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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?. HCV. 3.1% of world infected with HCV 20% of recruits in Egypt Expected to kill more Americans than HIV Transmitted through blood - PowerPoint PPT Presentation
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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?
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.
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
States
• 3 health states– S = Susceptibles– A = Acute infection– C = Chronic infection
• 2 social states– t = visits tattoo parlors– o = doesn’t
• 6 total states: So,St,Ao,At,Co,Ct
Non-tattooed population
A, C death rates
• rAS, rAC, rCS transition rates
S death+turning 50
= overall prevalence rate of non-tattoo transmission
• Time in years• Population = age 15-50
So
Ao Co
s
rAS
rAC
rCS
A C
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s
• k = flow of people turning 15• g = rate at which people not interested in tattoos = annual rate of getting tattoos
= 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) ∑i=0..4 1-(1-t)i
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s
t=(At+Ct)/(St+At+Ct)=(Ao+At+Co+Ct)/total
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
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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Conclusion and Discussion
• Regulating tattoo parlors is cheap and cost-effective
• Doesn’t 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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