How urbanization affects the epidemiology of emerging infectious diseases

Neiderud, Carl-Johan

Overcrowded housing in high-density populations in the slums can be a breeding ground for infectious diseases such as tuberculosis. The rate of tuberculosis has traditionally been higher in urban centres compared to rural (14, 15) . Studies in slum settlements in Dhaka City, Bangladesh, indicate a high prevalence of tuberculosis, which was almost twice as high compared to the overall national average and four times higher than the overall urban levels (16) . However, different patterns can be seen in different countries; for example, in Poland the rates of tuberculosis have shown only slightly lower incidence in rural population compared to urban, 21.9 per 100,000 versus 22.4 per 100,000 respectively (17) . Tuberculosis in the United States has declined in the twentieth century, and several factors such as improved nutrition status, socioeconomic status, overall public health, and new drug regimens have been thought to play a major role. However, in the mid-1980s a resurgence occurred which reached its peak in 1992, especially in urban areas among the homeless and incarcerated population (18) . The knowledge regarding symptoms, transmission, and prevention has been shown to be greater among the urban population in Pakistan's Punjab province compared to the rural population. Health-seeking behaviour was also better among the urban population, in the aspect of when to seek medical advice for early diagnosis and potential treatment (19) . Information about infectious diseases and how they spread in the community can help the individuals to protect themselves, but knowledge about the slums and the infectious diseases panorama is also crucial for local physicians. They need to know how to look for the correct diagnosis, even if their diagnostic tools might be limited. The right hypothesis from the start in these cases is even more important.