PneumoniaPneumonia, BacterialPneumonia, PneumococcalPseudomonas aeruginosaPseudomonas InfectionsAcute DiseaseLungPneumonia, ViralVirulenceCryptogenic Organizing PneumoniaPneumonia, PneumocystisMice, Inbred BALB CPneumonia, StaphylococcalPneumonia, Ventilator-AssociatedPneumonia, AspirationCommunity-Acquired InfectionsPneumonia, MycoplasmaPneumonia, LipidLung Diseases, InterstitialIdiopathic Interstitial PneumoniasStreptococcus pneumoniaeAnti-Bacterial AgentsMurine pneumonia virusPneumocystis jiroveciiPneumocystisLegionnaires' DiseaseBronchoalveolar Lavage FluidRadiography, ThoracicMycoplasma pneumoniaeCross InfectionPulmonary EosinophiliaTrimethoprim-Sulfamethoxazole CombinationBronchopneumoniaHospitalizationPneumonia, Progressive Interstitial, of SheepVentilators, MechanicalBronchoalveolar LavageRespiration, ArtificialIntensive Care UnitsRetrospective StudiesProspective StudiesFatal OutcomePneumonia of Swine, MycoplasmalPneumococcal VaccinesTreatment OutcomeAnti-Infective AgentsPneumocystis cariniiEmpyemaLegionella pneumophilaSeverity of Illness IndexInfluenza, HumanRisk FactorsLegionellaPneumococcal InfectionsChild, HospitalizedImmunocompromised HostPentamidineChlamydial PneumoniaBronchoscopyBacteremiaAIDS-Related Opportunistic InfectionsPasteurellosis, PneumonicRespiratory Tract InfectionsPulmonary FibrosisSputumKlebsiella InfectionsIncidence