246 Questions
Which family does Yellow Fever Virus belong to?
Flaviviridae
What is the primary vector for transmission of Chikungunya virus?
Aedes aegypti mosquito
Which virus is associated with Rift Valley Fever?
Bunyaviridae
What is the main method for diagnosis of Dengue virus infection?
PCR (Polymerase Chain Reaction)
What is the timeframe for the gradual reabsorption of extravascular compartment fluid in the recovery phase of dengue?
48-72 hours
What may happen if excessive IV fluids have been administered during dengue recovery?
Respiratory distress from massive pleural effusion and ascites
What is a potential consequence of lack of IV fluids administered during dengue recovery?
Dengue shock syndrome
What is almost always associated with profound shock and is in combination with thrombocytopenia, hypoxia, and acidosis in severe dengue cases?
Major bleeding
When should severe dengue be considered in a patient?
If the patient is a resident of high-risk area and has 2-7 days fever plus evidence of plasma leakage, significant bleeding, or altered level of consciousness
What are some unusual manifestations of dengue mentioned in the text?
Acute liver failure, encephalopathy, cardiomyopathy, encephalitis
What is a potential outcome of excessive fluid therapy during dengue recovery?
Pulmonary edema or congestive heart failure
What is the most common cause of death in dengue patients?
Profound shock, especially in cases with fluid overload
What is the main approach for Chikungunya treatment?
Supportive treatment as no specific antiviral therapy exists
How is Wolbachia utilized to control Ae. aegypti mosquito population?
Wolbachia-infected male mosquitoes render wild female mosquitoes' eggs unhatchable
What is the incubation period for Chikungunya fever?
1-12 days
What is the family of arboviruses including Chikungunya called?
Togaviridae
Which virus causes Rift Valley Fever?
Bunyaviridae
Where is Chikungunya primarily found?
Africa, India, and Southeast Asia
What type of tests are used for lab findings of Chikungunya?
Virus isolation, serological tests, and RT-PCR
How is Rift Valley Fever transmitted?
By mosquitoes and biting flies
What is the approach for prevention and control of Chikungunya?
Surveillance, early outbreak identification, and vector control
Which bacteria is utilized to control Ae. aegypti mosquito population?
Wolbachia
What are the clinical features of Chikungunya fever?
Joint pain and various symptoms
What is the common approach for treatment of Chikungunya fever?
Supportive treatment as no specific antiviral therapy exists
What are the natural reservoirs of arboviruses?
Animals, birds, and reptiles
How do arboviruses perpetuate in the environment?
Through transovarian transmission in arthropods
What is the primary mode of transmission for arboviruses?
Through the saliva of arthropods during biting
How do arboviruses maintain themselves in nature?
By cycling between a host and an arthropod vector
Where does viral multiplication occur in the body?
Myeloid and lymphoid cells or vascular endothelium
What are some common symptoms of arboviral diseases?
Diarrhea, vomiting, body aches, fever, and rashes
Which of the following are arthropod vectors for arboviruses?
Mosquitoes, sandflies, and ticks
What are used for diagnosing arbovirus infections?
Serology, direct detection tests, and culture
Which of the following arboviral infections has a vaccine available?
Yellow fever
What influences the constant distribution of arthropod vectors?
Socioeconomic, medical, and climatic factors
What is important in addressing arboviral infections?
One Health and Eco-Health approaches
What are the blood-sucking arthropods that can transmit arboviral diseases?
Mosquitoes, ticks, and sandflies
What is the primary vector for dengue?
Aedes Aegypti mosquito
What is the size range of the dengue virus?
40-60 nm
How does transmission of the dengue virus to humans occur?
Through mosquito saliva
What are the clinical manifestations of dengue?
High fever and severe headache
What is characteristic of the febrile phase of dengue?
Sudden high-grade fever, myalgia, headache
What does the critical phase of dengue involve?
Severe hemorrhage and organ impairment
How can severe dengue be detected?
Blood tests or CBC
What is crucial in increasing the survival rate of dengue patients?
Early clinical diagnosis and careful management
Who does dengue virus infection affect?
Infants, young children, and adults
What is the life cycle of the dengue virus?
Egg production, larval development, pupa emergence, mating of adult mosquitoes
What is the characteristic of Aedes Aegypti's feeding behavior?
Daytime feeder and indoor biter
Where does Aedes Aegypti lay its eggs?
Indoor artificial containers with water
Which arthropod vector is associated with the Rift Valley Fever virus?
Aedes
Which method is used for diagnosing Rift Valley Fever virus?
RT-PCR, ELISA, and culture from blood and tissues samples
Where is Yellow Fever virus mainly found?
West Africa and South America
What is the primary transmission vector for Japanese Encephalitis?
Culex mosquitoes
What is the primary method for preventing Rift Valley Fever?
Avoiding contact with infected animals and protecting against mosquitoes
Which virus causes a wide range of clinical symptoms, including hemorrhagic fever and encephalitis?
Flaviviridae
What is the history of dengue's pandemic spread?
Beginning in Southeast Asia after World War II and currently present in Africa, the Americas, Asia, the Caribbean, and the Pacific
What is the primary symptom of dengue infection with another serotype, especially serotype 2?
Dengue hemorrhagic fever causing hemorrhage or shock
What is the primary method for diagnosing dengue?
Serology tests
What was the significant event in 2020 related to dengue?
France and Italy reported autochthonous dengue cases
What is the primary characteristic of most human infections of Japanese Encephalitis?
Subclinical
What are the two major forms of Yellow Fever virus?
Urban and Jungle (sylvatic) yellow fever
Which virus is a member of the genus Morbillivirus?
Measles virus
What is the primary characteristic of rubella infection?
Congenital rubella syndrome
Which virus primarily causes parotitis and orchitis in males?
Mumps virus
What is the primary route of transmission for measles?
Respiratory transmission
When does the secondary viremia occur after exposure to measles virus?
5 to 7 days after exposure
What is the characteristic feature of Koplik's spots in measles?
They resemble grain of salt beneath the buccal mucous membrane
What is the cause of the maculopapular rash in measles?
Interaction of immune T cells with virus-infected cells
What is the most common cause of measles-related deaths?
Pneumonia
What is the rare but life-threatening complication characterized by behavioral and intellectual deterioration and seizures years after acute measles infection?
Subacute sclerosing panencephalitis (SSPE)
Which of the following is a characteristic of atypical/modified measles?
Shows mild signs and symptoms
What is the primary method for preventing measles?
Vaccination
What is the characteristic feature of the measles rash?
No scarring
What is the primary symptom of measles infection during the prodromal period?
Fever
What is the characteristic of the exanthem period in measles?
Rash is a sign of satisfactory immune response
What is the mean incubation period for measles?
10 days
Which of the following is a characteristic of the measles virus in the context of the described disease?
It can cause progressive mental deterioration and involuntary movements
What is the primary method for diagnosing atypical measles?
Serology (ELISA)
What is the distribution of measles worldwide?
Highly infectious and distributed worldwide
What is the primary habitat of the measles virus?
Human
What is the primary approach for preventing measles outbreaks?
Vaccination campaigns to achieve herd immunity
What is the incubation period for measles?
1-2 weeks
What is the primary mode of transmission for measles?
Respiratory droplets
What is the characteristic of the humoral immune response to measles infection?
Production of IgM, IgA, and IgG antibodies
What is the significance of atypical measles in the context of diagnosis?
It requires specific laboratory techniques like ELISA
What is the primary characteristic of measles infection in individuals with defective cell-mediated immunity?
Lack of rash development
What is the primary cause of immune suppression following measles infection?
Replication of virus within monocytes and other white blood cells
What is the primary characteristic of measles outbreaks before widespread vaccination campaigns?
Endemic infections punctuating every two to three years
What is the protective antibody percentage after the 1st dose of the measles-rubella vaccine?
95%
Which trimester of pregnancy has the highest risk for structural abnormalities in congenital rubella syndrome?
1st trimester
What is the main method for diagnosis of rubella?
Isolation from clinical specimens
What is the primary treatment approach for congenital rubella syndrome?
Supportive care
What is the recommended prophylaxis for rubella in certain cases?
Human immunoglobulin
Which diagnostic marker can be specific to congenital rubella syndrome?
Specific IgM and IgG observation
What is the primary method for preventing congenital rubella?
Active immunization
In which trimester does measles affect 85% of infants in third world countries?
1st trimester
Which trimester has the lowest risk of structural abnormalities in congenital rubella syndrome?
3rd trimester
What is the primary method for laboratory diagnosis of rubella?
Isolation from clinical specimens
What is the main approach for preventing rubella in certain groups?
Active immunization
What is the most common manifestation of congenital rubella syndrome?
Deafness
Which of the following is NOT a structural protein of the measles virus?
Neuraminidase (N)
What is the incubation period of measles?
