RNA VIRUSES NEGATIVE SENSE - MS SABADO AND MANUEL_20240524_085956_0000.pdf

RNA VIRUSES NEGATIVE SENSE

1. RNA VIRUSES
NEGATIVE SENSE
By: Ms. Sabado and Ms. Manuel

2. PARAMYXOVIRUSES
FILOVIRUSES
ARENAVIRUSES
BUNYAVIRUSES
ORTHOMYXOVIRUSES
RHABDOVIRUSES
TOPIC FOR DISCUSSION

3. PARAMYXOVIRUSES
PARAMYXOVIRIDAE
Mode of Transmission: Droplet Transmission
Genera include Morbillivirus, Paramyxovirus, and Pneumovirus.
Pathology: stimulate cell-to-cell fusion, resulting in multinucleated gigantic cells (syncytia)
Diagnosis: symptomatology; RT-PCR genome analysis of respiratory secretions
Therapy: symptomatic therapy (mostly for paramyxovirus); aerosolized ribavirin (RSV).
Prevention: vaccinations (MMR)

4. PARAMYXOVIRUSES: MEASLES VIRUS
MOT-respiratory secretions
 Spherical, helical nucleocapsid, no neuraminidase spikes
 I.P- 10-12 days
 PATHOGENESIS- lymphoid tissue of RT-bloodstream (primary viremia)- RE
system (secondary viremia)- epithelial surfaces.
 High fever, cough, conjunctivitis. KOPLIK’S SPOTS
 Maculopapular rash- neck, then rest of the body
 Recovery- 10-14 days

5. PARAMYXOVIRUSES: MEASLES VIRUS
Diagnosis
Direct demonstration - multinucleated giant cells virus particles in exfoliated
nasal cells by IF 
Isolation - during prodromal phase till up to 2 days post rash. primary human
embryo kidney, monkey kidney cells- CPE- MNGC with both intracytoplasmic
and intranuclear IB
Serology - specific IgM Ab by ELISA, HI and CFT for paired sera- 4 fold rise is
diagnostic.
Prophylaxis
1. Active immunization live attenuated- at 9 months
Firstly Edmonston strain- vaccination measles, then
Schwartz strain- effective only after 15 months
Edmonston –Zagreb strain- passage in human diploid cells- 1 dose, S/C route
MMR vaccine-single dose, S/C LA vaccine- intranasal aerosol
2. Passive immunisation-pooled sera containing Ab

6. PARAMYXOVIRUSES: MUMPS
Nasal or URT epithelial cells- blood salivary glands, testes, ovaries, pancreas,
meninges and kidneys
Shed in the saliva 2 days before to 9 days after the onset of salivary gland
swelling
(+) virus in urine up to 14 days after onset of symptoms
Malaise and fever is followed within a day by painful swelling of one or both
of the parotid (salivary) glands
A possible complication in males after puberty is orchitis - painful swelling of
one or both testicles.
 Inflammation of the ovary and pancreas can also occur.
 Disease is usually self-limiting within a few days
 Aseptic meningitis (usually resolving without problems) or postexposure
encephalitis (can prove fatal) are the most serious complications associated
with mumps.

7. PARAMYXOVIRUSES: MUMPS
Diagnosis
Cell culture1.
Specimen-saliva, spinal fluid or urine
Monkey kidney cell
CPE- cell rounding and giant syncytia formation
Serology- 4 fold rise in Ab titer in HI or CF2.
Ab vs S antigen- current infection
Ab Vs V antigen- past infection
Treatment
Symptomatic management
Prevention
live attenuated vaccine, used with measles and rubella virus vaccines (MMR)
Not a part of universal immunization programme.

