Incidence of and risk factors for hepatitis A in Italy: public health indications from a 10-year surveillance. SEIEVA Collaborating Group

Shellfish-Associated Enteric Virus Illness: Virus Localization, Disease Outbreaks and Prevention

Numerous outbreaks of shellfish-borne enteric virus illness have been reported worldwide. Most notable among the outbreaks are those caused by NoV and HAV. Lessons learned from outbreak investigations indicate that most outbreaks are preventable. Anthropogenic sources of contamination will continue to invade shellfish growing waters. Shellfish, by their very nature, will continue to bioconcentrate these contaminants, including enteric viruses. There is no quick fix for enteric virus contamination of shellfish; however, vigilance on behalf of the industry, regulatory agencies, and the consumer could substantially reduce the incidence of illness. Enhanced monitoring in all areas of shellfish production, harvesting, distribution, and processing would help to reduce viral illnesses. Pollution abatement and improved hygienic practices on behalf of the industry and consumers are needed. Improved analytical techniques for the detection of enteric viruses in shellfish will lead to enhanced shellfish safety and better protection for the consumer and the industry. Better reporting and epidemiological follow-up of outbreaks are keys to reducing the transmission of foodborne viral infections. It is anticipated that recent advances in analytical techniques, particularly for NoV, will lead to better monitoring capabilities for food and water and a reduction in the incidence of enteric virus illness among shellfish consumers.

HAV Immunity in Iranian Medical Students

BACKGROUND

Hepatitis A, a fecal-oral transmitted disease, which has been considered endemic in developing countries, seems to change its pattern in developing countries because of their improved socioeconomic status.

OBJECTIVES

In the present study, we aimed to determine the need of vaccination in 270 students at AJA University of Medical Sciences.

MATERIALS AND METHODS

The serum level of anti-HAV antibody was checked in 270 students of AJA University of medical students, and effect of different factors, including age, gender, pre-university entrance exam region, familial education, familial income, clean water availability, and previous history of jaundice were tested.

RESULTS

Of total 270 students, 30 were female. Their age ranged between 18 and 30 years old with the mean age of 20.58 years and just 34% of students had positive level of anti-HAV antibody. Age and sex had no role in positive serum level of anti-HAV antibody. According to analyzed data, lack of clean water availability, pre-university entrance exam region, lower family education, and poor health status estimation increased statistically the risk of HAV infection.

CONCLUSIONS

Because 66% of students were anti-HAV antibody negative and they will work as health care workers in future, our study suggest vaccinating all students accepted at AJA University of Medical Sciences.

Hepatitis A vaccination coverage among adults 18-49 years traveling to a country of high or intermediate endemicity, United States

BACKGROUND

Since 1996, hepatitis A vaccine (HepA) has been recommended for adults at increased risk for infection including travelers to high or intermediate hepatitis A endemic countries. In 2009, travel outside the United States and Canada was the most common exposure nationally reported for persons with hepatitis A virus (HAV) infection.

OBJECTIVE

To assess HepA vaccination coverage among adults 18-49 years traveling to a country of high or intermediate endemicity in the United States.

METHODS

We analyzed data from the 2010 National Health Interview Survey (NHIS), to determine self-reported HepA vaccination coverage (≥1 dose) and series completion (≥2 dose) among persons 18-49 years who traveled, since 1995, to a country of high or intermediate HAV endemicity. Multivariable logistic regression and predictive marginal analyses were conducted to identify factors independently associated with HepA vaccine receipt.

RESULTS

In 2010, approximately 36.6% of adults 18-49 years reported traveling to high or intermediate hepatitis A endemic countries; among this group unadjusted HepA vaccination coverage was 26.6% compared to 12.7% among non-travelers (P-values<0.001) and series completion were 16.9% and 7.6%, respectively (P-values<0.001). On multivariable analysis among all respondents, travel status was an independent predictor of HepA coverage and series completion (both P-values<0.001). Among travelers, HepA coverage and series completion (≥2 doses) were higher for travelers 18-25 years (prevalence ratios 2.3, 2.8, respectively, P-values<0.001) and for travelers 26-39 years (prevalence ratios 1.5, 1.5, respectively, P-value<0.001, P-value=0.002, respectively) compared to travelers 40-49 years. Other characteristics independently associated with a higher likelihood of HepA receipt among travelers included Asian race/ethnicity, male sex, never having been married, having a high school or higher education, living in the western United States, having greater number of physician contacts or receipt of influenza vaccination in the previous year. HepB vaccination was excluded from the model because of the significant correlation between receipt of HepA vaccination and HepB vaccination could distort the model.

CONCLUSIONS

Although travel to a country of high or intermediate hepatitis A endemicity was associated with higher likelihood of HepA vaccination in 2010 among adults 18-49 years, self-reported HepA vaccination coverage was low among adult travelers to these areas. Healthcare providers should ask their patients' upcoming travel plans and recommend and offer travel related vaccinations to their patients.

A unique HAV strain circulated in patients with acute HAV infection with different risk exposures in Tuscany, Italy

BACKGROUND

Acute Hepatitis A Virus (HAV) is reported to be an emergent problem in several developed countries.

OBJECTIVES AND STUDY DESIGN

The aim of this study was to analyse the HAV strains circulating among individuals with acute HAV infection, apparently transmitted by different routes, in several districts of Tuscany in central Italy, during the year 2008.

RESULTS

An outbreak of acute HAV infection occurred from May to August 2008 in Arezzo; 32 individuals were admitted to the hospital, in 25 of them at least a linkage with an infected food handler and/or household contacts was reported and in 3 homosexuality was a possible risk factor. In Florence, from January 2008 to August 2008, 41 individuals mainly homosexual men were admitted to two hospitals with the diagnosis of acute HAV. The phylogenetic analysis of VP1/2A region of HAV was used to characterize these HAV isolates. All viral sequences were assigned to genotype IA. All clustered in the same branch (bootstrap 82%) of phylogenetic tree, thus indicating the same circulating isolate. Apart of one isolate from France and one from Germany which were similar with the "Tuscany" strain reported here, high heterogeneity with the other European HAV strains reported in the GenBank in the last years, was observed.

