Viral Respiratory Tract Infections

• What are the common causes of respiratory infections in healthy individuals?

  Acute respiratory viruses
• How many respiratory infections do young children experience annually?

  5 to 9 respiratory infections per year
• How many children under 5 years die from respiratory infections according to WHO?

  1. 5 million children
• What percentage of respiratory infections are caused by viruses?

  20% to 30%
• How far can a sneeze travel?

  Approximately 8 meters
• What are the common clinical presentations of respiratory viruses?

  • Onset 1-3 days after infection
  • Inflammation of nasal passages
  • Symptoms persist for about 1 week
  • Complications: Otitis media (30%), sinusitis (8%)
  • Severe infections in elderly, immunocompromised, asthma, COPD, CF
• When were seasonal coronaviruses discovered?

  1960s
• What are the names of the seasonal coronaviruses discovered in the 2000s?

  NL63 and HKU1
• What family do rhinoviruses belong to?

  Picornaviridae family
• How many species of rhinoviruses are there?

  Three species
• What is the structure of rhinoviruses?

  + ssRNA, acid-labile, 100 serotypes
• What is the size of rhinovirus capsid?

  Ø25-30nm
• What is the genome structure of rhinoviruses?

  Capsid consists of 60 copies of VP1-4
• What type of virus are coronaviruses?

  + ssRNA virus
• What is the size range of coronaviruses?

  80-100nm
• How do common cold coronaviruses differ in terms of patient demographics and clinical manifestations?

  Some are mild, others severe in vulnerable groups
• What are the symptoms of pharyngitis?

  Sore throat, fever, pharyngeal inflammation
• What percentage of pharyngitis cases are viral infections?

  25% to 45%
• What type of virus is adenovirus?

  ds DNA virus
• How many serotypes of adenoviruses are known?

  At least 60 serotypes
• What is the peak age for croup?

  2 years
• What are the symptoms of croup?

  Fever, rhinorrhoea, nonproductive cough
• What is the treatment for croup?

  Supportive treatment
• What is the incubation period for respiratory syncytial virus (RSV)?

  3 to 5 days
• What is the major complication of RSV in young children?

  Hospital admissions
• What is the treatment for RSV?

  Ribavirin
• What is the natural reservoir for influenza A viruses?

  Wild birds
• What are the four types of influenza virus?

  A, B, C, D
• What is the difference between antigenic shift and drift in influenza viruses?

  Shift involves reassortment; drift involves mutations
• What is the estimated number of deaths from the 1918 influenza pandemic?

  25-50 million
• What is the primary mode of transmission for avian influenza H5N1 to humans?

  Close contact with infected birds
• What is the fatality rate of SARS-CoV?

  1. 5%
• What are the clinical symptoms of MERS-CoV?

  Flu-like illness, dyspnoea, chest pain
• How many COVID-19 cases were reported globally as of November 10, 2022?

  777 million cases
• What is the role of seasonal coronaviruses?

  Causes cold-like symptoms
• What are the risk factors for complicated influenza?

  • Neurological conditions
  • Hepatic conditions
  • Renal conditions
  • Pulmonary conditions
  • Chronic cardiac conditions
  • Diabetes mellitus
  • Severe immunosuppression
  • Age >65 years
  • Children <6 months
  • Pregnancy (up to 2 weeks postpartum)
  • Morbid obesity (BMI≥40)
• What are the treatment options for influenza?

  • Amantadine: M2 proton channel blocker
  • Oseltamivir: Neuraminidase inhibitor
  • Zanamivir: Neuraminidase inhibitor
  • Peramivir: Neuraminidase inhibitor
  • Laninamivir: Neuraminidase inhibitor
  • Baloxavir: Polymerase inhibitor
  • Favipiravir: Polymerase inhibitor
• What are the types of influenza vaccines available for the 2023 to 2024 season?

  • Quadrivalent Influenza Vaccine (QIVe)
  • Live attenuated influenza vaccine (LAIV)
  • Sub-unit Tetra, Quadrivalent Influenza Vaccine (QIVe)
  • Cell-based Quadrivalent Influenza Vaccine (QIVc)
  • Recombinant Quadrivalent Influenza Vaccine (QIVr)
  • Adjuvanted Quadrivalent Influenza Vaccine (aQIV)
• What are the components of the quadrivalent flu vaccine?

  • Two influenza A variants (H1N1 and H3N2)
  • Two influenza B variants (Victoria and Yamagata)
• What are the symptoms and complications of influenza?

  • Systemic symptoms persist for 3 to 5 days
  • Risk factors for complications include:
  • Neurological conditions
  • Chronic diseases
  • Age extremes