Giovanna Alfarone

Istituto Superiore di Sanità, Roma, Latium, Italy

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Publications (23)65.64 Total impact

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    ABSTRACT: Despite being a completely preventable disease, tetanus cases continue to occur in Italy and notification and hospitalization rates have been reported to be higher with respect to European and other industrialized countries. We examined statutory notification, hospitalization, mortality and seroprevalence data to describe tetanus epidemiology in Italy from 2001 to 2010. A total of 594 tetanus cases were notified, with an average annual incidence of 1.0/1,000,000 population. Most cases were unvaccinated or incompletely vaccinated. Eighty percent of cases occurred in subjects aged >64 years and a higher proportion of females with respect to males were reported in this age group. The annual number of hospital admissions was 1.4-1.7 times greater than the number of notifications in the same year. The mean annual number of reported deaths was 21. Seroprevalence data show progressively higher susceptibility levels with increasing age. Over 50% of persons aged 45-64 years and over two thirds of subjects ≥65 years had tetanus antibody levels <0.01IU/ml. Results show that tetanus is a continuing problem in Italy and, as in other countries, most cases occur in older adults, especially elderly women. The observed differences in notification and hospitalization rates suggest underreporting by physicians. In recent years, Italy has accounted for most cases reported annually in the European Union but different case definitions are used. In Italy, a confirmed case is one that meets the clinical case definition while the EU case definition classifies confirmed cases as those with laboratory confirmation of disease. The incidence of clinical tetanus in Italy is ten-fold higher than in other industrialized countries, like Australia and Canada, likely due to higher susceptibility levels in Italy. In view of the low prevalence of tetanus antibodies in adults ≥45 years, strategies to improve vaccine uptake in this population group need to be implemented.
    Vaccine 12/2013; · 3.77 Impact Factor
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    ABSTRACT: The characteristics of Group B Streptococcal (GBS) early onset (EOD) and late onset (LOD) neonatal infections in Italy were analyzed. Two periods were considered, a first 3-years period (2007-2010), when notification of GBS infections was enforced under the auspices of the Italian Ministry of Health, and a second 1 year period (2012) when reporting on neonatal GBS disease continued on voluntary basis. A standardized form was used to collect data on cases of neonatal GBS disease. They included both maternal and neonatal data. The two surveys underlined that preterm deliveries, precipitous labor and negatively GBS screened mothers are common causes of EOD occurrence, possibly explained by inadequate, or lack of, intrapartum antibiotic prophylaxis. Nevertheless, measures for reducing prevention failures and EOD incidence by an higher adherence to prevention strategies, as the Centre for Disease Control recommendations, are still possible and should be encouraged.
    Annali dell'Istituto superiore di sanita 12/2013; 49(4):370-375. · 0.76 Impact Factor
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    ABSTRACT: SUMMARYSerological surveys for diphtheria were conducted in six European countries including Czech Republic, Hungary, Ireland, Latvia, Luxembourg, Slovakia and one country outside Europe, Israel. For each country, a nationally representative population sample was collected across the entire age range and was tested for antibodies to diphtheria toxin. Although each national laboratory used its preferred assay, the results were all standardized to those of the in vitro neutralization test and expressed in international units (IU) which allowed comparative analyses to be performed. The results showed that increasing age is related to a gradual increase in seronegative subjects (<0·01 IU/ml of diphtheria antitoxin antibodies). This may reflect waning immunity following childhood vaccination without repeated booster vaccinations in adults. Differences in seronegativity were also found according to gender. In subjects aged 1-19 years, geometric mean titres of antitoxin are clearly related to the different vaccination schedules used in the participating countries. Although clinical disease remains rare, the susceptibility to diphtheria observed in these serosurveys highlights the importance of strengthened surveillance.
    Epidemiology and Infection 02/2012; · 2.87 Impact Factor
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    ABSTRACT: During a national surveillance program on Group B streptococci (GBS) maternal carriage and neonatal infections, a GBS strain isolated from a pregnant woman's vagino-rectal swab was non typable by either serological or molecular methods. Further molecular characterization demonstrated that the strain lacked the entire capsular locus, possibly by a recombination event that excised a 14,1 Kbase pairs genomic fragment extending from the regulatory protein cpsX gene to the neuA gene. The natural loss of the capsular locus by GBS isolated from a human has never been described so far. Such an event, while possibly a dead-end from the evolutionary point of view, leaves a still able-to-colonize organism unrecognizable by the vaccines currently under development.
