There are multiple ways to solve
this - one is technology and the other one is the age old methods of
'capacity building' and 'sensitisation'. Question is, are the latter
two areas of work for the India Programs office because they aren't
short term or easy. A via-media is to run all submission through some
http://turnitin.com/ type system to check. Or maybe a hybrid - where
they don't edit on the mainspace but say on a sandbox run in India by,
perhaps, the Chapter and then they graduate? It's easy to overwhelm
the system when so many students sign up - a ladder of evolution in to
a Wikipedia editor might help. As might the idea of pairing/twining
either the students together (they check each other) or student with
current editor (which may have already failed).