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)

TOTAL NAS Stockpile Requirements (in doses)

Adolescents and Adults:  51M
Children: 7M
= 58 million doses (5.8 million treatment courses)

TOTAL NAS Stockpile Requirements (in capsules)

Oseltamivir

75 mg: 41M
45 mg: 1.9M
30 mg: 7.3M

= 60.9 million capsules, or ‘dose equivalents’

Zanamivir

10 mg: 10.7M

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)

Page details

Date modified: