PARAMYXOVIRIDAE Flashcards
[?] RNA viruses
Enveloped
[?] nm
150-300
[?] symmetry
Helical
Genome:
Negative sense, linear, single stranded, nonsegmented RNA
Virus relicates in the [?]
cytoplasm
Virions penetrate the cell by [?] with the plasma membrane and exit by [?] from the plasma membrane without killing the cell
fusion; budding
Viruses induce cell-tocell fusion, causing multinucleated giant cells (?)
syncytia
causes many of the symptoms but is essential for control of the infection
Cell-mediated immunity
Respirovirus
Human parainfluenzaviruses 1 & 3
Morbillivirus
Measles virus
Rubulavirus
Mumps virus; Human parainfluenza viruses 2 & 4
Henipavirus
Hendra virus, Nipah virus
Pneumovirus
Human respiratory syncytial virus
Metapneumovirus
Human metapneumovirus
● non-segmented genome is 15-19 kb in length.
Respirovirus
● Virions can be either pleomorphic or filamentous.
Respirovirus
● Replication takes place in the cytoplasm.
Respirovirus
● Human parainfluenza viruses (HPIV) are classified into four serotypes. The most popular are HPIV-1 and HPIV-2.
Respirovirus
In babies, HPIV-3 causes bronchiolitis and pneumonia.
Respirovirus
● Human metapneumovirus (HMPV) is divided into four subtypes (A1, A2, B1, B2).
Respirovirus
The F (fusion) and G (attachment) proteins are two surface glycoproteins.
Respirovirus
Diseases: Measles or Rubeola
Morbillivirus
● causes fever with rashes (red measles)
Morbillivirus
● personality changes, loss of memory, muscle spasms, blindness
Morbillivirus
● incubation period: 7-13 days
Morbillivirus
● may also show conjunctivitis and pneumonia
Morbillivirus
MUMPS
Rubulavirus
● “to mump” (british word): grimace or grin (as a result of parotid gland swelling)
Rubulavirus
● Acute infectious disease due to “myxovirus parotiditis”
Rubulavirus
RNA paramyxovirus (Genus [?]) affecting mainly glands and nervous system
Rubulavirus
● Mortality is negligible
Rubulavirus
● a genus of negative-strand RNA viruses in the family Paramyxoviridae, order Mononegavirales containing six established species
Henipavirus
● pleiomorphic with spherical or filamentous structures (40- 2000 nm)
Henipavirus
● Nucleocapsids are visible in electron microscopy (18 nm)
Henipavirus
● HPIV and HMPV spread through droplets and touch.
Respirovirus
In children, HPIV causes upper respiratory infections and croup.
Respirovirus
a. Spread by viremia
Morbillivirus
● from the oropharynx leading to the RES
Morbillivirus
b. Secondary Viremia
Morbillivirus
● after 5-7 days
Morbillivirus
● spreads to the mucosa of repiratory, urogenital and GIT or CNS
Morbillivirus
● Respiratory Tract Entry: Mumps virus typically enters the body through the respiratory tract via inhalation of infected respiratory droplets.
Rubulavirus
● Initial Replication: The virus initially infects and replicates in the upper respiratory tract epithelial cells.
Rubulavirus
● Overcrowding
Rubulavirus
● Mode of transmission: droplet infection and direct contact with the infection person
Rubulavirus
● I.P.: 2-4 weeks
Rubulavirus
● Henipaviruses enter via respiratory tract or direct contact with infected animals.
Henipavirus
● Attachment to host cells occurs via specific ephrin-B2 and ephrin-B3 receptors on endothelial cells and neurons.
Henipavirus
● Fusion and entry into host cells facilitated by viral attachment and fusion glycoproteins.
Henipavirus
● Release of viral RNA genome into host cell cytoplasm.
Henipavirus
● Viral RNA replication leads to more viral proteins and genomes.
Henipavirus
● Cell-to-cell spread via syncytia formation allows direct viral transmission.
Henipavirus
● In young children, HMPV causes bronchiolitis.
Respirovirus
● Severe illness is more likely in the elderly and immunocompromised people.
Respirovirus
● Endemic worldwide
Morbillivirus
● Serious & highly contagious
Morbillivirus
● Usually found in non-immunized or partially -immunized
Morbillivirus
● Humans are the natural host
Morbillivirus
● 1-5 year age group
Morbillivirus
● Airborne, spread by contact with aerosolized respiratory secretion
Morbillivirus
● Age: mostly 5-9 yrs, but can be seen in any age
Rubulavirus
● Sex: females
Rubulavirus
● Immunity: less than 6 months of age infants are immune, life long immunity after one infection
Rubulavirus
● Any time but peak in winter and spring season
Rubulavirus
● Reservoir Hosts: Bats as Natural Reservoirs
Henipavirus
● Human infection appears to be as a result of contact with sick farm animals, and not direct contact with the bat hosts.
