Perinatal and TORCH Infections

Perinatal Infections

• Transcervical infections occur through microbial spread from the vaginal canal to the amniotic fluid.
• In transcervical infections, the organism passes to the fetus through inhalation of infected amniotic fluid or passage through the infected birth canal.
• Transplacental infection involves access to the fetal bloodstream by crossing the placenta through chorionic villi.
• Hep B, HIV, toxoplasma, malaria, and viral infections can be spread through transplacental infection.

TORCH Infections

• TORCH infections are transplacental infections
• TORCH includes: Toxoplasma, Treponema palladium, Rubella, Cytomegalovirus, and Herpes.
• Early gestation infections via TORCH can cause severe congenital and mental birth defects.
• Later gestation infections via TORCH causes inflammatory tissue disorders such as encephalitis, chorioretinitis, and myocarditis.

TORCH Screening

• TORCH screening helps in detecting infections in pregnant women, involving IgG and IgM antibodies.
• IgM indicates an acute, current infection.
• IgG indicates a previous infection with a pathogen.
• TORCH screening is routinely performed during the first prenatal visit.

Toxoplasma Gondii

• Toxoplasma gondii is a protozoan
• Toxoplasma gondii can be spread via transplacental infection if mom is infected during of shortly before pregnancy.
• Host is originally infected via food or water contaminated with cat feces.
• Toxoplasma gondii is more concerning for immunocompromised patients.
• Congenital toxoplasmosis is characterized by the "4 C's": cerebral calcifications, cephaly/cephalus, choreoretinitis and convulsions

Rubella Virus

• Rubella Virus is also known as "German Measles."
• It's an enveloped/positive-stranded RNA virus (Rubivirus of Matonaviridae family).
• Rubella is often misdiagnosed/unrecognized and 20-25% of cases are asymptomatic.
• Symptoms include mild maculopapular rash, low fever, and lymphadenopathy.
• Rubella has an incubation period of about 17 days.
• It is most contagious when a rash is present.
• Rubella can be transmitted through contact with respiratory secretions.

Rubella Vaccination

• The MMR vaccine (measles, mumps, rubella) is given to children between 12 months – 12 years in 2 doses.
• Pregnant women with no immunity should receive the vaccine (1 dose) immediately after giving birth.

Congenital Rubella Syndrome (CRS)

• CRS is a transplacental infection.
• It leads to miscarriages, stillbirth, cardiac defects, blindness, and deafness.

Cytomegalovirus (CMV)

• CMV is a double-stranded DNA virus.
• Immunocompromised individuals (pregnant, AIDS, transplant patients) and fetus infection can result in either localized or disseminated disease which is an opportunistic infection.
• There is a higher risk of complications in immunocompromised groups.
• CMV is a latent virus that stays in the body for life and can be reactivated.
• Cytomegalovirus mononucleosis causes mono.

Congenital CMV

• Congenital CMV is a transplacental infection.
• CMV is the most common infectious cause of birth defects in the US.
• 1 in 5 babies with congenital CMV will have birth defects.
• Health problems may manifest at birth or develop later in life, the most common being hearing loss.
• A symptom of Congenital CMV is a blueberry muffin rash.
• It can cause brain liver, spleen, and growth problems.

Herpes Simplex Virus (HSV)

• There are two types of HSV: Herpes Simplex type I and Herpes Simplex type II.
• Blisters/vesicles can appear around the mouth, rectum, and genitals.
• Flu-like symptoms may occur during an outbreak.

Congenital Herpes Simplex Virus

• Congenital HSV can occur via Transcervical (during vaginal delivery) or Transplacental transmission (more rare)
• Transcervical transmission of HSV can lead to deadly neonatal herpes
• Women with genital herpes need frequent prenatal care visits
• If genital herpes is present at the time of delivery, a C-section is likely to occur
• Antiviral agents can be used for treatment

Congenital Treponema Pallidium (Syphilis)

• Syphilis is transmitted transplacentally or transcervically
• Congenital syphilis is characterized by a palmar/solar rash.

Varicella-Zoster Virus (VZV)

• Varicella-Zoster Virus casuses "Chicken pox".
• It is a DNA virus in the herpesvirus group.
• VZV causes a central rash that spreads to the extremities.
• Ulcers, blisters, and papules can be present at the same time.
• Incubation period for VZV is 14–16 days.
• It's transmitted through person-person contact/inhalation of aerosolized vesicular fluid.
• VZV stays latent in sensory nerve ganglia, and reactivation causes Herpes Zoster (Shingles).

