Serosurvey against H5 and H7 avian influenza viruses in Italian poultry workers.

Highly pathogenic (HP) and low pathogenic (LP) avian influenza viruses (AIVs) belonging to H5 and H7 subtypes have been found to be associated with human infection as the result of direct transmission from infected poultry. Human infections by AIVs can cause mild or subclinical disease, and serosurveys are believed to represent an important tool to identify risk of zoonotic transmission. Therefore, we sought to examine Italian poultry workers exposed during LPAI and HPAI outbreaks with the aim of assessing serologic evidence of infection with H5 and H7 AIVs. From December 2008 to June 2010 serum samples were collected from 188 poultry workers and 379 nonexposed controls in Northern Italy. The hemagglutination inhibition (HI) assay using horse red blood cells (RBCs) and a microneutralization (MN)-enzyme-linked immunosorbent assay test were used to analyze human sera for antibodies against the following H5 and H7 LPAI viruses: A/Dk/It/4445/07(H5N2); A/Ty/It/2369/09(H5N7); A/Ty/It/218-193/ 10; A/Ck/It/3775/99(H7N1); A/Ty/It/214845/03(H7N3); and A/Dk/It/332145/09(H7N3). Since previous studies identified low antibody titer to AIVs in people exposed to infected poultry, a cutoff titer of > or = 1:10 was chosen for both serologic assays. Only HI-positive results confirmed by MN assay were considered positive for presence of specific antibodies. The Fisher exact test was used to analyze differences in seroprevalence between poultry workers and control groups, with the significance level set at P < 0.05. MN results showed a proportion of H7-seropositive poultry workers (6/188, i.e., 3.2%), significantly higher than that of controls (0/379), whereas no MN-positive result was obtained against three H5 LPAI subtypes recently identified in Italy. In conclusion, the survey indicated that assessing seroprevalence can be an important tool in risk assessment and health,surveillance of poultry workers.

Surveillance of hospitalised patients with influenza-like illness during pandemic influenza A(H1N1) season in Sicily, April 2009-December 2010.

This paper describes the epidemiology of hospitalised cases with influenza-like illness (ILI) and laboratory-confirmed influenza A cases in Sicily (Italy) during the 2009 influenza pandemic. The first ILI case diagnosed as infected with pandemic influenza A(H1N1)2009 in Sicily was reported in June 2009 and it rapidly became the dominant circulating strain. In the period from 30 April 2009 through 31 December 2010, a total of 2,636 people in Sicily were hospitalised for ILI and 1,193 were laboratory-confirmed for influenza A. Basic demographic and clinical information for all hospitalised patients was collected and population mortality rates (PMRs) and case fatality ratios (CFRs) were calculated. The median age of hospitalised patients infected with pandemic influenza A(H1N1)2009 was significantly lower than that of hospitalised ILI cases in general (18.0 vs. 32.1 years; p<0.0001). Among adults, women were more susceptible than men. The majority of clinical presentations were mild, but 6.6% of hospitalised patients required admission to an intensive care unit, of whom 26.3% had confirmed influenza A. Twenty-four fatal cases were documented. The age group of 45­54 year-olds showed the highest PMRs once hospitalised, while CFRs were higher in elderly patients of 65 years and older. All fatal cases were confirmed as influenza A(H1N1)2009 and most of them had established risk factors for influenza complications.

Influenza A pandemic (H1N1) 2009 virus outbreak in a cat colony in Italy.

In April 2009, a novel H1N1 influenza A virus (pH1N1) was recognized as the cause of the flu pandemic in humans. Here, we report the isolation of pH1N1 virus from the lung homogenates of two cats, which died after severe respiratory symptoms. The cats belonged to a cat colony consisting of 90 caged cats and were found dead following a 2-week period of respiratory and gastrointestinal diseases in the colony. During the outbreak, 25 cats died and 50% of the animal colony showed anorexia, depression, respiratory and gastrointestinal symptoms. Histological examination of the lungs of the two tested cats displayed lesions centred on terminal airways with epithelial bronchiolar hyperplasia and alveolar necrosis. Influenza A virus was detected in the lung tissues by immunohistochemistry and real-time RT-PCR (rRT-PCR). Partial sequences of haemagglutinin (HA) genes and complete sequences of neuraminidase (NA) genes of the two isolates displayed high similarity to the pH1N1 viruses circulating in humans (99% for HA gene and 100% for NA gene). To determine whether the pandemic virus had circulated among cats, serum samples and pharyngeal swabs were collected from 38 cats of the colony. Serum samples were tested by ELISA to detect antibodies against pH1N1 nucleoprotein and by hemagglutination-inhibition test, while pharyngeal swabs were examined by pH1N1 specific rRT-PCR. Twenty-one (55%) of the tested cats carried antibodies against the isolated strain and two swabs were positive for the presence of pH1N1 RNA. Our results confirm that the pH1N1 virus was able to infect cats and raise the hypothesis of the circulation of the virus within the colony being due to cat-to-cat transmission. The case reported here provides, to the best of the authors' knowledge, the first description of the pH1N1 infection involving numerous cats that lived in a restricted area with limited contact with humans.