CONCLUSION

The detection of a unique HAV isolate circulating in different Tuscany districts, suggests sequential transmission of HAV infection in this geographical area through possible links among acute hepatitis cases. The application of safe food handling practices and vaccination of homosexual men may contribute to the prevention of HAV infection.

Acute hepatitis A in Italy: incidence, risk factors and preventive measures

The incidence of, and risk factors for, acute hepatitis A (AHA) were assessed by using data collected from the Italian surveillance system of acute viral hepatitis (SEIEVA). To this end, a case-control study within a population-based surveillance for acute viral hepatitis was performed. AHA incidence has been estimated since 1991; the association with considered risk factors was analysed from 2001 to 2006 employing cases of acute hepatitis B (AHB) as controls. The incidence of AHA declined from 4 / 100 000 in 1991 to 1.4/100 000 in 2006, with a peak during 1996-1998 due to an outbreak in southern Italy. The incidence of AHA was highest among persons aged 15-24 years. The case-fatality rate was 2.9 / 10 000. Contact with individuals with AHA [adjusted OR (OR(adj)) = 3.8, 95% CI 2.7-5.5; population-attributable risk (PAR) = 7.5%], travelling to endemic areas (OR(adj) = 3.1, 95% CI = 2.6-3.8; PAR = 19.5%), ingestion of raw shellfish (OR(adj) = 1.8, 95% CI = 1.6-2.1; PAR = 26.6%), and cohabitation with day care children (OR(adj) = 1.3, 95% CI = 1.01-1.7; PAR = 2.3%) were the main important risk factors. In 2003, an outbreak, with high case-fatality rate occurred among intravenous drug users, in a central Italian town. A weak association was found for male homosexuality when acute hepatitis C cases were employed as controls (OR(adj) = 1.4 CI, 95% CI = 1.1-1.9). Hepatitis A virus infections are currently occurring more frequently in adults, in whom the disease is most severe. In conclusion, looking at the attributable risks, at present most of the AHA infections are due to shellfish consumption, travel to endemic areas and contact with patients with AHA. Vaccination of individuals at increased risk of infection, as well as persons with underling liver disease and those at increased risk of complications, combined with surveillance of shellfish retail outlets are efficient control measures.

Epidemiological and virological characterization of a large community-wide outbreak of hepatitis A in southern Italy

A large outbreak of hepatitis A virus (HAV) infection occurred in 2004 in Campania, a region of southern Italy, with 882 cases reported between 1 January and 1 August. The local public health authorities and the Italian National Institute of Health carried out investigations in order to characterize the agent, identify the source of infection and the route of transmission, and implement appropriate control measures. A web-based reporting system enhanced the flow of information between public health authorities, providing real-time epidemic curves and frequency distributions. The same 1B HAV genotype was found in 90% of sera from a subset of patients with acute disease, suggesting a local common source. A case-control study in the municipality with the highest attack rate showed that raw seafood consumption, in particular if illegally sold in water, was strongly associated with HAV illness. Samples of seafood systematically collected from retailers were found contaminated by HAV.

Acute Hepatitis with Severe Cholestasis and Prolonged Clinical Course Due to Hepatitis A Virus Ia and Ib Coinfection

BACKGROUND

Acute viral hepatitis due to hepatitis A virus is a self-limited illness that infrequently has a severe clinical course.

METHODS

We analyzed the virological characteristics of acute hepatitis A in a patient with a severe clinical presentation (peak total and conjugated bilirubin levels, 65.5 mg/dL and 40.1 mg/dL, respectively) and a course of disease that lasted 7 months.

RESULTS

Hepatitis A virus sequencing revealed coinfection with 2 subgenotypes of hepatitis A virus (Ia and Ib) as etiological factors of the illness.

CONCLUSIONS

Hepatitis A virus Ia and Ib coinfection may have accounted for the prolonged and severe course of illness.

Universal mass vaccination against hepatitis A

When first introduced in 1992 the hepatitis A vaccine was recommended for individuals at high risk of exposure. This policy was not expected to have a significant impact on disease incidence at population level in view of the epidemiology of the hepatitis A virus (HAV). More recently two countries, Israel and Bahrain, and regions or subpopulations in others (Australia, China, Byelorussia, Italy, Spain, US) have embarked upon more ambitious vaccination programmes that aim to immunize whole birth cohorts. After a brief survey of the virology and epidemiology of HAV, the disease burden it inflicts and a short history of the development of HAV vaccines--both live (in China) and killed vaccines are available--he vaccination programmes introduced in the countries mentioned above are described. The results have been spectacular: disease incidence, not only in the vaccinated cohorts but also in the whole population, have plummeted within a few years of the start of mass vaccination. There is now convincing evidence that the vaccine confers herd immunity if the main spreaders of the virus are targeted for immunization. This finding should encourage other countries to start mass vaccination programmes against HAV, particularly as pharmacoeconomic studies are beginning to show that such a strategy could be a cost-effective way of controlling the disease. It is now even conceivable to eradicate HAV. In fact, this should be easier to achieve than polio eradication as HAV vaccines confer more durable immunity than polio vaccines. However, the global disease burden of HAV is generally thought not to be high enough to justify such an undertaking in the foreseeable future.

