ARCHIVED: Appendix 5: The Management of the National Antiviral Stockpile: Options Report - Calculations for National Antiviral Stockpile targets

Appendix 5:  Calculations for National Antiviral Stockpile Targets

Population of approximately 33 million people in Canada

• 29 million adolescents and adults (12+ years)
• 4 million children (1 to <12 years)

(Source:  Statistics Canada, 2008, Population Estimates (preliminary postcensus)

Planning Assumptions

• Projected attack rate (medium severity pandemic) – 35%
• Projected number of ill people seeking medical treatment for adults, adolescents and children is half of those who are ill – 17.5%

(Source:  Canadian Pandemic Influenza Plan for the Health Sector, 2006)

NAS Projected Targets

• Target stockpile composition is 80% oseltamivir and 20% zanamivir for those aged 7+
  • A standard treatment course for oseltamivir and zanamivir is equal to 10 doses.
• Amantadine (additional 10% of total stockpile amount) is used in combination with other antivirals in cases of severe illness
  • A standard treatment course for amantadine is equal to 10 capsules (200 mg x 5) for adults aged 10-64 (children aged 1-9 require smaller doses)

Adolescents and Adults (ages 12+)

29M x 17.5% = 5.1 million will need treatment
5.1M treatment courses = 51 million doses required

Stockpile Requirements:

51M doses x 0.8 = 40.8M doses oseltamivir (75mg)
51M doses x 0.2 = 10.2M doses zanamivir (10 mg)

Children (ages 1 - <12)

4M x 17.5% = .7 million will need treatment
.7 M treatment courses are calculated for children in the following way:

4M children consisting of (approximately):

• 1M children aged 1 to <4 (treatment of 10x30mg oseltamivir capsules)

1M x 17.5% = 178,000 will need treatment
178,000 treatment courses = 1.78 million doses required

• 1.1M children aged 4 to <7 (treatment of 10x45mg oseltamivir capsules)
  1.1M x 17.5% = 187,000 will need treatment
  187,000 treatment courses = 1.87 million doses required
• 1.98M children aged 7 to <12 (treatment of 20x30 mg oseltamivir capsules OR 10 doses zanamivir)
  1.98M x 17.5% = 346,500 will need treatment
  • 346,500 x 0.8 = 277,000 treatment courses = 2.77 million doses oseltamivir required
  • 346,500 x 0.2 = 69,000 treatment courses = .69 million doses zanamivir required

Amantadine Calculations for NAS:
5.8 million treatment courses in NAS x .10 = 580,000 amantadine courses needed

580,000 treatment courses = 5.8M capsules (or 2.9M ‘doses’ if 2 capsules taken at once)

Amantadine Calculations for NAS:
5.8 million treatment courses in NAS x .10 = 580,000 amantadine courses needed

580,000 treatment courses = 5.8M capsules (or 2.9M ‘doses’ if 2 capsules taken at once)