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A R Zanetti

Publications and source records attributed to A R Zanetti.

At least 19 recordsLinked to original sources
PubMed2002

Safety and immunogenicity of 23-valent pneumococcal polysaccharide vaccine in HIV-1 infected former drug users.

The immunogenicity of 23-valent pneumococcal polysaccharide vaccine was assessed in 57 HIV-1 infected former intravenous drug users and in 20 HIV-1 negative controls. The effect of vaccination on HIV-1 infection was studied in a subgroup of 38 patients, 60% of whom under highly active antiretroviral therapy (HAART). Antibody to capsular polysaccharides from Streptococcus pneumoniae serotypes 3, 4, 6B, 19F, 23 F, and changes in CD4+ count, HIV-1 RNA, proviral DNA and HIV-1 phenotype were measured in pre- and post-vaccination samples. Vaccinations were well-tolerated. The rate of responders was higher (P<0.05) in HIV-1 negative than in HIV-1 infected individuals. No difference in antibody response was found within HIV-1 infected patients stratified according to CD4+ counts. Post-vaccination antibody geometric mean concentrations (GMCs) to the five antigens were higher (P<0.05) than baseline in HIV-1 negative subjects, but not in HIV-1 positive individuals. Those with CD4+ >500 cells/mm(3) showed a significant increase of antibody against type 3 only. Immunisation caused no significant changes in CD4+ counts and in either plasma HIV-1 RNA nor proviral DNA levels. Pneumococcal vaccination does not induce virological or immunological deterioration in HIV infected patients, but the antibody response to a single dose of vaccine is poor.

Adult↗
PubMed2001

Effectiveness of hepatitis B vaccination in babies born to hepatitis B surface antigen-positive mothers in Italy.

This study examined 522 children born to hepatitis B surface antigen (HBsAg)-positive mothers from 1985 through 1994 and evaluated the protection provided by anti-hepatitis B virus (HBV) immunization at birth. Babies were given hepatitis B immunoglobulin and hepatitis B vaccine at birth. At 5-14 years after immunization, 17 children (3.3%) were anti-HB core antigen positive, and 3 also were HBsAg positive. One carrier child had a double mutation, with substitution of proline-->serine at codons 120 (P120S) and 127 (P127S) within the a determinant of HBsAg. Of the 522 children, 400 (79.2%) of 505 still had protective anti-HBsAg titers > or =10 mIU/mL. Thus, HBV vaccination of children born to HBsAg-positive mothers is effective and confers long-term immunity. There is no evidence that the emergence of HBV escape mutants secondary to the immune pressure against wild-type HBV is of concern.

Adolescent↗
PubMed2001

Safety and immunogenicity of a conjugate vaccine against Haemophilus influenzae type b in splenectomized and nonsplenectomized patients with Cooley anemia.

Patients with thalassemia are at increased risk for infections, especially after undergoing splenectomy. Vaccinations and antimicrobial prophylaxis are recommended in these patients, but the optimal immunization schedule for Haemophilus influenzae type b (Hib) vaccine is unknown. The immunogenicity of a conjugate Hib vaccine was investigated in 57 patients with thalassemia, 32 of whom had undergone splenectomy. Anti-capsular antibodies to Hib (anti-polyribosylribitol phosphate) were measured before vaccination and 2, 6, 12, 24, and 36 months after vaccination. Immunization was well tolerated. All patients achieved protective (>1 microg/mL) antibody levels. Antibody titers declined after the initial postvaccination increase, becoming undetectable in 4 patients and decreasing to concentrations of 0.15-1 microg/mL in another 2 patients when tested 2-3 years after vaccination. Hib conjugate vaccine is safe and immunogenic in patients with thalassemia major; however, additional studies are needed to assess the need and timing of booster vaccination to maintain long-term immunity.

Adolescent↗
PubMed2001

Update on hepatitis B vaccination in Italy 10 years after its implementation.

