74 Questions
Which virus is responsible for causing measles?
Measles virus
What is the general term for the spikes on the surface of the mumps virus?
Hemagglutinin-neuraminidase glycoproteins
Which virus is also known as the genus Morbillivirus?
Measles virus
Which of the following is NOT true regarding Rubella?
Also known as measles
True or False: Active immunization for Rubella gives lifelong immunity to an individual.
True
During primary viremia, the virus spreads and replicates in the blood. In secondary viremia, infected persons begin to shed the virus from the nasopharynx 6-14 days after exposure for 3-8 days after rash onset.
Both statements are incorrect.
The presence of this component differentiates mumps from measles virus.
Neuraminidase
Which heart-related disease in congenital rubella syndrome is due to the abnormal development of the fetal heart during the first 8 weeks of pregnancy?
Pulmonary Atresia
The following are complications associated with mumps EXCEPT:
Blindness
Which of the following does not belong to the classical triad of Rubella in infected neonates?
Congenital defects
The Urabe strain for Mumps vaccine has an appreciable incidence of post-vaccination meningitis. Mumps V antigen and S antigen both consist predominantly of nucleoprotein (NP).
The first statement is correct and the second statement is incorrect.
Which of the following is NOT true regarding measles?
Also known as German measles
Organogenesis period happens in what stage of pregnancy?
First 8 weeks of pregnancy
This method of laboratory diagnosis can be used to detect viral mumps RNA and fosters a rapid confirmation for the diagnosis.
PCR
What is the primary viremia period for measles infection?
2 to 4 days after exposure
What is the prodromal period of measles characterized by?
Fever, sneezing, coughing, and Koplik's spots
What causes the appearance of the maculopapular rash during the exanthem period of measles?
Interaction of immune T cells with virus-infected cells
What is a clear sign during the exanthem period of measles that a satisfactory immune response is in progress?
Presence of rash
What is a rare but life-threatening complication of measles?
Subacute sclerosing panencephalitis (SSPE)
In which population are most measles-related deaths caused by complications more common?
Children in populations with high levels of malnutrition and lack of adequate healthcare
What is the mean incubation period for measles?
10 days
Where does the initial replication of measles occur?
Locally in tracheal and bronchial epithelial cells
What is the characteristic appearance of Koplik's spots, which are pathognomonic for measles?
Resembles a grain of salt just beneath the mucosa
What is the primary mode of transmission for measles?
Respiratory droplets
What is the characteristic appearance of the measles rash?
Light pink or dull red, discrete maculopapules that coalesce to form blotches
What is the most common cause of death in measles cases?
Complications such as pneumonia and encephalitis
What is the most common manifestation of congenital rubella?
Deafness
Which laboratory investigation is necessary for the diagnosis of congenital rubella?
Serology, PCR, and viral isolation
What is the preferred method for diagnosing congenital rubella in infants?
Viral isolation
What is the recommended treatment for congenital rubella?
Supportive measures
What type of immunization is available for routine immunization against rubella?
Live virus attenuated by human diploid fibroblast cells
What percentage of protective antibody does the rubella vaccine provide after the 1st dose?
95%
Who is the rubella vaccine contraindicated for?
Pregnant women
What is the purpose of passive prophylaxis for rubella?
To provide temporary protection
What is the risk of structural abnormalities from rubella in the 1st trimester?
Highest
Which type of infection is more than 50% subclinical?
Congenital rubella
What is the aim of active immunization with the rubella vaccine?
To prevent congenital rubella
What is the most common manifestation of measles in infants in third world countries?
Pneumonia
Which cellular receptor does the measles virus attach to?
CD-46
What is the incubation period of measles?
10 to 12 days
What is the primary mode of transmission of the measles virus?
Respiratory secretions
Which protein is NOT encoded by the measles virus?
Hemagglutinin protein
What is a characteristic sign of measles?
Koplik's spots
What is the typical duration of recovery from measles?
10-14 days
What is the major cause of measles-related mortality among young children?
Bronchopneumonia
What is the family to which the measles virus belongs?
Paramyxoviridae
What is the characteristic rash pattern of measles?
