Parameter | Value | Description | Source |
---|---|---|---|
Duration of steady relationships | (1,2)1 | The duration of steady partnerships among Amsterdam MSM is reported to have an expected value of 1.5 years. | [20] |
Duration of the asymptomatic stage for the untreated | ℬ (26,0.5)2 | This stage lasts 13 years for people with a failed treatment or without any therapy. | |
Duration of the asymptomatic stage for the successfully treated | ℬ (52,0.5) | This stage lasts a mean value of 22.5 years for people with a successful treatment. And the duration is likely increased to a mean value of 26 years, thanks to the wide use of HAART and the improvement in the therapy regimens. | |
Frequency of sexual actions per year between steady partners (with infected at stage AP) | (30)3 | The frequency of either URAI or UIAI between steady partners is 15 per year. | [20] |
Frequency of sexual actions between steady partners in the first 3 months and the last 9 months, respectively (with infected at stage PI) | (8) &(22) | The PI stage lasts for about 3 months which is shorter than the 1-year time step, so that we divide individuals' first year of infection into two periods. Thus, the frequencies in these two periods adds up to 30. | [20] |
Transmission probability per URAI/UIAI4 act (with infected at stage PI) | 0.22/0.044 | ||
Transmission probability per URAI/UIAI act (with infected at stage AP) | 0.011/0.0022 | The infected in the last 9 months of PI contribute the same to transmission possibility per act as they do at stage AP. | |
Reduction in risky behavior along casual partnerships for men who have a steady partner | 0.84 | Men may make an agreement with his steady partner to be monogamous or to have no UAI outside the relationship, leading to less risky behavior. | see Sec. 2 in [20] |
Moderate (default) treatment-induced infectivity reduction factor5 | (0.1,0.5)6 | ART can moderately reduce transmission probability by 50-90%. | [32] |
Optimistic treatment-induced infectivity reduction factor | (0.01,0.1) | ART can optimistically reduce transmission probability by 90-100%. | [32] |
Initial population size | 2299 | People involved in all substudies add up to 2299. | [22] |
The power-law degree distribution's exponent γ in this study | 1.6 | MSM population follows a power-law degree distribution with a value of γ in the interval between 1.5 and 2. | [17] |
The power-law degree distribution's maximum degree kmax | 200 | We assume so. | |
The fraction of vertices with a degree of 0 | 0.01 | We assume that a small portion in a population not having any contact. |