Since the beginning of the Italian program of immunization against hepatitis B, vaccine has been given to more than 9 million children, with an outstanding record of safety and efficacy. The coverage rate is globally around 94%, with differences between Northern and Southern regions, the latter having the lower acceptance rate. According to the National Surveillance System (SEIEVA), the incidence of acute hepatitis B per10(5) inhabitants declined from 5.4 in 1990 to 2.9 in 1998. The reduction was even greater among 15-24-year-old individuals, where the incidence rate per 10(5) decreased from 17.3 to 4.2 in the same period. In parallel with the decline of hepatitis B, Delta hepatitis has also dropped significantly. We expect that by the year 2003 (12 years after the beginning of the program) this vaccination strategy will have led to the protection of all Italians aged 0-24 years, who are those at the higher risk for acquiring hepatitis B virus (HBV) and for developing the chronic carrier state.

Adolescent↗
PubMed2001

Influenza vaccination of HIV-1-positive and HIV-1-negative former intravenous drug users.

The immunogenicity of an anti-influenza vaccine was assessed in 409 former intravenous drug user volunteers and its effect on the levels of HIV-1 RNA, proviral DNA and on CD4+ lymphocyte counts in a subset HIV-1-positive subjects was measured. HIV-1-positive individuals (n = 72) were divided into three groups on the basis of their CD4+ lymphocyte counts, while the 337 HIV-1-negative participants were allocated into group four. Haemagglutination inhibiting (HI) responses varied from 45.8 to 70% in the HIV-1-positive subjects and were significantly higher in group four (80.7% responses to the H1N1 strain, 81.6% to the H3N2 strain, and 83% to the B strain). The percentage of subjects with HI protective antibody titres (> or = 1:40) increased significantly after vaccination, especially in HIV-1 uninfected subjects. Immunization caused no significant changes in CD4+ counts and in neither plasma HIV-1 RNA nor proviral DNA levels. Therefore, vaccination against influenza may benefit persons infected by HIV-1.

Adolescent↗
PubMed2000

Association between neonatal blood microtransfusions in the 1960s and hepatitis C virus infection.

In the 1960s, a common practice in Italy was to give a few mL of blood or plasma to underweight or preterm newborns. We postulated that this practice might be the cause of hepatitis C virus (HCV) infections seen today in adults with a negative history, and no recall of such transfusions. We examined the transfusion files of children admitted to the Department of Paediatrics during 1968-74, and found that 613 children had been transfused within the first year of life. Of 57 traceable patients, 28 are now positive for antibodies to HCV, 17 of whom received at least one microtransfusion from a common donor who is also positive.

Adult↗
PubMed2000

Dominant role of host selective pressure in driving hepatitis C virus evolution in perinatal infection.

The dynamics of the genetic diversification of hepatitis C virus (HCV) populations was addressed in perinatal infection. Clonal sequences of hypervariable region 1 of the putative E2 envelope protein of HCV were obtained from four HCV-infected newborns (sequential samples spanning a period of 6 to 13 months after birth) and from their mothers (all samples collected at delivery). The data show that the variants detected between birth and the third month of life in samples from the four newborns were present in the HCV populations of their mothers at delivery. In the newborns, a unique viral variant (or a small group of closely related variants) remained stable for weeks despite active viral replication. Diversification of the intrahost HCV population was observed 6 to 13 months after birth and was substantially higher in two of the four subjects, as documented by the intersample genetic distance (GD) (P = 0.007). Importantly, a significant correlation between increasing GD and high values for the intersample K(a)/K(s) ratio (the ratio between anoffymous and synonymous substitutions; an index of the action of selective forces) was observed, as documented by the increase of both parameters over time (P = 0.01). These data argue for a dominant role of positive selection for amino acid changes in driving the pattern of genetic diversification of HCV populations, indicate that the intrahost evolution of HCV populations is compatible with a Darwinian model system, and may have implications in the designing of future antiviral strategies.

Amino Acid Sequence↗
PubMed2000

GBV-C/hepatitis G virus in acute nonA-E hepatitis and in acute hepatitis of defined aetiology in Italy.