10 to 12 days
Which cellular receptor does the measles virus attach to?
CD-46 receptor
What is a characteristic sign of measles infection?
Koplik's spots
What is the primary mode of transmission for the measles virus?
Respiratory secretions
Which of the following is a consequence of measles virus infection?
Generalized immunosuppression
What is a major cause of measles-related mortality among young children?
Bronchopneumonia
How many serotypes of the measles virus are recognized?
1
Which of the following animals can be affected by the measles virus?
Seals
What is the characteristic cellular response to measles virus replication?
Syncytium formation
What is essential for tracking outbreaks and identifying significant antigenic variations in measles virus strains?
Molecular surveillance
Which of the following is a symptom of measles infection?
Conjunctivitis
Which of the following is NOT true regarding Rubella?
Also known as measles
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
Which of the following is NOT true regarding Mumps?
Active immunization for Mumps gives lifelong immunity to an individual.
Which of the following is NOT true regarding Measles vaccine?
It is a type of inactivated vaccine.
T/F Active immunization for Rubella gives lifelong immunity to an individual.
True
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
Which of the following is correct regarding measles?
It is caused by a negative ssRNA virus.
Which of the following is a characteristic feature of the measles rash?
Maculopapular rash starting from the face and spreading downwards
What is the primary method for preventing congenital rubella?
Vaccination of susceptible individuals
What are the natural reservoirs of arboviruses?
Rodents and birds
What is the primary cause of a persistent measles infection leading to a Progressive degenerative CNS disease?
Defective form of measles virus in the brain cell
What is the significance of the presence of humoral antibodies in measles immunity?
Indicates immunity for a lifetime
What is the primary method for diagnosing measles through laboratory diagnosis?
Serology (ELISA)
What is the primary mode of transmission for measles?
Respiratory droplets
What is the distribution of measles worldwide?
Worldwide
What is the incubation period for measles?
2-3 weeks
What is the primary method for preventing measles?
Vaccination
What is the primary habitat of the measles virus?
Human
What is the primary characteristic of atypical measles?
Lack of rash
What is the primary method for diagnosing atypical measles in hospitals?
Serology (ELISA)
What is the primary characteristic of measles infection in individuals with defective cell-mediated immunity?
Lack of rash
What is the primary method for detecting severe dengue?
Detection of plasma leakage
What is the primary cause of immune suppression following measles infection?
Cytokine storm
What is the mean incubation period for measles?
14-21 days
What is the characteristic feature of the measles rash?
Maculopapular rash
Which trimester has the lowest risk of structural abnormalities in congenital rubella syndrome?
3rd trimester
What is the primary method for diagnosing atypical measles?
PCR testing
Which of the following is NOT true regarding Mumps?
It can cause deafness
What is the primary method for preventing congenital rubella?
Routine immunization
What is the characteristic of Aedes Aegypti's feeding behavior?
Diurnal feeding
What is the primary symptom of measles infection during the prodromal period?
Fever
What are some common symptoms of arboviral diseases?
Arthralgia, myalgia, rash
What is the distribution of measles worldwide?
Endemic
What is the primary vector for dengue?
Aedes Aegypti
What is the primary site of initial measles virus replication?
Tracheal and bronchial epithelial cells
When does the secondary viremia occur after exposure to measles virus?
4 to 6 days
What is the characteristic appearance of Koplik's spots in measles?
Resembles grain of salt just beneath the mucosa
What causes the maculopapular rash in measles?
Interaction of immune T cells with virus-infected cells in the small blood vessels
What is the significance of the absence of rash in measles infection?
Indicates a severe form of the disease
What is the most common cause of measles-related deaths?
Pneumonia
In which condition does giant cell pneumonia occur as a complication of measles?
Immunodeficient children
What is the rare complication characterized by progressive mental deterioration and seizures years after an acute measles infection?
SSPE (subacute sclerosing panencephalitis)
What is the mean incubation period for measles?
10 days
What is the most common complication of measles in partially immune persons?
Atypical rash
What is the primary cause of most measles-related deaths in developing countries?
Malnutrition
What is the primary characteristic of the exanthem period in measles?
Maculopapular rash
Which of the following is NOT true regarding Mumps vaccine?
The vaccine primarily consists of the H protein
Which of the following is NOT a complication associated with Mumps?
Blindness
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
Which of the following does not belong to the classical triad of Rubella in infected neonates?
Congenital defects
Which of the following is NOT true regarding Rubella?
