What describes re-emerging pathogens?

Re-emerging pathogens are those that were once under control and considered manageable within public health parameters but have returned to prominence, causing renewed health threats. This resurgence can occur due to various factors, including antibiotic resistance, changes in human behavior, environmental shifts, or breakdowns in vaccination programs.

Understanding this concept helps clarify why these pathogens can become a significant concern despite previous control measures. These pathogens often require renewed public health strategies and interventions to mitigate their impact, as they can lead to outbreaks or increased incidences of disease in communities that may have thought they were safe from them. In contrast, the other options refer to newly discovered pathogens, those considered no longer a concern, or pathogens that exclusively affect animals, which do not fit the definition of re-emerging pathogens.