same communities. Among the Canadian Inuit, the prevalence of HBV infection is approximately 5%, or 20 times that of non-Aboriginal Canadians, while the risk of exposure to HBV is 25%, or five times higher. Regarding the First Nations population, preliminary data suggest the prevalences of HBV infection (0.3% to 3%) and exposure (10% to 22%) are similar to rates in non-Aboriginals residing in the same regions and participating in similar high risk activities. Serological evidence of HCV infection (anti-HCV) is more common in the Canadian Inuit and First Nations (1% to 18%) than the remainder of the Canadian population (0.5% to 2%); however, viremia (HCV-RNA positivity) is less common (less than 5% versus 75% of anti-HCV positive individuals, respectively). Viral hepatitis is common in the Canadian Inuit and First Nations populations. In the absence of coexisting human immunodeficiency virus infection and alcohol abuse, the outcomes of HBV and HCV appear to be more benign than in non-Aboriginal Canadians.

Task profile and risk of occupational hepatitis A infection in sewerage workers.

The aim of the study was to assess to what extent parameters of task-related occupational exposure influence anti-hepatitis A virus (anti-HAV) seroprevalence in sewerage workers, using a new instrument for classification of exposure. A new instrument for the assessment of work-related infection hazards was developed based on expert interviews, evaluation of literature and theoretical considerations. It was included in a questionnaire for collecting detailed information on occupational exposure, safety awareness, safety behaviour and socio-demography. Anti-HAV status was assessed for all (n = 343) (non-vaccinated) study participants. Marked differences in task profile and task-related exposure within the group of sewerage workers were found, underlining the necessity of a detailed exposure analysis. In a multivariate model three risk factors that were related significantly to anti-HAV positivity were identified: age, country of origin and task-related exposure. Since task profiles and occupational exposure differ strongly within the job category of sewerage workers. evaluation of endangerment has to reflect individual task-related exposure. The task-exposure matrix developed and presented in this study is a practicable and valid instrument for exposure assessment and may be used for the exposure analysis of further biological agents in this working environment. Besides the known risk parameters age and origin, our study demonstrates a dose-response relationship between the degree of occupational exposure and the anti-HAV seroprevalence. Therefore, an effective worksite HAV-prevention programme should consider all technical, structural and educational measures that help to reduce individual exposure.

Changing epidemiology of hepatitis A and hepatitis E in urban and rural India (1982-98).

The epidemiology of hepatitis A virus (HAV) and hepatitis E virus (HEV) was assessed among age-stratified urban high socioeconomic, lower middle socioeconomic status and rural populations from western India in 1998. When compared with previous surveys, a clear shift from high to intermediate endemicity of HAV was evident only for higher socioeconomic population (1982-98), raising the possibility of outbreaks of hepatitis A in this category. A decrease in anti-HAV positivity was noted in rural children aged 6-10 years. Lower circulation of HEV was noted among < 25-year-old urban higher socioeconomic and rural individuals. For both viruses, the lower middle socioeconomic populations were comparable in 1982 and 1998. Socioeconomic status and family size (odds ratio = 23 and 1.6, respectively) were independently associated with anti-HAV positivity. Age, lower middle socioeconomic status and well water were significant independent variables for HEV infection (odds ratio = 5.7, 2.4 and 1.9, respectively). Hence, vaccination policy for hepatitis A needs to be reviewed.

A prevalence study of hepatitis A virus infection in a migrant community: Is hepatitis A vaccine indicated?

Background: The Advisory Committee on Immunization Practices recommends routine hepatitis A vaccination of children living in communities with high rates of hepatitis A. Rates among children living in migrant farm worker families are unknown. Methods: Participants recruited from the 1243 migrant children aged 2 to 18 years in Okeechobee County, Florida, were administered a questionnaire. A blood sample was taken for testing for antibodies to hepatitis A virus (anti-HAV), and hepatitis A vaccine was administered. Results: Of 244 (20%) participating children, 125 (51%) were anti-HAV–positive. Seropositivity increased with age from 34% (2- to 5-year-olds) to 81% (≥14-year-olds) (P <.0001). In multivariate analysis, age (odds ratio [OR] = 1.2/year; 95% CI = 1.1 to 1.3), having a Mexican-born father (OR = 12.2; 95% CI = 2.2 to 227.9), and age on moving to the United States (OR = 1.3/year; 95% CI = 1.0 to 1.6) were independently associated with anti-HAV positivity. Among US-born children aged 2 to 5 years who had never left the United States, 33% were anti-HAV–positive. Conclusions: Anti-HAV prevalence among migrant children in Okeechobee County, including the youngest US-born children, is high, indicating ongoing transmission of HAV. Children in this and other US migrant communities may benefit from hepatitis A vaccination. (J Pediatr 2001;138:705-9)

Infection with hepatitis A and TT viruses and socioeconomic status in Rio de Janeiro, Brazil.

