HCV Transmission and Tattoo Parlors

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HCV Transmission and Tattoo Parlors

• Is it cost-effective to regulate tattoo parlors
  to reduce the spread of HCV?
• At what prevalence level is it cost-effective?

2
HCV

• 3.1 of world infected with HCV
• 20 of recruits in Egypt
• Expected to kill more Americans than HIV
• Transmitted through blood
• Transfusions, sex, mother-child, unsterilized
  medical equipment, injection drug use,
• Most frequently through needle sharing(developed
  countries)
• Transfusion now screened
• What about tattooing?
• Conflicting data.

3
Model

• Compartmental infectious disease model
• With costly control
• Similar to HIV but
• HCV more infectious
• HCV infection less costly
• Considers both tattoo and non-tattoo modes of
  transmission
• Not additive

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States

• 3 health states
• S Susceptibles
• A Acute infection
• C Chronic infection
• 2 social states
• t visits tattoo parlors
• o doesnt
• 6 total states So,St,Ao,At,Co,Ct

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Non-tattooed population

• ?A, ?C death rates
• rAS, rAC, rCS transition rates
• ?S deathturning 50
• ? overall prevalence
• ? rate of non-tattoo transmission
• Time in years
• Population age 15-50

?s
So
rCS
rAS
??
rAC
Ao
Co
?A
?C
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• k flow of people turning 15
• g rate at which people not interested in
  tattoos
• ? annual rate of getting tattoos

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• ? P(infection infected equipment)
• ? P(equipment infected) ?f(?t)
• ? P(use of equipment on HCV person infects
  equipment)
• f(?t) P(use of equipment on HCV person)
• Typically equipment used 5 times before replaced
• f(?t) (1/5) ?i0..4 1-(1-?t)i

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?t(AtCt)/(StAtCt) ?(AoAtCoCt)/total
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Control

• Control is sterilization of equipment
• ? 0 (or close to)
• Time
• ? time of regulation
• T planning horizon (15 years in baseline)
• Discounting (3 in baseline)
• Outcomes
• ?(?,T) total discounted number of
  sterilizations
• I(?,T) total discounted number of infections

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Cost-effectiveness

• Cost
• ? cost of sterilization
• ? cost infection
• Not really accounting for health quality
• Regulate at time t2 versus t1
• Benefit/Cost ratio /
• BC(t1,t2) (I(t2,T)-I(t1,T))/(S(t2,T)-S(t1,T))
  ?/?

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Base Case
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Uncertainty in ???????
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Is a dynamic model needed?
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Conclusion and Discussion

• Regulating tattoo parlors is cheap and
  cost-effective
• Doesnt capture averted secondary infections
  beyond horizon
• More tattoos (?) may decrease BC
• Dynamic model crucial to capturing secondary
  infections
• Would an age structured model make sense?
• What about HIV?

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Next Time

• Network models the effect of reducing
  concurrency on HIV transmission

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