The test for 'syphilis' was developed by

$PID$ (Pelvic Inflammatory Disease) is a characteristic of which of the following?

Which of the following diseases are completely curable if detected early and treated properly?
$I -$ Gonorrhoea,$II -$ Syphilis,$III -$ Genital herpes,$IV -$ Chlamydiasis,$V -$ Genital warts,$VI -$ Trichomoniasis,$VII -$ Hepatitis-$B$,$VIII -$ $AIDS$

What is the full form of $PID$?

Syphilis is caused by:

In case of a person suffering from syphilis, the chancre formation occurs during