Comparison of hepatitis A and E virus infections among healthy children in Mongolia: evidence for infection with a subgenotype IA HAV in children

To compare the epidemiologic profiles of hepatitis A virus (HAV) and hepatitis E virus (HEV) infections in children in Mongolia, the prevalence of HAV and HEV infections was investigated serologically and molecularly among 717 apparently healthy individuals of 0-20 years of age (mean +/- standard deviation, 8.6 +/- 4.9 years) using serum samples obtained between October 2005 and January 2006. Total antibody against HAV (anti-HAV [total]) was detected in 494 (68.9%) of the 717 subjects, while IgG antibody against HEV (anti-HEV IgG) was detected in only five subjects (0.7%) (P < 0.0001). All five subjects who had anti-HEV IgG, were negative for anti-HEV IgM and HEV RNA. Anti-HAV was detectable in 24 (75.0%) of the 32 infants aged 7 days to 6 months, but not in any of the 8 infants aged 7 to <12 months. The prevalence of anti-HAV was 19.5% (17/87) in the age group of 1-3 years, and it increased to 50.0% (69/138) in the age group of 4-6 years, and further to 81.4% (105/129) in the age group of 7-9 years. Of note, 97.2% of the subjects in the age group of 16-20 years had anti-HAV. The presence of HAV RNA was tested in all 717 subjects, and three children of 1, 4, or 8 years of age were found to have detectable HAV RNA (subgenotype IA). No subject had a history of hepatitis or jaundice. In conclusion, HEV infection was uncommon, but HAV infection lacking overt clinical features was prevalent among children in Mongolia.

Immunogenicity of hepatitis A-inactivated vaccine administered to seronegative infants, and serological follow-up 12 months after second dose

AIM

To evaluate a) the safety and immunogenicity of anti-HAV-inactivated vaccine administered during the first year of life to anti-HAV seronegative babies, and b) the antibody persistence in a low/intermediate endemic area.

METHODS

After having obtained informed written consent from mothers, 92 babies were vaccinated at 4 and 10 mo of age. All babies were seronegative at birth and did not present HAV-RNA shedding in three serial stool samples taken at 1, 2 and 3 mo of age.

RESULTS

No general side effects (fever > 38 degrees C) were observed. After the first dose of vaccine, 70/82 (85.4%) babies developed anti-HAV > 10 mIU/ml and 36/82 (43.9%) > 20 mIU/ml. After the second dose of vaccine, all babies developed a titre > 20 mIU/ml, and GMT was 877 mIU/ml. After 1 y of follow-up, the decreasing rate was similar to that reported for adult populations. Furthermore, three babies doubled the titre observed 1 mo after the second dose, indicating the possible spread of HAV even in a low/intermediate endemic area.

CONCLUSION

Anti-HAV vaccine is safe, immunogenic and able to induce immune memory, and can be integrated into the routine infant immunization schedule during the first year of life.

Distinct changing profiles of hepatitis A and E virus infection among patients with acute hepatitis, patients on maintenance hemodialysis and healthy individuals in Japan

To compare the epidemiologic profiles of hepatitis A virus (HAV) and hepatitis E virus (HEV) infections in Japan, the prevalence of clinical or subclinical HAV and HEV infections was investigated serologically and molecularly among 128 consecutive patients (age, mean +/- standard deviation, 37.5 +/- 14.7 years) who contracted acute hepatitis between 1989 and 2005 in a city hospital, and among 416 hemodialysis patients (60.1 +/- 12.6 years) and 266 medical staff members (34.6 +/- 11.4 years) at the same hospital, using stored periodic serum samples collected since the start of hemodialysis or employment, respectively. Between 1989 and 1995, among 93 patients with acute hepatitis, 51 (54.8%) were diagnosed with hepatitis A and only one patient with hepatitis E. Between 1996 and 2005, however, among 35 patients, only 3 (8.6%) were diagnosed with hepatitis A and 2 (5.7%) with hepatitis E. Although subclinical HEV infection was recognized in four hemodialysis patients (one each in 1979, 1980, 1988, and 2003) and two medical staff members (1978 and 2003) in previous studies, none of the 191 hemodialysis patients who had been negative for anti-HAV at the start of hemodialysis contracted HAV infection during the observation period of 7.6 +/- 6.4 years. Only one (0.4%) of the 246 medical staff members who had been negative for anti-HAV at the start of employment acquired hepatitis A during the observation period of 7.9 +/- 8.0 years: none had subclinical HAV infection. Clinical or subclinical HEV infection has occurred rarely during the last three decades, while HAV infection has markedly decreased at least since 1996.

Measurement and reporting of burden of disease for hepatitis A: results of the EUROHEP.NET feasibility survey

BACKGROUND

European countries use a wide variety of surveillance systems and prevention measures for viral hepatitis. Each system is adapted to the local situation and an overview was never mapped out at European level. The EUROHEP.NET Project is a European Commission-funded feasibility study for a future network on surveillance and prevention of vaccine-preventable hepatitis. We analysed the measurement and reporting of burden of disease for hepatitis A (HA) and B (HB) in the participating countries.

METHODS

Twenty-eight countries were invited to participate in this study. An online survey was available from the project's website (www.eurohep.net). The questions concerned the organisation of the surveillance system, case definition, burden of disease, epidemiology, and vaccination strategies. The responses on data sources and the numeric data related to burden of disease for HA for the period 1997-2001 were analysed.

RESULTS

Twenty-two countries completed the survey for hepatitis A. Data on total number of hospitalisations and deaths were available from 17 and 18 countries, respectively, although sometimes not complete. Data on hospitalisation days, number of liver transplants and proportion of these due to HAV were often not available.

CONCLUSION

Surveillance systems on burden of disease for hepatitis A show a wide diversity among the participating countries. The introduction of a standardised system of data collection at the European Union level according to ICD-10 but respecting the local current practices is a primary need, especially for data that should be collected in all countries, like hospitalisation and mortality. A link to surveillance databases is also strongly recommended.

