M. A. De Marco

Circulation of Influenza Viruses in Wild Waterfowl Wintering in Italy During the 1993–99 Period: Evidence of Virus Shedding and Seroconversion in Wild Ducks

Abstract 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.

Long-term Monitoring for Avian Influenza Viruses in Wild Bird Species in Italy

M.A. De Marco1*, E. Foni2, L. Campitelli3, E. Raffini4, M. Delogu5 and I. Donatelli3 1Istituto Nazionale per la Fauna Selvatica, Ozzano Emilia (BO); 2Istituto Zooprofilattico Sperimentale della L ombardia e dell’Emilia Romagna, Parma; 3Department of V irology, Istituto Superiore di Sanita, Rome; 4Istituto Zooprofilattico Sperimentale della L ombardia e dell’Emilia Romagna, L ugo (RA); 5Department of Public Health and Animal Pathology, Faculty of Veterinary Medicine, University of Bologna, Italy *Correspondence: Istituto Nazionale per la Fauna Selvatica ‘ A. Ghigi ’, 9 V ia Ca’ Fornacetta, 40064 Ozzano Emilia (BO), Italy E-mail: infs.adem@iperbole.bologna.it

Ecological Aspects of Influenza A Virus Circulation in Wild Birds of the Western Palearctic

M. Delogu1*, M.A. De Marco2, I. Donatelli3, L. Campitelli3 and E. Catelli1 1Dipartimento di Sanita Pubblica Veterinaria e Patologia Animale, Facolta di Medicina Veterinaria, Universita degli Studi di Bologna, Ozzano Emilia (BO); 2Istituto Nazionale per la Fauna Selvatica, Ozzano Emilia (BO); 3L aboratory of V irology, Istituto Superiore di Sanita, Rome, Italy. *Correspondence: Dipartimento di Sanita Pubblica Veterinaria e Patologia Animale, Facolta di Medicina Veterinaria, Universita degli Studi di Bologna, 50 via T olara di Sopra, 40064 Ozzano Emilia (BO), Italy E-mail: delogu@vet.unibo.it

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.

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

SUMMARY. 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 ≥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.

Influenza viruses: structure and interspecies transmission mechanisms.

I. Donatelli1*, L. Campitelli1, S. Puzelli1, C. Affinito1, M.A. De Marco2, M. Delogu3 and G. Barigazzi4 1L aboratory of V irology, Istituto Superiore di Sanità, Rome; 2Istituto Nazionale per la Fauna Selvatica ‘ A. Ghini ’, Ozzano Emilia (Bo); 3Department of Public Health and Animal Pathology, Facoltà di Medicina Veterinaria, Università di Bologna, Ozzano Emilia (Bo), 4Istituto Zooprofilattico Sperimentale della L ombardia ed Emilia, Parma, Italy *Correspondence: L aboratorio di V irologia, Istituto Superiore di Sanità, V iale Regina Elena, 299, 00161, Roma, Italy E-mail: donatell@iss.it