BACKGROUND: The South Korean criteria for occupational diseases were amended in July 2013. These criteria included formaldehyde as a newly defined occupational carcinogen, based on cases of “leukemia or nasopharyngeal cancer caused by formaldehyde exposure”. This inclusion was based on the Internal Agency for Research on Cancer classification, which classified formaldehyde as definite human carcinogen for nasopharyngeal cancer in 2004 and leukemia in 2012. METHODS: We reviewed reports regarding the causal relationship between occupational exposure to formaldehyde in Korea and the development of these cancers, in order to determine whether these cases were work-related. RESULTS: Previous reports regarding excess mortality from nasopharyngeal cancer caused by formaldehyde exposure seemed to be influenced by excess mortality from a single plant. The recent meta-risk for nasopharyngeal cancer was significantly increased in case-control studies, but was null for cohort studies (excluding unexplained clusters of nasopharyngeal cancers). A recent analysis of the largest industrial cohort revealed elevated risks of both leukemia and Hodgkin lymphoma at the peak formaldehyde exposure, and both cancers exhibited significant dose-response relationships. A nested case-control study of embalmers revealed that mortality from myeloid leukemia increased significantly with increasing numbers of embalms and with increasing formaldehyde exposure. The recent meta-risks for all leukemia and myeloid leukemia increased significantly. In South Korea, a few cases were considered occupational cancers as a result of mixed exposures to various chemicals (e.g., benzene), although no cases were compensated for formaldehyde exposure. The peak formaldehyde exposure levels in Korea were 2.70–14.8 ppm in a small number of specialized studies, which considered anatomy students, endoscopy employees who handled biopsy specimens, and manufacturing workers who were exposed to high temperatures. CONCLUSION: Additional evidence is needed to confirm the relationship between formaldehyde exposure and nasopharyngeal cancer. All lymphohematopoietic malignancies, including leukemia, should be considered in cases with occupational formaldehyde exposure.
Biopsy ; Case-Control Studies ; Classification ; Cohort Studies ; Endoscopy ; Formaldehyde ; Hodgkin Disease ; Humans ; Korea ; Leukemia ; Leukemia, Myeloid ; Mortality ; Nasopharyngeal Neoplasms ; Occupational Diseases ; Occupational Exposure ; Plants ; Workers' Compensation

Mayaro virus (MAYV) is a mosquito-transmitted alphavirus that produces an acute, usually non-fatal, febrile illness including Mayaro fever. Like other alphaviruses, the MAYV E1 and E2 envelope glycoproteins are major viral surface antigens that play a key role in host recognition and infection. Here, we report expression and purification methods for recombinant MAYV E1 (rE1) and rE2 using a baculovirus system. Enzyme-linked immunosorbent assays (ELISA) revealed that rE1 and rE2 were antigenic and reacted with human anti-MAYV IgG and IgM. Cross-reactivity was also confirmed with human anti-Chikungunya virus (CHIKV) IgG and IgM. Furthermore, we developed an immunochromatographic strip test (IST) with rE2 to diagnose MAYV infection. Thus, purified rE2 may be valuable tool for rapidly diagnosing MAYV infection.