Maculopapular rash
What is the process involved in measles virus replication?
Attachment, penetration, uncoating
What is the characteristic cellular response to measles virus replication?
Syncytium formation
What is crucial in determining significant antigenic drifts of the measles virus over time?
Molecular surveillance
Which type of immunity does natural infection with measles provide?
Cellular immunity
What is the characteristic appearance of Koplik's spots, which are pathognomonic for measles?
White or bluish-white spots on the buccal mucosa
What is the primary mode of transmission of the measles virus?
Respiratory droplets
What is the characteristic cellular response to measles virus replication?
Suppression of cell-mediated response
What laboratory investigation is necessary for the diagnosis of atypical measles?
Serology (ELISA)
What is the characteristic appearance of the measles rash?
Small, raised, red spots that start on the face and spread to the body
What is the incubation period of measles?
7-10 days
What is the primary viremia period for measles infection?
6-14 days after exposure
What is crucial in determining significant antigenic drifts of the measles virus over time?
Viral RNA sequencing
What is the most common manifestation of measles in infants in third world countries?
Pneumonia
What is the risk of structural abnormalities from rubella in the 1st trimester?
90%
What is the characteristic rash pattern of measles?
Centripetal distribution
What is the characteristic sign that can be looked for in the diagnosis of measles using serology (ELISA)?
Koplik’s spots
What is the primary cause of serious secondary infections in measles patients?
Immune suppression caused by the infection
Which type of immunity confers lifelong immunity to measles?
Natural infection
What is the role of cytotoxic T lymphocytes in measles recovery and protection?
Provide protection against subsequent infection
What is the most widely used laboratory technique for diagnosing atypical measles?
Serology (ELISA)
What is the distribution of measles?
Worldwide
When does measles become communicable?
4 days before and after onset of rash
What is the primary cause of mortality in measles?
Increase in < 1-year-old and malnourished individuals
What is the primary means of transmission for measles?
Respiratory droplets
What is the role of IgM antibodies in the diagnosis of measles?
Indication of acute infection
What is the primary method used for laboratory diagnosis of measles?
Serology (ELISA)
What is the primary method of achieving herd immunity against measles?
Vaccination campaigns
Study Notes
Measles Virus: Structure, Replication, and Clinical Presentation
- Measles remains a leading cause of death in young children globally, causing an estimated 6 million deaths annually, with 164,000 deaths in 2008, primarily affecting children under 5 years old.
- The measles virus belongs to the Paramyxoviridae family and is a human disease that does not occur in animals.
- The virus is transmitted through respiratory secretions, spreading via coughing and sneezing through close personal contact.
- The measles virus encodes at least 6 virion structural proteins, including the nucleoprotein, viral polymerase protein, envelope H protein, F protein, and M protein.
- The virus attaches to the cellular receptor CD-46, and the receptor for measles virus is CD-46 or Membrane Cofactor Protein Regulator for complement activation.
- The viral replication process involves virus attachment, penetration, and uncoating, followed by transcription, translation, RNA replication, and maturation.
- Measles virus infection causes immunosuppression, predisposing individuals to secondary opportunistic infections, particularly bronchopneumonia, a major cause of measles-related mortality among young children.
- The clinical presentation of measles includes an incubation period of 10 to 12 days, followed by a prodromal period with symptoms such as high fever, cough, coryza, and conjunctivitis.
- The appearance of Koplik's spots and a maculopapular rash on the face and head, which spreads rapidly to the trunk and limbs, are characteristic signs of measles.
- Other manifestations include bronchitis, pneumonitis, and occasionally diarrhea, with recovery typically occurring in 10-14 days with desquamation of the skin.
- Measles virus replication in tissue culture and certain organs of the intact organism is characterized by the formation of giant multinucleated cells (syncytium formation), resulting from the action of the viral spike F protein.
- Ongoing molecular surveillance is crucial in determining whether significant antigenic drifts evolve over time, enabling precise epidemiologic tracking of outbreaks and their origins.
Test your knowledge of the measles virus with this quiz on its structure, replication, and clinical presentation. Explore key facts about the virus, its transmission, structural proteins, replication process, clinical symptoms, and impact on public health.
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