The role of GBV-C/HGV in the aetiology of acute non A-E hepatitis and its impact on the course of acute hepatitis of defined aetiology were investigated by detecting viral RNA by RT-PCR and antibody to the E2 protein of GB virus C (anti-E2) by EIA. Ninety-eight patients with acute nonA-E hepatitis, 35 patients with acute hepatitis A, 63 with acute hepatitis B, 29 with acute hepatitis C and 270 controls were enrolled in this study. The prevalence of GBV-C/HGV RNA was similar among patients with acute nonA-E hepatitis (3.1%), with acute hepatitis A (2.9%), and controls (3.7%), but significantly higher (P < 0.05) among those with hepatitis B or C (19.0% and 48.3%, respectively). Similar figures were obtained considering the total rate of GBV-C/HGV exposure (viral RNA or anti-E2 positivity). The majority (24/30 or 80%) of GBV-C/HGV RNA positive patients reported a parenteral source of exposure whereas the remaining 20% denied having known risk factors. The liver function test values and the rate of chronic hepatitis B and C were similar in patients co-infected and in those not co-infected with GBV-C/HGV. This study excludes a significant role of GBV-C/HGV infection in the aetiology of acute nonA-E hepatitis in Italy. Concomitant GBV-C/HGV and HBV or HCV infection does not worsen the clinical course of illness among patients with acute hepatitis.

Acute Disease↗
PubMed1999

Novel hepatitis E virus (HEV) isolates from Europe: evidence for additional genotypes of HEV.

Hepatitis E infection is associated with areas in which hepatitis E virus (HEV) infection is endemic. Acute infections in industrialized nations are usually linked to travel to endemic areas. Recently, an acute hepatitis infection in a patient from the United States (US), with no recent foreign travel history, was linked to a novel strain of HEV. Although a few additional cases have been reported from patients who have not traveled to endemic areas, the source of these infections has not been determined. The objective of this study was to identify additional HEV isolates from patients with acute infection who had no recent history of travel to areas where HEV is considered endemic, and to determine the genetic relationship between these and other HEV isolates. Viral RNA was isolated from serum and polymerase chain reaction (PCR) was performed using consensus primers based on a number of HEV isolates. HEV sequence in open reading frame (ORF) 1 and ORF2 was identified in three patients from nonendemic areas, one from Italy and two from Greece. Comparative and phylogenetic analyses were performed. The Greek and Italian isolates were significantly divergent from two isolates from the US and isolates identified previously from HEV-endemic regions. The Italian isolate was distinct from the two Greek isolates. In addition, the two Greek isolates were significantly divergent from each other. Phylogenetic analysis indicated that the Italian and two Greek isolates represent three new genotypes of HEV, distinct from the Burmese, Mexican, and US genotypes.

Asia↗
PubMed1999

Identification of a novel variant of hepatitis E virus in Italy.

Hepatitis E infection is typically associated with areas in which hepatitis E virus (HEV) is endemic. Except for a few cases in Europe and in the United States, acute hepatitis E is usually associated with travel to endemic areas. We set out to determine the etiologic role of HEV in acute non-A-C hepatitis in Italy. The presence of HEV-RNA and antibody was determined in 218 patients diagnosed with acute viral non-A-C hepatitis. Acute hepatitis E infection was defined by the presence of HEV-RNA in sera and positivity for IgM anti-HEV and seroconversion to IgG anti-HEV. Acute hepatitis E was found in 10.1% of the patients with acute non-A-C, with 95.5% exhibiting a benign course. A more severe course was observed in a patient co-infected with HAV and HEV. Most cases were travelers to endemic areas, although 18.2% reported no travel. One patient was from a household with an infected patient. Sequence analyses of the polymerase chain reaction (PCR) product derived from a patient who never visited endemic areas, identified an isolate that is divergent significantly from all reported isolates of HEV (79.5-85.8% nucleotide identity). Evidence from this study suggests that HEV accounts for approximately 10% of acute non-A-C viral hepatitis in Italy, diagnosed generally in travelers returning from endemic areas. However, the identification of a new HEV variant in an individual who never indicated travel or contact with individuals associated with endemic areas, suggests that this virus may be native to Italy.

