WBR0154

Author	[[PageAuthor::William J Gibson (Reviewed by Alison Leibowitz [1] and Yazan Daaboul, M.D.)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Microbiology
Sub Category	SubCategory::Reproductive
Prompt	[[Prompt::A 36-year-old gravida-2 para-2 woman, with a past medical history of hypertension, obesity, and diabetes mellitus, brings her son to the emergency department for increasing irritability, fever, and a rash. The mother explains she gave birth to her infant 3 weeks ago in a foreign country. She reports that she had painful genital lesions during delivery but were left untreated. Shortly after admission, the child develops a seizure. An MRI of the brain reveals a right temporal lobe infiltrate. Which of the following is most likely responsible for this patient's condition?]]
Answer A	AnswerA::HIV
Answer A Explanation	AnswerAExp::HIV infection in newborns may be transmitted from infected mothers who have significant viral load. Untreated newborns usually have a less acute presentation and develop recurrent opportunistic infections.
Answer B	AnswerB::Syphilis
Answer B Explanation	[[AnswerBExp::While mothers can transmit syphilis to their infants during pregnancy, a syphilis infection typically manifests differently from the symptoms demonstrated in this vignette. In some cases, syphilis infection in newborns can cause hydrops fetalis, a potentially fatal complicatio of the disease. Congenital syphilis may cause saber shins and characteristic facial abnormalities, such as “saddle noses” or Hutchinson’s teeth (incisors with a central notching).]]
Answer C	AnswerC::Cytomegalovirus
Answer C Explanation	[[AnswerCExp::While cytomegalovirus (CMV) can be transmitted from a mother to her child, the finding of temporal lobe encephalitis is more consistent with HSV-2 infection.]]
Answer D	AnswerD::Gestational diabetes mellitus
Answer D Explanation	[[AnswerDExp::Gestational diabetes mellitus is a condition in which women with no history of diabetes have high glucose levels during the course of pregnancy. Gestational diabetes usually develops after 24 weeks of gestation, which is why screening for gestational diabetes is recommended between 24 and 28 weeks. Gestational diabetes does not usually lead to seizures or temporal lobe encephalitis in infants.]]
Answer E	AnswerE::HSV-2
Answer E Explanation	AnswerEExp::Herpes simplex virus (HSV2) transmission often occurs during the peripartum period. Herpes infection may cause a vesicular rash and temporal lobe encephalitis that results in seizures and high-grade fever.
Right Answer	RightAnswer::E
Explanation	[[Explanation::Herpes simplex virus (HSV) encephalitis is a serious life-threatening complication of neonatal HSV infection that may result in irreversible neurologic sequelae. While neonatal HSV may be transmitted in the intrauterine, peripartum, and the postpartum periods, the majority of transmissions occur in the peripartum period from a mother with active HSV genital lesions during delivery. Infants with CNS HSV present with seizures, tremors, lethargy, and irritability. On physical examination, patients often have high-grade fever and bulging fontanelles. The majority of patients also have an active vesicular HSV rash during the course of the CNS disease. On imaging, neonates with HSV encephalitis often have temporal lobe encephalitis or diffuse encephalitis. The disease is suspected based on clinical manifestations and imaging. Unlike other HSV infections, serology is not very helpful to diagnose neonatal HSV infection given the presence of transplacentally acquired maternal IgG. PCR or viral culture are useful diagnostic techniques to confirm clinical suspicion. HSV encephalitis requires antiviral therapy with acyclovir HSV-1 and HSV-2 are 2 of 8 human herpesviruses. They are large, enveloped double-stranded DNA viruses with an icosahedral capsid. While labial herpes is almost always caused by HSV-1, genital herpes may be caused by either HSV-1 or HSV-2. HSV is also one of the ToRCHHeS infections, which are infections that can be transmitted vertically from the mother to the infant during pregnancy. The infections corresponding with the ToRCHHeS are: Toxoplasma gondii, Rubella virus, cytomegalovirus, Herpes, HIV, and syphilis. Educational Objective: Neonatal encephalitis may be caused by herpes simplex virus (HSV). HSV transmission often occurs during the peripartum period from a pregnant woman who has active genital lesions. Herpes infection may cause a vesicular rash and temporal lobe encephalitis that results in seizures and high-grade fever. References: Kimberlin DW. Neonatal herpes simplex infection. Clin Microbiol Rev. 2004;17(1):1-13. First Aid 2014 page 174]]
Approved	Approved::Yes
Keyword	WBRKeyword::Microbiology, WBRKeyword::Viruses, WBRKeyword::Herpes, WBRKeyword::HSV, WBRKeyword::HSV2, WBRKeyword::Encephalitis, WBRKeyword::Seizure, WBRKeyword::Virus, WBRKeyword::DNA virus, WBRKeyword::Newborn, WBRKeyword::Pediatrics, WBRKeyword::Congenital, WBRKeyword::Brain, WBRKeyword::Infection
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