Pneumonia, ViralInfluenza A virusOrthomyxoviridae InfectionsInfluenza, HumanPneumoniaInfluenza A Virus, H1N1 SubtypePneumonia, BacterialInfluenza VaccinesPneumonia, PneumococcalInfluenza B virusInfluenza in BirdsInfluenza A Virus, H3N2 SubtypeCryptogenic Organizing PneumoniaInfluenza A Virus, H5N1 SubtypePneumonia, PneumocystisPneumonia, StaphylococcalHemagglutinin Glycoproteins, Influenza VirusPneumonia, Ventilator-AssociatedPneumonia, AspirationOrthomyxoviridaeCommunity-Acquired InfectionsPneumonia, MycoplasmaPneumonia, LipidPandemicsInfluenza A Virus, H9N2 SubtypeInfluenza A Virus, H3N8 SubtypeLungInfluenza A Virus, H2N2 SubtypeLung Diseases, InterstitialDisease OutbreaksNeuraminidaseHemagglutination Inhibition TestsInfluenza A Virus, H7N7 SubtypeOseltamivirInfluenza A Virus, H7N9 SubtypeSeasonsHemagglutinins, ViralInfluenza A Virus, H5N2 SubtypeIdiopathic Interstitial PneumoniasStreptococcus pneumoniaeVaccinationAntibodies, ViralAnti-Bacterial AgentsReassortant VirusesBirdsHospitalizationAntiviral AgentsBronchoalveolar Lavage FluidMurine pneumonia virusPneumocystis jiroveciiInfluenza A Virus, H1N2 SubtypeVaccines, InactivatedPneumocystisRadiography, ThoracicLegionnaires' DiseaseCross InfectionMycoplasma pneumoniaeBronchopneumoniaAmantadineZanamivirRespiratory Tract InfectionsRetrospective StudiesMadin Darby Canine Kidney CellsPoultryPulmonary EosinophiliaTrimethoprim-Sulfamethoxazole CombinationProspective StudiesIntensive Care UnitsDogsDucksPneumococcal VaccinesRespiration, ArtificialPneumonia, Progressive Interstitial, of SheepNasopharynxTreatment OutcomeBronchoalveolar LavagePopulation SurveillanceVentilators, MechanicalFatal OutcomeMice, Inbred BALB CTime FactorsInfluenzavirus CSentinel SurveillanceRisk FactorsViral Matrix ProteinsAntigens, ViralRimantadineImmunocompromised HostSwine DiseasesUnited StatesSeverity of Illness IndexInfant, NewbornIncidenceVirus ReplicationInfluenza A Virus, H7N3 SubtypePneumococcal InfectionsCross ProtectionInfluenzavirus AChild, HospitalizedPneumonia of Swine, Mycoplasmal