How urbanization affects the epidemiology of emerging infectious diseases

Neiderud, Carl-Johan

Global travel shows no signs of decline and the interconnected megacities around the world make global surveillance even more important when it comes to contagious infectious diseases. Measurements to stop the spread need to be taken at the original location, but knowledge about the specific disease needs to be passed on to the global community and local health workers in other parts of the world. This global surveillance and alert system needs to be fast and efficient to, if possible, reduce the impact. The expected rise of travel makes it critical for the future global health and the possibility to react in time for possible threats. Zoonotic disease a challenge for the future Rapid and sometimes uncontrolled urbanization can, in certain circumstances, lead to closer encounters with wildlife. Human influence on the ecosystems creates meeting points for new and potential zoonotic diseases, which could have a profound impact for both local and global health. The global trends of urbanization push people to previously untouched ecosystems. New housing in the outskirts of big cities can potentially be meeting points for new and already known zoonotic diseases. Of 335 emerging infectious diseases, which have been recognized between 1940 and 2004, more than 60% have been zoonotic diseases (55) . Living in close contact to domesticated animals and hunt for 'bush-meat' can also be risk factors for an infectious disease to make the jump from the animal host to humans. Major deforestation creates closer contact between humans and bats and even primates, who can potentially be host for 'new' viruses. A better understanding, surveillance, and prevention of zoonotic diseases would be of great value, to both prevent and manage this upcoming threat for global health. Hot spots for this transmission have been found and they often correlate where the process of urbanization is on the clear rise (56) . Even if it is not always the urban population who is at the front of new encounters with wildlife, it can still have an effect on urban health. The trend of people moving to cities are at the highest, where many of these new encounters with ecosystems take place, and infectious diseases can be introduced to these growing urban environments. The sometimes uncontrolled growth of cities pushes residents to untouched ecosystems when new housing expands.