OBJECTIVE: To simulate the probability of HCV transmission from an HCV 
seropositive index patient to susceptible household contacts through non-sexual 
exposures.
METHODS: A modified Reed-Frost stochastic simulation model was used to assess 
the probability of HCV transmission from an HCV seropositive index patient to 
susceptible household contacts through non-sexual exposures. This mathematical 
model does not require the specification of infection onset times for 
individual, nor is it necessary to identify the chains of household infections. 
Therefore, this model can be used with serologic data on detected asymptomatic 
infections. The HCV serological data on 341 non-sexual household contacts of 86 
HCV seropositive index patients were used in this simulation study. The 
frequency distribution of HCV infection of susceptibles for each household size 
of 4-8 initial susceptibles was calculated. A maximum likelihood procedure was 
used to estimate the non-sexual household transmission parameter for HCV 
infection for the range of household sizes studied and was used in 1000 
stochastic iterations. The goodness-of-fit test was carried out to compare the 
observed proportions of households where HCV transmission occurred to one or 
more initial susceptible with mean expected simulated proportions of such 
households with varying sizes ranging from 4 to 8 initial susceptibles.
RESULTS: The maximum likelihood estimates (90% probability interval (PI)) of 
binomial probability of HCV transmission within households with varying number 
of initial susceptible non-sexual household contacts ranged from 0.248 (90%PI: 
0.031, 0.560) to 0.164 (90%PI: 0.011, 0.440) for household size of 4 and 8 
respectively. The χ(2) goodness-of-fit test of observed and mean expected 
simulated proportions of households wherein at least one of the susceptibles was 
infected revealed good fit for households of all sizes examined (P ≥ 0.96). In a 
household, the probability of HCV transmission from the index HCV seropositive 
patient to susceptible via non-sexual contacts tended to decrease linearly as 
the household size increased from four to seven.
CONCLUSION: Intra-household HCV transmission through non-sexual contacts may 
have substantial impact on HCV transmission and needs to be considered in an HCV 
control program.