Primary Hepatitis A vaccination failure is a rare although possible event: results of a retrospective study

A case of Hepatitis A occurred in a traveller in spite of a complete course of immunization with a combined HAV and HBV vaccine [Taliani G, Sbaragli S, Bartoloni A, Santini MG, Tozzi A, Paradisi F. Hepatitis A vaccine failure: how to treat the threat. Vaccine 2003;21(31):4505-6]. A retrospective study was performed to evaluate whether the failure was primary or could be attributed to a specific lot of vaccine or to its inadequate handling and/or storage. Two distinct populations of vaccinees were selected in a 1:2 proportion. The case group (N=31) included subjects who were vaccinated in the same period and with the same lot and batch of vaccine as the case. The control group (N=62) included subjects who received different lot and batch of the same vaccine as the case group. A persisting antibody response to HAV vaccine was found among all subjects (anti-HAV >20mIU/ml). The overall anti-HBs seropositivity rate (anti-HBs >10mIU/ml) was 74%, without significant difference between the case (77%) and the control group (73%; P>0.05). The reported Hepatitis A case can be attributed to a rare primary vaccine failure rather than to inefficacy of a specific lot of vaccine or to inappropriate vaccine handling or storage. Our study supports the indications for use of combined Hepatitis A+B immunization in travellers at risk for both infections, but stresses the need for information on correct hygienic behaviours while abroad.

Changing prevalence, clinical features, and outcome of acute hepatitis in Spain (1982-2003)

BACKGROUND

Diagnostic and preventive measures have contributed to a change in the epidemiology of acute hepatitis. The purpose of the present paper was to assess the changing prevalence of acute hepatitis from 1982 to 2003.

METHODS

Trends in the epidemiology, clinical findings, and outcome of acute viral hepatitis from 1982 to 2003 were examined. A total of 548 episodes of acute hepatitis diagnosed between 1982 and 2003, the clinical course of which was monitored up to the year 2003, were included. Annual changes as well as for the intervals 1982-1992 and 1993-2003 were compared.

RESULTS

Severe infections occurred in 1.3% of cases, with a mortality of 0.6%, with progression into chronicity in 25.1%. The annual incidences of acute hepatitis and the comparative intervals 1982-1992 and 1993-2003 showed a decline of parenterally -B, delta and C virus- transmitted infections, unchanged number of cases of acute hepatitis A, an increase in the number of cases of drug-induced hepatitis, increase in median ages, and a decrease in the proportion of hepatitis in injecting drug users. Ages of patients with hepatitis A tended to increase.

CONCLUSIONS

A decline of parenterally transmitted acute hepatitis was documented throughout a 22-year period, while the number of cases of hepatitis A was unchanged and that of drug-induced hepatitis increased. Evaluation of the current targeted hepatitis A vaccination approach and adequate pharmacovigilance measures are required in the near future.

Clinical and virological improvement of hepatitis B virus-related or hepatitis C virus-related chronic hepatitis with concomitant hepatitis A virus infection

BACKGROUND

We evaluated the clinical and virological characteristics of hepatitis A virus infection in persons concomitantly infected with hepatitis B virus (HBV) or hepatitis C virus (HCV).

METHODS

We enrolled 21 patients with acute hepatitis A and chronic hepatitis with no sign of liver cirrhosis, 13 patients who were positive for hepatitis B surface antigen (case B group), 8 patients who were anti-HCV positive (case C group), and 21 patients with acute hepatitis A without a preexisting liver disease (control A group). Two control groups of patients with chronic hepatitis B (control B group) or C (control C group) were also chosen. All control groups were pair-matched by age and sex with the corresponding case group.

RESULTS

Fulminant hepatitis A was never observed, and hepatitis A had a severe course in 1 patient in the case B group and in 1 patient in the control A group. Both patients recovered. On admission, HBV DNA was detected in 1 patient in the case B group (7.7%) and in 13 patients (50%) in the control B group; HCV RNA was found in no patient in the case C group and in 16 patients (81.2%) in the control C group. Of 9 patients in the case B group who were followed up for 6 months, 3 became negative for hepatitis B surface antigen and positive for hepatitis B surface antibody, 2 remained positive for hepatitis B surface antigen and negative for HBV DNA, and 4 became positive for HBV DNA with a low viral load [corrected] Of 6 patients in the case C group who were followed up for 6 months, 3 remained negative for HCV RNA, and 3 had persistently low viral loads.

CONCLUSION

Concomitant hepatitis A was always self-limited, associated with a marked inhibition of HBV and HCV genomes, and possibly had a good prognosis for the underlying chronic hepatitis.

Exposure to HAV infection in patients with chronic liver disease in Italy, a multicentre study

We carried out a multicentre study on 2830 patients with chronic liver disease from 79 liver units (25 in northern, 24 in central and 30 in southern Italy) to evaluate naturally acquired immunity against hepatitis A virus (HAV) in relation to age, sex, geographical area of origin and entity of liver disease, and to define the strategy for specific vaccination. Antibody to HAV (anti-HAV) was detected in 1514 (53.5%) of the 2830 patients tested; the prevalence was 50.4% in males and 59.1% in females. Both in central and southern Italy the prevalence of anti-HAV positive subjects increased with increasing age from 43.3 and 44.7%, respectively, in the 0-30-year-old subjects to 80.1 and 68.3%, respectively, in those aged over 60 years. The overall prevalence was much lower in northern Italy, as were the variations from one age group to another, from 28.4% in the 0-30-year-old subjects to 38% in those aged over 60 years. 40.6% of patients with cirrhosis lacked naturally acquired protection against HAV; this percentage was higher in northern (60.5%) than in central (34.9%, P < 0.0001) and southern Italy (27.6%, P < 0.0001). The high prevalence of patients in Italy with chronic hepatitis or cirrhosis who lack naturally acquired immunity to HAV warrants the implementation of vaccination programmes against hepatitis A in such patients.

An outbreak of hepatitis A virus infection with a high case-fatality rate among injecting drug users

BACKGROUND/AIMS

In 2002, the first reported outbreak of hepatitis A virus (HAV) infection involving mostly intravenous drug users (IDU) occurred in Italy. We attempted a thorough evaluation of the outbreak, including epidemiological, clinical and virological analyses.

METHODS

We conducted an epidemiological investigation, including a case-control study, to identify the source and the modes of HAV transmission. Hepatitis B and C (HCV) viruses and human immunodeficiency virus (HIV) coinfections were clinically analysed. Sequence analysis of the VP1/2A junction of the HAV isolates was also performed.

