Board Review 8/6/24

A 15yo previously healthy male (wt 65kg) high school football player presents to your office with fevers to 102F x 2 days associated with muscle aches and vomiting a few days after participating in the Indiana State Fair's hot dog eating contest. In between watching TikToks on his phone, he complains of intense throat pain, limiting his ability to eat. His older sister implies the intensity of his participation in the hot dog eating contest is the culprit. As a good ID physician, after collecting an extensive exposure history, you begin your physical exam and see these oral findings.

What treatment do you recommend?

• Valacyclovir 1gm BID

• Supportive measures only

• Acyclovir 400mg TID

• Avoid contact sports for six months

Answer explanation

Herpangina = posterior oral cavity, soft palate

Hand-Foot-Mouth-Disease and HSV gingivostomatitis = anterior oral cavity, hard palate

It's Monday, and you're on call for Eskenazi ID consults. One of the OB/GYN staff asks for your advice on the following situation: a 22yo G1P0 Sudanese refugee is in active labor at 33wga. She revealed to the admitting team that she works as a nanny and was asked to supervise a "chicken pox party" last week. This is her first visit to a healthcare setting in pregnancy.

Which of the following risk factors places her newborn at HIGHEST risk for mortality?

• Lack of maternal vaccination

• Exposure to active VZV within 5 days of delivery

• Working with unvaccinated children

Answer explanation

Varicella infection has a higher case fatality rate in infants when infection occurs in the birthing parent from 5 days before to 2 days after delivery

• - little opportunity for development and transfer of antibody across the placenta prior to delivery

• - infant’s cellular immune system is immature.

You're in morning clinic and your first patient is a 49-year-old male third grade school teacher with HIV infection. He complains of fatigue.

He was recently started on dolutegravir, tenofovir, and emtricitabine after presenting with CD4 count =75 cells/uL and viral load = 100,000. His hemoglobin was 13g/dl prior to therapy but is now 6g/dl.

Chemistries are unremarkable including liver function tests, haptoglobin and LDH.

He has no evidence of blood loss and has negative stool tests for occult blood. 

He had a urinary tract infection last week and was started on ciprofloxacin. He also takes vitamin C. No one in his household has been ill, but some of the children in his class had been out last month with fever and facial rash. 
Which of the following tests is most likely to determine the etiology of his symptoms?

• Parvovirus IgM

• HIV genotype testing

• Parvovirus DNA PCR

• Peripheral blood smear

Answer explanation

Serum parvovirus DNA detection by PCR can be used in immunocompromised individuals when IgM may be less reliable

Timeline to positivity for antibody testing:

Exposure --->7 to 10 days = IgM (+)

---> 15 days = IgG (+)

IDweek is in sunny (but expensive) LA this year. You decide to moonlight in the local urgent care to save up for your trip. A 3yo previously healthy girl presents with these skin lesions accompanied by her paternal grandmother. During the visit, the grandmother reveals that the patient's parents are separated, and she recently stayed with her mother and her formerly incarcerated boyfriend. As part of your return precautions and counseling, you discuss:

• that if similar lesions appear in the genital area, the Department of Child Services should be notified

• that her granddaughter's fingernails may fall off in the coming weeks

• that the grandmother is not at risk of contracting the same illness

• All of the above

Answer explanation

Hand, Foot, and Mouth Disease

(vesicular stomatitis with exanthem)

• highly contagious to other family members

• Most often Coxsackie A but may also be Coxsackie B and Enterovirus EV71

• Lesions can occur extremities, mouth, and genitals due to self-inoculation (not necessarily a sign of abuse)

CMV accounts for about _____ % of cases of infectious mononucleosis

Answer explanation

primary EBV causes 80% of infectious mononucleosis while CMV accounts for about 20%

You're attending your best friend's destination wedding in Cancun, Mexico and enjoying a refreshing mixed drink when one of the guests finds out that you are an infectious diseases doctor. He quickly brings his wife over to you for your expert guidance. She is a 35yo woman with nine months of "hand symptoms" which started soon after backpacking across Latin America. After careful questioning, you find out that she had a brief febrile illness at the beginning of her travels with associated myalgias, rash, and palmar skin peeling. You look at her hands and see this:

Which is the most likely infectious etiology?