Also known as measles
Which of the following is NOT true regarding Active immunization for Rubella?
It primarily consists of the L protein
Which of the following is NOT a characteristic of the measles virus in the context of the described disease?
Primarily consists of the L protein
Which of the following is NOT true regarding Measles vaccine?
The vaccine primarily consists of the H protein
Which of the following is NOT true regarding Rubella vaccine?
The vaccine primarily consists of the H protein
What is the incubation period of measles?
10 to 12 days
How many virion structural proteins does the measles virus encode?
6
What is the primary cause of immune suppression following measles infection?
Decrease in delayed type hypersensitivity
Which cellular receptor does the measles virus attach to?
CD-46
What are the characteristic signs of measles infection?
All of the above
What is the primary mode of transmission for the measles virus?
Respiratory secretions
What is the primary vector for transmission of Chikungunya virus?
Aedes aegypti
What is the primary habitat of the measles virus?
Humans
What is the mean incubation period for measles?
14 days
What is the primary method for preventing congenital rubella?
Vaccination
What is the primary characteristic of measles infection in individuals with defective cell-mediated immunity?
Giant multinucleated cell formation
What is the primary method for diagnosis of rubella?
Serological testing
What is the primary site of initial measles virus replication?
Respiratory epithelium
Which of the following is NOT a characteristic of the rubella virus in the context of the described disease?
Causes gastroenteritis
What is the primary mode of transmission for mumps?
Respiratory droplets
What is the primary method for diagnosing congenital rubella syndrome?
Isolation from clinical specimens
What is the primary characteristic of the measles-rubella vaccine?
It has no complications
What is the primary mode of passive prophylaxis for rubella?
Human immunoglobulin
What is the primary risk factor for structural abnormalities in congenital rubella syndrome?
Gestational age
When was the measles-rubella vaccine first available for routine immunization?
1969
What is the primary method for laboratory diagnosis of rubella?
Serology
What is the primary manifestation of congenital rubella syndrome in infants?
Hearing loss
What is the primary characteristic of treatment for congenital rubella syndrome?
Mainly supportive
What is the primary method for active immunization against rubella?
Subcutaneous injection
What is the primary risk factor for measles in infants in third world countries?
Gestational age
What is the primary characteristic of the measles-rubella vaccine's contraindications?
Contraindicated in pregnancy
What is the primary characteristic of the accidental vaccinations in susceptible pregnant women?
No clinical adverse effects on the mother
What is the primary cellular receptor to which the measles virus attaches?
CD-46
Which of the following is a characteristic sign of measles infection?
Koplik’s spots
What is the incubation period for measles?
10-12 days
What is the primary cause of generalized immunosuppression following measles infection?
Decreased interleukin production
Which family does the measles virus belong to?
Paramyxoviridae
What is the primary mode of transmission for the measles virus?
Respiratory secretions
What is the major cause of measles-related mortality among young children?
Opportunistic infections
What is the characteristic feature of measles virus replication?
Giant multinucleated cells and syncytium formation
What is the only known natural species recognized to be infected by the measles virus?
Humans
What is the primary cause of measles-related death in immunocompromised individuals?
Secondary bacterial infections
What is the primary method for tracking outbreaks and identifying significant antigenic drifts in measles virus strains?
Molecular surveillance
What is the primary method for preventing measles?
Vaccination
What is the mean incubation period for measles?
7-14 days
What is the primary site of initial measles virus replication?
Tracheal and bronchial epithelial cells
What is the characteristic appearance of Koplik’s spots in measles?
Resembles grain of salt just beneath the mucosa
What is the primary cause of most measles-related deaths?
Complications such as pneumonia and encephalitis
What is the significance of the presence of humoral antibodies in measles immunity?
Suggests a satisfactory immune response
What is the characteristic of the exanthem period in measles?
Clear sign of immune response and recovery
What is the primary method for preventing measles?
Vaccination with MMR (Measles, Mumps, Rubella) vaccine
What is the primary mode of transmission for measles?
Respiratory droplets
What is the primary cause of immune suppression following measles infection?
Viral invasion of lymphocytes
What is the primary characteristic of atypical measles?
Occurs in partially immune persons
What is the distribution of measles worldwide?
Endemic in many developing countries
What are some common complications of measles?
Pneumonia, encephalitis, and giant cell pneumonia
Which of the following is a characteristic of subacute sclerosing panencephalitis (SSPE)?
Onset of behavioral and intellectual deterioration occurs years after an acute measles infection
What is the primary method for diagnosing measles?
