IDBR - Respiratory Viral infections Flashcards
Describe the types of Influenza virus?
Flu A, B, C. Flu A: 16 HA types, 9N types, responsible for seasonal drift. Huge reservoir in fowl Causes disease in poultry Point Mutations in neuraminidase lead to resistance to NAIs
Minor complications of Influenza?
- Croup
- Bronchiolitis
- Asthma exacerbation
- OM
- Sinusitis/parotitis
Groups at risk for complications of Influenza?
45 y/o with CC: fever, diarrhea, myalgia, sore throat, and dyspnea. Hypotensive and hypoxemic. CBC shows mild leukopenia, everything else normal. 3 days prior he was inspecting poultry operations in Jiangsu, China.
- H1N1?
- H3N2
- H5N1
- H7N9?
- Influenza B?
H7N9
Name the influenza A viruses that infects human
Basics of H7N9?
- Avian to human transmission
- some intrinsic and some emergent oseltamivir resistance
- 22% case fatality
basics of seasonal influenza transmission?
5 days ago (january), healthy 25 year old female developed fever, myalgia, sore throat, and malaise, dx with influenza with slow improvement. 16 hours ago, she becomes hypotensive, diarrhea, abdominal pain, with a diffuse erythematous rash.
On exam, slow to respond, diffuse, rales, mild non-focal abdominal tenderness. CXR diffuse infiltrates, WBC 5500 (60% poly,30% bands). Platelets 40K, creatinine 1.9, AST and ALT 2x normal, with normal ammonia level. Erythoderma on exam.
What is the most likely cause of this influenza complication?
- Reyes syndrome
- Staph aureus pneumonia with TSS
- GN sepsis with ARDS
- Pneumococcal meningitis
- Viral encephalitis
Staph Aureus with Toxic Shock Syndrome
what are the severe complications of influenza?
18 yo HS student with F/C/cough, myalgia in January. Given azithromycin, rest, NSAIDs, but fever, cough, continue becomes progressively dyspneic and weak. T39, P150, RR24-30, BP 120/50. Crackles throughout base and an S3 gallop. Influenza PCR positive. WBC 9K, creatinine 1.9, BNP high, CXR shows diffuse b/l infiltrates and cardiomegaly. Requires V-A ECMO.
What is the most likely cause of this influenza complication?
- pneumococcal PNA
- Staph aureus pneumonia w/purulent pericarditis
- Influenza cardiomyopathy
- MIS-C due to recent COVID infection
- Viral pericarditis with effusion
- PE due to hypercoaguable state
influenza cardiomyopathy
what are the non-respiratory complications of influenza?
20 year old woman s/p 18 days from HSCT in january, engrafted 3 days ago. Develops fever, hypoxemia, b/l lung infiltrates, and requires intubation. Nasal swab is negative by rapid test for influenza. Which of the following is the next best action?
- Do not initiate anti-influenza therapy due to rapid test. The timing suggests idiopathic pulmonary syndrome (engraftment)
- Initiate anti-influenza therapy empirically and send tracheal aspirate/BAL for influenza PCR?
- Send IgG and IgM for influenza
- Send RSV EIA and initiate empiric IV ribavirin
initiate anti-influenza therapy empirically and send tracheal aspirate or BAL for influenza PCR
how do you make the diagnosis of influenza? serology?
clinical dx as good as rapid PCR in high peak seasons!
influenza in transplant patients pearls?
32 y/o nurse, 34 weeks pregnant, during influenza season. Gets symptoms, seen at urgent care where rapid test positive, and given Azithromycin. 72 hours later, gets fever, tachypnea, decreased UO with CXR showing bl hazy infiltrates. She’s hospitalized.
what is the correct statement?
- she should get supportive care only since >48 hours
- Oseltamivir is relatively CI in pregnancy
- Zanamaivr is clearly preferred b/c of low systemic absorption
- Oseltamivir should be started ASAP
Oseltamavir should be started ASAP
what are the recommended medications for influenza treatment? prophylaxis?
- oseltamivir, zanamivir, baloxavir
- Empiric treatment for pregnant women and up to 2 weeks postpartum
- duration 5 days
- initiating tx within 2 days of symptoms results in M&M reduction
- Pregnancy should not be CI to oral oseltamivir or zanamivir use
Basics of baloxavir?
