Healthcare-associated Clostridium difficile infection: role of correct hand hygiene in cross-infection control

Introduction - Clostridium difficile (CD) is the most common cause of health-care-associated infectious diarrhea and incidence and severity have increased in recent years. The main cause of hospital’s acquired cross infections can be attributed to incorrect hand hygiene. We described the epidemiology of CD infection (CDI) in a teaching hospital in Southern Italy during a two years surveillance period and evaluated the health-care workers compliance to hand hygiene.Methods - CDI Incidence rates were calculated as the number of patients with positive C. difficile toxin assay per 10,000 patient-days. Compliance with hand hygiene was the ratio of the number of performed actions to the number of opportunities observed. Approximately 400 Hand Hygiene (HH) opportunities/year /ward were observed.We finally checked out if any correlation could be found.Results - From January 2015 to December 2016 a total number of 854 CD determinations were performed in patients with clinical symptoms of diarrhea. The search for toxins A and B was positive in 175 cases (21,2 %), confirming the diagnosis of CDI.Compliance to hand hygiene was significantly inversely associated with the number of CDIs: the lower the compliance of  health-care workers with hand hygiene the higher was the number of cases of CDIs (p=0.003).Conclusion - According to our results proper handwashing of health-care workers appears to be a key intervention in interrupting CD cross infections regardless of age and type of department in which the patient is admitted. 

Use of the T-spot.TB test for the diagnosis of latent tuberculosis infection

Background:Tuberculosis (TB) represents a major health problem both in developing and both in industrialized countries.The identification of individuals latently infected with Mycobacterium tuberculosis (Mtb) play a key role for the efficacy of TB control. These individuals with a latent tuberculosis infection (LTBI), especially those with high risk of reactivation (e.g. HIV + / AIDS-infected individuals, patients undergoing immunosuppressive therapy and children younger than 5 years) could benefit from a preventive treatment with isoniazid reducing the risk of progression from LTBI to active TB. Until recently, detection of LTBI has relied on the tuberculin skin test (TST), but despite the widespread use in clinical practice,TST does not reliably diagnose LTBI because several drawbacks, e.g. lacking in specificity, particularly in who were exposed to non-tuberculous mycobacteria (NTM) or were vaccinated with Bacille Calmette-Guerin (BCG) In addition, in young subjects,TST sensitivity is hampered by impaired T cell function leading frequently to false negative results.These several drawbacks limit the use of TST for the diagnose an LTBI in patients who may benefit from preventive chemotherapy. On the other hand, an accurate diagnosis of LTBI avoid the over-treatment of those patients with a positive TST results but not latently infected with Mtb. Recently, new tests based on the detection of interferon-gamma (IFN-γ) after stimulation with Mtb-specific antigens: Early secretory Antigenic Target-6 (ESAT-6) and Culture Filtrate Protein-10 (CFP-10) have been proposed for the diagnosis of active TB and LTBI. Methods: During the period from January 2009 to June 2009, in our laboratory 70 patients were tested with T-SPOT.TB (Oxford Immunotech, Abingdon, United Kingdom).We enrolled transplant patients and subjects ongoing transplant, patients immigrants from high prevalence TB countries, patients screened for immunosuppressive treatment, HIV / AIDS – infected individuals.We also tested 3 patients with clinical / radiological suspicion of active TB and 3 patients with positive tuberculin skin test and with a positive direct examination for mycobacteria in the urinary sediment. Results: In 2 patients with symptoms suggestive of TB in place,T-SPOT.TB showed a higher response of (IFN-g), more than 100 spots.Among individuals ongoing renal transplant, 6 patients tested T-SPOT.TB positive and 4 subjects were T.SPOT.TB -negative. Two patients with an autoimmune disease showed an high response to Mtb-specific antigens with T-SPOT.TB test tested before to start any treatment.T-SPOT.TB test tested strongly negative in 4 paediatric patients and in one HIV-infected individuals, regardless a positive response to a internal positive response (phytohaemagglutinin (PHA), suggesting a normal immune response. Conclusions:This preliminary data suggest that the T.SPOT.TB showed high sensitivity and specificity, producing a strongly negative response to Mtb-specific antigens in subjects who had a history of previous BCG-vaccination. In addition, T-SPOT.TB test provides, unlike the TST, indication about the potential immunosuppression of tested patient with an internal positive control that can highlight the production of IFN- γ by lymphocytes resulting in the application of this test in immunocompromised patients, e.g. children and transplantated patients and others

"Con gli occhi dietro la nuca". Scrittura e memoria visuale nell'opera di Gesualdo Bufalino