    European Journal of Clinical Microbiology 05/2011; 31(3):233-5. · 3.02 Impact Factor
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    ABSTRACT: A multiplex PCR assay for the identification of serotypes Ia to IX of Streptococcus agalactiae was developed. By using a single PCR reaction containing a mix of 19 primers the assay identified each serotype by the analysis of the unique two or three bands pattern on agarose gel.
    Journal of microbiological methods 11/2009; 80(2):212-4. · 2.43 Impact Factor
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    ABSTRACT: Group B streptococci (GBS) comprising three different sets of isolates (31 invasive, 36 noninvasive, and 24 colonizing isolates) were collected in Italy during the years 2002 to 2005. Clonal groups were established by pulsed-field gel electrophoresis (PFGE), and selected isolates were studied by multilocus sequence typing (MLST). GBS isolates were also characterized by classical and molecular techniques for serotyping and protein gene and antibiotic resistance profiling. Some serotypes were significantly associated with a particular isolate population: serotype Ia more frequently corresponded to invasive strains than other strains, serotype V was more frequently encountered among noninvasive strains, and nontypeable strains were more common among isolates from carriers. Four major clonal groups accounted for 52.7% of all isolates: PFGE type 1/clonal complex 1 (CC1) comprised mainly serotype V isolates carrying the alp3 gene, PFGE type 2/CC23 encompassed serotype Ia isolates with the alp1 or alpha gene, PFGE type 3/CC17 comprised serotype III isolates carrying the rib gene, and PFGE type 4/CC19 consisted mainly of serotype II isolates possessing the rib gene. The same serotypes were shared by isolates of different clonal groups, and conversely, isolates belonging to the same clonal groups were found to be of different serotypes, presumably due to capsular switching by the horizontal transfer of capsular genes. Erythromycin resistance (prevalence, 16.5%; 15 resistant isolates of 91) was restricted to strains isolated from patients with noninvasive infections and carriers, while tetracycline resistance was evenly distributed (prevalence, 68.1%; 62 resistant isolates of 91). Most erythromycin-resistant GBS strains were of serotype V, were erm(B) positive, and belonged to the PFGE type 1/CC1 group, suggesting that macrolide resistance may have arisen both by clonal dissemination and by the horizontal transfer of resistance genes.
    Journal of Clinical Microbiology 10/2007; 45(9):2909-16. · 4.07 Impact Factor
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    ABSTRACT: To investigate the epidemiology and characteristics of invasive group A streptococcal (GAS) disease over 11 years in Italy, this study compared the emm types and the superantigen toxin genes speA and speC as well as the erythromycin, clindamycin, and tetracycline susceptibilities of 207 invasive GAS strains collected during two national enhanced surveillance periods (1994 to 1996 and 2003 to 2005) and the time between each set of surveillance periods. The present study demonstrated that emm1 strains were consistently responsible for about 20% of invasive GAS infections, while variations in the frequencies of the other types were noted, although the causes of most cases of invasive infections were restricted to emm1, emm3, emm4, emm6, emm12, and emm18. During the 1994 to 1996 surveillance period, an emm89 epidemic clone spread across the northern part of Italy. A restricted macrolide resistance phenotype-type distribution of the bacteriophage-encoded speA toxin as well as of macrolide resistance genes was noted over time. Indeed, the recent acquisition of macrolide resistance in previously susceptible emm types was observed.