8. PARAMYXOVIRUSES: PARAINFLUENZA VIRUS
Surface spikes: H & N same spike, fusion on different spike
Both humans and animals infected
Four serotypes: 1, 2, 3 & 4
MOT: respiratory droplet
The infection is acquired through inhalation of infected droplet nuclei or
directly through contact with infected secretions. The incubation period is
generally 2-6 days
Presentation:
Parainfluenza 1, 2, 3: laryngotracheobronchitis (croup)
Subglottal swelling
Seal bark” cough
Parainfluenza 4: mild URTI

9. PARAMYXOVIRUSES: PARAINFLUENZA VIRUS
Diagnosis
direct demonstration- immunofluorescence ELISA 1.
isolation –primary human or monkey kidney cells continous cell lines(H292)2.
haemadsorption of guinea pig RBC
Serology- CFT, ELISA3.
RT-PCR4.
Treatment
Nebulized cold
Hot steam

10. PARAMYXOVIRUSES: RESPIRATORY SYNCYTICAL
VIRUS (RSV)
Most important cause of pneumonia and bronchiolitis in
infants
Fusion proteins- syncytia formation
Humans and chimpanzees- natural host
2 serotype: A & B
MOT: respiratory droplet
Clinical
infants- bronchiolitis, pneumonia1.
young children- otitis media2.
older children and adults common cold3.

11. PARAMYXOVIRUSES: RESPIRATORY SYNCYTICAL
VIRUS (RSV)
Diagnosis: immunofluorescence
Isolation in cell culture- + CPE
serology
RT-PCR
Treatment
Aerosolized Ribavirin
Ribavirin + hyperimmune globulins
Prevention
NO VACCINE
Palivizumab-prophylaxis, monoclonal ab vs. fusion protein

12. FILOVIRUSES
A-MARBURG
B-EBOLA
Illness is characterized by the rapid onset of fever, malaise, muscle pain, headache, and the inflammation the pharynx.
Six days following vomiting and bloody diarrhea. individuals may develop maculopapular rash with bleeding at needle sites and
bodily orifices.
Bleeding (Platelet dysfunction - abnormalities of coagulation, DIC formation)- internal bleeding to start with, then from
every orifice of body, oven from EYES.
Necrosis of liver, spleen, lungs & lymph nodes.- giving their own symptoms.
Attack on collagen & cartilage.
Pharyngitis, cough, dyspnoea, abd.pain.
Multi organ failure
Patients look like zombie.
Irritability amnesia. control of higher centers is lost
Haematamasis along with pieces of intestines
Filoviruses have very special affinity for Testes (orchitis) & ovaries (ovaritis)
Death in 7 to 15 days.

13. FILOVIRUSES
Transmission
The disease is spread through bodily fluids, including blood, excrement, saliva, and vomit.
Needles - was commonest cause in African Hospitals.
Rarely it is S.T.D.
Diagnosis
Serology using Musoke antibodies.
- Marburg-Musoke
-E. Sudan-Boniface 76
-E. Zaire-Mayinga
Microscopy
G.pig innoculation-orchitis & ovaritis & large cosinophilic cytoplasmic inclusion bodies.(Ebola)
ELISA or RIA
Treatment
No antiviral meds have proved effective
Prevention
rVSV – ZEBOV vaccine (vaccine for Ebola virus)

14. Transmission
Rodent-Rodent
Horizontal (aerosolized urine, faeces, saliva, bites)
Rodent - Human
Aerosolized secreta
inoculation via cuts, bites
contaminated fomites, food
Rodent consumption
Human-Human
contaminated secretions, sexual
Inoculation
ARENAVIRUSES

15. ARENAVIRUSES
Treatment
Supportive
Immunotherapy
Decreases mortality rate from 165%-1% in Janin VHF NB: 10% develop a neurological
syndrome 4-6 water Unsuccessful in Lassa Fever
Ribavirin
Must be administered IV and early (within 6 days)
Decreases mortality from 55%-5% in Lassa Fever 30mg/kg LD
Then 15mg/kg 4 hrs for 4 days
Then 7.5mg/kg 8hrs for 6 days
Should be considered in any serious arenavirus infection
Prevention & Control
Interrupt transmission
Rodent to human ep. Rodent control in BH
Human to human
Specimens to Laboratory workers
Prophylaxis
Close contacts or possible bioterrorist exposures-should not be given ribavirin, but closely
monitored for fever. If fever confirmed, then ribavirin therapy should be began
expectantly

