Toxoplasmosis is a disease caused by the protozoan parasite Toxoplasma gondii and is associated with eating raw or undercooked meat and through handling of infected cat feces and infected mice or farm animals. It can also be transmitted through eating unwashed fruits or vegetables whose surfaces have become contaminated with the parasite.

Acute infection produces symptoms such as rash, fever, malaise, lymphadenopathy, headaches, and/or sore throat. Changes in vision or eye pain may also be present. Symptoms are frequently mistaken for influenza or mononucleosis and can occur 1-2 weeks after exposure. Previous maternal infection provides immunity.

Infections during pregnancy are associated with spontaneous abortion, preterm delivery, fetal demise, or congenital infection with symptoms appearing at birth. Toxoplasmosis titers are performed to determine infection. Approximately 10% of infected infants exposed to the disease develop chorioretinitis, pneumonia, jaundice, and thrombocytopenia purpura. This rate increases to approximately 60% if exposed during the third trimester. They may also suffer permanent neurological deficits.

The drugs of choice for this infection include spiramycin, sulfadine, pyrimethamine, and folinic acid. Pyrimethamine is not recommended during the first trimester because of the potential for teratogenicity. If the patient is allergic to sulfonamides, an alternative is to treat with clindamycin or azithromycin.

This category includes infections such as group B streptococcus (GBS), varicella (chickenpox), hepatitis, and human immunodeficiency virus. Varicella is in the family of all herpes viruses. Once exposed to it, varicella can remain dormant in the dorsal root of the ganglia for many years before reactivating. It is transmitted through direct contact with respiratory secretions from an infected individual. The incubation period is approximately 10-14 days.

Signs and symptoms include fever, malaise, and a generalized pruritic vesicular rash on the body. The vesicles evolve to pustules that crust over before resolving. Individuals are considered contagious 24 hours before the onset of the rash and until all the lesions have completely crusted over. Treatment is aimed at prevention by individuals becoming immunized preconceptually. Symptomatic relief includes acetaminophen for fevers and cool or tepid baths to relieve itching. In severe infections, intravenous acyclovir may be safely used in all trimesters of pregnancy.

Once an individual has had varicella zoster, they usually have lifetime immunity. However, in pregnant women who have not had the disease or vaccination, an infection during the first trimester carries an approximate 10-20% risk for congenital defects, such as mental retardation, growth retardation, limb and digit hypoplasia, and eye anomalies. These signs usually develop within the first 10 days of the neonates’ life.

Group B streptococcus (GBS) is a gram-positive bacterium that is normally found in the vaginas of nonpregnant women and in approximately 9-23% of healthy pregnant women. It causes vertical transmission (from mother to infant) during birth and is the leading cause of neonatal infections in the United States.

Women with GBS are generally asymptomatic; however, once the infection has progressed, patients may initially complain of fever. Late signs and symptoms include uterine tenderness (amnionitis), foul-smelling amniotic fluid, and tachycardia.

The current recommendations are to screen all pregnant women at 35-37 weeks’ gestation for GBS by obtaining vaginal and anorectal cultures. All positive results are treated with antibiotics such as penicillin G or ampicillin. Monitoring of the newborn for respiratory distress or signs of infection should be performed.

Rubella, also known as German measles, is caused by the rubella virus. The infection is transmitted by respiratory contact with an infected individual. Patients commonly report fever, myalgias, arthralgias, lymphadenopathy, and a nonpruritic rash. It is vertically transmitted. Rubella is diagnosed based on signs and symptoms and a hemagglutination inhibition antigen test.

Fetal complications are much more serious than maternal complications and can cause miscarriage, congenital anomalies known as congenital rubella syndrome, and death. The incidence of such anomalies is 50-90% if infection occurs during the first trimester. Malformations of the fetal heart and brain occur if exposure happens during the first 2 months. If infection occurs after the fourth month, hearing loss, mental retardation, intrauterine growth retardation, and systemic infections can occur in the fetus.

Vaccination against rubella is widely available, but women are recommended to be screened during the initial prenatal visit to determine immunity. Otherwise, vaccination should take place a minimum of 3 months before conception or in the immediate postpartum period. It is contraindicated in pregnant women. It is not contraindicated in breast-feeding women.

Cytomegalovirus (CMV) is a DNA virus in the herpes family that is transmitted maternally through sexual contact, blood transfusions, or respiratory contact. Women are at risk for contracting CMV if they work or have children in day care or in institutions for the mentally retarded.

Infected women are primarily asymptomatic but may present with flulike symptoms and elevated liver function tests. A positive CMVspecific antigen IgM test confirms the presence of an infection. Women with a positive infection need to decide on elective termination of the pregnancy due to the high rate of fetal anomalies associated with CMV. Reactivation of a previous infection can also occur because there is no immunity once the disease has been contracted.

Currently, there is no therapy to treat CMV. Proper hand-washing techniques, good hygiene, and safe sex help to prevent spreading the virus to others.

Approximately 20% of the adult population has been diagnosed with herpes simplex virus type 2 (HSV-2). Genital herpes is a recurrent lifelong viral infection that can reoccur at any time. The virus can be shed at any time without symptoms.

Approximately 2% of women acquire HSV-2 during pregnancy. It is associated with a high rate of infant mortality (40-60%) if primary infection occurs during either the first trimester or near the time of delivery.

Signs and symptoms include painful vesicular lesions on or around the inner and outer labia, fever, malaise, and dysuria. Diagnosis is based on clinical symptoms, viral cultures of the lesions, and type-specific serological testing for HSV. Oral antiviral medications are used to decrease the severity of the outbreak along with topical antibiotic ointments or creams to prevent secondary bacterial infections. If the outbreak occurs near or at the time of delivery, a cesarean section is recommended to prevent complications and transmission to the newborn.