Congenital Infections — MCQs

10 questions

Symptomatic neonatal CNS involvement is most commonly seen in which group of congenital intrauterine infections?

A neonate on routine examination at birth was found to have hepatomegaly. Rest of the examination was essentially unremarkable. On investigations, Anti-HCMV antibodies were found to be positive. What sequelae in later life is the child at risk of?

In early congenital syphilis, which is not seen?

A child presented with microcephaly, hepatomegaly and periventricular calcification. What is the best specimen for diagnosis of CMV by PCR?

Rubella is known to cause all of the following conditions except:

All of the following statements are true about congenital rubella except

Congenital Rubella Syndrome includes all except

A 30 month old deaf boy whose development is slower than normal is being followed for congenital cytomegalovirus (CMV) infection in your clinic.The child's mother is pregnant again and is worried about her new baby. Which of the following is true?

Symptomatic neonatal CNS involvement is most commonly seen in which group of congenital intrauterine infections?

Q10

An infant presents with hepatosplenomegaly and thrombocytopenia. Neuroimaging with CT shows periventricular calcifications. What is the most likely diagnosis?

Congenital Infections Indian Medical PG Practice Questions and MCQs

Question 1: Symptomatic neonatal CNS involvement is most commonly seen in which group of congenital intrauterine infections?

A. Rubella and toxoplasmosis
B. CMV and syphilis
C. Rubella and HSV
D. CMV and toxoplasmosis (Correct Answer)

Explanation: ***CMV and toxoplasmosis*** - Both **cytomegalovirus (CMV)** and **Toxoplasma gondii** are well-known causes of congenital infections that frequently lead to significant and symptomatic central nervous system (CNS) involvement in neonates. - Congenital CMV can cause **microcephaly**, **periventricular calcifications**, **hearing loss**, and developmental delay, while congenital toxoplasmosis can result in **hydrocephalus**, **intracranial calcifications**, **chorioretinitis**, and seizures. *Rubella and toxoplasmosis* - While **toxoplasmosis** causes significant CNS involvement, **congenital rubella syndrome** typically presents with cataracts, heart defects (e.g., patent ductus arteriosus), and hearing loss, with CNS involvement being less consistently severe or frequently symptomatic in the immediate neonatal period compared to CMV or toxoplasmosis. - Although rubella can cause **encephalitis** or **meningoencephalitis**, these are not as common or consistently severe as the direct destructive CNS lesions seen with CMV or toxoplasmosis. *CMV and syphilis* - **CMV** is a major cause of neonatal CNS symptoms. However, **congenital syphilis** primarily affects bones, skin, and mucous membranes (e.g., "snuffles"), with CNS involvement typically presenting as **meningitis**, **hydrocephalus**, or neurodevelopmental delays, but often not as overtly symptomatic in the immediate neonatal period as CMV or toxoplasmosis. - While syphilis can cause neurosyphilis, the spectrum and severity of immediate symptomatic CNS involvement are distinct from the widespread calcifications and structural abnormalities seen with CMV or toxoplasmosis. *Rubella and HSV* - **Rubella** primarily causes classic congenital defects in eyes, ears, and heart, with CNS effects being less common and severe. - **Congenital herpes simplex virus (HSV)** infection, while causing severe CNS disease (e.g., encephalitis) when disseminated, is relatively rare overall compared to CMV and toxoplasmosis, and often presents with skin, eye, and mouth lesions first.

Question 2: A neonate on routine examination at birth was found to have hepatomegaly. Rest of the examination was essentially unremarkable. On investigations, Anti-HCMV antibodies were found to be positive. What sequelae in later life is the child at risk of?