    Journal of Clinical Microbiology 08/2007; 45(7):2249-56. · 4.07 Impact Factor
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    Letters in Applied Microbiology 03/2007; 44(2):224-7. · 1.63 Impact Factor
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    ABSTRACT: Streptococcus pyogenes infections often fail to respond to antibiotic therapy, leading to persistent throat carriage and recurrent infections. Such failures cannot always be explained by the occurrence of antibiotic resistance determinants, and it has been suggested that S. pyogenes may enter epithelial cells to escape antibiotic treatment. We investigated 289 S. pyogenes strains isolated from different clinical sources to evaluate their ability to form biofilm as an alternative method to escape antibiotic treatment and host defenses. Up to 90% of S. pyogenes isolates, from both invasive and noninvasive infections, were able to form biofilm. Specific emm types, such as emm6, appeared to be more likely to produce biofilm, although variations within strains belonging to the same type might suggest biofilm formation to be a trait of individual strains rather than a general attribute of a serotype. Interestingly, erythromycin-susceptible isolates formed a significantly thicker biofilm than resistant isolates (P < 0.05). Among resistant strains, those carrying the erm class determinants formed a less organized biofilm than the mef(A)-positive strains. Also, prtF1 appeared to be negatively associated with the ability to form biofilm (P < 0.01). Preliminary data on a selection of strains indicated that biofilm-forming isolates entered epithelial cells with significantly lower efficiency than biofilm-negative strains. We suggest that prtF1-negative macrolide-susceptible or mef(A)-carrying isolates, which are poorly equipped to enter cells, may use biofilm to escape antimicrobial treatments and survive within the host. In this view, biofilm formation by S. pyogenes could be responsible for unexplained treatment failures and recurrences due to susceptible microorganisms.
    Journal of Clinical Microbiology 09/2006; 44(8):2721-7. · 4.07 Impact Factor
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    ABSTRACT: Enterococci are opportunistic pathogens which today represent one of the leading causes of nosocomial infections. We have examined a collection of 52 Enterococcus faecalis isolated from orthopedic infections to determine if they were characterized by a specific pattern of virulence factors. The isolates were evaluated for biofilm formation, presence of genes coding the enterococcal surface protein (esp) and gelatinase (gelE), as well as for gelatinase production. While the rate of esp-positive isolates was comparable to that found among strains from other clinical sources, we found a significantly higher rate of strong biofilm formers and gelatinase producers. Particularly high was the rate of gelE-carrying strains expressing the gene. Data suggest that these two factors in particular may play an important role in enterococcal infections associated with biomaterials.
    The International journal of artificial organs 05/2006; 29(4):402-6. · 1.76 Impact Factor
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    ABSTRACT: The presence of fibronectin binding protein genes sfb, fba and prtF1 was evaluated by PCR in a collection of Streptococcus pyogenes strains from invasive diseases and from throat swabs. Sfb and fba genes were found in comparable percentage among the two groups, while prtF1 gene was significantly more frequent among isolates from throat. Each emm type appeared to have a peculiar set of fibronectin binding protein genes, also characterized by the same number of tandem repeats. None of the tested genes appeared to be related to the ability of GAS to invade epithelial cells, independently of the source of isolation.
    International Congress Series 01/2006; 1289:243-245.
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    ABSTRACT: Streptococcus pyogenes (group A streptococci; GAS) recovered from paediatric pharyngitis (101 isolates) and asymptomatic children (79 isolates) in the same geographical area and period, as well as isolates collected during an enhanced national surveillance programme for GAS invasive diseases (79 isolates), were screened for the incidence of the streptococcal pyrogenic exotoxin (spe) genes speA and speC, as well as the macrolide-resistance genes erm(B), erm(A) subclass erm(TR) and mef(A), and typed by emm sequencing. The speA gene was detected with comparable incidence among throat isolates (13.9 % of asymptomatic children and 16.8 % of pharyngitis isolates) and in 25 % of invasive cases; in contrast, speC incidence was, surprisingly, higher in paediatric populations (55.4 % in pharyngitis isolates and 65.8 % in asymptomatic children) than in invasive isolates (30 %; P < 0.0001). Macrolide resistance was detected in 26.6, 38.0 and 37.6 % of strains belonging to invasive, asymptomatic and pharyngitis populations, respectively. The different incidences of exotoxin and antibiotic-resistance genes among populations did not appear to have an intrinsic clinical significance, but may reflect the propensity of these traits to be associated with certain emm types independent of the source from which the strains were isolated. Further investigations with larger emm-type populations are warranted to confirm this.
