tetano
Editor, Senior Moderator
Citation: Piralla A, Pariani E, Rovida F, Campanini G, Muzzi A, et al. (2011) Segregation of Virulent Influenza A(H1N1) Variants in the Lower Respiratory Tract of Critically Ill Patients during the 2010–2011 Seasonal Epidemic. PLoS ONE 6(12): e28332. doi:10.1371/journal.pone.0028332
Antonio Piralla1, Elena Pariani2, Francesca Rovida1, Giulia Campanini1, Alba Muzzi3, Vincenzo Emmi4, Giorgio A. Iotti5, Antonio Pesenti6, Pier Giulio Conaldi7, Alessandro Zanetti2, Fausto Baldanti1*, and the Severe Influenza A Task Force
1 Struttura Semplice Virologia Molecolare, Struttura Complessa Virologia e Microbiologia, Fondazione Istituto Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy, 2 Dipartimento di Sanità Pubblica-Microbiologia-Virologia, Università degli Studi di Milano, Milan, Italy, 3 Struttura Complessa Direzione Medica di Presidio, Fondazione Istituto Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy, 4 Struttura Complessa Anestesia e Rianimazione I, Fondazione Istituto Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy, 5 Struttura Complessa Anestesia e Rianimazione II, Fondazione Istituto Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy, 6 Struttura Complessa Anestesia e Rianimazione, Azienda Ospedaliera San Gerardo, Monza, Italy, 7 Laboratorio di Patologia Clinica, Microbiologia e Virologia Istituto Mediterraneo per i Trapianti e Terapie ad Alta Specializzazione, Palermo, Italy,
Abstract Top
Background
Since its appearance in 2009, the pandemic influenza A(H1N1) virus circulated worldwide causing several severe infections.
Methods
Respiratory samples from patients with 2009 influenza A(H1N1) and acute respiratory distress attending 24 intensive care units (ICUs) as well as from patients with lower respiratory tract infections not requiring ICU admission and community upper respiratory tract infections in the Lombardy region (10 million inhabitants) of Italy during the 2010–2011 winter-spring season, were analyzed.
Results
In patients with severe ILI, the viral load was higher in bronchoalveolar lavage (BAL) with respect to nasal swab (NS), (p<0.001) suggesting a higher virus replication in the lower respiratory tract. Four distinct virus clusters (referred to as cluster A to D) circulated simultaneously. Most (72.7%, n = 48) of the 66 patients infected with viruses belonging to cluster A had a severe (n = 26) or moderate ILI (n = 22). Amino acid mutations (V26I, I116M, A186T, D187Y, D222G/N, M257I, S263F, I286L/M, and N473D) were observed only in patients with severe ILI. D222G/N variants were detected exclusively in BAL samples.
Conclusions
Multiple virus clusters co-circulated during the 2010–2011 winter-spring season. Severe or moderate ILI were associated with specific 2009 influenza A(H1N1) variants, which replicated preferentially in the lower respiratory tract.
http://www.plosone.org/article/info...osone/PLoSONE+(PLoS+ONE+Alerts:+New+Articles)
Antonio Piralla1, Elena Pariani2, Francesca Rovida1, Giulia Campanini1, Alba Muzzi3, Vincenzo Emmi4, Giorgio A. Iotti5, Antonio Pesenti6, Pier Giulio Conaldi7, Alessandro Zanetti2, Fausto Baldanti1*, and the Severe Influenza A Task Force
1 Struttura Semplice Virologia Molecolare, Struttura Complessa Virologia e Microbiologia, Fondazione Istituto Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy, 2 Dipartimento di Sanità Pubblica-Microbiologia-Virologia, Università degli Studi di Milano, Milan, Italy, 3 Struttura Complessa Direzione Medica di Presidio, Fondazione Istituto Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy, 4 Struttura Complessa Anestesia e Rianimazione I, Fondazione Istituto Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy, 5 Struttura Complessa Anestesia e Rianimazione II, Fondazione Istituto Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy, 6 Struttura Complessa Anestesia e Rianimazione, Azienda Ospedaliera San Gerardo, Monza, Italy, 7 Laboratorio di Patologia Clinica, Microbiologia e Virologia Istituto Mediterraneo per i Trapianti e Terapie ad Alta Specializzazione, Palermo, Italy,
Abstract Top
Background
Since its appearance in 2009, the pandemic influenza A(H1N1) virus circulated worldwide causing several severe infections.
Methods
Respiratory samples from patients with 2009 influenza A(H1N1) and acute respiratory distress attending 24 intensive care units (ICUs) as well as from patients with lower respiratory tract infections not requiring ICU admission and community upper respiratory tract infections in the Lombardy region (10 million inhabitants) of Italy during the 2010–2011 winter-spring season, were analyzed.
Results
In patients with severe ILI, the viral load was higher in bronchoalveolar lavage (BAL) with respect to nasal swab (NS), (p<0.001) suggesting a higher virus replication in the lower respiratory tract. Four distinct virus clusters (referred to as cluster A to D) circulated simultaneously. Most (72.7%, n = 48) of the 66 patients infected with viruses belonging to cluster A had a severe (n = 26) or moderate ILI (n = 22). Amino acid mutations (V26I, I116M, A186T, D187Y, D222G/N, M257I, S263F, I286L/M, and N473D) were observed only in patients with severe ILI. D222G/N variants were detected exclusively in BAL samples.
Conclusions
Multiple virus clusters co-circulated during the 2010–2011 winter-spring season. Severe or moderate ILI were associated with specific 2009 influenza A(H1N1) variants, which replicated preferentially in the lower respiratory tract.
http://www.plosone.org/article/info...osone/PLoSONE+(PLoS+ONE+Alerts:+New+Articles)