MERS-CoV Infection in a Pregnant Woman in Korea

Jeong, Soo Young; Sung, Se In; Sung, Ji-Hee; Ahn, So Yoon; Kang, Eun-Suk; Chang, Yun Sil; Park, Won Soon; Kim, Jong-Hwa

Lastly, the remaining question was whether the virus could cross the placenta causing significant infection in the fetus, and whether MERS could cause vertical transmission. Camel-tohuman transmission, and human-to-human transmission via contact, droplet, and possibly airborne routes are the known modes of transmission (18, 19) . However, there are no data about perinatal transmission of MERS-CoV. Moreover, if the mother mounts an appropriate immune response to produce enough neutralizing antibodies without serious conditions, passive antibodies transferred from mother to fetus may have a protective effect on the fetus. There is only one case reporting the mother's serologic data previously (15) , in which stillbirth occurred at approximately 5 months of gestation, although the mother had MERS-CoV antibody by ELISA (titer 1:1,600) , immunofluorescent antibody (IFA), and microneutralization titer assay (titer 1:80). In our case, although the mother had IgG antibody (titer 1:100 by IIFT), antibody was not detected in neonatal serum. This finding may provoke different interpretations in regard to the role of maternal antibodies in the fetus or to transmission of maternal antibodies, necessitating more data in the future. To know whether prenatal transmission of MERS-CoV can occur, collection of samples including amniotic fluid, placenta, and umbilical cord is needed from an infected pregnant patient.