Serology (ELISA)
What is the primary mode of transmission for measles virus?
Respiratory droplets
What is the characteristic of humoral immune response to measles infection?
Production of IgM, IgA, and IgG antibodies
What is the mean incubation period for measles?
1-3 weeks
What is the primary habitat of the measles virus?
Human
What is the most common cause of measles-related deaths?
Secondary infections due to immune suppression
What is the distribution of measles worldwide?
Endemic in countries with large populations of susceptible children
What is the characteristic of the exanthem period in measles?
Appearance of maculopapular rash
What is the primary symptom of measles infection during the prodromal period?
Cough, coryza, and conjunctivitis
What is essential for tracking outbreaks and identifying significant antigenic variations in measles virus strains?
Genetic determination of the virus
What is the cause of serious secondary infections in measles?
Immune suppression
Which of the following statements about measles vaccine is correct?
Measles vaccine is a type of live attenuated vaccine that starts at 6 to 9 months of age.
Which of the following is NOT a characteristic of Mumps V antigen and S antigen?
Mumps V antigen and S antigen both consist predominantly of nucleoprotein (NP).
Which of the following is NOT true regarding Rubella?
Also known as measles.
During which stage of pregnancy does organogenesis period happen?
First 8 weeks of pregnancy.
Which of the following are complications associated with mumps?
Blindness.
Which method of laboratory diagnosis can be used to detect viral mumps RNA and fosters a rapid confirmation for the diagnosis?
PCR.
Which of the following does not belong to the classical triad of Rubella in infected neonates?
Congenital defects.
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.
Which of the following statements about primary and secondary viremia is correct?
Both statements are incorrect.
The presence of this component differentiates mumps from measles virus.
Neuraminidase.
Study Notes
Arboviruses and Their Characteristics
- Aedes is an arthropod vector of the Rift Valley Fever virus, diagnosed using RT-PCR, ELISA, and culture from blood and tissues samples.
- There is no FDA-approved treatment for Rift Valley Fever, and prevention methods include avoiding contact with infected animals and protecting against mosquitoes.
- Flaviviridae causes a wide range of clinical symptoms, including hemorrhagic fever and encephalitis, and is spread by a mosquito vector affecting humans and birds.
- Japanese Encephalitis, a flavivirus transmitted by Culex mosquitoes, was first discovered in Japan and large-scale epidemics occur in China, India, and other parts of Asia.
- Yellow Fever virus, also a flavivirus, is mainly found in West Africa and South America, with two major forms: Urban and Jungle (sylvatic) yellow fever.
- Most human infections of Japanese Encephalitis are subclinical, but in clinical cases, life-threatening encephalitis occurs.
- Dengue, known as "break-bone fever," is a mosquito-borne febrile illness primarily occurring in tropical and subtropical regions, with four main serotypes.
- Dengue infection with another serotype, especially serotype 2, predisposes individuals to dengue hemorrhagic fever, causing hemorrhage or shock, especially in children.
- There is no specific therapy for Japanese Encephalitis, but a vaccine is available, while dengue diagnosis involves serology tests and no specific therapy is available, but a vaccine is available.
- Dengue has a history dating back to 1779-1780, with a pandemic beginning in Southeast Asia after World War II, and it is currently present in Africa, the Americas, Asia, the Caribbean, and the Pacific.
- The two cycles of dengue are the Jungle Cycle (Sylvatic/Enzootic) and the Urban Cycle (Epidemic), and in the Philippines, 893 new dengue cases were reported in epidemiologic week 2023, with a total of 111,813 cases reported as of August 26, 2023.
- In 2020, France and Italy reported autochthonous dengue cases, and the five countries reporting the most cases were Brazil, Paraguay, Mexico, Vietnam, and Malaysia.
Measles Virus: Structure, Replication, and Clinical Presentation
- Measles remains a leading cause of death among young children, causing 6 million deaths annually, with 164,000 deaths in 2008, mostly in children under 5.
- Measles is caused by the Paramyxovirus, belonging to the family Paramyxoviridae, and primarily affects humans through respiratory secretions.
- The virus encodes at least 6 virion structural proteins, including Nucleoprotein (N), Viral Polymerase Protein (P and L), Hemagglutinin (H), Fusion (F), and Matrix (M) proteins.
- Measles virus attaches to the CD-46 cellular receptor and undergoes a process of attachment, penetration, uncoating, transcription, translation, and RNA replication during viral replication.