RESULTS

Of the 47 symptomatic cases, 35 were IDUs. The only associated risk factor was contact (not related to injecting practices) with a jaundiced person (odds ratio: 5.8; 95% confidence interval: 1.3-29.9). Of the cases, 58% were anti-HCV positive and 4.7% anti-HIV positive. Three individuals died of acute liver failure: 2 were HCV-coinfected alcohol abusers, with underlying liver cirrhosis; 1 was HCV/HIV-coinfected. HAV-RNA was found in 15 of the 24 tested patients: genotype IB (8 cases) and IIIA (7 cases) were detected.

CONCLUSIONS

HAV was probably transmitted through the fecal-oral route, although parenteral transmission cannot be excluded. The high fatality rate was probably due to severe underlying liver damage. The occurrence of this outbreak highlights the need for routine HAV vaccination for IDUs.

Hypertransaminasemia in childhood as a marker of genetic liver disorders

BACKGROUND

The widespread use of routine biochemical assays has led to increased incidental findings of hypertransaminasemia. We aimed to evaluate the prevalence of different causes of raised aminotransferase levels in children referred to a university department of pediatrics.

METHODS

We investigated 425 consecutive children (age range, 1-18 years) with isolated hypertransaminasemia. All patients had raised aminotransferase levels on at least two occasions in the last month before observation. Cases due to major hepatotropic viruses were excluded.

RESULTS

During the first 6 months of observation, 259 children showed normalized liver enzymes. Among the remaining 166 patients with hypertransaminasemia lasting for more than 6 months, 75 had obesity-related liver disease; 51, genetic disorders; 7, autoimmune hepatitis; 5, cholelithiasis; 3, choledochal cyst; and 3, celiac disease. Among the 51 children with genetic disorders, 18 had Wilson disease; 14, muscular dystrophy; 4, alpha-1-antitrypsin deficiency; 4, Alagille syndrome; 4, hereditary fructose intolerance; 3, glycogen storage disease (glycogenosis IX); 2, ornithine transcarbamylase deficiency; and 2, Shwachman's syndrome. In 22 children, the hypertransaminasemia persisted for more than 6 months in the absence of a known cause.

CONCLUSIONS

Genetic disease accounted for 12% of cases of isolated hypertransaminasemia observed in a tertiary pediatric department. A high level of suspicion is desirable for an early diagnosis of these disorders, which may present with isolated hypertransaminasemia and absence of typical clinical signs.

Feasibility of vaccination in preventing secondary cases of hepatitis A virus infection

Although the secondary transmission of hepatitis A virus (HAV) infection is preventable through vaccination, it is not known whether the vaccination of household contacts is feasible. To this end, we conducted a prospective cohort study among the household contacts, 40 years of age or less, of all persons infected with primary HAV infection (index cases) and admitted to eight hospitals in southern Italy within 7 days of onset. Household contacts were vaccinated, and serum samples were taken at vaccination and after 14 and 45 days. Secondary cases were defined as those with IgM seroconversion occurring at least two weeks after enrollment. Coprimary cases were those assumed to have had the same exposure as the index case. Susceptible cases were those who were negative for both IgG and IgM. A total of 495 household contacts participated (acceptance rate of 65%); 65% were vaccinated within 4 days of admission of the index case and 95% within 7 days. At enrollment, 196 (39.6%) household contacts were immune (IgG-positive serum). During follow-up, 19 (3.8%) were IgM-positive: 13 (2.6%) were coprimary cases and 6 (1.2%; 95% CI: 0.2-3.2) secondary cases (5 identified at 14 days from vaccination and 1 at 45 days). Of the 241 susceptible cases, 192 (79.7%) had developed IgG antibodies at 14 days and only 3 (1.2%) did not develop IgG antibodies at 45 days. The 65% acceptance rate and the finding that 95% of the participating household contacts were vaccinated within 7 days of the index case's hospitalization indicate that timely vaccination is indeed feasible. The necessity of returning for the collection of blood samples probably decreased the acceptance rate.

Outbreak of infection with hepatitis A virus (HAV) associated with a foodhandler and confirmed by sequence analysis reveals a new HAV genotype IB variant

An outbreak of infection with hepatitis A virus associated with a foodhandler and involving 26 subjects occurred in Southern Italy. Sequence analysis of the VP3-VP1 and VP1-P2A junctions confirmed that the outbreak was due to a point source and allowed the identification of a new genotype IB variant. This report confirms the usefulness of sequence-based molecular fingerprinting during outbreaks.

HAV replication in acute hepatitis with typical and atypical clinical course

The correlation between the length of viremia as detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and the clinical course of hepatitis A virus (HAV) infection was studied. Sixty-six consecutive patients with acute hepatitis A who were admitted to hospital in two infectious disease units in southern Italy were enrolled: 57 had a self-limited course of the disease (typical course), 4 a prolonged course, and 5 relapsing hepatitis. Plasma HAV RNA was sought by RT-PCR, using primers made at 5'-NTR of HAV, designed to amplify a 273-bp fragment and detected by 2% agarose gel and by hybridization with a specific biotinylated probe. In four patients with prolonged acute hepatitis A, the plasma HAV RNA, which was positive on the day of admission to hospital, was found to be negative from day 62, 46, 84, and 105, respectively, after the onset of the symptoms. In patients with relapsing hepatitis, HAV viremia paralleled the clinical and biochemical course of disease. In all patients with a typical self-limiting course, clearance of plasma HAV RNA was observed within 20 days of the onset of symptoms. In most patients, plasma HAV viremia became undetectable before the normalization of serum aminotransferases, underlining the importance of the immune reaction in the pathogenesis of acute hepatitis A. The data also suggest that the detection of plasma HAV RNA after 20 days of illness may predict a prolonged course of the disease, but relapsing hepatitis remains unpredictable on the basis of plasma HAV determination.