16. BUNYAVIRUSES
Bunyavirus, any virus belonging to the family Bunyaviridae.
a very large family
single-strand, enveloped RNA viruses (more than 300 viruses)
consists of five genera of viruses:
Orthobunyavirus,
Phlebovirus,
Nairovirus,
Hantavirus, and
Tospovirus (Tospoviruses infect only plants).
Most transmitted by arthropods (e.g., ticks, mosquitoes, and sand flies)
cause serious human disease, including certain types of viral hemorrhagic fever.
The name Bunyavirales derives from Bunyamwera where the original type
species Bunyamwera orthobunyavirus was first discovered.
Ellioviricetes is named in honor of late virologist Richard M. Elliott for his early
work on bunyaviruses.
Bunyamwera is a town in Bundibugyo District, Uganda
Lower classifications: Orthohantavirus, Arenavirus, Lassa mammarenavirus, Lat
mammarenavirus
Higher classification: Ellioviricetes
Scientific name: Bunyavirales
Kingdom: Orthornavirae
Phylum: Negarnaviricota

17. BUNYAVIRUSES
Laboratory Diagnosis
by isolating the virus,
detecting RNA by RT-PCR, or
by showing a fourfold or greater rise in antibody titer between acute- and
convalescent-phase sera. .
The virus can be isolated from blood (or from brain, liver, and other organs
postmortem) during the viremic phase, but not usually after the third day of
fever.
Prevention
depends on the reservoir, amplifying hosts and how the viruses are transmitted,
i.e. the vector, whether ticks or mosquitoes and which animals are involved.
general hygiene
limiting contact with vector saliva, urine, feces, or bedding.
No licensed vaccine for bunyaviruses.

18. ORTHOMYXOVIRUSES
MOT:
aerosols of respiratory secretions
MEMBERS:
Influenzavirus A;
Influenzavirus B;
Influenzavirus C;
Thogotovirus which are tick-borne viruses, and
Isavirus which includes infectious salmon anemia virus
MORPHOLOGY:
ellipsoidal with particles 100–120 nm in diameter, or filamentous with
particles 80–100 nm in diameter and up to 20 µm long

19. ORTHOMYXOVIRUSES
Diagnosis
Virus growth in tissue cultures is detected by testing for hemadsorption:
red cells are added to the culture and adhere to virus budding from infected cells.
If the culture tests positive, serologic tests with specific antisera may be used to identify the
virus
Treatment
Amantadine and rimantadine are the only specific antiviral treatments available for influenza.
As in the case of prophylaxis, they are effective only against type A virus. When administration is
started early in the course of illness, drugs hasten the disappearance of fever and other
symptoms

20. RHABDOVIRUSES
GENUS:
Lyssavirus,
Vesiculovirus,
Ephemerovirus, and
Novirhabdovirus.
MOT:
transfer of saliva in a bite puncture wound.
MORPHOLOGY:
Common to all members of the family is a distinctive rod- or bullet-
shaped
PATHOGENESIS:
Rhabdoviruses generally enter via a bite or a wound infected with saliva.
Initially, the virus replicates at the site and then infects CNS tissue.
INCUBATION PERIOD:
6 days up to 1 year
average 30-70 days.
virus spreads rapidly via the nerves. CNS damage produces the
symptoms of disease.
Neurons accumulate ribonucleoprotein as intracytoplasmic inclusions.
Infection of the thalamus, hypothalamus or pons may occur.

21. RHABDOVIRUSES
DIAGNOSIS:
Unvaccinated persons are often negative for virus-neutralizing antibodies until late in the
course of disease. Virus isolation from saliva, positive immunofluorescent skin biopsies or virus
neutralizing antibody (from cerebrospinal fluid, or serum of a non-vaccinated patient)
TREATMENT:
Immediate First Aid: 1.
The virus remains localized at the site of the wound for a period of time. To help recovery,
wash the wound with soap and water as soon as possible, and follow with application of an
antiseptic.
Vaccine: 2.
Human Diploid Cell Vaccine:
HDCV should be given intramuscularly on days 0, 3, 7, 14, and 28, followed by a booster dose
on day 90.
nervous tissue vaccine, or duck embryo vaccine.
Human Rabies Immune Globulin.
PREVENTION:
Rabies is the only human disease that can be prevented by active immunization after
infection. This is possible due to the long incubation period of the virus.
Pre-Exposure Immunization: Anyone at high risk of contact with rabid animals may seek pre-
exposure prophylaxis.

22. THANK YOU!