Generalities:

Parotitis or Mumps caused by RNA virus. It affects the testicles and bladder, it is a cause of Infertility, it can also cause meningitis. Associated with Parotid plus two other viruses gives True Sjögren Syndrome.

Possible pathological causes:

A. Diphtheria
B. Bordetella Pertussis
C. Tuberculosis
D. M.B. Leprae
E. Rabies virus
F. Treponema Pallidum
G. Herpes 2
H. Influenza virus
I. Aphthous virus
J. HIV Aids
K. Escobiasis, Scabies
L. Streptococcus Fecalis
M. Enterobacter pneumoniae
N. Neisseria Gonorreae
O. Streptococcus Fragilis
P. Leishmania
Q. Ballantidium typhus

Also check the pair of Parotids