The use of hepatitis a vaccination in Italy: an economic evaluation

We report on the conduct and results of an economic model of two different strategies of vaccination against hepatitis A in Italy. In strategy 1 (universal vaccination), all newborns are vaccinated simultaneously with MMR at 15 months and all 12 year olds are vaccinated with combined hepatitis A and B vaccine. In strategy 2 (contacts' vaccination) only subjects with a close social and spatial relationship with the sick are vaccinated. In strategy 1 costs per avoided case and net costs per avoided case values are always very high. Net costs become very low when newborns and 12 year olds are vaccinated, and become negative (indicating a potential gain) when 12 year olds are vaccinated. From an economic viewpoint, universal vaccination appears recommendable only in epidemic conditions. For strategy 2 our model shows that cost for avoidable case are very low and net costs for avoided case are always negative, showing the potential presence of an absolute benefit. We conclude that in Italy mass vaccination appears economically worthwhile only during epidemics but vaccination of contacts is an economically worthwhile routine measure.

Risk groups for hepatitis A virus infection

We report the conduct and results of a systematic search for evidence of risk of infection with hepatitis A virus (HAV) among blood transfusion recipients, travellers, the military, healthcare workers, sewage workers, foodhandlers, day care assistants, institutionalised subjects, blood transfusion recipients, drug addicts, homosexuals, prisoners and other risk groups such a liver transplantees. We report our recommendations for the use of the HAV vaccine in these groups.

The role of vaccine in controlling hepatitis A epidemics

We report the conduct and results of a review of recent literature to describe various types of epidemics and outbreaks in Italy or countries with similar epidemiological profiles and to assess vaccine use in outbreak situations. We identified three scenarios most likely to occur in Italy: outbreaks occurring in small closed communities (nursery or a primary school), outbreaks in communities of limited dimensions (small towns or villages) and open community settings in which epidemics occur at regular intervals (person-to-person transmission). In closed communities we recommend vaccination of family members and school personnel living or working in close proximity to the index case as well as classmates. We also recommend vaccination when there is a proof of secondary transmission within the community. In small open communities we recommend vaccination of more susceptible age groups such as children and adolescents. For large open communities the only practicable alternative strategy is vaccination of close family contacts of acute cases couple with non-immunity boosting control measures.

Hepatitis A: post-exposure prophylaxis

We report on the findings of an exploratory review of evidence published in English from 1945 to identify the best post-exposure prophylaxis treatment and the longest acceptable interval after exposure for prophylaxis to be effective. We found no evidence that post-exposure administration of currently available immunoglobulins is effective in preventing hepatitis A infection and disease. The use of immunoglobulins for immunoprophylaxis should not be widely recommended until a systematic review of the evidence has been conducted. We recommend that active immunization to secondary contacts of exposed and vaccinated subjects be offered.

Anti-hepatitis A virus seroprevalence and seroconversion in a cohort of patients with chronic viral hepatitis

BACKGROUND

Patients with chronic hepatitis C infected by hepatitis A virus have a substantial risk of fulminant hepatitis or death, while the course of hepatitis A virus is uncomplicated in most subjects with chronic hepatitis B.

AIM

To evaluate the prevalence of anti-hepatitis A virus antibodies and the incidence of hepatitis A virus seroconversion in a nationwide sample of 530 patients with chronic hepatitis B and/or hepatitis C infection initially susceptible to this infection after a follow-up of some years.

RESULTS

The overall anti-hepatitis A virus prevalence was 85.7%, with no difference between males and females. By the age of 50 years, almost all patients were found to have been exposed to hepatitis A virus. After a mean follow-up period of 76 months the overall anti-hepatitis A virus seroconversion rate in the 76 initially susceptible individuals was 1.2 per 100 person/years. However, it was 0.3 per 100 person/years in those hepatitis B surface antigen positive but 3.36 per 100 person/years in those anti-hepatitis C virus positive. None of the seroconverters was affected by a clinically evident disease or showed deterioration of underlying chronic liver disease.

CONCLUSIONS

The present study shows that Italian patients >50 years of age with chronic liver disease have already been exposed to hepatitis A virus suggesting that anti-hepatitis A virus screening is not advisable in these subjects.

Foodborne viruses

Foodborne and waterborne viral infections are increasingly recognized as causes of illness in humans. This increase is partly explained by changes in food processing and consumption patterns that lead to the worldwide availability of high-risk food. As a result, vast outbreaks may occur due to contamination of food by a single foodhandler or at a single source. Although there are numerous fecal-orally transmitted viruses, most reports of foodborne transmission describe infections with Norwalk-like caliciviruses (NLV) and hepatitis A virus (HAV), suggesting that these viruses are associated with the greatest risk of foodborne transmission. NLV and HAV can be transmitted from person to person, or indirectly via food, water, or fomites contaminated with virus-containing feces or vomit. People can be infected without showing symptoms. The high frequency of secondary cases of NLV illness and - to a lesser extent - of hepatitis A following a foodborne outbreak results in amplification of the problem. The burden of illness is highest in the elderly, and therefore is likely to increase due to the aging population. For HAV, the burden of illness may increase following hygienic control measures, due to a decreasing population of naturally immune individuals and a concurrent increase in the population at risk. Recent advances in the research of NLV and HAV have led to the development of molecular methods which can be used for molecular tracing of virus strains. These methods can be and have been used for the detection of common source outbreaks. While traditionally certain foods have been implicated in virus outbreaks, it is clear that almost any food item can be involved, provided it has been handled by an infected person. There are no established methods for detection of viruses in foods other than shellfish. Little information is available on disinfection and preventive measures specifically for these viruses. Studies addressing this issue are hampered by the lack of culture systems. As currently available routine monitoring systems exclusively focus on bacterial pathogens, efforts should be made to combine epidemiological and virological information for a combined laboratory-based rapid detection system for foodborne viruses. With better surveillance, including typing information, outbreaks of foodborne infections could be reported faster to prevent further spread.