- cap -dependent polymerase inhibitor
- non-inferior to oseltamivir in 2 phase 3 studies
- superior for influenza b in patients with risk factors
- shorter duration of shedding
- resistance mutations emerge on tx in 10-20% of patients.
basics of antiviral prophylaxis?
Influenza Anti-viral pearls?
Zanamivir
ACIP recommends routine influenza vaccinations for? what type?
- all persons aged 6 months or older
- QIIV (quadrivalent Inactivated influenza vaccine) - H1N1, H3N2, B yamagata, B Victoria
vaccine pearls to tell patients?
- efficacy varies by year and group
- generally 50-70%, lower in special pop
- In HIV patients, response related to CD4 count
- Major mismatch occurs at least every 10 years.
- Can be given in patients with egg allergies
- Recombinant influenza vaccine (RIV, FluBloc) is available and contains no egg protein
- Consultation with allergist to egg no longer recommended
- Anaphylaxis to flu vaccine is still a CI.
*
describe the newer flu vaccines?
In patients hospitalized with CAP, what is the top 3 viral pathogens in >65 years old.
- Human rhinovirus
- influenza A or B
- Strep pneumo
what findings suggest viral vs bacterial CAP?
What are the respiratory viruses in HSC transplant patients to watch out for? Tx?
18 year old presents in march in portland OR in congregate facilitywith several days of fever, cough, chest pain, tachypnea hypoxia, and conjunctivitis with WBC 3.0, platelets 160, CRP 2.5, AST 75. 2 days later, in the ICU. You suspect?
- Pneumococcal PNA
- borrelia hermsii with ARDS
- Adenovirus
- Hantavirus pulmonary syndrome
- MRSA pneumonia
- Group A strep with TSS
- Adenovirus.
- Pneumococcal - can’t explain conjunctivitis
- Hantavirus - no exposure
- no MRSA -absence of effusion
- no TSS
basics of Adenovirus?
basics of adenovirus in transplant patients?
71 y/o M w/COPD MI admitted in January for progressive dyspnea, cough, tachypnea, low grade fever, rhinitis. Spending more time with young child who has bronchiolitis. CXR shows bilateral perihilar infiltrates c/w pna. The recommended strategy pending lab results regarding isolation should be:
- put him in a regular 2 bedded room with standard precautions
- Put him in a single room with standard precautions
- put him in a single room with contact/droplet precautions
- put him in an airborne isolation room with airborne isolation
Put him in a single room with contact/droplet precautions
Multiplex PCR of nasal swab shows RSV, patient has CXR showing bilateral infiltrates. Which of the following is correct?
- RSV is an incidental finding which may cause URI symptoms
- RSV likely accounts for an infiltrate. He should be immediately started on palivizumab (synagis) and ribavirin.
- RSV likely accounts for infiltrate. Support care is appropriate
- He has a high risk of CAP and should be started on vanc/zosyn.
RSV likely accounts for infiltrate. Supportive care is appropriate.
basics of RMSV, hMPV in older adults?
basics of RSV?
- Incubation period 2-8 days
- Diagnosed by PCR
- No indication for palivizumab
- inhaled ribavarin controversial
- Oral ribavarin appears equally effective.
basics of human metapneumovirus?
basics of parainfluenza virus?
basics of MERs - coronavirus?
35 y/o man admitted to the ICU in july with fever, dyspnea, hypotension. 5 days PTA c/o flu. Recently camped in yosemite national park which has rodent infestation issues. Has a parakeet, dogs, kittens, owns a hot tube. 2 kids in daycare have a URI. Labs HCT 52, WBC 6.0 (20% bands, 45% poly,s 2+ atypical lymphs), platelets 90K
AST 105, PT 18, PTT 25, CXR shows bilteral infiltrates leading to white out. which of the following is mostly likely cause?
- Adenovirus
- influenza
- anthrax
- coxiella burnetii
- hantavirus pulmonary syndrome
answer is hantavirus.
basics of hantavirus pulmonary syndrome?
what are the stages of hantvavirus pulmonary syndrome?
what are the critical clues to hantapulmonary syndrome?
pneumonia with ARDS +
