RNA viruses- Orthomyxoviridae (Influenza), Paramyoxoviridae and Rhabdoviridae, coronaviridae

family Orthomyoxoviridae

influenza type a

influenza type b

influenza type c

Influenza Type A

80% of all infections

pandemics and epidemics

multiple subtypes (H1,2,3; N1,2,3)

Can infect humans, avian, swine

Influenza type B

causes 20 % of all infections

epidemic but less severe

human infection only

influenza type c

rare, human infection only

characteristics of Orthomyxoviridae

spherical, enveloped, negative- ssRNA

8 genes

peplomers associated with Hemagglutinin (H#) and Neuraminidase (N#)

Hemagglutinin in influenza viruses is important for

virus entry

neuraminidase in influenza viruses is important for

virus exit/release from cells

antigenic drift

very small changes occur in the virus RNA over time that make the H and N proteins different

Antigenic shift

reassortment

2 viruses infect the same cell and a mix of the viruses is made

transmission of Orthomyxoviridae-influenza

inhalation of aerosol droplet

hand to mucous membrane

symptoms of Orthomyxoviridae-influenza

target respiratory epithelial cells

high fever, headache, myalgia, coryza, pharyngeal pain, shortness of breath, coughing, bronchitis

pneumonia as a secondary bacterial infection in immunocompromised patients

prevention and treatment for Orthomyoxoviridae-Influenza

Tri- or Quad-valent vaccination

Tamiflu within the first 48 hours of symptoms

Paramyoxoviridae family includes

Human parainfluenza virus 1-4

Mumps

Measles

Respiratory Syncytial virus

Human metapneumovirus

Paramyoxoviridae structure

enveloped nucleus

+ssRNA strand

Human Parainfluenza virus 1&3 Genus

Respirovirus

Human parainfluenza virus 2&4 genus

rubulavirus

Human parainfluenza virus 1-2 in children

coup

upper respiratory infection

apnea

barking cough

human parainfluenza virus 3 in children under 2 years old

bronchiolitis

human parainfluenza virus 4 in children

less severe infections

less virulent

uncommonly detected in lab

Mumps Family and genus names

Paramyxoviridae, Rubulavirus

mumps has ___ genes

7

mumps infection symptoms

parotitis that progresses to mild viral meningitis

affects pancreas, joints, gonads

large bump on side of face due to swollen salivary glands

treatments for mumps

live-attenuated vaccine (MMR or MMRV)

Measles genus/family names

Paramyxoviridae/ Morbillivirus

measles has ___ genes

6

measles progression

fever, cough, runny nose, conjunctivitis

koplik spots 2-3 days post initial infection

red raised rash starting at hairline and spreading down body 3-5 days post initial infection

measles complications

pneumonia

subacute sclerosing panencephalitis

definition of R0

expected number of secondary cases after initial case

R0 for measles

11-18

Respiratory syncytial virus (RSV) family and genus names

Paramyxoviridae, Pneumovirus

RSV has ___ genes

11

RSV is a ____ respiratory infection for all ages

recurrent

the most common cause of respiratory disease in children <1 year old

RSV

symptoms of RSV

apnea

croup

bronchitis

bronchiolitis

pneumonia

treatments for RSV

monoclonal antibody treatment (synagis)

vaccine (ribavirin)

recombinant protein therapies

Rabies virus family and genus

Rhabdoviridae, Lyssavirus

rabies virus structure

enveloped

bullet-shaped virions

5 genes

rabies virus

zoonotic

transmitted through infected saliva by bites, contact of mucus membranes, human-human transplantation of affected body parts

causes encephalitis

Clinical phases of rabies

prodromal phase

furious phase

dumb phase

coma phase

prodromal phase of rabies

fever

nausea

vomiting

headache

fatigue

pain/burning/tingling at site of wound

not specific to rabies

furious phase of rabies

agitiation

disorientation

seizures

twitching

hydrophobia

dumb phase of rabies

paralyzed

disorientation

stupors

coma phase of rabies

severe neurological impairment loss of consciousness inability to respond

leads to death

diagnosis of rabies virus in animals

detection of viral antigen or nucleic acid from brain tissue of animal that bit

immunoflurescence

diagnosis of rabies in humans

detection of virus from saliva, serum, spinal fluid

skin biopsy for rabies antigen

treatment of rabies in humans

rabies immunoglobulin (HRIG) given by mg/kg of pt body weight

vaccination

supportive care

Milwaukee protocol

antiviral

interferon alpha

medically induced coma

ketamine given to stop viral replication

vaccine

steroids to stop brain inflammation

only had few successes

+ssRNA, enveloped mRNA can produce

proteins

conoronaviridae

severe acute respiratory syndrome corona virus-2 COVID-19

betacoronavirus family name

coronaviridae

Coronavirus symptoms

fever, chills, cough, shortness of breath, difficulty breathing, fatigue, muscle or body aches, headache, loss of taste/ smell, sore throat, congestion, nausea, vomiting, diarrhea, persistent pain or pressure in chest, confusion, bluish lips or face

comorbidity with highest chance of developing Coronavirus

cardiovascular disease

coronavirus progression past normal symptoms

stroke, clotting issues, vascular damage

transmission of Coronaviridae

aerosol respiratory droplets from person to person

healthcare workers easily infected

treatments for coronaviridae

quarantine

immunosuppressive agents

antivirals

plasma therapy

monoclonal antibody therapies

supportive care

vaccination

Severe Acute Respiratory Syndrome Corona Virus (SARS-CoV)

10% fatality rate

1st infection in Asia

13 genes

symptoms of SARS-CoV

high fever, headache, malaise, body aches, mild respiratory symptoms, some diarrhea

transmission of SARS-CoV

aerosol respiratory droplets person-to-person,

healthcare workers at severe risk of infection

treatments and prevention of SARS-CoV

quarantine

supportive care

experiment with anti-virals

Middle-East Respiratory Corona Virus (MERS-CoV)

36% fatality rate

1st infection in Saudi Arabia

10 genes

Symptoms of MERS-CoV

fever, dyspnea, nonproductive cough, chills/rigors, headache, myalgia, sore throat, coryza, productive cough, dizziness, nausea, vomiting, diarrhea, abdominal pain

MERS-CoV can progress to

leukopenia, lymphopenia, thrombocytopenia, elevated lactate dehydrogenase levels

Progressive pneumonitis, acute respiratory distress syndrome, refractory hypoxemia, respiratory failure, extrapulmonary complications, kidney injury, hypotension, hepatitis, septic shock

MERS-CoV transmission

camel to person via mucus membranes

person to person

healthcare workers problematic for acquisition of infection

Treatment/ prevention of MERS-CoV

supportive care

quarantine

experiment with anti-virals