TORCH Infections Overview

Overview

This lecture explains TORCH infections, which are pathogens capable of crossing the placenta and causing harm to a developing fetus.

The blood-placental barrier protects the fetus from pathogens, similar to the blood-brain barrier in the nervous system.
Some pathogens can cross the placenta and cause fetal infections, known as TORCH infections.

T — Toxoplasmosis: Caused by Toxoplasma gondii, a protozoan found in cat feces; pregnant women should avoid kitty litter.
O — Other: Includes syphilis, chickenpox (varicella), hepatitis B, HIV, and fifth disease (erythema infectiosum/“slapped cheek” disease).
R — Rubella: Also called German measles; can cause congenital rubella syndrome (CRS) with deafness, cataracts, heart, and brain defects.
C — Cytomegalovirus: Generally mild, but can cause serious issues in immunocompromised pregnant women and their fetuses.
H — Herpes Simplex Virus (HSV) Types 1 & 2: Can affect the mouth and genitals, leading to neonatal herpes.

Listeria monocytogenes: Causes listeriosis, can cross the placenta, leading to miscarriage or fetal harm.
Pregnant women should avoid deli meats and unpasteurized foods to reduce risk.

Pregnancy naturally suppresses the immune system to prevent immune rejection of the fetus.
This immunosuppression increases susceptibility to infections.

TORCH infections — Group of infections that can cross the placenta and cause fetal harm.
Blood-placental barrier — Selective barrier between maternal and fetal blood.
Erythema infectiosum — Fifth disease, a childhood rash with “slapped cheek” appearance.
Congenital rubella syndrome (CRS) — Birth defects caused by maternal rubella infection.

Review recommended foods and activities to avoid during pregnancy to prevent TORCH and Listeria infections.
Study the clinical effects of each TORCH infection on fetal development.