As folate is vital in the first trimester of pregnancy for healthy fetal development, the use of antifolates is strongly contraindicated in pregnancy and carries significant teratogenic risk. Low doses of methotrexate can deplete folate stores and cause side-effects that are similar to folate deficiency.
Cause of Adult Mumps. Adult mumps is caused by an infection with the mumps virus, which is found worldwide. The mumps virus is an RNA (ribonucleic acid) virus from the family Paramyxovirus of the genus Rubulavirus. The mumps virus only infects humans.
Encephalitis caused by the herpes simplex virus is the leading cause of more severe cases in all ages, including newborns. A number of viruses for which there is now a vaccine may also cause encephalitis. These include: 1  Measles.2  Mumps. 3  Polio.4  Rabies. 5  Rubella. 6  Varicella (chickenpox).ncephalitis caused by the herpes simplex virus is the leading cause of more severe cases in all ages, including newborns. A number of viruses for which there is now a vaccine may also cause encephalitis. These include: 1  Measles. 2  Mumps. 3  Polio. 4  Rabies.