Detection of hepatitis A virus in mussels from different sources marketed in Puglia region (South Italy)

Hepatitis A virus (HAV) infection is endemic in Puglia (South Italy). Epidemiological studies indicate that shellfish consumption, particularly mussels, is a major risk factor for HAV infection, since these products are eaten raw or slightly cooked. Nested reverse transcriptase-polymerase chain reaction (RT-PCR) has been shown to be a sensitive technique for the detection of HAV in mussels. The aim of the present study was to detect the presence of HAV in a large sample of mussels by nested RT-PCR and to confirm the presence of infectious viral particles in positive samples by cell culture infection and RT-PCR confirmation. Two hundred and ninety samples of mussels from different sources were collected between December 1999 and January 2000. One hundred samples were collected before being subjected to depuration, 90 after depuration, and 100 were sampled in different seafood markets. HAV-RNA was detected in 20 (20.0%) of non-depurated mussels, in 10 (11.1%) of depurated samples, and in 23 (23.0%) of samples collected in the shellfish markets, without any significant difference in the prevalence of positive samples by collection sources (chi2 = 4.79, p = 0.09). Of the 53 samples found positive by nested RT-PCR, 18 (34.0%) resulted positive by cell culture assay. No relationship between viral contamination and bacterial contamination was found (p = 0.41). This study confirms the usefulness of molecular techniques in detecting HAV in shellfish and, thus, for the screening of a large sample of naturally contaminated mussels. Improved shellfish depuration methods are needed to obtain virus-safe shellfish and reduce the risk for public human health.

The survival of hepatitis A virus in fresh produce

Fresh produce has been repeatedly implicated as the source of human viral infections, including infection with hepatitis A virus (HAV). The objective of the present study was to evaluate the HAV adsorption capacity of the surface of various fresh vegetables that are generally eaten raw and the persistence of the HAV. To this end, the authors experimentally contaminated samples of lettuce, fennel, and carrot by immersing them in sterile distilled water supplemented with an HAV suspension until reaching a concentration of 5 log tissue culture infectious dose (TCID50)/ml. After contamination, the samples were stored at 4 degrees C and analysed at 0, 2, 4, 7, and 9 days. To detect the HAV, RT-nested-PCR was used; positive samples were subjected to the quantitative determination using cell cultures. The three vegetables differed in terms of their adsorption capacity. The highest quantity of virus was consistently detected for lettuce, for which only a slight decrease was observed over time (HAV titre = 4.44 +/- 0.22 log TCID50/ml at day 0 vs. 2.46 +/- 0.17 log TCID50/ml at day 9, before washing). The virus remained vital through the last day of storage. For the other two vegetables, a greater decrease was observed, and complete inactivation had occurred at day 4 for carrot and at day 7 for fennel. For all three vegetables, washing does not guarantee a substantial reduction in the viral contamination.

Closed-circuit system for the depuration of mussels experimentally contaminated with hepatitis A virus

In Italy, the consumption of raw or slightly cooked mussels represents the most important risk factor for the transmission of hepatitis A virus (HAV). Although there exist effective methods for the bacterial depuration of contaminated mussels, these methods are poorly effective on enteric viruses. The objective of the present study was to evaluate the effectiveness of a closed-circuit depuration system that uses both ozone and UV light for disinfecting water and that allows salinity and temperature, important parameters for the metabolism of mussels (Mytilus galloprovincialis), to be maintained at constant levels. The results showed that this depuration method decreased the viral load (from 1.72 log 50% tissue culture infective dose [TCID50] ml(-1) to <1 log TCID50 ml(-1) within 24 h and from 3.82 log TCID50 ml(-1) to <1 log TCID50 ml(-1) within 48 h). However, in both cases, after 120 h of depuration, a residual amount of virus capable of replicating in cells was detected. These results show that depuration, even if performed with advanced systems, may not guarantee the absence of virus.

Vaccination policy against hepatitis A in Italy

In Italy, improved sanitation and living conditions have led to a decline in the rate of hepatitis A infection among children generating an increasing proportion of adults susceptible to this virus. Shellfish consumption is a major source of infection while person to person transmission is important in the spread of infection and in the maintenance of outbreaks. Thus prevention of secondary HAV infection is a crucial point. A randomised controlled trial of hepatitis A vaccine in household contacts of people with sporadic HAV infection in Italy has shown a protective efficacy of 82% (CI 20-96%). The two secondary infections in the vaccine group were symptomless, suggesting that the disease expression may be weaker in vaccinated subjects.

Sequence variations of precore/core and precore promoter regions of hepatitis B virus in patients with or without viral reactivation during cytotoxic chemotherapy

Reactivation of the hepatitis B virus (HBV) is a well-described complication among cancer patients undergoing cytotoxic chemotherapy. Mutations in the preC/C and the preC promoter regions of HBV have been reported in some patients who developed this condition. A G-to-A mutation at nt 1896 in the preC/C region (HBeAg negative/ anti-HBe positive) has been associated with more severe liver disease than that caused by wild type virus. In addition, it has been suggested that patients with these mutations may be more likely to reactivate than those with the wild type virus. Whether or not such mutations were present before the commencement of or developed during the course of cytotoxic chemotherapy is not known. In this study, 28 cancer patients (consisting of 14 consecutive patients who developed HBV reactivation and another 14 who had no reactivation during cytotoxic chemotherapy) are reported. The objectives were firstly, to determine the prechemotherapy HBeAg status and nucleotide sequences of the preC/C and preC promoter regions of HBV in order to determine if these parameters affected the rate of reactivation, and secondly, for those who developed reactivation, to determine whether the mutations were present before chemotherapy or developed during, possibly as a result of, cytotoxic chemotherapy. HBV DNA was amplified by PCR and nucleotide sequencing performed on samples taken prior to chemotherapy and at the time of reactivation. Results revealed that 16 of the 28 patients were HBeAg negative/anti-HBe positive. Of these 16, four (57%) of the seven patients who had nt 1896 mutation, but only one (17%) of the six who had the wild type HBV genome, developed reactivation. Three had no detectable HBV DNA. In the majority of cases, the type of virus, i.e. wild/mutant at preC/C, that was detected during the reactivation was identical to that detected in the pretreatment samples. With respect to the preC promoter region, the two commonest mutations detected were at nt 1762 (A to T) and nt 1764 (G to A). When this region was translated into amino acid sequences, stop codons leading to truncated X protein at carboxyl terminus were found in four patients, three of whom developed HBV reactivation. We conclude that chronic HBV carriers who are HBeAg negative/anti-HBe positive with nt 1896 mutation (G to A) may be more likely to develop HBV reactivation during cytotoxic chemotherapy than those with the wild type virus. Cytotoxic chemotherapy does not appear to select out mutant HBV, or to be consistently mutagenic in patients who develop HBV reactivation. The occurrence of stop codons in the amino acid sequences of the X protein in three patients who developed HBV reactivation, including one who was detected only at the time of reactivation, is of particular interest, as such mutant viruses remain replication competent.