    Journal of Medical Microbiology 11/2005; 54(Pt 10):913-7. · 2.30 Impact Factor
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    ABSTRACT: Five cases of diphtheria were reported in Italy between January 1990 and June 2001. Three cases were confirmed microbiologically by the isolation of toxigenic Corynebacterium diphtheriae (two cases) and Corynebacterium ulcerans (one case). Over the same period, 11 cases of non-toxigenic C. diphtheriae infection were reported to the Italian Public Health Institute, from which the causative organism was isolated from a skin infection in one case and from the throat in the other ten. Seven of the throat isolates were associated with fever, severe pharyngitis and tonsillitis and were all biotype gravis. Because there are no standardized breakpoints, the antimicrobial sensitivities of C. diphtheriae were determined in accordance with the National Committee for Clinical Laboratory Standards guidelines for Streptococcus spp. other than Streptococcus pneumoniae. MICs for penicillin ranged between 0.125 and 0.250 mg l(-1) and 7 out of 11 strains had a minimal bactericidal concentration (MBC)/MIC ratio >or= 32. All strains were sensitive to clindamycin (MIC <or= 0.25 mg l(-1)), rifampicin (MIC <or= 1 mg l(-1)) and tetracycline (MIC <or= 2 mg l(-1)), and showed moderate susceptibility to cefotaxime (MIC 0.75-1.5 mg l(-1)). Molecular typing (ribotyping) demonstrated the presence of several distinct ribotypes. The ribotype designated 'D11' has been documented amongst strains isolated in the UK, Russia, Germany, Romania and Sweden. Ribotype 'D75' has only been documented in the UK. The C. ulcerans strain had a ribotype pattern identical to that found in recent isolates from the UK.
    Journal of Medical Microbiology 02/2003; 52(Pt 2):181-8. · 2.30 Impact Factor
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    ABSTRACT: We evaluated the reactogenicity and immunogenicity of a booster dose of diphtheria–tetanus vaccine administered at the age of school-entry, comparing a low-dose vaccine (dT) to the standard paediatric dose (DT). Participants were randomly assigned to receive one of the two vaccines; the study was evaluator-blinded. The frequency of side-reactions was similar when comparing the two groups, except when considering local redness and swelling, which were significantly more frequent among the DT group. The post-booster geometric mean titre of diphtheria antibodies in the DT group was twice as high as that in the dT group (14.1 IU/ml versus 7.7 IU/ml; P<0.001). The higher antibody response and the comparable reactogenicity indicate that DT should be used as booster at school-entry, particularly if additional booster doses during adolescence or adulthood are not administered.
    Vaccine 10/2001; · 3.49 Impact Factor
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    ABSTRACT: Synthetic oligodeoxynucleotides containing CpG immunostimulatory sequences (ISS) have been shown to act as potent adjuvants of type 1 immune responses when co-administered with protein or peptide vaccines. We have recently shown that ISS can increase the anti-polysaccharide (CHO) and anti-tetanus toxoid (TT) or anti-diphtheria (CRM) toxoid antibody levels if used as adjuvant of anti-Haemophilus influenzae type b (Hib) CHO vaccine conjugated with TT or CRM. The analysis of anti-TT and anti-CRM IgG subclasses showed a significant increase in IgG2a, IgG2b and/or IgG3 in the presence of ISS. Anti-TT and anti-CRM antibodies were shown to neutralize the activity of both the tetanus and diphtheria toxin in vivo or in vitro tests respectively. These data show that ISS have the potential to increase host antibody response against both the CHO and the protein component of a conjugated vaccine, and encourage the investigation to identify strategies of vaccination with schedules aimed at the valuation of protein carriers as protective immunogens.
