• Clinical science

Congenital TORCH infections

Summary

Congenital infections are caused by pathogens transmitted from mother to child during pregnancy (transplacentally) or delivery (peripartum). They can have a substantial negative impact on fetal and neonatal health. The acronym TORCH stands for the causative pathogens of congenital infections: Toxoplasma gondii, others (including Treponema pallidum, Listeria, Varicella, and parvovirus B19), rubella virus, cytomegalovirus (CMV), and herpes simplex virus (HSV). TORCH infections can cause spontaneous abortion, premature birth, and intrauterine growth restriction (IUGR). These infections can also cause abnormalities in the CNS, the skeletal and endocrine systems, and the complex organs (e.g., cardiac defects, vision and hearing loss). Prophylaxis is of great importance during pregnancy. Primary prevention includes vaccination for varicella and rubella (prior to pregnancy), hygiene measures (washing hands and avoiding certain foods), and screening for syphilis during pregnancy. Affected infants require regular follow-ups to monitor for hearing loss, ophthalmological abnormalities, and developmental delays.

Several other pathogens can also be vertically transmitted during pregnancy and have detrimental effects on the fetus and/or newborn. These include HIV in pregnancy, perinatal hepatitis B, group B Streptococci, E. coli, gonococcal infections and chlamydial infections, West Nile virus, Zika virus, measles virus, enterovirus, and adenovirus. The pathogens are discussed in more detail in their respective learning cards.

Overview

Infection Clinical features Diagnosis Treatment Prevention
Toxoplasmosis
Syphilis
Listeriosis
  • Avoidance of unpasteurized dairy products
  • Avoidance of cold deli meats
Varicella zoster virus (VZV)
Parvovirus B19
  • Frequent hand washing
  • Pregnant women with risk factors for TORCH infection should avoid potentially contaminated workplaces (e.g., schools, pediatric clinics) [3]
Rubella
  • Supportive care
Cytomegaly virus (CMV)
  • Frequent hand washing
  • Pregnant women with risk factors for TORCH infection should avoid potentially contaminated workplaces (e.g., schools, pediatric clinics) [4]
Herpes simplex virus (HSV)
  • Premature birth, IUGR
  • Skin, eyes, and mouth involvement: vesicular lesions, keratoconjunctivitis
  • Localized CNS involvement: meningitis
  • Disseminated disease: multiple organ involvement, sepsis
  • Viral culture
  • PCR for HSV DNA

Transplacental transmission occurs following primary infection of a seronegative mother during pregnancy. Maternal IgM antibodies, which are unable to cross the placenta, form first. Protective IgG antibodies, which are able to cross the placenta, have not yet been formed, so the infant is not protected from infection via the placenta.

In general, the earlier the TORCH infection occurs during pregnancy, the more severe the complications!

Attenuated live vaccines (measles, mumps, rubella, and varicella) are contraindicated in pregnancy! Conception should be avoided for at least 3 months after immunization with live vaccines!References: [5][6]

Congenital toxoplasmosis

Epidemiology

∼ 1:10,000 live births per year in the US

Pathogen

Toxoplasma gondii

Transmission

  • Mother
    • Cat feces
    • Raw or insufficiently cooked meat
    • Unpasteurized milk (especially goat milk)
    • See “Etiology” in toxoplasmosis.
  • Fetus
    • Transplacental transmission
      • Transmission rate
        • Third trimester: ∼ 70%
        • First trimester: ∼ 15%

Clinical features

Diagnostics

Treatment

  • Mother: : immediate administration of spiramycin
  • Fetus: : When confirmed or highly suspected, switch to pyrimethamine, sulfadiazine, and folinic acid.
  • Newborn: pyrimethamine, sulfadiazine, and folinic acid

Prevention

  • Avoid raw, undercooked, and cured meats.
  • Wash hands frequently, especially after touching soil (e.g., during gardening).
  • Avoid contact with cat litter.

The 4 Cs of congenital toxoplasmosis: Cerebral calcifications, Chorioretinitis, hydroCephalus, and Convulsions!
References:[7][8][9][6][10]

Congenital syphilis

Epidemiology

∼ 23:100,000 live births per year in the US

Pathogen

Treponema pallidum

Transmission

  • Mother
    • Sexual contact (contact with infectious lesion)
    • See “Etiology” in syphilis.
  • Fetus: transplacental transmission from infected mother
    • Increased risk of transmission with recent syphilis infection
    • Risk of transmission increases with gestational age
  • Neonate: perinatal transmission during birth

Clinical features

Diagnosis

Treatment

14 days of IV penicillin G for both pregnant women and newborns

Prevention

Hutchinson triad: interstitial keratitis, sensorineural hearing loss, Hutchinson teeth

References:[11][12][13][14][15][16][17]

Congenital listeriosis

Epidemiology

∼ 3:100,000 live births per year in the US

Pathogen

Listeria monocytogenes

Transmission

  • Mother
    • Contaminated food: especially raw milk products
    • Other possible sources: fish, meat, and industrially processed vegetables (e.g., ready-made salads)
    • See “Etiology” in listeriosis.
  • Fetus
    • Transplacental transmission from an infected mother
    • Direct contact with infected vaginal secretions and/or blood during delivery

Clinical features

Diagnosis

Culture from blood or CSF samples (pleocytosis)

Treatment

IV ampicillin and gentamicin (for both mother and newborn)

Prevention

  • Avoidance of soft cheeses
  • Avoidance of potentially contaminated water and food: See “Food and water safety” in food poisoning.
  • Nationally notifiable condition: Listeriosis must be reported to the local or state health department.