Congenital Varicella-Zoster Virus Syndrome

• Congenital Varicella-Zoster Virus is transmitted transplacentally or transcervically.
• Congenital VZV syndrome is caused by maternal VZV infection during the 1st/early 2nd trimester (rare).
• It is characterized by scarring of skin+limb eye and brain abnormalities.
• Neonatal VZV occurs when pregnant women with no immunity spread varicella to the infant 5 days before-2 days after delivery.
• The varicella vaccine is contraindicated in pregnant patients.
• Pregnant women who contract VZV are at increased risk of primary pneumonia.

Human Papilloma Virus (HPV)

• HPV is a double-stranded DNA virus that replicates in the nucleus of host cells.
• It causes benign or malignant warts in humans.
• HPV is associated with cervical cancer.

Fetal HPV Infection

• Fetal HPV infection may occur transcervically (birth/amniotic fluid) or transplacentally (rare).
• HPV can be detected in amniotic fluid.
• HPV lesions in infants at the time of birth suggest an infection.

Zika Virus

• Zika Virus is spread via the Aedes mosquito.
• The symptoms are usually mild: fever, rash, joint pain, and conjunctivitis.
• There's no vaccine/treatment for it.
• Infection is confirmed with a blood/urine test.

Congenital Zika Syndrome

• A transplacental transmission.
• It causes severe birth defects (some are present at birth, while some may develop later in life).
• Symptoms/Signs include microcephaly, hearing loss, vision problems, seizures, and brain development delays.

Streptococcus Agalactiae (Group B Strep)

• Streptococcus Agalactiae is transmitted transcervically during vaginal birth.
• It's the most common cause of neonatal meningitis, sepsis, and pneumonia.
• Streptococcus Agalactiae is associated with premature delivery.
• Disease onset can be early (first week of life) or late (2 weeks–3 months after birth).
• Gram (+) coccus.
• S. agalactiae produces CAMP factor which enhances hemolysis of S. aureus resulting in arrowhead hemolysis.
• Hippurate hydrolysis positive (helps differentiate from S. pyogenes).
• The polysaccharide capsule prevents phagocytosis.

Listeria Monocytogenes

• Listeria monocytogenes is associated with eating unpasteurized dairy products or undercooked meat.
• It is a small facultative intracellular pathogen.
• Listeria monocytogenes can survive refrigeration, stomach acids, and bile salts through protective action of stress response genes.
• When the bacteria are in host cells the acidic pH of phagolysosome activates the bacteria's exotoxin and phospholipases.
• Bacteria produces Listeriolysin – cytotoxin that allows for survival within phagocytes.
• Disseminated disease can spread to the liver and spleen.
• Characteristics: Gram-positive, Catalase positive, beta-hemolytic, umbrella-shaped motility, end-over-end tumbling motility, Esculin hydrolysis positive, CAMP-positive

Listeriosis

• Listeriosis in healthy adults is asymptomatic/flu-like.
• Disease in immunocompromised can lead to spontaneous abortions, sepsis, or meningitis.
• Neonatal disease can be early-onset (acquired transplacentally) or late-onset (after birth).
• Early-onset is associated with premature, stillbirth, or abortion.
• Granulomatosis infantiseptica: disseminated abscesses/granulomas in multiple organs 2-3 weeks after birth (high mortality).

Hepatitis

• Hepatitis can be caused by DNA or RNA viruses that causes chronic/acute liver infections in humans.
• Symptoms include fatigue, nausea, low fever, jaundice, and dark urine.

Hepatitis B (HBV)

• Hepatitis B follows blood born/body fluid transmission.
• The most common mode of transmission is from mother to child: transcervical, transplacental, or postnatal.
• The higher the viral load in the mother, the more likely the baby is to acquire hepatitis.

Hepatitis C (HCV)

• Hepatitis C occurs with blood born/body fluid transmission.
• Infants with HCV acquire it through transplacental (contact with infected maternal body fluids during birth)
• A low risk transmission.
• Children with HCV are at an increased risk of liver cancer and cirrhosis later in life.

