Review Question - QID 217206

This neonate has congenital rubella infection, as evidenced by congenital cataracts (bilateral lens opacification), "blueberry muffin" rash (diffuse violaceous macules), and a patent ductus arteriosus (continuous murmur). Prevention of neonatal rubella requires either a previously-cleared maternal infection (maternal immunity) or maternal vaccination with the measles, mumps, and rubella (MMR) vaccine before pregnancy.

Neonatal rubella is caused by the rubella virus and is most likely to occur if maternal infection occurs before 16 weeks of gestation. Vertical transmission of the rubella virus through the placenta may lead to infection of the fetus and proliferation of the virus may lead to intrauterine fetal demise. Signs of neonatal rubella include sensorineural hearing loss, congenital heart disease (including patent ductus arteriosus, septal defects, and pulmonary artery stenosis), cataracts, and a "blueberry muffin" rash. Neonatal rubella infection may be prevented by maternal vaccination with the MMR vaccine prior to pregnancy. The MMR vaccine is a live, attenuated vaccine and is, therefore, contraindicated during pregnancy and must be administered prior to pregnancy. Previous evidence of cleared maternal infection or vaccination (i.e., positive anti-Rubella IgG) is routinely ordered to verify maternal immunity in the prenatal period. Management of neonatal rubella consists of supportive care. Complications of congenital rubella include blindness, cardiac arrhythmia, and death.

Oster et al. studied the cardiovascular malformations found in congenital rubella syndrome. The authors found that branch pulmonary artery stenosis and patent ductus arteriosus were common malformations in these patients. They recommended that evaluation for both of these malformations be performed in patients with suspected congenital rubella syndrome.

Figure/Illustration A show the skin of a patient with neonatal rubella and the characteristic "blueberry muffin" pattern consisting of diffuse violaceous macules (red arrow).

Incorrect Answers:
Answer 1: Maternal avoidance of undercooked meats is recommended to avoid neonatal toxoplasmosis. Toxoplasmosis is caused by the single-celled parasite Toxoplasma gondii, which can be transmitted through consumption of undercooked meat or contact with cat feces. Neonatal toxoplasmosis also presents with a "blueberry muffin" rash but is distinguished from neonatal rubella by diffuse intracranial calcifications, hydrocephalus, and chorioretinitis.

Answer 2: Maternal avoidance of unpasteurized milk is recommended to avoid exposure to Listeria monocytogenes. Neonatal infection with L. monocytogenes presents with neonatal sepsis (hemodynamic instability and fever), meningitis, and granulomatosis infantiseptica (diffuse nodular rash).

Answer 4: Maternal penicillin administration may be required in cases of maternal syphilis infection to prevent congenital syphilis. Syphilis is caused by the bacterium Treponema pallidum. Congenital syphilis presents with copious nasal secretions, a maculopapular rash of the palms and soles, osteochondritis, a saddle nose, anterior bowing of the tibia, and perioral fissures.

Answer 5: Maternal vaccination with the MMR vaccine is contraindicated in pregnancy as the vaccine is a live, attenuated vaccine. Only the influenza vaccine and Tdap vaccine are recommended during pregnancy.

Bullet Summary:
Neonatal rubella infection presents with sensorineural hearing loss, cardiac anomalies (such as patent ductus arteriosus), cataracts, and a "blueberry muffin" rash and can be prevented by maternal vaccination with the MMR vaccine or previous clearance of rubella infection prior to pregnancy.