Adolescent↗
PubMed1999

Licensed recombinant hepatitis B vaccines protect chimpanzees against infection with the prototype surface gene mutant of hepatitis B virus.

The emergence in vaccinated individuals of hepatitis B virus (HBV) mutants with amino acid substitutions within the a determinant of the surface protein has raised the possibility that such variants represent neutralization escape mutants. We previously demonstrated that one such mutant HBV, strain AS, with an arginine substituted for glycine at surface gene codon 145, was infectious and pathogenic in seronegative chimpanzees. In the present study, the protective efficacy of licensed hepatitis B vaccines was evaluated against challenge with this mutant virus. Four chimpanzees were immunized with 1 of 2 licensed recombinant hepatitis B vaccines. Shortly after the chimpanzees developed antibodies to hepatitis B surface antigen (anti-HBs), they were challenged intravenously with mutant HBV strain AS. Two unvaccinated chimpanzees served as positive controls. The 4 vaccinated chimpanzees did not develop evidence of HBV infection or hepatitis during 2 years following virus challenge. In contrast, the 2 unvaccinated chimpanzees developed HBV infection and hepatitis. Serum anti-HBs in the vaccinated chimpanzees reacted not only with wild-type surface antigen, but also with mutant surface antigen by competition enzyme-linked immunosorbent assay (ELISA). Thus, immunization of chimpanzees with licensed recombinant hepatitis B vaccines stimulates anti-HBs that is broadly reactive and affords protection against infection with a surface gene mutant of HBV, suggesting that properly immunized individuals are not at significant risk of infection with this prototype variant strain of HBV.

Animals↗
PubMed1999

Hepatitis A vaccination in chronic carriers of hepatitis B virus.

Because hepatitis A infection may be more severe in patients with chronic liver disease, we vaccinated 33 children who were chronic HBsAg carriers against hepatitis A virus. Anti-hepatitis A virus seroconversion rates after the first, second, and third doses were 90.9%, 96.9%, and 100%, respectively.

Adolescent↗
PubMed1999

Mother-to-infant transmission of hepatitis C virus.

The rate of mother-to-infant transmission of hepatitis C virus (HCV) is approximately 5%, but is higher when the mother is co-infected with HIV Vertical transmission is restricted to infants whose mothers are viraemic. The risk of transmission increases with increasing maternal viral load but a specific cut-off value predicting infection cannot be defined. There is no specific HCV genotype which is preferentially transmitted. The mode of delivery (caesarean versus vaginal) does not appear to influence the rate of transmission, but firm evidence is lacking. There is no evidence to suggest an increased risk of HCV transmission through breast feeding. Pregnancy is not contra-indicated in HCV-infected women. Without drugs to treat established infections in mothers and infants and interventions to prevent vertical transmission, routine HCV screening is not recommended in pregnant women.

Female↗
PubMed1999

Effect of ursodeoxycholic acid administration in patients with acute viral hepatitis: a pilot study.

BACKGROUND: Ursodeoxycholic acid (UDCA) is able to improve biochemical markers of cholestasis, with a parallel decrease in transaminases, in various cholestatic liver diseases. AIM: To evaluate the effects of UDCA administration on acute viral hepatitis-related cholestasis and the course of acute viral hepatitis. METHODS: Seventy-nine consecutive patients with acute viral hepatitis (HBV: 43, HCV: 11, HAV: 15, HEV: 3, Non A-E: 7) were randomized to receive either UDCA for 3 weeks or no treatment. Liver biochemistry and serum bile acid determinations were run at weekly intervals. RESULTS: No significant differences were observed in mean percentage decreases in transaminases between treated and untreated patients. By contrast, cholestatic indexes decreased significantly more quickly in patients treated with UDCA than in controls, and this effect was more evident in patients with increasing alanine transaminase levels at admission. After a peak at the end of the first week of therapy, serum levels of conjugated ursodeoxycholic acid (CUDCA) showed a gradual decrease. Conjugated cholic acid (CCA) and chenodeoxycholic acid (CCDCA) showed a progressive decrease with the resolution of viral hepatitis, but no influence of UDCA administration was observed. CONCLUSIONS: Our study demonstrates that UDCA significantly improves cholestatic indices in patients with acute viral hepatitis, but this effect does not seem to affect the course of the illness.

