Injection

Injection

name: str

Name of interaction in the params file.

get_num_acts(model, rel) classmethod

Simulate random transmission of HIV between two PWID agents through injection.

Parameters:

Name	Type	Description	Default
model	model.TITAN	The currently running model	required
rel	agent.Relationship	The relationship in which the interaction is happening	required

Source code in titan/interactions/injection.py

@classmethod
def get_num_acts(cls, model: "model.TITAN", rel: "agent.Relationship") -> int:
    """
    Simulate random transmission of HIV between two PWID agents through injection.

    args:
        model: The currently running model
        rel: The relationship in which the interaction is happening
    """

    # make sure both agents have Inj drug type, should only be possible for
    # the relationship to have the injection interaction type if both agents PWID
    assert rel.agent1.drug_type == "Inj"
    assert rel.agent2.drug_type == "Inj"

    agent_params = (
        rel.agent1.location.params.demographics[rel.agent1.race]
        .sex_type[rel.agent1.sex_type]
        .injection
    )
    partner_params = (
        rel.agent2.location.params.demographics[rel.agent2.race]
        .sex_type[rel.agent2.sex_type]
        .injection
    )

    mean_num_acts = (
        min(agent_params.num_acts, partner_params.num_acts)
        * model.calibration.injection.act
    )
    share_acts = poisson(model.np_random, mean_num_acts)

    if share_acts < 1:
        return 0

    if (
        rel.agent1.syringe_services.active or rel.agent2.syringe_services.active  # type: ignore[attr-defined]
    ):  # syringe services program risk
        p_unsafe_injection = features.SyringeServices.enrolled_risk
    else:
        p_unsafe_injection = agent_params.unsafe_prob

    # diagnosis risk reduction
    if rel.agent1.hiv.dx or rel.agent1.hiv.dx:  # type: ignore[attr-defined]
        p_unsafe_injection *= 1 - model.params.hiv.dx.risk_reduction.injection

    for n in range(share_acts):
        if model.run_random.random() > p_unsafe_injection:
            share_acts -= 1

    return share_acts