Objectives Epidemiological investigation (EI) of Industrial Safety and Health Acts in Korea is a legal terminology that means a requested investigation when a more in-depth evaluation of work-relatedness is needed in process of work-related disease (WRD) compensation or for the preventive purpose. The objectives of this study are to report the changes of occupational infectious disease (OID) in South Korea and to introduce the EI cases of OID during the past 25 years.

Methods We confirmed the current status and the changes of infectious disease compensation by querying the industrial disaster database. Through the EI database of OSHRI, we identified 67 cases of biological factor exposure. Besides 36 preventive investigations, 31 cases were done for WRD compensation process. Eight cases not due to bacteria, virus, or fungi were excluded among them. So we reviewed the 23 cases’ reports.

Results OID were most frequent in 2009, because of influenza A (H1N1) pandemic. Among 23 EI cases, 14 cases (60.9%) approved the working relevance, 7 (30.4%) were disapproved, 2 (8.7%) were undecidable. Ten cases were bacterial infection, 8 were viral infection, 2 were fungal infection, and the others were combined or unknown infection. Nine cases were hazard group (HG) 2 of Health and Safety Executive, 11 cases were HG 3. Eight cases worked for medical institutions, 3 were building custodians, 2 worked in the construction industry, and 2 were sweepers.

Conclusions OID were easier to be approved for compensation claim than the diseases occurred by physical or chemical agent, because the causal relationships are quite clear. Even though many of EI cases had unclear infection source, judgement are only divided into two results; high and low working relevance. So when judging work-relatedness investigators should suggest most plausible infection source by considering the all steps of chain of infection and the working patterns.