Henipavirus
Viral culture, antigen detection, and serology, PCR
Respirovirus
Nasopharyngeal swabs, aspirates, and washes are optimal specimens
Respirovirus
History and Symptoms
Morbillivirus
Presence of Koplik’s Spots
Morbillivirus
Serologic Testing: Blood tests can detect specific antibodies (IgM and IgG) against the measles virus.
Morbillivirus
IgM is detectable from day 3 after rash onset, and IgG from days 7–14.
Morbillivirus
Viral Detection: Reverse transcriptionpolymerase chain reaction (RT-PCR) on respiratory specimens (such as throat swabs, nasal swabs, or saliva) can detect measles virus RNA.
Morbillivirus
Virus isolation—possible in renal cell lines, growth slow
Morbillivirus
Direct detection of virus antigen in clinical specimens by immunoflourescent technique.
Rubulavirus
● SPECIMENS for viral isolation include; saliva, CSF, and urine.
Rubulavirus
● CELL LINE: Monkey kidney cells are preferred for virus isolation.
Rubulavirus
● OUTCOME: Cytopathic effect in the form of multinucleate giant cell formation is detected; Haemadsorption test.
Rubulavirus
Serology: Test employed include
● HAI test, CFT test and ELISA test.
Rubulavirus
● Unequivocal diagnosis can be made only by laboratory tests such as IHC, cell culture isolation, PCR, or serology.
Henipavirus
● IHC can reveal widespread presence of Nipah virus antigens in endothelial and smooth muscle cells of blood vessels, as well as in various parenchymal cells
Henipavirus
● There is no vaccine.
Respirovirus
● Aerosolized ribavirin can be used for treatment if necessary.
Respirovirus
● In hospital wards, infected patients may be isolated.
Respirovirus
Treatment: Supportive therapy
Morbillivirus
● Rest and Hydration
Morbillivirus
● Fever Control
Morbillivirus
● Vitamin A Supplementation
Morbillivirus
● Isolation and Rest
Morbillivirus
● Vaccination (MMR Vaccine)
Morbillivirus
● Herd Immunity
Morbillivirus
● Vaccination Campaigns
Morbillivirus
● Vitamin A Supplementation
Morbillivirus
● Public Health Measures
Morbillivirus
● Health Education
Morbillivirus
● Supportive care
Rubulavirus
● Case should be isolated till symptoms subside
Rubulavirus
● Contacts should be kept under surveillance
Rubulavirus
● Immunization
Rubulavirus
● Mumps vaccine: Live attenuated,0.5 ml, IM MMR vaccine
Rubulavirus
Travelers should not consume fallen fruit, raw date palm sap, or products made from raw sap.
Henipavirus
A Hendra virus vaccine for horses has been licensed in Australia and has potential future benefit to prevent Henipavirus infections in humans, but no licensed vaccines for humans currently are available.
Henipavirus
● Rhinorrhea, pharyngitis, laryngitis, croup, bronchitis, and pneumonia are some of the symptoms.
Respirovirus
● Wheezing in children is possible.
Respirovirus
● Flu-like symptoms can occur in adults.
Respirovirus
● Cough, Coryza, Conjunctivitis, Photophobia
Morbillivirus
● High hever
Morbillivirus
● Koplik Spots : grain of salts
Morbillivirus
● surrounded by red halo
Morbillivirus
● rashes on the head and body vesicular lesions that lasts for 24 to 48 hours, usually 12 mm
Morbillivirus
● One third cases: asymptomatic
Rubulavirus
● Initial symptoms: ear ache on affected side, pain and stiffness on opening the mouth
Rubulavirus
● Pain and swelling due to involvement of parotid, sublingual and submandibular glands,
Rubulavirus
● Swelling subsides in 1-2 weeks Can affect testes, pancreas, ovaries, prostate, CNS
Rubulavirus
● Severe cases: Fever 3-5 days
Rubulavirus
● Orchitis (25-40% ): 7-10 days after parotitis, with high fever (Unilateral in 75% orchitis cases, Most common extra-salivary gland manifestation in adults)
Rubulavirus
● Epididymitis
Rubulavirus
● Pancreatitis(4%)
Rubulavirus
● Mild form of meningitis
Rubulavirus
● Thyroiditis, Neuritis, Hepatitis, Ovaritis, Oophoritis (5% adult women)
Rubulavirus
● Spontaneous abortion (25% in pregnancy)
Rubulavirus
● Hearing loss, Polyarthritis, Encephalitis, Cerebellar ataxia
Rubulavirus
● severe influenza-like illness with dizziness, headache, fever, and myalgias.