La critica bufaliniana ha identificato una indubbia relazione di scrittura letteraria e memoria visuale nell opera di Gesualdo Bufalino. Collocandosi in questa direzione di studi, questo lavoro ha inteso esplorare, sul doppio canale della fotografia e del cinema, il funzionamento della scrittura del ricordo. Il linguaggio iconico funziona infatti in Bufalino come un commutatore di materiali mnestici dentro il linguaggio scritto. Si è soprattutto trattato di rilevare come il cinema e la fotografia assumano spesso il ruolo di agenti del ricordo, ma siano anche dei codici dai quali la scrittura ricava forme e importa tecniche. Ovviamente tale uso implica l evidenza del carattere finzionale dell operazione memoriale, che questo studio intende non tanto come una ri-costruzione autoriale del passato sulla base di tracce ed evidenze documentarie, quanto come una costruzione narrativa in cui i vuoti del ricordo sono riempiti dall attività immaginativa. Cinema e fotografia sono sembrati come due poli di uno stesso flusso di influenze della visualità sulla scrittura. Sicché questa lettura, accanto al tema della memoria cui dedica il primo capitolo, ha isolato testi in cui prevale l uno ovvero l altra. La cinefilia dell autore, infine, oltre a fornire un serbatoio immenso di immagini, ha poi mostrato, grazie al ritrovamento di alcuni autografi, un ottima competenza e originalità nell interpretazione dei testi filmici, con peculiare attenzione alle pratiche citazionarie e alle potenzialità espressive del linguaggio indicale

Identification of Coagulase-Negative Staphylococci by Using the BD Phoenix System in the Low-Inoculum Mode▿

The new “low-inoculum” mode of the Phoenix system was evaluated to identify clinical coagulase-negative staphylococci. API ID32 Staph panels were used as comparators, and discrepancies were resolved by 16S rRNA and tuf gene analysis. The system correctly identified 90.5% of isolates, with a mean time of 10.2 h. Accuracy was satisfactory for Staphylococcus epidermidis, S. saprophyticus, and S. haemolyticus

Syphilis serology: Seroprevalence in a selected population and considerations on the Euroline WB test

Introduction: The clinical diagnosis of syphilis is always supported by appropriate laboratory tests and the test results are interpreted with reference to the patient’s history. In the diagnosis of syphilis, the use of tests based on antibody search that recognize both treponemal and reaginic antigens increases the diagnostic chances. Our study discusses the various serological and alternative tests currently available along with their limitations, and relates their results to the likely corresponding clinical stage of the disease. Methods: in our laboratory were analyzed 264 sera and 4 liquor (123 Females, 145 Males). 187 patients are subject at low risk for luetic infection, including pregnant woman, patient with organ transplant, outpatients or hospitalized undergoing routine serological, and 81 from patients with confirmed syphilis including 4 pregnant women in antibiotic treatment, patients with suspected disease, HIV positive and patients with autoimmune diseases with Cardiolipin positive. All sera were tested with ELISA Anti-Treponema pallidum Screen (IgG / IgM) and in parallel with agglutination tests VDRL and TPHA. On all positive sera was tested Euroline-WB EUROIMMUN and reading done with the program EuroLineScan. Results: by ELISA Anti-Treponema pallidum Screen IgG / IgM 162 sera were negative and 106 sera positive (39.5%), distributed as follows: 45 (42%) with a value greater than 200 RU / ml, 43 (41% ) with a value> 22 RU / ml and 18 (17%) with a borderline value between> 16 to <22 RU / ml. The execution of the Blot IgG showed: 18 negative sera, 6 with borderline value with one only band of specific antigens (p15, p45, p47 or p17), while 82, including 4 liquor (neurolue), were certainly positive showing more than one band antibody to the treponemal antigens. Only one patient had in place at the time of screening, an initial infection; in fact, there was a single clear positivity in the IgM protein bands, while 7 sera was uncertain values. It is reported 11 positivity for IgM Cardiolipin, while Cardiolipin IgG was detected with a high positivity in 34 sera. The presence of borderline values and / or positivity for a single protein band can be attributed to a unspecific reaction caused by autoimmune diseases or related cross-reactions with other Spirochete or to other Borrelia. Conclusions: The immunoblot test gave useful information at epidemiological and clinical level. The deepening with a confirmation test with proteic antigens and cardiolipin identifies false reactivity, but also indicates the specific reactivity to past infection and a better characteriation in the different stages of disease. In our study in the latent forms there are relevant discrepancies among the various tests. Compare to traditional methods, anti-cardiolipin antibodies positivity in our confirmatory test has the advantage of providing non subjective interpretation, being based upon the EuroLineScan program