Molecular surveillance of pandemic influenza A(H1N1) viruses circulating in Italy from May 2009 to February 2010: association between haemagglutinin mutations and clinical outcome.

Haemagglutinin sequences of pandemic influenza A(H1N1) viruses circulating in Italy were examined, focusing on amino acid changes at position 222 because of its suggested pathogenic relevance. Among 169 patients, the D222G substitution was detected in three of 52 (5.8%) severe cases and in one of 117 (0.9%) mild cases, whereas the D222E mutation was more frequent and evenly distributed in mild (31.6%) and severe cases (38.4%). A cluster of D222E viruses among school children confirms reported human-to-human transmission of viruses mutated at amino acid position 222.

Notch-1 stimulates survival of lung adenocarcinoma cells during hypoxia by activating the IGF-1R pathway.

Hypoxic microenvironment supports cancer stem cell survival, causes poor response to anticancer therapy and tumor recurrence. Inhibition of Notch-1 signaling in adenocarcinoma of the lung (ACL) cells causes apoptosis specifically under hypoxia. Here, we found that Akt-1 activation is a key mediator of Notch-1 pro-survival effects under hypoxia. Notch-1 activates Akt-1 through repression of phosphatase and tensin (PTEN) homolog expression and induction of the insulin-like growth factor 1 receptor (IGF-1R). The latter seems to be the major determinant of Akt-1 stimulation, as Notch-1 signaling affects Akt-1 activation in PTEN(-/-) ACL cells. Both downregulation of insulin receptor substrate 1 (IRS-1) and dominant-negative IGF-1R sensitized ACL cells to gamma-secretase inhibitor (GSI)-induced apoptosis. Conversely, overexpression of IGF-1R protected ACL cells from GSI toxicity. Inhibition of Notch-1 caused reduced IGF-1R expression, whereas forced Notch-1 expression yielded opposite effects. Chromatin immunoprecipitation experiments suggested Notch-1 direct regulation of the IGF-1R promoter. Experiments in which human ACL cells were injected in mice confirmed elevated and specific co-expression of Notch-1(IC), IGF-1R and pAkt-1 in hypoxic tumor areas. Our data provide a mechanistic explanation for Notch-1-mediated pro-survival function in hypoxic ACL tumor microenvironment. The results identify additional targets that may synergize with Notch-1 inhibition for ACL treatment.

Influenza surveillance in birds in Italian wetlands (1992-1998): is there a host restricted circulation of influenza viruses in sympatric ducks and coots?

We report the results of a 6-year serological and virological monitoring performed in ducks and coots in Italy, in order to assess the degree of influenza A virus circulation in these birds during wintering. A total of 1039 sera collected from 1992 to 1998 was screened by a double antibody sandwich blocking ELISA (NP-ELISA): seroprevalence of antibodies to influenza A viruses was significantly higher in ducks compared to coots (52.2% vs. 7.1%, respectively). The hemagglutination-inhibition (HI) assay, performed on NP-ELISA positive sera, showed that 16.9% of these duck sera and 33.3% of these coot sera had antibodies to at least one influenza virus HA subtype: ducks showed HI antibodies against most of the HA subtypes, except for the H3, H4, H7, and H12; coots were seropositive to the H3 and H10 subtypes, only. From 1993 to 1998, 22 virus strains were obtained from 802 cloacal swabs, with an overall virus isolation frequency of 2.7%. Viruses belonging to the H1N1 subtype were by far the most commonly circulating strains (18/22) and were isolated mainly from ducks (17/18). The remaining viruses were representative of the H10N8, H5N2 and H3N8 subtypes. Our data indicate some differences between influenza A virus circulation in sympatric ducks and coots and a significant antigenic diversity between some reference strains and viruses recently isolated in Italy.

Circulation of influenza viruses in wild waterfowl wintering in Italy during the 1993-99 period: evidence of virus shedding and seroconversion in wild ducks.

The mechanisms of perpetuation of influenza A viruses in aquatic birds, their main reservoir in nature, have not yet been completely clarified. One hypothesis is that they continue to circulate in waterfowl throughout the year, even though virus isolations during the winter months are rare. We analyzed influenza virus circulation in wild ducks in Italy during six winter seasons (1993-99), using virus isolations and serological analyses. It was apparent that influenza A viruses were constantly circulating in wild birds during all the seasons considered. Moreover, seroconversion rates (obtained from ducks recaptured during the same season) suggest a frequency of influenza infections higher than expected on the basis of the virus isolation rates.