Human Immunodeficiency Virus (HIV)

• HIV is a blood-borne pathogen.
• It is a retrovirus, no capsule, icosahedral capsid, that uses reverse transcriptase
• HIV attacks T-lymphocytes (CD4) impairing humoral and innate immunity
• HIV Can lead to the development of AIDS.
• Sub-type B is the most common.

Congenital HIV

• Congenital HIV transmission: transplacental, transcervical (during birth), or postnatal (breastfeeding).
• Transmission rate from mother to child is around 1%.
• Treatment of the mother during pregnancy reduces the risk of transmission.
• PCR testing in neonates is recommended.

Chlamydia Trachomatis

• It is an obligate intracellular bacterium.
• Elementary body serves as the infectious form that enters the host cell.
• Reticulate body is the intracellular form that replicates within the host cell.
• The best choice for lab diagnosis is the Nucleic acid amplification test (NAATs).

Congenital Chlamydia

• It is transmitted transcervically
• It causes conjunctivitis and pneumonia (if untreated)

Neisseria Gonorrhoeae

• Gram-negative diplococci, oxidase positive
• Media: Thayer-Martin or Martin Lewis agar

Congenital Gonorrhoeae

• Can cause conjunctivitis or septic arthritis.

Coxsackievirus

• Coxsackievirus is also known as "Hand Foot and Mouth Disease"
• Person-person transmission occurs via bodily secretions.
• Common in children; produces rash in blisters that appear on hands feet and diaper area
• can also cause Throat and tonsil ulcers
• Coxsackie B is the most common enterovirus cause of myocarditis

Rubeola Virus

• Rubeola Virus is also known as Measles
• Spread via airborne respiratory droplets; HIGHLY contagious if unvaccinated.
• Koplik spots appear 1-2 days before the rash
• A rash that begins on face/hairline and travels down, high fever, and conjunctivitis
• The incubation period is 7-14 days
• Can cause complications such as encephalitis, ear infections, and pneumonia

Haemophilus Influenzae

• Haemophilus Influenzae is the #1 cause of infant bacterial meningitis
• the Hib vaccine reduces incidence
• TINY Gram-negative coccobacilli
• Grows on chocolate agar – this is bc media contains hemin (Factor X) and NAD (Factor V).

Bordetella Pertussis

• TINY Gram-negative bipolar coccobacilli
• Grows on Bordet Gengou-Agar with a “mercury droplet” appearance
• Needs nicotinic acid for growth
• Fimbriae allow bacteria to attach to ciliated columnar epithelial cells
• Causative bacteria of whooping cough

Pseudomonas Aeruginosa

• Gram-negative oxidase-positive bacilli
• Beta-hemolytic on blood agar
• Produces pyocanin (green-blue pigment)
• Has a Grape-like odor
• Causes otitis externa, skin infections, pneumonia in CF patients and opportunistic infections

Burkholderia Cepacia

• Causes life-threatening infections in patients with cystic fibrosis or chronic granulomatous disease
• Stains Small, round, tan colonies

Campylobacter Jejuni

• Gram-negative spiral rods that have a seagull wing appearance
• Oxidase/catalase positive with optimal growth temperature of 42 degrees C
• Hydrolyzes sodium hippurate
• It is the Most common cause of gastroenteritis (> 10 bowel movements a day)
• Infection occurs via puppies or ingestion of contaminated poultry / milk
• Has a high association with triggering Guillain Barre syndrome
• Cephalosporin resistant

Rotavirus

• Causes severe watery diarrhea, vomiting, and fever
• Most common in children and infants
• Two available vaccines: RotaTeq (2, 4, and 6 months) or Rotarix (2 and 4 months)
• The first dose should be given before the child is 15 weeks old and doses completed by 8 months via drops in mouth.

Enterobius Vermicularis Ova

• Pinworm that infects human intestines (most common in children)
• Anal itching, especially at night
• On microscope shells appear thick and hyaline

Candida Albicans

• Part of the normal microbial flora but becomes an opportunistic fungal infection if overgrowth occurs
• causes Diaper rash as well as Oral/esophageal thrush
• Microscopy characteristics include budding yeast + pseudohyphae
• In lab tests- Germ tube test (definitive identification) = C. albicans yeast cells will produce germ tubes within 2 hours