Across • Active • Always • Animal • Availability • Budding • Cell • Commonly • Death • Depending • Depends • Destroyed • Determined • Diffusion • Dying • Efficiency • Employ • Exclusively • From • Happens • Harm • Host • Infected • Infections • Joints • Lead • Load • Locations • Muscles • Nervous • Occur • Occurs • Often • Passive • Process • Rapid • Receptors • Refers • Regardless • Relies • Results • Severity • Solely • Spread • Their • Tract • Types • Virus • Viruses • Yes