Maria Serena Gallone

Outbreak of Salmonella infantis gastroenteritis among people who had eaten at a hash house in southern Italy.

OBJECTIVES To describe an outbreak of acute gastroenteritis in people who had eaten at a hash house in southern Italy. STUDY DESIGN Case-control study. METHODS A clinical case of gastroenteritis was defined as a person who had eaten at the hash house from 29 August to 4 September 2011 and who experienced defined gastrointestinal symptoms within 72 hours, or a person with a laboratory-confirmed salmonella infection without symptoms. A convenience sample was enrolled as the control group. Environmental and human samples were collected, and Salmonella infantis was identified by polymerase chain reaction. Univariate analysis was performed for each food type, and multivariate analysis was performed for each food type and demographic variable (gender, age). RESULTS Twenty-three cases of gastroenteritis were notified between 1 and 4 September 2011, two of which were admitted to the local hospital. Multivariate analysis showed that porchetta [odds ratio (OR) 22.0, 95% confidence interval (CI) 3.2-152.6, z = 3.13, P = 0.002] and roasted meat (OR 14.4, 95% CI 1.7-122.0, z = 2.45, P = 0.014) were associated with gastrointestinal symptoms. Environmental and human isolates exhibited the same sequence type (ST 32). CONCLUSIONS This experience highlighted that, in the control of a foodborne outbreak, integrated epidemiological and laboratory surveillance enables rapid identification of the source of infection, thus reducing the risk of an epidemic.

Communication about vaccinations in Italian websites: a quantitative analysis.

Babies’ parents and people who look for information about vaccination often visit anti-vaccine movement’s websites, blogs by naturopathic physicians or natural and alternative medicine practitioners. The aim of this work is to provide a quantitative analysis on the type of information available to Italian people regarding vaccination and a quality analysis of websites retrieved through our searches. A quality score was created to evaluate the technical level of websites. A research was performed through Yahoo, Google, and MSN using the keywords “vaccine” and “vaccination,” with the function “OR” in order to identify the most frequently used websites. The 2 keywords were input in Italian, and the first 15 pages retrieved by each search engine were analyzed. 149 websites were selected through this methodology. Fifty-three per cent of the websites belonged to associations, groups, or scientific companies, 32.2% (n = 48) consisted of a personal blog and 14.8% (n = 22) belonged to some of the National Health System offices. Among all analyzed websites, 15.4% (n = 23) came from anti-vaccine movement groups. 37.6% reported webmaster name, 67.8% webmaster e-mail, 28.6% indicated the date of the last update and 46.6% the author’s name. The quality score for government sites was higher on average than anti-vaccine websites; although, government sites don’t use Web 2.0 functions, as the forums. National Health System institutions who have to promote vaccination cannot avoid investing in web communication because it cannot be managed by private efforts but must be the result of Public Health, private and scientific association, and social movement synergy.

Adverse events following immunization: is this time for the use of WHO causality assessment?

In recent years, public health authorities in industrialized countries have noted an increase in the numbers of parents choosing not to have their children vaccinated and in the activities of ‘antivaccination’ movements. Doubts about vaccine safety and lack of surveillance of adverse events following immunization (AEFI) are the most frequent themes proposed by antivaccination movements. This editorial aims to critically analyze the use of AEFI assessment procedures among national health authorities and public health researchers. In fact, the WHO recommended and published a systematic and standardized causality assessment process for serious AEFI, providing a method for individual causality assessment to be used by staff of national immunization programs, regulatory authorities and pharmacovigilance or surveillance departments. The last update was published in March 2013 but to date, an Internet search reveals no information or reports on AEFI surveillance that uses the WHO AEFI causality assessment.

Clostridium difficile infection among hospitalized HIV-infected individuals: epidemiology and risk factors: results from a case-control study (2002-2013)

BackgroundHIV infection is a risk factor for Clostridium difficile infection (CDI) yet the immune deficiency predisposing to CDI is not well understood, despite an increasing incidence of CDI among such individuals. We aimed to estimate the incidence and to evaluate the risk factors of CDI among an HIV cohort in Italy.MethodsWe conducted a retrospective case-control (1:2) study. Clinical records of HIV inpatients admitted to the National Institute for Infectious Disease “L. Spallanzani”, Rome, were reviewed (2002-2013). Cases: HIV inpatients with HO-HCFA CDI, and controls: HIV inpatients without CDI, were matched by gender and age. Logistic regression was used to identify risk factors associated with CDI.ResultsWe found 79 CDI episodes (5.1 per 1000 HIV hospital admissions, 3.4 per 10000 HIV patient-days). The mean age of cases was 46 years. At univariate analysis factors associated with CDI included: antimycobacterial drug exposure, treatment for Pneumocystis pneumonia, acid suppressant exposure, previous hospitalization, antibiotic exposure, low CD4 cell count, high Charlson score, low creatinine, low albumin and low gammaglobulin level. Using multivariate analysis, lower gammaglobulin level and low serum albumin at admission were independently associated with CDI among HIV-infected patients.ConclusionsLow gammaglobulin and low albumin levels at admission are associated with an increased risk of developing CDI. A deficiency in humoral immunity appears to play a major role in the development of CDI. The potential protective role of albumin warrants further investigation.