Use of the T-spot.TB test for the diagnosis of latent tuberculosis infection

Background:Tuberculosis (TB) represents a major health problem both in developing and both in industrialized countries.The identification of individuals latently infected with Mycobacterium tuberculosis (Mtb) play a key role for the efficacy of TB control. These individuals with a latent tuberculosis infection (LTBI), especially those with high risk of reactivation (e.g. HIV + / AIDS-infected individuals, patients undergoing immunosuppressive therapy and children younger than 5 years) could benefit from a preventive treatment with isoniazid reducing the risk of progression from LTBI to active TB. Until recently, detection of LTBI has relied on the tuberculin skin test (TST), but despite the widespread use in clinical practice,TST does not reliably diagnose LTBI because several drawbacks, e.g. lacking in specificity, particularly in who were exposed to non-tuberculous mycobacteria (NTM) or were vaccinated with Bacille Calmette-Guerin (BCG) In addition, in young subjects,TST sensitivity is hampered by impaired T cell function leading frequently to false negative results.These several drawbacks limit the use of TST for the diagnose an LTBI in patients who may benefit from preventive chemotherapy. On the other hand, an accurate diagnosis of LTBI avoid the over-treatment of those patients with a positive TST results but not latently infected with Mtb. Recently, new tests based on the detection of interferon-gamma (IFN-γ) after stimulation with Mtb-specific antigens: Early secretory Antigenic Target-6 (ESAT-6) and Culture Filtrate Protein-10 (CFP-10) have been proposed for the diagnosis of active TB and LTBI. Methods: During the period from January 2009 to June 2009, in our laboratory 70 patients were tested with T-SPOT.TB (Oxford Immunotech, Abingdon, United Kingdom).We enrolled transplant patients and subjects ongoing transplant, patients immigrants from high prevalence TB countries, patients screened for immunosuppressive treatment, HIV / AIDS – infected individuals.We also tested 3 patients with clinical / radiological suspicion of active TB and 3 patients with positive tuberculin skin test and with a positive direct examination for mycobacteria in the urinary sediment. Results: In 2 patients with symptoms suggestive of TB in place,T-SPOT.TB showed a higher response of (IFN-g), more than 100 spots.Among individuals ongoing renal transplant, 6 patients tested T-SPOT.TB positive and 4 subjects were T.SPOT.TB -negative. Two patients with an autoimmune disease showed an high response to Mtb-specific antigens with T-SPOT.TB test tested before to start any treatment.T-SPOT.TB test tested strongly negative in 4 paediatric patients and in one HIV-infected individuals, regardless a positive response to a internal positive response (phytohaemagglutinin (PHA), suggesting a normal immune response. Conclusions:This preliminary data suggest that the T.SPOT.TB showed high sensitivity and specificity, producing a strongly negative response to Mtb-specific antigens in subjects who had a history of previous BCG-vaccination. In addition, T-SPOT.TB test provides, unlike the TST, indication about the potential immunosuppression of tested patient with an internal positive control that can highlight the production of IFN- γ by lymphocytes resulting in the application of this test in immunocompromised patients, e.g. children and transplantated patients and others

Single Photon Avalanche Diodes: Towards the Large Bidimensional Arrays

Single photon detection is one of the most challenging goals of photonics. In recent years, the study of ultra-fast and/or low-intensity phenomena has received renewed attention from the academic and industrial communities. Intense research activity has been focused on bio-imaging applications, bio-luminescence, bio-scattering methods, and, more in general, on several applications requiring high speed operation and high timing resolution. In this paper we present design and characterization of bi-dimensional arrays of a next generation of single photon avalanche diodes (SPADs). Single photon sensitivity, dark noise, afterpulsing and timing resolution of the single SPAD have been examined in several experimental conditions. Moreover, the effects arising from their integration and the readout mode have also been deeply investigated

Epidemiology, Microbiology and Severity of Bronchiolitis in the First Post-Lockdown Cold Season in Three Different Geographical Areas in Italy: A Prospective, Observational Study

The aim of this study was to understand the epidemiology, disease severity, and microbiology of bronchiolitis in Italy during the 2021–2022 cold season, outside of lockdowns. Before COVID-19, the usual bronchiolitis season in Italy would begin in November and end in April, peaking in February. We performed a prospective observational study in four referral pediatric centers located in different geographical areas in Italy (two in the north, one in the center and one in the south). From 1 July 2021 to 31 January 2022, we collected all new clinical diagnoses of bronchiolitis in children younger than two years of age recording demographic, clinical and microbiological data. A total of 657 children with a clinical diagnosis of bronchiolitis were enrolled; 56% children were admitted and 5.9% required PICU admission. The first cases were detected during the summer, peaking in November 2021 and declining into December 2021 with only a few cases detected in January 2022. RSV was the commonest etiological agent, while SARS-CoV-2 was rarely detected and only since the end of December 2021. Disease severity was similar in children with RSV vs. non-RSV bronchiolitis, and in those with a single infectious agent detected compared with children with co-infections. The 2021–2022 bronchiolitis season in Italy started and peaked earlier than the usual pre-pandemic seasons, but had a shorter duration. Importantly, the current bronchiolitis season was not more severe when data were compared with Italian published data, and SARS-CoV-2 was rarely a cause of bronchiolitis in children younger than 24 months of age