The head of the Japan Bank for International Cooperation has contracted rubella after attending meetings on the sidelines of last week’s Group of 20 summit in Osaka, sources said Friday.

A JBIC official declined to comment on who Gov. Tadashi Maeda, 61, might have mingled with at the meetings. The two-day summit ended last Saturday.

“We cannot disclose the information out of consideration for the relationship with the people he met,” the spokesman said.

According to NHK, Maeda met with members of the Russian delegation at side events during the two-day summit period.

Rubella, also known as German measles, spreads when an infected person coughs or sneezes. Once infected, it takes about two to three weeks for skin spots, fever and other symptoms to show.

If unborn babies are infected through their mothers in the early stages of pregnancy, they can suffer birth defects including impaired hearing, cataracts and heart disorders.