A seroprevalence survey on varicella among adults in the vaccination era in Apulia (Italy)

In 2006, the Apulia Region (Italy) introduced universal routine vaccination (URV) against varicella disease. The coverage for one dose of varicella vaccine at 24 month of age reached 91.1% in 2010 birth-cohort. Vaccination coverage for the second dose at 5-6 years was 64.8% for the cohort 2005, and 28.8% for adolescents born in 1997. The aim of the present study is to evaluate the pattern of immunity/susceptibility to varicella in Apulian adults by a seroprevalence survey carried out 6 years after the introduction of URV. The study was carried out from May 2011 to June 2012 among blood donors of the Department of Transfusion Medicine of Policlinico General Hospital in Bari. Subjects were enrolled by a convenience sample. For each enrolled patient we collected a sample of serum of 5 ml. Anti-VZV IgG in collected sera were analyzed by chemiluminescence (CLIA). We enrolled 1769 subject; 1365 (77.2%) were male with a mean age of 38.4 ± 11.7 years. 93% (95% CI=91.7-94.1) of enrolled subject presented a titre of anti-VZV IgG >164 mIU/mL. GMT of anti-VZV IgG titre was 1063.4 mIU/ml and no difference was observed between different age group. According to our data, URV did not seem to have any impact on susceptibility among adults and in particular we did not note any cluster of susceptible subjects among young adults. Also in the vaccination era, we did not note that the average age of infection shifts among adults and then we could exclude an increase of case of complicated varicella related to the URV.

Serosurveillance of hepatitis A in a region which adopted the universal mass vaccination

Abstract Hepatitis A is a common infectious disease worldwide that was endemic in many regions of Southern Italy, such as Apulia region. After a large hepatitis A outbreak occurred between 1996 and 1997, in Apulia an active-free immunization program that was targeted to new-borns and adolescents was started. The aim of this study is to investigate the hepatitis A seroprevalence in the adult Apulian population 18 years after the immunization program introduction, in order to evaluate the risk of new epidemics onset. The study was carried out from May 2011 to June 2012 among blood donors from Department of Transfusion Medicine and Blood Bank of Policlinico General Hospital in Bari. Participants signed a written consent and filled out a questionnaire including items on demographic characteristics, risk factors, disease memory, and raw food consumption. Serum samples, collected from each patient, were tested for anti-HAV using the chemiluminescent microparticle immunoassay. Vaccination status against hepatitis A was checked on Regional Digital Immunization Registry (GIAVA). In total 1827 donors agreed to participate (77.7% male) with a mean age of 38.4 ± 11.7 years. However, 1172 (64.1%) donors were seropositive with no difference by sex. The highest proportion of seronegative subjects was in the 27 to 35 years age group. 91.8% of 1-dose vaccinated subjects (n = 190/207; 95%CI = 87.2–95.1) and 96.1% (n = 171/178; 95%CI = 92.1–98.1) of 2-doses vaccinated subjects were immune to the disease. Sensitivity of disease memory in unvaccinated subjects was 14.4% (95%CI = 12.2–16.7), specificity was 97.8% (95%CI = 96.3–98.8), positive predictive value was 91% (95%CI = 85.3–95), and negative predictive value was 42.6% (95%CI = 40–45.2). Raw seafood consumption in unvaccinated subjects was associated with the anti-HAV IgG positivity (OR = 2.1; 95%CI = 1.7–2.7; z = 7.4; P < 0.0001). The vaccination program seems to have changed the virus circulation pattern, with a higher seronegativity rate among subjects not included in the vaccination strategy: 67% of susceptible subjects were among younger people aged 27 to 35 years. Immunization program implementation with a catch-up strategy may be needed to avoid a possible increase of hepatitis A incidence and outbreaks in Apulia. Epidemiological surveillance should be continued and vaccination should actively be offer for free to all the cases contacts, in order to prevent new outbreaks onset.

