Which statement about new emerging human infectious diseases is true?

The statement that more than 50% of new emerging human infectious diseases are vector-borne or zoonotic is supported by extensive epidemiological studies. Emerging infectious diseases often stem from pathogens that are transmitted through vectors, such as mosquitoes or ticks, or they are of zoonotic origin, meaning they are transmitted from animals to humans. This classification is crucial in understanding the dynamics of disease emergence, as environmental changes, human encroachment on wildlife habitats, and globalization contribute to the increased interaction between humans and animal reservoirs.

Zoonotic diseases, which account for a significant proportion of emerging diseases, can arise from a variety of animal species, not exclusively from domestic animals but also from wildlife. The interconnectedness of these vectors and animal species plays a critical role in the transmission pathways that ultimately lead to outbreaks in human populations. Understanding this relationship helps in shaping public health strategies and preventive measures to combat these emerging infectious diseases.

While the other statements attempt to classify the nature of emerging infectious diseases, they do not accurately reflect the comprehensive data that highlight the importance of vector-borne and zoonotic origins in the emergence of these diseases.