Other Paramyxoviridae Flashcards
Parainfluenza structure & classification
Family: Paramyxoviridae
Genus:
Serotypes — Four major serotypes of human PIVs 1-4. PIV-1 and -3 are members of the Respirovirus genera, whereas PIV-2 and -4 are members of the Rubulavirus genera.
Enveloped (-)ss RNA
Baltimore: V
nucleocapsid protein (N), phosphoprotein (P), matrix protein (M), fusion glycoprotein (F), hemagglutinin-neuraminidase glycoprotein (HN), and polymerase (L)
The HN glycoproteins are involved in attachment of the virus to the host cell via interactions with sialic acid residues on the cell surface [10]. This interaction allows the F protein to mediate virus-cell membrane fusion, which is required for nucleocapsid entry and infection of the host cell. The neuraminidase portion of the HN protein mediates budding of progeny virions from the surface of infected cells
Rinderpest & Newcastle
Family: Paramyxoviridae
Genus:
Rinderpest: Morbillivirus (same as measles)
Newcastle: Avulavirus
(-)ssRNA enveloped
Rinderpest: Cattle - Fever, Discharge from nose and eyes, Necrotic lesions on the gums, lips and tongue
Other damage in the upper and lower digestive tracts, Enteritis followed by diarrhoea, Dehydration, Death
Only 1 of 3 diseases eradicated by vaccination.
Newcastle: Poultry - respiratory disease, but depression, nervous manifestations, or diarrhoea.
Vaccine: Live LaSota strain vaccine
Nipah
Family: Paramyxoviridae
Genus: Henipavirus
(-)ssRNA Enveloped
Baltimore: V
NiV strains are divided into two clades (Clade I: NiV-B in Bangladesh and India, and Clade II: NiV-M in Malaysia) which suggests two separate NiV introductions in these countries
Reservoir: Pteropus bats
Receptor: Ephrin-B2 (EFNB2) and ephrin-B3 (EFNB3)
Incubation: 4-21 days
Clinical: 11% asymptomatic. RTI. Meningoencephalitis. A small proportion of patients can have relapses or delayed onset of encephalitis (weeks, months or even years post-recovery) with fatal outcome
Mortality: 45-70%
Diagnostics: RT-PCR - developmental assay offered @ RIPL
Therapeutics: NiV-specific immunotherapeutic treatments (such as m102.4 monoclonal antibody against the G protein) are under development and evaluation - compassionate use in India.
Remdesivir & Ribavirin - unclear benefit.
Vaccine: Chadox vaccine in trials.
HeV horse vaccine some cross protection.
Hendra
Family: Paramyxoviridae
Genus: Henipavirus
(-)ssRNA Enveloped
Baltimore: V
Reservoir: Pteropus bats
Clinical: equine encephalitis. Human encephalitis.
Diagnostics: Sequencing. Developmental RT-PCR RIPL.
Therapeutics: Mabs used - m102.4. binds to the immunodominant NiV/HeV receptor-binding glycoprotein (GP).
Vaccine: sub-unit horse vaccine. No human vaccines but in trials.
Mortality- 60% but only 7 human cases in the literature.
Langya & Mojiang
Family: Paramyxoviridae
Genus: Henipavirus
(-)ssRNA Enveloped
Baltimore: V
Langya Reservoir: Crocidura Shrew
Mojiang Reservoir: Rattus rats
Epidemiology: China
Clinical: Respiratory & IFI.
Diagnostics: sequencing, RT-PCR assays in China.
Therapeutics: Nil specific.
Vaccines: No
Mortality:
Langya - 0% (0/35)
Mojiang - 100% (3/3)
PIV serotype causing severe disease
3
PIV treatment
- Case reports and small case series have shown variable results for the use of aerosolized, oral, or intravenous ribavirin for the treatment of PIV infection in hematopoietic cell transplant (HCT) and solid organ transplant recipients [51,63,98-102]. Ribavirin is often considered for treatment of PIV infection in lung transplant recipients because of the association between PIV infection and chronic lung allograft dysfunction (CLAD). However, evidence supporting its use is limited.
- We generally do not use IVIG for treatment, as there are insufficient data to support its use [51,103]. However, some experts favor IVIG use for patients with severe infections, particularly in patients with hypogammaglobulinemia
- DAS181 (an inhaled recombinant sialidase fusion protein) is a promising investigational agent for the treatment of parainfluenza infections. In vitro, DAS181 has been shown to inhibit PIV infection by enzymatically removing the sialic acid moiety of the PIV receptor
PIV vaccine
There is no licensed vaccine for PIV.
In trials:
●Bovine PIV-3 (BPIV-3), a virus that is antigenically related to human PIV-3 (hPIV-3), has been evaluated in clinical trials as a vaccine candidate to protect against PIV-3 in children and infants. However, seroconversion rates to hPIV-3 have been modest.
●Sendai virus (SeV) is a mouse PIV-1 candidate vaccine for hPIV-1, as well as a vector for other respiratory viruses. An SeV-based vaccine carrying the respiratory syncytial virus (RSV) F gene demonstrated safety and transient viral genome detection in a phase 1 study in adults, an initial step toward developing a combination RSV and hPIV-1 vaccine for children.
HMPV
Family: Paramyxoviridae
Genus: Pneumovirus (along with RSV)
(-)ss RNA enveloped
Baltimore: V
4 subtypes: A1, A2, B1, B2
Has an F protein similar to RSV (33% similarity)
Incubation: 3-6 days
Syndrome: IFI, pneumonia
Diagnostics: RT-PCR
Therapeutics: Nil. MAbs under trial.
NO vaccine
Pigeon Paramyxovirus & Peste de Petits Ruminants
PPV - severely immunosuppressed patients - Pneumonia and conjunctivitis
PPR - Goat measles - Greece and Romania outbreak 2024
