Ever since Hippocrates expressed the view that environmental factors can influence disease incidence, attempts have been made to link the emergence of disease, especially outbreaks of infectious diseases, with the various factors that contribute to their occurrence. Among the possible causes favoring the spread of pathogens and the increase in the incidence of infectious diseases, environmental and social conditions are mentioned. An unprecedented set of new conditions has made the human population more vulnerable and more susceptible to infectious diseases than ever before. It is possible that the observed contemporary patterns of development and spread of infectious diseases may be seen as heralds of a new stage of epidemiological transformation characterized by an increased risk of infectious disease epidemics. In past centuries, one of the hallmarks of infectious disease plagues has been their unpredictability. Currently, warning forecasts prepared by scientists do not always translate into preventive measures.

Introduction Urbanisation is a global process leading to development of urban infrastructure and thus an increase in the population of urban areas. Health threats, including epidemics of infectious diseases that may break out in growing urban areas, can spread quickly and their effects could spread outside of the local territory. Purpose To outline the relationship between globalising, post-modern urbanisation processes, in particular the specific form of extended urbanisation, and the risks posed by infectious diseases that could give rise to new epidemics or pandemics. State of knowledge Health risks occurring at the local level of an urban area react to, and simultaneously affect, health situation occurring at an indefinite distance from the original site of the event. An important impact on the situation are the expanding or newly emerging urban areas, which cause negative changes in social conditions, and the increase in spatial mobility of the global population, which facilitates the spread of infectious diseases. Summary Understanding 21st century urban trends is the key to improving collective health. Adopting a "public health perspective" regarding values and attitudes towards social phenomena and reality, as well as the necessary methods of conduct, seems to be one of the main challenges of the current era in which people around the world, regardless of the country's development status and level of resources, currently live in within one “ecosystem of infectious diseases”. Planned and controlled urbanization, taking into account the achievements of modern epidemiology, including molecular epidemiology, will help will help along the remediation of the cities of the future.