One way to classify<unk> s is by time and how humans were involved in the emergence: * Newly<unk> s – diseases that were not previously described in humans, such as HIV/AIDS * Re-emerging<unk>  diseases – diseases that have spread to new places or which previous treatments no longer control, such as methicillin-resistant Staphylococcus aureus * Deliberately<unk> s – diseases created by humans for bioterrorism * Accidentally<unk> s – diseases created or spread unintentionally by humans, such as vaccine-derived poliovirus
Emerging infectious disease
Opportunistic infection
Virus latency
Notifiable disease
Blood-borne disease
Intentional contagion of infection
Reverse zoonosis
Spillover infection