Airborne Viral diseases Flashcards
Influenza, covid-19, smallpox, chickenpox, shingles, measles, rubella
CA - Influenza
Influenza virus
- enveloped, 8 RNA segments, spikes
Influenza types A,B,C,D - based on capsid protein
VF - influenza
- protein spikes:
HA (H) spikes
NA (N) spikes - antigenic variation - involving genetic recombination & formation of hybrid viruses
Sxs - influenza
Acute sxs
Chills, fever, headache, muscle aches
Prevention - influenza
Multivalent vaccine, nasal spray flu vaccine (it is a live, weakened virus)
Pre-disposing factors - influenza
Very young & elderly
Reservoirs - influenza
1 - human
2 - birds, farm animals
Transmission - influenza
Droplet & airborne transmission
Treatment - influenza
Antivirals
Diagnosis - influenza
Difficult to diagnose bc of acute sxs
Misc - influenza
Type A - most caused flu pandemic
Spanish flu pandemic killed more than 20 million people (in 1918)
CA - covid 19
SARS-CoV-2
- single strand RNA, enveloped, spikes
VF - covid
- Ability to multiple in ciliated epithelial cells of respiratory tract
- has spikes !
Reservoir - Covid
1- animals (bats!!!, intermediate animal hosts)
2- humans
Transmission - covid
Zoonotic, droplet transmission, fomites, airborne
SARS - covid
Severe acute respiratory syndrome
MERS - covid
Middle Eastern respiratory syndrome
Prevention - covid
Practice good respiratory hygiene (wash hands, maintain social distancing)
- vaccines !
Incubation period - covid
Average 4-5 days
Up to 14 days
Sxs - covid
- fever, headache, fatigue, dry cough, loss of taste and smell
- shortness of breathe —> respiratory failure
- septic shock —> multiple organ failure (in severe cases)
Pre-disposing factors - covid
Crowds, poor health
Diagnosis - covid
PCR & antigen, antibody tests
Treatment - covid
- 80% needs no treatment
- severe cases ; antivirals, steroids, antibodies
CA - smallpox
AKA Variola
Variola virus
- enveloped, DNA virus
Variola major - 20-60% mortality
Variola minor - <1% mortality
VF - smallpox
Produces protein called SPICE (Small pox inhibitor of compliment enzymes)
What does SPICE do? It inhibits compliment protein activation
Transmission - smallpox
Airborne
Sxs - smallpox
Viremia: skin infections & pus-filled lesions
Diagnosis - smallpox
Serological tests
Prevention - smallpox
Vaccine= live Vaccinia virus (cowpox virus)
Has mild to sever side effects
Misc - smallpox
- highly infectious
- potential for bioterrorism
- completely eradicated from human population
CA - chickenpox
Varicella Zoster virus
- herpesviridae family
- HHV-3
- enveloped DNA
VF - chickenpox
- multiplies in epithelial cells of upper respiratory tract —> viremia —> targets skin —> rash
- virus becomes latent in CNS (hides in nervous system)
Reservoir - chickenpox
Humans
Transmission - chickenpox
Droplet
Sxs - chickenpox
Fever, headache, itchy raised rash, fluid filled vesicles on face, chest, and back
Diagnosis - chickenpox
Based on type of rash & location
Predisposing factors - chickenpox
Daycare centers
Prevention - chickpox
Varicella vaccine - live attenuated vaccine
What is called when scab falls off? - chickenpox
Pockmark
Incubation period - chickenpox
10-21 days
Treatment - chickenpox
- Calamine lotion to relieve itching
- non-aspirin medication in children (otherwise may get brain dysfunction)
Chickenpox is AKA
Varicella
Shingles is AKA
Herpes zoster
CA - shingles
Reactivation of the latent varicella zoster virus
Misc - shingles
Reactivation - virus travels along sensory nerves of the skin
- limited to one side of the body
Sxs - shingles
- band-like rash - fluid filled raised rash
- very painful (post-hermetic neuralgia)
- blisters scab in 7-10 days
Pre-disposing factors - shingles
Elderly & stress —> weak immune system —> Reactivation of latent varicella zoster virus
Diagnosis - shingles
Based on sxs (type of rash & location)
Prevention - shingles
Via shingles/zoster vaccine called Shingrix
Treatment - shingles
Antiviral drugs may relieve/supress sxs
(Only management)
EX. Acyclovir
Measles AKA
Rubeola
(AKA ruby, the mom)
CA - measles
Rubeola virus
- enveloped, spikes, RNA virus
- antigenic stable (there’s a vaccine, not like influenza)
VF - measles
H & F protein spikes allow for attachment
Reservoir - measles
Humans
Transmission - measles
Droplet
- virus enter blood stream (Viremia) which targets the skin —> rash
Incubation period - measles
10-21 days
Sxs - measles
- HIGH FEVER, runny nose, dry cough, CONJUNCTIVITIS
- koplik spots (husband) - clustered white lesions on oral mucosal (inside cheeks)
- MERGING MACULAR rash
- starts on face, neck, trunk, extremities
Diagnosis - measles
Based on sxs (-koplik spots in mouth and type of rash + location) ; serological tests
Treatment - measles
No Rx available
- supportive care only
Prevention - measles
- Monovalent measles vaccine (contains a single strain of pathogen)
- MMR vaccine
Misc - measles
- encephalitis in 1 out of 1000 cases
- viral pneumonia aka atypical pneumonia
rubella AKA as
German measles OR 3 day measles
(Aka Ruby’s daughter)
CA - rubella
Rubella virus
- non-enveloped, NO spikes, RNA virus
Reservoir - rubella
Humans
Transmission - rubella
Droplet
Incubation period - rubella
2 - 3 weeks
Sxs - rubella
- MILD/NO FEVER, runny nose, cough, CONJUNCTIVITIS
- DISCRETE MACULAR rash (3-5 days) starts on face, neck, trunk, extremities
Diagnosis - rubella
Based on sxs(discrete macular rash); serology
Treatment - rubella
No specific Rx available
- supportive care only
Prevention - rubella
MMR vaccine
Congenital Rubella Syndrome
- maternal infection during 1st trimester
- fetal damage
- baby will have cataracts, cardiac abnormalities, deafness, intellectual disabilities
- 15% mortality within 1st year of life
Misc - rubella
Infections confer for life long immunity