- 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, a maculopapular rash, and subsequent desquamation of the skin are characteristic signs of measles infection.
- Measles virus infection causes generalized immunosuppression, leading to a decrease in delayed type hypersensitivity, interleukin production, and antigen-specific lymphoproliferative responses.
- Immunocompromised individuals are predisposed to secondary opportunistic infections, such as bronchopneumonia, a major cause of measles-related mortality among young children.
- The measles virus is only known to infect humans and is recognized by a single serotype, with subtle antigenic and genetic variations among wild-type strains.
- The virus is transmitted through respiratory secretions, mainly via coughing and sneezing, and can cause serious disease in natural species such as seals, dolphins, and horses.
- Measles virus replication leads to the formation of giant multinucleated cells and syncytium formation, characterized by intranuclear inclusions and viral protein synthesis.
- Ongoing molecular surveillance is essential for tracking outbreaks and identifying significant antigenic drifts in measles virus strains.
Measles Virus: Structure, Replication, and Clinical Presentation
- Measles remains a leading cause of death among young children, causing 6 million deaths annually, with 164,000 deaths in 2008, mostly in children under 5.
- Measles is caused by the Paramyxovirus, belonging to the family Paramyxoviridae, and primarily affects humans through respiratory secretions.
- The virus encodes at least 6 virion structural proteins, including Nucleoprotein (N), Viral Polymerase Protein (P and L), Hemagglutinin (H), Fusion (F), and Matrix (M) proteins.
- Measles virus attaches to the CD-46 cellular receptor and undergoes a process of attachment, penetration, uncoating, transcription, translation, and RNA replication during viral replication.
- 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, a maculopapular rash, and subsequent desquamation of the skin are characteristic signs of measles infection.
- Measles virus infection causes generalized immunosuppression, leading to a decrease in delayed type hypersensitivity, interleukin production, and antigen-specific lymphoproliferative responses.
- Immunocompromised individuals are predisposed to secondary opportunistic infections, such as bronchopneumonia, a major cause of measles-related mortality among young children.
- The measles virus is only known to infect humans and is recognized by a single serotype, with subtle antigenic and genetic variations among wild-type strains.
- The virus is transmitted through respiratory secretions, mainly via coughing and sneezing, and can cause serious disease in natural species such as seals, dolphins, and horses.
- Measles virus replication leads to the formation of giant multinucleated cells and syncytium formation, characterized by intranuclear inclusions and viral protein synthesis.
- Ongoing molecular surveillance is essential for tracking outbreaks and identifying significant antigenic drifts in measles virus strains.
Measles Virus: Structure, Replication, and Clinical Presentation
- Measles remains a leading cause of death among young children, causing 6 million deaths annually, with 164,000 deaths in 2008, mostly in children under 5.
- Measles is caused by the Paramyxovirus, belonging to the family Paramyxoviridae, and primarily affects humans through respiratory secretions.
- The virus encodes at least 6 virion structural proteins, including Nucleoprotein (N), Viral Polymerase Protein (P and L), Hemagglutinin (H), Fusion (F), and Matrix (M) proteins.
- Measles virus attaches to the CD-46 cellular receptor and undergoes a process of attachment, penetration, uncoating, transcription, translation, and RNA replication during viral replication.
- 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, a maculopapular rash, and subsequent desquamation of the skin are characteristic signs of measles infection.
- Measles virus infection causes generalized immunosuppression, leading to a decrease in delayed type hypersensitivity, interleukin production, and antigen-specific lymphoproliferative responses.
- Immunocompromised individuals are predisposed to secondary opportunistic infections, such as bronchopneumonia, a major cause of measles-related mortality among young children.
- The measles virus is only known to infect humans and is recognized by a single serotype, with subtle antigenic and genetic variations among wild-type strains.
- The virus is transmitted through respiratory secretions, mainly via coughing and sneezing, and can cause serious disease in natural species such as seals, dolphins, and horses.
- Measles virus replication leads to the formation of giant multinucleated cells and syncytium formation, characterized by intranuclear inclusions and viral protein synthesis.
- Ongoing molecular surveillance is essential for tracking outbreaks and identifying significant antigenic drifts in measles virus strains.
Test your knowledge of arboviruses and their characteristics with this quiz. Explore topics such as transmission vectors, geographic distribution, clinical symptoms, and diagnostic methods for arboviral diseases such as Rift Valley Fever, Japanese Encephalitis, Yellow Fever, and Dengue.
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