Emerging respiratory infectious diseases: Clinical aspects for rapid identification and management

Emerging respiratory infectious diseases increasingly arise at the human-animal-environment interface and challenge clinicians with rapidly evolving diagnostic, therapeutic, and infection-control decisions. This narrative review summarizes clinically relevant viral and bacterial pathogens that may present as severe respiratory disease, but are easily mistaken for common community-acquired infections during early illness. We focus on zoonotic influenza A viruses, including contemporary H5N1, Middle East respiratory syndrome coronavirus (MERS-CoV), hantaviruses, Nipah virus, and inhalational bacterial threats such as anthrax, pneumonic plague, tularemia, and melioidosis. These infections may progress from non-specific symptoms to severe pneumonia, acute respiratory distress syndrome, shock, neurological complications, disseminated infection, or death. Timely recognition depends on careful assessment of travel, occupational and recreational exposures, animal contact, outbreak signals, and pathogen-specific syndromic clues. Multiplex molecular diagnostics can support early triage and exclusion of common pathogens, but targeted PCR, culture, serology, sequencing, and reference laboratory confirmation remain essential. Management requires prompt supportive care, appropriate isolation, public health notification, and pathogen-directed antimicrobial, antiviral, antitoxin, or prophylactic strategies where available. By integrating clinical presentation, diagnostics, treatment, vaccines, and One Health considerations, this review aims to translate knowledge on emerging infections into practical bedside preparedness.