Acute Disease↗
PubMed1999

Pediatric migration and hepatitis A risk in host population.

Hepatitis A virus (HAV) circulation in a given area is closely related to socioeconomic standards. Following the improvement of living conditions, HAV seroprevalence rates in the population have decreased steadily during the last decades in many Western European countries, including Italy, thereby leading to a shift of risk of disease towards older age groups. Since the severity of the disease closely parallels age, a higher incidence of symptomatic cases in adults is now reported in Europe and the United States, being travel-related to a large extent. Intrafamilial person-to-person spread is also an important source of infection and transmission from children to parents may occur due to the lack of immunity in the general population. In the last two decades, Italy has been the destination of an increasing number of migrants from developing countries, where HAV is highly endemic. Furthermore, international adoption programmes cause pediatric populations from HAV endemic countries to increase in low endemic areas, possibly leading to secondary cases in close contacts.7 The aim of this paper is to report the epidemic HAV outbreak which occurred among the voluntary nursing staff of a pediatric Rwandan refugee community hosted in a village of the Brescia Province, in northern Italy.

Adult↗
PubMed1999

Outcome of mother to infant acquired GBV-C/HGV infection.

Twelve children born to hepatitis C virus antibody GBV-C/HGV RNA positive mothers who acquired GBV-C/HGV infection by the vertical or perinatal route were studied. Most (91%) were persistently GBV-C/HGV RNA positive up to 12 months of age. Four out of six cases who acquired GBV-C/HGV alone had normal alanine amino transferase activities. Long lasting evidence of hepatocellular injury was detected only in children with GBV-C/HGV and hepatitis C virus and HIV coinfection.

Flaviviridae↗
PubMed1998

Multicenter trial on mother-to-infant transmission of GBV-C virus. The Lombardy Study Group on Vertical/Perinatal Hepatitis Viruses Transmission.

Evidence indicates that the GBV-C or hepatitis G virus can cause persistent infection in humans, but little is known on the importance of vertical transmission. To assess the risk of mother-to-infant transmission and the clinical outcome of infected babies, we investigated 175 anti-HCV positive mothers and followed-up their children for 3-33 months. GBV-C RNA was detected by RT-PCR and anti-E2 antibody was assayed by EIA. Thirty-four (19.4%) women were GBV-C RNA positive and transmission occurred to 21 (61.8%) babies; 20 (95.2%) acquired GBV-C alone, and one (4.8%) GBV-C and HCV. Maternal factors such as intravenous drug use, HIV coinfection, HCV-RNA positivity, and type of feeding were not correlated with GBV-C transmission. GBV-C RNA remained persistently positive in all infected babies but one baby who seroconverted to anti-E2. Seven (35%) babies with GBV-C alone developed marginally elevated ALT; the baby with HCV and GBV-C co-infection had the highest ALT peak value (664 IU/l). Seven of the 141 (5%) babies born to the GBV-C RNA negative mothers acquired HCV and six (85.7%) had abnormal ALT. The mean ALT peak value was significantly higher (P < 0.05) for babies with HCV than for those with GBV-C. None of the children with GBV-C or with HCV became icteric. GBV-C is frequently present in anti-HCV positive women. The infection is transmitted efficiently from mother to baby and rate of transmission is much higher than that for HCV. GBV-C can cause persistent infection in babies but usually without clear evidence of liver disease.

Adult↗