Frequent integration of precore/core mutants of hepatitis B virus in human hepatocellular carcinoma tissues

The development of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) frequently follows persistent HBV infection and may arise in individuals who are hepatitis B e antigen (HBeAg) negative, indicating the possible presence of precore/core mutants. It is unclear whether precore/core mutants are associated with tumour development or are selected for after chromosomal integration of the wild-type viral DNA. We studied the status and sequence variation of the precore/core region of HBV in 56 patients with HBV-associated HCC and in various corresponding non-tumour tissues by Southern blot analysis, polymerase chain reaction and direct sequencing. Southern blot showed that integrated HBV DNA existed in 43 of 56 HCC tissues. Sequence analysis revealed mutations in 65% of the HCC (26/40) and 45% (14/31) of the corresponding non-tumour tissues. The mutation at nucleotide (nt) 1896, known to prevent HBeAg synthesis, was detected in 40% (16/40) of the tumours and in 35.4% (11/31) of the non-tumour tissues. Other mutations were found at nt 1899 (eight of 40 in HCC; three of 31 in non-tumour tissues), nt 1898 (seven of 40 in HCC; two of 31 in non-tumour tissues), nt 1912 (seven of 40 in HCC; none of 31 in non-tumour tissues) and nt 1886 (three of 40 in HCC; none of 31 in non-tumour tissues). To determine whether this finding merely reflected the prevalence of such mutants in this geographical region, HBV DNA from the sera of patients (also in this region) with acute and chronic hepatitis were sequenced. The nt 1896 mutant was found in 5.6% (one of 18) of patients with acute hepatitis B and in 22.8% (nine of 35) of patients with chronic hepatitis B. However, the nt 1898 mutation was not found in any of these sera. The precore/core mutant was observed with increasing frequency from acute hepatitis to chronic hepatitis, non-tumour and HCC, and this difference in frequency was significant between HCC and acute hepatitis B groups (P < 0.01), suggesting that the precore/core mutant or hepatocytes harbouring this mutant may be under immune selection and that such mutations may facilitate integration and subsequent tumour development.

Inactivation of hepatitis A virus in heat-treated mussels

Hepatitis A is a widespread infectious disease world-wide. In Italy, shellfish consumption was shown to be a major risk factor for hepatitis A infection, especially when these products are eaten raw or slightly cooked. The aim of the present study was to evaluate Hepatitis A virus (HAV) resistance in experimentally contaminated mussels treated at different temperatures (60, 80 and 100 degrees C) for various times. The presence of HAV was evaluated by cell culture infection and reverse transcriptase-polymerase chain reaction confirmation. The experiments, carried out on HAV suspension and contaminated mussel homogenate both containing about 10(5) 50% tissue culture infectious dose ml-1, showed that, under our experimental conditions, the treatments at 60 degrees C for 30 min, 80 degrees C for 10 min and an immersion at 100 degrees C for 1 min were not sufficient to inactivate all the viruses; it was necessary to prolong the treatment at 100 degrees C for 2 min to completely inactivate the virus. Thus it is advisable to eat only cooked shellfish, paying particular attention to the times and temperatures used in the cooking process, since evidence suggests that the shellfish body may protect the virus from the heat effect.

Efficacy of hepatitis A vaccine in prevention of secondary hepatitis A infection: a randomised trial

BACKGROUND

Hepatitis A vaccination stops outbreaks of hepatitis A infection, but its efficacy against infection after exposure has not been proven. We investigated the use of hepatitis A vaccine to prevent secondary infections with hepatitis A virus (HAV).

METHODS

We did a randomised controlled trial of hepatitis A vaccine in household contacts of people with sporadic HAV infection (index cases). Households (index cases and contacts) were randomly assigned to the vaccine group or unvaccinated group, according to the study week in which they were enrolled. All household contacts in the vaccine group received vaccination at the time of entry to the study.

FINDINGS

During 45 days of follow-up, secondary infection had occurred in ten (13.3%) of 75 households (two families had two cases each) in the untreated group and in two (2.8%) of 71 households in the vaccine group. The protective efficacy of the vaccine was 79% (95% CI 7-95). The number of secondary infections among household contacts was 12 (5.8%) of 207 in the unvaccinated group and two (1.0%) of 197 in the vaccinated group. Therefore, 18 individuals needed to be vaccinated to prevent one secondary infection.

INTERPRETATION

Hepatitis A vaccine is effective in the prevention of secondary infection of HAV and should be recommended for household contacts of primary cases of HAV infection.

Safety and immunogenicity of hepatitis A vaccine in infants: a candidate for inclusion in the childhood vaccination programme

Forty-eight infants received a single dose (720 ELISA units = 0.5 ml) of inactivated hepatitis A vaccine at the fifth month of age with booster at the 11th month of age, together with the second and third doses of the vaccines compulsory under Italian law (diphtheria, tetanus, oral polio and hepatitis B). Overall, the seroconversion rate was 100%. The anti-HAV geometric mean titre (GMT) reached 3,021 mIU/ml in infants born to anti-HAV-negative mothers, but only 399 mIU/ml in infants born to anti-HAV-positive mothers. Hepatitis A vaccine was immunogenic, safe and well tolerated without significant side-effects. There seems to be no reason for not including it in childhood vaccination programmes particularly in low endemic HAV areas.