The article "The Impact of COVID-19 on Modern Slavery" by Angharad Smith and Dr James Cockayne as a contribution to Delta 8.7 mentions that there are 40.3 million people estimated to be in human trafficking. In fact, the authors explain three current COVID-19 impacts:
1) heightening risks for those already exploited
2) increasing the risks of exploitation, including child labour and child marriage
3) disrupting response efforts.
Read more: https://delta87.org/2020/03/impact-covid-19-modern-slavery/?mc_cid=86b5480022&mc_eid=43e62b03bf