A. Intellectual disability
B. Renal failure
C. Sensorineural hearing loss (Correct Answer)
D. Hepatic fibrosis

Explanation: ***Sensorineural hearing loss*** - **Congenital CMV infection** is the leading cause of non-genetic sensorineural hearing loss (SNHL) in children, affecting a significant proportion of infected neonates. - SNHL can be **progressive, unilateral or bilateral**, and may manifest years after birth, necessitating long-term audiological monitoring. *Intellectual disability* - While CMV can cause **neurological complications** and intellectual disability, these are more common in symptomatic congenital CMV infections with **microcephaly, intracranial calcifications**, or severe neurological impairment at birth. - In a neonate with only hepatomegaly and no overt neurological signs, **SNHL is a more prevalent and specific long-term sequelae** than intellectual disability. *Renal failure* - **Kidney involvement** in congenital CMV is rare and generally not a primary long-term sequela. - Though CMV can rarely cause interstitial nephritis or direct viral cytopathic effects in the kidneys, leading to transient renal dysfunction, it **does not typically lead to progressive renal failure** in later life. *Hepatic fibrosis* - While congenital CMV can cause **hepatitis** and hepatomegaly, significant long-term hepatic fibrosis directly attributable to CMV, leading to liver failure in later life, is **uncommon**. - Most hepatic abnormalities in congenital CMV tend to **resolve spontaneously**, and severe chronic liver disease is rare.

Question 3: In early congenital syphilis, which is not seen?

A. Keratitis (Correct Answer)
B. Vesicular rash
C. Chorioretinitis
D. Rhinitis

Explanation: ***Keratitis*** - **Keratitis** (inflammation of the cornea) is a manifestation of **late congenital syphilis**, typically appearing in children older than 2 years. - It is often associated with other features of **Hutchinson's triad**, which includes **Hutchinson's teeth** and **sensorineural hearing loss**. *Vesicular rash* - A **maculopapular rash**, which can sometimes be vesicular or bullous, is a common finding in **early congenital syphilis**, particularly on the palms and soles. - This rash is a sign of active infection and can be highly infectious due to the presence of **spirochetes**. *Chorioretinitis* - **Chorioretinitis** (inflammation of the choroid and retina) is an important ocular manifestation of **early congenital syphilis**. - It can lead to significant vision impairment if not promptly diagnosed and treated. *Rhinitis* - Known as **"snuffles,"** rhinitis is a classic and common symptom of **early congenital syphilis**, often presenting with mucopurulent or hemorrhagic nasal discharge. - The nasal discharge contains infectious **Treponema pallidum** and can cause significant respiratory distress in infants.

Question 4: A child presented with microcephaly, hepatomegaly and periventricular calcification. What is the best specimen for diagnosis of CMV by PCR?

A. CSF
B. Blood
C. Liver biopsy
D. Urine (Correct Answer)

Explanation: ***Urine*** - **Urine** is the most sensitive and commonly used specimen for diagnosing **congenital CMV infection** via PCR, especially in neonates, due to high viral shedding in urine. - A positive urine CMV PCR within the first 2-3 weeks of life is highly indicative of **congenital CMV**, which can cause symptoms like **microcephaly**, **hepatomegaly**, and **periventricular calcifications**. *CSF* - While CMV can be detected in **CSF** in congenital infections, particularly in symptomatic cases with neurological involvement, it is less sensitive than urine for initial diagnosis. - **CSF PCR** is typically reserved for evaluating central nervous system involvement and may not detect systemic infection as reliably as urine. *Blood* - **Blood PCR** for CMV can be positive in congenital infection, but it can also be positive in postnatal CMV acquisition or maternal viremia without congenital transmission. - The presence of viral DNA in blood is transient, and its sensitivity for diagnosing congenital infection is generally lower than that of urine. *Liver biopsy* - **Liver biopsy** is an invasive procedure and is not the primary diagnostic method for CMV infection, although histological examination can reveal characteristic viral inclusions if there is significant hepatic involvement. - It carries risks and is typically performed only when other diagnostic methods are inconclusive or when assessing the extent of liver damage.

Question 5: Rubella is known to cause all of the following conditions except:

A. Conduction defects
B. VSD
C. Microcephaly
D. Glaucoma (Correct Answer)

Explanation: ***Glaucoma*** - While rubella can cause **ocular defects** such as **cataracts** and **pigmentary retinopathy**, glaucoma is not a typical congenital manifestation of rubella syndrome. - **Congenital glaucoma** is more commonly associated with other genetic syndromes or developmental anomalies. *Microcephaly* - **Microcephaly** is a recognized neurological complication of congenital rubella syndrome, resulting from impaired brain development due to viral infection. - The rubella virus can interfere with the **proliferation and migration** of neuronal cells during fetal development. *VSD* - **Ventricular septal defect (VSD)** is a common congenital heart defect associated with congenital rubella syndrome. - Other cardiac anomalies seen include **patent ductus arteriosus (PDA)** and **pulmonary artery stenosis**. *Conduction defects* - **Conduction defects** and other **cardiac arrhythmias** can occur in congenital rubella syndrome due to direct viral damage to the developing cardiac conduction system. - This can manifest as **bradyarrhythmias** or various degrees of **heart block**.

