Spillovers from humans to wildlife are NOT a factor in the emergence and spread of infectious diseases. Instead, factors such as global travel, population density, and habitat alteration significantly contribute to the spread of these diseases.
The factor that is NOT a factor in the emergence and spread of dangerous infectious diseases like HIV/AIDS, Ebola, West Nile, SARS, Lyme disease, and Zika is A. spillovers from humans to wildlife. The other options are all known to contribute to the spread of infectious diseases.
Modern air travel (B), population increase (C), changing settlement patterns (D), and commercial expansion (E) have all played a role in facilitating the spread of infectious diseases by increasing human proximity, disrupting ecosystems, and facilitating rapid global travel which can spread disease vectors across continents.
Significant factors such as global travel, population density, and habitat alteration are some of the primary drivers in the spread of infectious diseases. They can cause diseases that typically affected animals to be transmitted to humans, often with deadly consequences. These factors, coupled with others such as climate change and urbanization, have led to an increase in the occurrence of infectious diseases.