References:[18][17][19][20][21][22][23]

Congenital varicella infection

Epidemiology

  • Seroprevalence in the general population is ∼ 95%.
  • Most mothers have been vaccinated, so congenital infection is rare.

Pathogen

Varicella-zoster virus (VZV)

Transmission

  • Mother
  • Fetus: transplacental transmission from an infected mother

Clinical features

Diagnosis

Treatment

Prevention

  • Immunization of seronegative women before pregnancy
  • VZIG in pregnant women without immunity within 10 days of exposure
  • Nationally notifiable condition: Varicella must be reported to the local or state health department

References:[24][17][25][26]

Congenital parvovirus B19 infection

Epidemiology

  • ∼ 5% incidence in pregnant women per year in the US
  • Higher prevalence in daycare workers and elementary school teachers

Pathogen

Parvovirus B19

Transmission

  • Mother
    • Mainly via aerosols
    • Rarely hematogenous transmission
    • See fifth disease.
  • Fetus: transplacental transmission from infected mother

Clinical features

  • Severe anemia and possibly fetal hydrops
  • Fetal demise and miscarriage/stillbirth in approximately 10% of cases (Risk is highest in the first and second trimesters.)
  • Most intrauterine infections do not result in fetal developmental defects.

Diagnosis

  • Mother: serologic assays for IgG and IgM against parvovirus B19
    • Positive IgM and negative IgG: very recent infection → refer to specialist
    • Positive IgM and IgG: acute infection → refer to specialist
    • Positive IgG and negative IgM: maternal immunity → reassurance
    • Negative IgG and negative IgM: no maternal immunity → counseling
  • Fetus

Treatment

Intrauterine fetal blood transfusion in cases of severe fetal anemia

Prevention

  • Hand hygiene (frequent hand washing)
  • Pregnant women with risk factors for TORCH infection should avoid potentially contaminated workplaces (e.g., schools, pediatric clinics)

References:[27][28][29][30]

Congenital rubella infection

Epidemiology

Most mothers have been vaccinated, so congenital infection is rare.

Pathogen

Rubella virus

Transmission

Clinical features

Diagnosis

Treatment

  • Intrauterine rubella infection
    • < 16 weeks: Counsel to terminate pregnancy.
    • > 16 weeks: reassurance
  • Congenital rubella syndrome: supportive care (based on individual disease manifestations) and surveillance (including monitoring for late-term complications)

Prevention

Triad of congenital rubella syndrome: CCC = Cataracts, Cochlear defects, Cardiac abnormality
References:[7][31][32][33][34][35][36][37]

Congenital CMV infection

Epidemiology

∼ 1% of live births per year in the US

Pathogen

Cytomegalovirus

Transmission

Clinical features

Diagnosis

Differential diagnosis [38]

Treatment

Prevention

  • Frequent hand washing, especially after contact with bodily secretions of small children (e.g., diaper changing)
  • Avoidance of food sharing with children
  • Avoidance of kissing small children on the mouth

Congenital toxoplasmosis may manifest with symptoms similar to those of congenital CMV infection!
References:[40][41][42]

Congenital herpes simplex virus infection

Epidemiology

∼ 1:3,000–10,000 live births per year

Pathogen

Mainly herpes simplex virus 2 (HSV-2); in rare cases HSV-1

Transmission

  • Mother
  • Fetus: Transplacental transmission from an infected mother (rare)
  • Newborn: perinatal transmission during birth (∼ 30% transmission rate if mother has not yet undergone seroconversion at time of delivery)

Clinical features

Diagnosis

  • Mother: typically clinical diagnosis
  • Fetus: The ultrasound may show CNS abnormalities.
  • Newborn (and mother)
    • Standard: viral culture of HSV from skin lesions, conjunctiva, oro/nasopharynx, or rectum
    • Alternative: PCR for HSV DNA (CSF, blood)

Treatment

Prevention

HSV should be considered in infants up to 6 weeks of age with vesicular skin lesions, persistent fever with negative cultures, and/or symptoms of meningitis, encephalitis or sepsis. A high index of suspicion is warranted in neonatal HSV. Skin, eye, and mouth disease has a good prognosis if detected and treated early!
References:[43][44][45][46]