Question 6: All of the following statements are true about congenital rubella except

A. Infection after 16 weeks of gestation results in major congenital defects (Correct Answer)
B. It is diagnosed when IgG antibodies persist for more than 6 months
C. It is diagnosed when the infant has IgM antibodies at birth
D. Most common congenital defects are deafness, congenital heart disease and cataract

Explanation: *** Infection after 16 weeks of gestation result in major congenital defects*** - The risk and severity of **congenital rubella syndrome (CRS)** are highest when the mother is infected during the **first trimester** of pregnancy. - After **16 weeks of gestation**, the risk of major congenital defects with CRS significantly decreases, although **late-onset manifestations** such as hearing loss can still occur. *It is diagnosed when Ig G antibodies persist for more than 6 months* - **Persistence of IgG antibodies** beyond 6-12 months in an infant is a strong indicator of congenital rubella, as maternal IgG antibodies typically wane by this age. - This persistence signifies that the infant's own immune system is producing antibodies in response to **persistent viral infection**, which is characteristic of CRS. *M.C. congenital defects are deafness, congenital heart disease and cataract* - The classic triad of **congenital rubella syndrome** includes **sensorineural deafness**, **congenital heart defects** (such as patent ductus arteriosus or pulmonary artery stenosis), and **ocular abnormalities** (such as cataracts or retinopathy). - These are indeed the most common and significant birth defects associated with early gestational rubella infection. *It is diagnosed when the infant has IgM antibodies at birth* - The presence of **rubella-specific IgM antibodies** in a newborn's blood at birth or shortly thereafter is diagnostic of congenital rubella infection. - IgM antibodies do not cross the placenta, so their presence in the infant indicates that the infant's immune system has produced them in response to an **intrauterine infection**.

Question 7: Congenital Rubella Syndrome includes all except

A. SN deafness
B. Cataract
C. VSD
D. Intracerebral hemorrhage (Correct Answer)

Explanation: ***Intracerebral hemorrhage*** - This is not a typical manifestation of **Congenital Rubella Syndrome** (CRS). Symptoms of CRS primarily include sensory, cardiac, and ocular defects, not bleeding into the brain. *SN deafness* - **Sensorineural (SN) deafness** is a very common and characteristic symptom of **Congenital Rubella Syndrome**, often bilateral, due to damage to the organ of Corti. - It is one of the classic triad of manifestations of CRS. *Cataract* - **Cataracts** (clouding of the lens) are a prominent ocular defect in CRS, often leading to significant vision impairment or blindness. - Ocular defects like cataracts and **microphthalmia** are part of the classic clinical picture. *VSD* - **Ventricular Septal Defect (VSD)** is a common cardiac anomaly seen in CRS, caused by rubella virus infection during heart development. - Other common cardiac defects include **Patent Ductus Arteriosus (PDA)** and **Pulmonary Artery Stenosis**.

Question 8: A 30 month old deaf boy whose development is slower than normal is being followed for congenital cytomegalovirus (CMV) infection in your clinic.The child's mother is pregnant again and is worried about her new baby. Which of the following is true?

A. The new infant should be isolated from the older child
B. The mother has antibodies to CMV that are passed to the fetus (Correct Answer)
C. Termination of pregnancy is advised
D. The mother's infection cannot become reactivated