Henipavirus
● can progress to severe encephalitis with confusion, abnormal reflexes, seizures, and coma respiratory symptoms also might be present
Henipavirus
Classified into two major species: Human respiratory syncytial virus (HRSV) and Bovine respiratory syncytial virus (BRSV
Pneumovirus
Human Metapneumovirus
● Genomic Features: Four genetic lineages (A1, A2, B1, B2) identified through genetic sequencing.
Metapneumovirus
● Unique Proteins: Fusion (F) and attachment (G) proteins aid in viral attachment and entry into host cells.
Metapneumovirus
● Syncytia Formation: Ability to cause syncytia (fusion of infected cells), leading to cellto-cell spread.
Metapneumovirus
● They enter the body through inhalation of respiratory droplets containing the virus or direct contact with contaminated surfaces.
Pneumovirus
● spread from person to person via respiratory droplets
Metapneumovirus
● Infects the respiratory tract epithelium, causing bronchiolitis, pneumonia, and respiratory distress.
Metapneumovirus
Exhibits seasonal patterns, with increased transmission occurring during colder months in temperate climates (fall to spring).
HRSV
This seasonality contributes to outbreaks and increased rates of infection, especially among young children.
HRSV
Seasonal patterns vary by region but often coincide with periods of stress on cattle herds, such as during transportation, housing changes, or weather fluctuations.
BRSV
● Global distribution, causing respiratory infections, particularly in children, elderly, and immunocompromised individuals.
Metapneumovirus
● Seasonality: Commonly seen in late winter, spring, and early summer.
Metapneumovirus
● Molecular Tests (RT-PCR):
HRSV
● Antigen Detection Tests
HRSV
● Viral Culture
HRSV
● Reverse transcription-polymerase chain reaction (RT-PCR) on respiratory samples (nasopharyngeal swabs, sputum) to detect viral RNA.
Metapneumovirus
● Other Tests: Viral culture, immunofluorescence assays, serology, and antigen detection.
Metapneumovirus
● Hand Hygiene
Pneumovirus
● Respiratory Hygiene: coughing or sneezing, and proper disposal of used tissues
Pneumovirus
● Avoiding Close Contact:
Pneumovirus
● Cleaning and Disinfection:
Pneumovirus
● Isolation and Quarantine Measures
Pneumovirus
● Majority of the children infected can be managed at home with supportive care
Metapneumovirus
● Hydration via Intravenous fluid and antiviral medications in severe cases
Metapneumovirus
● Bronchodilators and corticosteroids
Metapneumovirus
● Hygiene practices
Metapneumovirus
● Handwashing
Metapneumovirus
● Covering mouth while coughing/sneezing
Metapneumovirus
● Don’t share food or eating utensils
Metapneumovirus
● Practice social distancing especially when sick
Metapneumovirus
Mild Respiratory Illness: infections can manifest as mild coldlike symptoms
HRSV
● Runny or stuffy nose
HRSV
● Cough
HRSV
● Sneezing
HRSV
● Sore throat
HRSV
● Low-grade fever
HRSV
● Severe Respiratory Illness in Infants and Young Children
HRSV
In younger populations, particularly infants and toddlers, infections can lead to more severe respiratory illnesses
HRSV
● Bronchiolitis
HRSV
● Pneumonia
HRSV
● Wheezing and difficulty breathing
HRSV
● Cyanosis
HRSV
Respiratory Disease in Calves: primarily affects calves and can result in respiratory illness, with clinical signs
Pneumovirus
● Fever
Pneumovirus
● Nasal discharge
Pneumovirus
● Coughing
Pneumovirus
● Difficulty breathing
Pneumovirus
● Reduced appetite
Pneumovirus
● Decreased weight gain
Pneumovirus
● Bronchiolitis
Metapneumovirus
● Croup
Metapneumovirus
● Pneumonia
Metapneumovirus
● Astma exacerbation
Metapneumovirus
● Rhinorrhea
Metapneumovirus
● Cough
Metapneumovirus
● Fever
Metapneumovirus
● Conjunctivitis
Metapneumovirus
● Vomiting, Diarrhea
Metapneumovirus
● Detection of specific antibodies (IgM, IgG) against HMPV indicating recent or past infection.
Metapneumovirus