    Vaccine 05/2001; · 3.49 Impact Factor
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    ABSTRACT: Immunity to diphtheria was assessed in serum samples obtained from 3111 healthy Italian males and females aged 0-84 years. Diphtheria antitoxin was tested using a double-antigen, time-resolved fluorescence immunoassay (DA-DELFIA). According to internationally accepted criteria, antitoxin concentrations < 0.01 IU/ml indicate susceptibility to diphtheria, those > or = 0.01-0.09 IU/ml provide basic or inadequate protection, and concentrations > or =0.1 IU/ml are protective. By these criteria, 9.9% (95% CI 8.9 to 11.18) of the participants were susceptible to diphtheria, 30.2% (95% CI, 28.6 to 31.9) had basic protection, and 59.9% (95% CI, 58.1 to 61.6) were protected. The prevalence of unprotected individuals showed an age-related increase, up to the 45-49-year-old age group for females and the 50-54-year-old age group for males (34.9% and 31.3% of individuals, respectively). The prevalence of immunity did not significantly differ in relation to sex in any of the age groups. These results indicate that booster shots should be routinely provided to the adult population in order to maintain a protective level of diphtheria antibodies.
    European Journal of Clinical Microbiology 01/2001; 19:433-437. · 3.02 Impact Factor
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    Vaccine 01/2001; 20(5):989-989. · 3.49 Impact Factor
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    ABSTRACT: Immunity to diphtheria was assessed in serum samples obtained from 3111 healthy Italian males and females aged 0-84 years. Diphtheria antitoxin was tested using a double-antigen, time-resolved fluorescence immunoassay (DA-DELFIA). According to internationally accepted criteria, antitoxin concentrations < 0.01 IU/ml indicate susceptibility to diphtheria, those > or = 0.01-0.09 IU/ml provide basic or inadequate protection, and concentrations > or =0.1 IU/ml are protective. By these criteria, 9.9% (95% CI 8.9 to 11.18) of the participants were susceptible to diphtheria, 30.2% (95% CI, 28.6 to 31.9) had basic protection, and 59.9% (95% CI, 58.1 to 61.6) were protected. The prevalence of unprotected individuals showed an age-related increase, up to the 45-49-year-old age group for females and the 50-54-year-old age group for males (34.9% and 31.3% of individuals, respectively). The prevalence of immunity did not significantly differ in relation to sex in any of the age groups. These results indicate that booster shots should be routinely provided to the adult population in order to maintain a protective level of diphtheria antibodies.
    European Journal of Clinical Microbiology 06/2000; 19(6):433-7. · 3.02 Impact Factor
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    ABSTRACT: Strains of a new polysaccharide type of group B streptococci (GBS), type VII, have been isolated from human carriers and invasive infections. Some of these strains bear the protein antigen c or R, as do other GBS serotypes. The capsular type polysaccharide is sialylated and this residue is involved in the immunodeterminant structure. All type VII strains examined were virulent in CD-1 mice; the LD50 after intraperitoneal (i.p.) challenge was 4.57 (SD 0.12) x10(7) cfu for the reference strain and 5.49 (SD 1.5) x10(7) cfu for clinical isolates. A particular feature of this serotype was the ability to induce septic arthritis not only when injected intravenously (i.v.), but also when injected i.p. Rabbit antiserum against the capsular type VII polysaccharide exhibited opsonic activity in a phagocytosis assay and protective activity against infection.
    Journal of Medical Microbiology 12/1999; 48(11):983-90. · 2.30 Impact Factor
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    ABSTRACT: Group B streptococcal antigens stimulated tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1), and IL-6 production in human blood cultures in a concentration- and time-dependent fashion. The minimal concentrations of type-specific polysaccharides, lipoteichoic acid, and group-specific polysaccharide required to produce these effects were, respectively, 0.01, 1, and 10 microg/ml. Cell separation experiments indicated that monocytes were the cell type mainly responsible for cytokine production. Time course studies indicated that TNF-alpha was released before the other cytokines. TNF-alpha, however, did not appear to directly induce IL-1beta, as shown by blockade experiments with anti-TNF-alpha antibodies. IL-6 levels were moderately but significantly decreased by anti-TNF-alpha. These data indicate that several products from group B streptococci are able to directly stimulate human monocytes to release TNF-alpha, IL-1beta, and IL-6. These findings may be clinically relevant, since proinflammatory cytokines can mediate pathophysiologic changes during sepsis.
    Infection and Immunity 11/1997; 65(10):4017-21. · 4.07 Impact Factor