Explanation: ***The mother has antibodies to CMV that are passed to the fetus*** - The mother has a history of CMV infection, meaning she has developed **antibodies** against the virus. These maternal **IgG antibodies** can cross the placenta and provide passive immunity to the fetus. - This passive immunity helps protect the unborn baby from initial infection or reduce the severity of disease if exposure occurs, although it doesn't guarantee complete protection. *The new infant should be isolated from the older child* - Isolation is generally not necessary in this scenario because CMV is widespread and transmission through casual contact is common; strict isolation would be impractical and not significantly reduce risk. - While CMV can be shed in urine and saliva, the risk of symptomatic infection in the new infant from an older sibling with congenital CMV, especially if the mother is seropositive, is relatively low. *Termination of pregnancy is advised* - Termination of pregnancy is a major medical decision and is not advised solely based on a previous CMV infection in an older child. - The risk of severe congenital CMV in a subsequent pregnancy when the mother is already seropositive is significantly lower compared to a primary maternal infection during pregnancy. *The mother's infection cannot become reactivated* - CMV is a **herpesvirus** that establishes **latency** after primary infection, meaning it can reactivate later in life. - While reactivation can occur, particularly in immunocompromised individuals, it typically poses a much lower risk to a developing fetus compared to a primary infection during pregnancy, especially if the mother has pre-existing antibodies.

Question 9: Symptomatic neonatal CNS involvement is most commonly seen in which group of congenital intrauterine infections?

A. Rubella and HSV
B. CMV and Toxoplasmosis (Correct Answer)
C. CMV and Syphilis
D. Rubella and Toxoplasmosis

Explanation: ***CMV and Toxoplasmosis*** - **Cytomegalovirus (CMV)** is the **most common congenital infection** causing symptomatic neonatal CNS involvement, affecting 0.5-2% of live births and being the leading cause of non-genetic sensorineural hearing loss and neurological disability. - CMV causes **microcephaly, periventricular intracranial calcifications, ventriculomegaly, seizures**, and developmental delay. - **Toxoplasmosis** is the second most common, presenting with the classic triad of **hydrocephalus, diffuse intracranial calcifications, and chorioretinitis**. - Together, these two represent the **most frequently encountered** causes of symptomatic congenital CNS disease. *Rubella and HSV* - While both can cause neurological complications, they are **not the most common** causes of congenital CNS involvement. - **Rubella** is now rare due to widespread vaccination programs. - **HSV** as a true **congenital intrauterine infection is extremely rare**; most neonatal HSV is acquired **perinatally during delivery** or postnatally, not as a congenital infection. *Rubella and Toxoplasmosis* - While **Toxoplasmosis** is indeed a common cause of congenital CNS disease, **Rubella** is now uncommon due to vaccination. - This combination doesn't represent the most frequently seen pair compared to CMV and Toxoplasmosis. *CMV and Syphilis* - **CMV** is correct as the most common cause, but **Syphilis** primarily causes multi-system involvement including hepatosplenomegaly, skin rashes, and bone abnormalities. - While **neurosyphilis** can occur, CNS involvement is less consistently present compared to **Toxoplasmosis**, which characteristically causes the classic triad with prominent CNS features.

Question 10: An infant presents with hepatosplenomegaly and thrombocytopenia. Neuroimaging with CT shows periventricular calcifications. What is the most likely diagnosis?

A. Congenital rubella syndrome
B. Congenital herpes simplex virus infection
C. Congenital toxoplasmosis
D. Congenital cytomegalovirus infection (Correct Answer)

Explanation: ***Congenital cytomegalovirus infection*** - **Periventricular calcifications** on neuroimaging are a classic and highly suggestive finding for congenital CMV infection. - **Hepatosplenomegaly** and **thrombocytopenia** are common systemic manifestations of congenital CMV, which can be severe. *Congenital rubella syndrome* - Rubella typically causes **sensorineural hearing loss**, ocular abnormalities (e.g., cataracts), and congenital heart defects (e.g., patent ductus arteriosus), rather than periventricular calcifications. - While hepatosplenomegaly and thrombocytopenia can occur, the specific brain calcification pattern points away from rubella. *Congenital herpes simplex virus infection* - HSV infection in neonates presents with a variety of symptoms, including skin vesicles, keratoconjunctivitis, and seizures. - Brain imaging often shows **focal necrosis** or **encephalitis**, not typically periventricular calcifications unless it's a very widespread and destructive process. *Congenital toxoplasmosis* - Congenital toxoplasmosis classic triad includes **chorioretinitis**, **hydrocephalus**, and **intracranial calcifications**, but these calcifications are typically scattered or diffuse rather than strictly periventricular. - While hepatosplenomegaly and thrombocytopenia can be present, the specific location of calcifications is a key differentiating factor.

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