Active offer of vaccinations during hospitalization improves coverage among splenectomized patients: An Italian experience

In 2014, an Italian hospital implemented a protocol for pneumococcal, meningococcal, and Haemophilus influenzae type b vaccines offer to splenectomized patients during their hospitalization. After 1 year, coverage for recommended vaccinations increased from 5.7%-66.7% and the average time between splenectomy and vaccines administration decreased from 84.7-7.5 days.

Monitoring the process of measles elimination by serosurveillance data: The Apulian 2012 study.

In 2003 Italy adopted the National Plan for Measles and Congenital Rubella Elimination, but some outbreaks of measles are still occurring, as the target coverage rate (≥ 95%) for new-borns has currently not been achieved. In order to support the monitoring of the measles elimination programme, the authors carried out a survey about the seroprevalence of measles among Apulia young adults. The study was carried out from May 2011 to June 2012 among blood donors of the Department of Transfusion Medicine of Policlinico General Hospital in Bari. Subjects were enrolled by a convenience sampling. For each enrolled patient we collected a 5 mL serum sample. Collected sera were tested by chemiluminescence (CLIA) for anti-Measles IgG. We enrolled 1764 subjects; 1362 (77.2%) were male with a mean age of 38.4 ± 11.7 years. Anti-Measles IgG titre was >16.5UA/mL in 95.1% (95% CI=94.1-96.1) of enrolled subjects with a Geometric Mean Titre (GMT) of 2.3 ± 0.4, which did not differ dividing the enrolled subjects into age groups. As our data showed, the universal routine vaccination changed the epidemiological pattern among adults, in particular young adults (18-24 years), who showed lowest seropositivity rates; in these groups of population there is a risk of the onset of outbreaks due to the presence of susceptible population. This is a paradox linked to the vaccination strategy: when coverage rates keep sub-optimal, measles is more likely to affect young adults and a higher percentage of complications is expected. According to our data, health authorities have to plan a mop-up strategy to actively offer measles vaccination to susceptible young adults.

Clinical benefits of routine varicella vaccination for adults

Varicella is a highly contagious disease caused by varicella zoster virus. In children, it is generally a mild to moderate illness while it is often more severe in adults, with serious complications as dehydration, pneumonia, bleeding problems, infection or inflammation of the brain, secondary bacterial infections, sepsis, toxic shock syndrome, bone infections, joint infections and deaths. Some groups of adults are at major risk of complications, in particular immunocompromised persons as subjects with impaired humoral immunity and who is receiving systemic steroids, persons who live or work in environments in which transmission of varicella is likely, health-care personnel and pregnant women. After the introduction of Universal Mass Vaccination (UMV), the first mathematical models suggested that vaccination will lead to a shift in the average age at infection from children to adults with an increasing numbers of complicated forms, nevertheless new models predicted that, although an upward shift in the age at infection may occur, the overall morbidity due to varicella is likely to decrease. Current literature seems to suggest that for public health authorities the key action to prevent an increase of varicella incidence among adults is to achieve high vaccination coverage among babies and adolescents in countries who adopted UMV.

HBV seroprevalence after 25 years of universal mass vaccination and management of non-responders to the anti-Hepatitis B vaccine: An Italian study among medical students

According to international guidelines, healthcare workers and medical students immunized against HBV are periodically tested for anti‐HBs IgG. Subjects who show an anti‐HBs titre <10 mUI/mL must receive additional vaccine doses to induce a measurable antibody response. This study aimed to evaluate the long‐time immunogenicity of anti‐hepatitis B vaccination in a sample of medical students and residents of the University of Bari who attended the Hygiene Department for biological risk assessment (April 2014‐June 2017). The strategy for the management of nonresponder subjects was evaluated. A total of 3676 students and residents were invited for testing according to a standardized protocol. Anti‐HBs IgG was tested for in 3140 (85.4%) subjects: 1174/3140 (37.7%) subjects were negative. 14.6% (128/808) of subjects who received the vaccine during their 12th year of life and 45.8% (1056/2305) of subjects immunized during the first year of life (P < 0.0001) were negative. 1005/1174 (85.6%) seronegative subjects received a booster dose, and 903/1005 (89.9%) were tested for anti‐HBs 1 month after the booster dose: 82/903 (9.1%) subjects were still negative. Of these, 56/82 (68.3%) received 2 additional doses of vaccine and 52/56 (92.9%) were tested 1 month after the third dose: 50/52 subjects (96.2%) developed a positive titre. In conclusion, several medical students, immunized at birth or at young age against HBV, did not develop protective titres against the virus. Our management strategy (booster retest; for negative subjects, 2 doses and retest) seems consistent with the purpose of evidencing immunological memory.