Influenza Virus Micro401 Case Study #5 Alvaro Gomez Sheila Laqui Jensen Lau November 8, 2007.
-
Upload
alberta-fox -
Category
Documents
-
view
213 -
download
0
Transcript of Influenza Virus Micro401 Case Study #5 Alvaro Gomez Sheila Laqui Jensen Lau November 8, 2007.
Influenza VirusMicro401 Case Study #5
Alvaro Gomez
Sheila Laqui
Jensen Lau
November 8, 2007
Case Study #5 - InfluenzaIn late December a 22 year old man suddenly experienced
flu-like symptoms.
Headache Myalgia Malaise Dry Cough Fever
Worsened Cough Nausea Vomiting
Initial Symptoms Later Symptoms
His family had experienced similar symptoms two weeks prior.
Influenza virus Background
(-)ss RNA virus Orthomyxoviridae family Influenza A & B are
Endemic - Winter,
peaks Dec - JanMc Queen Nancy, micro 401, Lect 5
Differential DiagnosisOther Flu-Like Symptoms
Respiratory Syncytial Virus (RSV) Meningitis Pneumonia Adenovirus Parainfluenza
www.cdc.gov
Molecular Lab Tests Viral Culture
Immunofluorescence (IF)
Enzyme Immunoassay (EIA)
Real-Time PCR (RT-PCR)
Hemagglutination inhibition (HI)Ellis, J, S. Rev, Med. Virol. Vol 12, 375-389 2002
Lab Tests - Viral CultureAdvantages
Disadvantages Whole Virus
Measured Virus recoverable
Requires Infectious Virus
Highly Skilled Technicians
Time (3-7days) Cost
Lab Tests - IFAdvantages
Disadvantages Time (2h-1day) Requires Intact
Cells Highly Skilled Specialized
equip. Cost
Lab Tests - EIAAdvantages
Disadvantages Time (15min-1day) High Throughput Low-Skill
No Virus Recoverable
Lab Tests - RT-PCRAdvantages
Disadvantages Sensitive Allows Further
Molecular Analysis High Throughput Time (1-2days)
Highly Skilled Specialized
Equip. Cost
Lab Tests - HIAdvantages
Disadvantages High Throughput Sensitive Specific Time (2 days) Cost
Retrospective Paired Samples
Needed
Tissue Test
Nasopharyngeal (Swab or Aspirate) Bronchoalveolar Lavage Serum (HI) Chest Radiography (Pneumonia) Lumbar Puncture (Meningitis)
Final Diagnosis Viral Culture (6 days results) IF (1 day) EIA (1 day) Lumbar Puncture negative for Meningitis X-ray scan negative for Pneumonia
Patient’s results came back positive for Influenza B antigens
Anti-Influenza Drugs Amantadine
Pre-exposure prophylaxis & treatment of influenza A
Blocks M2 proton channel Necessary for
uncoating
Influenza resistance detected in 2005
Zhuang, Xiaowei. “Zhuang Group – Cell Entry Project.” Cellular entry of viruses and non-viral gene delivery vectors. 18 October 2007. Harvard University. 6 November 2007. <http://zhuang.harvard.edu/cellentry.html>.
Bright, Rick, et. al. Adamantane Resistance Among Influenza A Viruses Isolated Early During the 2005-2006 Influenza Season in the United States . The Journal of the American Medical Association. 2006;295:(doi:10.1001/jama.295.8.joc60020). 6 November 2007. <jama.ama-assn.org/cgi/content/full/295.8.joc60020v1>.
Dimmock, N.J., et. al. Introduction to Modern Virology – 6th ed. Blackwell Publishing. Malden, MA. 2007.
Anti-Influenza Drugs NA Inhibitors
Zanamivir (Relenza®) & Oseltamivir (Tamiflu®) Pre-exposure prophylaxis & treatment of influenza A & B
“Flu Wiki.” Neuraminidase Inhibitors. 19 December 2006. Melanie Matson. 6 November 2007. <http://www.fluwikie.com/pmwiki.php?n=Consequences.NeuraminidaseInhibitors>.
Fiore, Anthony, et. al. “Morbidity and Mortality Weekly Report.” Prevention and Control of Influenza: Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2007 . 13 July 2007. Centers for Disease Control and Prevention. 1 November 2007. <http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5606a1.htm>.
Spread through large particle respiratory droplets & airborne transmission
Incubation period 1-4 days Adults infectious up to 5
days after illness onset Children infectious up to
10 days after illness onset
People at Risk People 65 years or older Children in general Adults & children with
chronic heart or lung diseases, diabetes, kidney disease or anemia
Immunocompromised individuals
Fiore, Anthony, et. al. “Morbidity and Mortality Weekly Report.” Prevention and Control of Influenza: Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2007. 13 July 2007. Centers for Disease Control and Prevention. 1 November 2007. <http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5606a1.htm>.
Transmission of Influenza
Genetic VariabilityAntigenic shift:Major change in the influenza
A virus subtypes HA and NA protein changes –
population has little immunity for mutant virus
Two Patterns of influenza A: Annual epidemics in most
countries Every 10-12 years-
extensive pandemics http://virology-online.com/viruses/Influenza.htm
Mc Queen NANCY, micro 401, Lec 5
How does the virus change?Antigenic Drift Produces new virus strains
not recognized by the body’s immune system
Occurs continuously over time
This “drift” creates new virus strains that the immune system does not recognize or has little or no resistance for
http://virology-online.com/viruses/Influenza.htm
Mc Queen Nancy, micro 401, Lect 5
THANK YOU!!!