The prevalence of antibodies directed against the enterically transmitted hepatitis A virus (HAV) was measured in 2 groups of people living in Rio de Janeiro, Brazil. Of 1,056 health care workers (HCWs), 778 (73.7%) were anti-HAV positive. A high prevalence of anti-HAV antibodies (85.7%) was also found among 274 voluntary blood donors (BDs). TT virus (TTV) is a DNA virus that has been found in the sera of patients with post-transfusion hepatitis of unknown etiology. Occurrence of virus shedding suggests that the fecal-oral route may be an important mode of TTV transmission, particularly in the developing world. The presence of TTV DNA was analyzed by PCR in the sera of 191 HCWs and 151 BDs. TTV was detected in 65.4% of HCWs and 79.5% of BDs. In both groups, a family income of < US$400 per month and a level of education of < 11 y of schooling were found to be risk factors for HAV infection. Furthermore, a low family income was associated with TTV viremia in the HCW group. However, the presence of TTV DNA was associated with neither low level of education nor anti-HAV positivity.

Pattern of Hepatitis A and Hepatitis B Virus Markers in Cases of Acute Sporadic Hepatitis and in Healthy School Children from North West India

The pattern of viral markers in acute sporadic hepatitis in 329 children and those in 334 healthy school children from North West India were studied. Hepatitis A was found to be the commonest infection in sporadic cases (78 per cent). Of these, 86 per cent were under 10 years and 50 per cent less than 5 years of age. Hepatitis B was positive in 8 per cent, non-A non-B in 13 per cent, A as well as B in 1 per cent, and none had Delta virus infection. Viral markers in healthy school children showed anti-HAV IgG positivity in 96 and 85 per cent in those belonging to low and high socio-economic groups, respectively, indicating past infection. HBsAg was positive in 1 per cent of cases. Viral hepatitis is an important public health problem in children and warrants active immunization.

Antibodies to hepatitis E and A viruses among patients with non-alcoholic chronic liver disease in Taiwan.

The prevalence of hepatitis E virus (HEV) and hepatitis A virus (HAV) infection in patients with non-alcoholic chronic liver disease (CLD) was assessed. Antibody levels to HEV (anti-HEV) and HAV (anti-HAV) were evaluated in 100 pairs of CLD patients and healthy controls. The prevalence of anti-HEV was higher in patients (10.0%) than in controls (0%; p = 0.0001). There was no difference in anti-HAV positivity between patients (95%) and controls (93%). The patient group with anti-HEV was older (p = 0.024) and had more smokers (p = 0.03), having a higher prevalence of antibodies to hepatitis C virus (p = 0.02). Patients with anti-HAV were older than patients without (p = 0.0001). The prevalence of anti-HAV in patients more than 30 years old was higher than younger patients (95.1% versus 73.6%, p = 0.011). HEV may superinfect on chronic liver disease in an area hyperendemic for hepatitis A and B.

Incidence of hepatitis A virus infection among an Italian military population.

In 1990, a prospective serological survey to estimate the rate of clinical and inapparent infection with hepatitis A virus (HAV) was performed in a cohort of 1,268 soldiers, 18-24 years old, during an 8 month period in the Campania region in Italy. At the time of enrollment 318 (25%) of the 1,268 soldiers were positive for total antibodies to HAV (anti-HAV). None of them was positive for IgM anti-HAV. Among the 950 susceptible subjects who were followed up for 8 months, eight (0.8%) later seroconverted to anti-HAV positivity. This figure corresponds to an incidence of 1.3/100 person/years (eight seroconversions during 633.3 years of observation). There were two clinical (with presence of IgM-anti-HAV) and six inapparent infections. The clinical/subclinical HAV ratio was 1:3. These findings indicate that the risk of HAV infection among soldiers residing in this area is not negligible.

Appearance and persistence of hepatitis A IgM antibody in acute clinical hepatitis A observed in an outbreak.

143 patients with acute hepatitis A observed during a common source outbreak were tested for IgM class antibody to hepatitis A virus (IgM anti-HAV) by commercially available solid phase radioimmunoassays. All patients were IgM anti-HAV positive though six of them were initially negative when tested within three days after the onset of symptoms. The levels of IgM anti-HAV peaked two to four weeks after onset, and declined gradually thereafter. The probability of IgM anti-HAV positivity was 25% at the end of the sixth month, and 3.4% at the end of the ninth month after onset. No significant sex or age difference in the persistence of IgM anti-HAV was observed. It was suggested that the timing of the assay and the level of IgM anti-HAV should be considered in the etiological diagnosis of acute hepatitis.

Radioimmunoassay for detection of antibody to hepatitis A virus. Results of clinical evaluation.

The performance of a solid-phase radioimmunoassay (HAVAB) for the detection of antibody to hepatitis A virus (HAV) was evaluated in clinical studies. The procedure was reproducible by eight investigators, and laboratory-to-laboratory variations were minimal. The sensitivity of the test was about equal to or slightly greater than that of immune adherence hemagglutination (IAHA) for detecting antibody in serum, but IAHA gives somewhat higher titer values than HAVAB. A survey of the incidence of anti-HAV in selected populations revealed an overall frequency of 48% and a correlation with age and lower socioeconomic status. The specificity of the test was demonstrated with specimens from patients who had clinical hepatitis A. Seroconversion to anti-HAV positivity was demonstrated with HAVAB to coincide with onset of illness, about two to three weeks earlier than it was detected by IAHA. HAVAB provided a convenient test for demonstrating the immune status of subjects, and was useful as an aid in diagnosing hepatitis A.