import re
msg='He was paid USD 2,000.00 & USD 500 on 19-02-2018 at 08:15:24.'
rx = r'USD\s*(\d{1,3}(?:,\d{3})*(?:\.\d+)?)'
res = [int(float(x.replace(',',''))) for x in re.findall(rx, msg)]
print(res)
aW1wb3J0IHJlCm1zZz0nSGUgd2FzIHBhaWQgVVNEIDIsMDAwLjAwICYgVVNEIDUwMCBvbiAxOS0wMi0yMDE4IGF0IDA4OjE1OjI0LicKcnggPSByJ1VTRFxzKihcZHsxLDN9KD86LFxkezN9KSooPzpcLlxkKyk/KScKcmVzID0gW2ludChmbG9hdCh4LnJlcGxhY2UoJywnLCcnKSkpIGZvciB4IGluIHJlLmZpbmRhbGwocngsIG1zZyldCnByaW50KHJlcyk=