• Chikungunya virus

• Parvovirus B19

• Rubella Virus

• HIV

Answer explanation

35% of Chikungunya cases may develop chronic joint symptoms

Parvovirus B19, chikungunya, and rubella are all associated with arthritis, most commonly of the small joints such as hands and wrists. The arthritis associated with rubella usually lasts up to a few weeks.

Chronic arthritis is rare in rubella but is described in both parvovirus and chikungunya

You're almost done with Adult ID Fellowship, and you find your (almost) dream job in a community private practice. The one drawback - you have to cover pediatric ID questions from the newborn nursery and the ER. In preparation, you do a service week at Riley.
On your first day, you get a frazzled phone call from a PICU fellow asking for ID consultation on 3do former 38wga girl transferred from an outside nursery with AHRF. E-CPR activation can be heard on the speaker overhead, and your phone call ends as the PICU initiates ECMO .

With an interpreter, you gather the following information from the patient's mother: she is a G6P6 woman who immigrated from Chile in the past couple months. She recalls having a flu-like illness in the first trimester after traveling through Brazil. She also notes her older son has an atrial septal defect. Right before delivery, the entire family had viral URI symptoms.

Which of the following tests is most likely to determine the etiology of the neonate's presentation?

• Maternal T. Cruz Ab testing

• Genetics testing for congenital heart defects

• Neonatal Zika PCR testing

• Maternal Respiratory Viral Panel

Answer explanation

Neonatal EV Myocarditis

Presents with rapid onset of heart failure; respiratory distress; tachycardia, +/- fevers, may rapidly progress to circulatory collapse

Most newborns with life-threatening EV disease are infected by vertical transmission from the infected mother in the perinatal period

• (CRITICAL PERIOD = 5 days prior to birth + 2 days following)

60%-70% of women who give birth to infected infants have a febrile illness during the last week of pregnancy

You're on your second day of service at Riley, and the ER asks for consultation on this 13mo's rash. The patient's father appears haggard and sleep-deprived, reporting his daughter has been inconsolable with fevers reaching 104F the past couple days. He is frustrated, as of course, since being in the ER, she has been afebrile and smiling happily. Her father also notes that she received her routine 1yo vaccines (including MMR) at her well-child visit last week.

What is the most likely etiology of her symptoms?

• Atypical Measles

• Roseola infantum

• Post-Rubella Vaccination side effect

• HIV

Answer explanation

HHV-6B (roseola) typically presents with HIGH fevers with associated irritability, coryzal symptoms, and GI upset, for up to three days

Resolution of fever coincides with appearance of rose-pink papules or maculopapular blanching non-pruritic rash over the trunk and face

Measles and rubella typically have concurrent rash AND fever or even rash preceding fever

Atypical measles is due to inactivated (killed) virus vaccination and subsequent exposure to wild-type virus (killed virus vaccination stopped in 1967)

Lucky you! It's a brand new day at the Rileys', and the ER is calling for help evaluating this 9mo girl's facial rash. Feeling helpful, they note she attends daycare, and her older brother just received his kindergarten shots including MMR-V. There is no rash elsewhere and it does not itch. They are about to order airborne isolation for this patient, and you:

• agree!

  This is chicken pox.

• disagree! This is HSV.

• hang up. That's a job for the Health Department to figure out.

Answer explanation

Herpes simplex stomatitis, primary infection with extension to the face

Lesions are generally in the same stage and start in one area.

Multiple dermatomes can be involved in primary infection and immunocompromised individuals.

VZV (chicken pox) will have a diffuse distribution across the body with lesions in various stages. Her brother's recent immunization is unlikely to lead to active VZV infection.

Your next consult is from the PICU - 12yo Amish boy transferred from an outside hospital for altered mentation and rigidity. He is intubated for airway protection and notably febrile to 40.2C with tachycardia to 160s, BP 130/70. There is no rash on physical exam. While gathering your exposure history, you learn that he enjoys harvesting honey from their apiary (bee farm) and swimming in their local fresh water lake. He is one of seven children, but the family mentions he has always been the "black sheep" with an odd personality and episodic jerking of his extremities, felt to be tics.

Which viral infection most likely led to his current symptoms?

• Enterovirus E68

• Coxsackievirus B2

• Echovirus 4

• Measles

Answer explanation

Subacute sclerosing panencephalitis due to measles

• - rare degenerative central nervous system disease characterized by behavioral and intellectual deterioration and seizures

• - generally occurs 7 to 11 years after wild-type measles virus infection (especially if unvaccinated)

• - highest rates occur in children infected before 2yo