  The outbreak of the COVID-19 pandemic triggers infodemic over online social
networks. It is thus important for governments to ensure their official
messages outpace misinformation and efficiently reach the public. Some
countries and regions that are currently worst affected by the virus including
Europe, South America and India, encounter an additional difficulty:
multilingualism. Understanding the specific role of multilingual users in the
process of information diffusion is critical to adjust their publishing
strategies for the governments of such countries and regions. In this paper, we
investigate the role of multilingual users in diffusing information during the
COVID-19 pandemic on popular social networks. We collect a large-scale dataset
of Twitter from a populated multilingual region from the beginning of the
pandemic. With this dataset, we successfully show that multilingual users act
as bridges in diffusing COVID-19 related information. We further study the
mental health of multilingual users and show that being the bridges,
multilingual users tend to be more negative. This is confirmed by a recent
psychological study stating that excessive exposure to social media may result
in a negative mood.
