The history of infectious disease in Korea began with the first recorded epidemic in BC 15. 'Germ theory' was introduced to Korea in 1915 and heralded the beginning of Korea's modern scientific understanding of infection. Until the 1980s, highly contagious infections were the dominant types of infectious diseases. However, improvements in hygiene and healthcare associated with improved socio-economic status produced significant reduction in the number and severity of epidemics. This resulted in the less contagious diseases such as nosocomial infection or infection in immunocompromised hosts, to become the focus of Korean healthcare efforts. In Korea today, antimicrobial resistance is the primary focus of the clinical field.