Table 1 Injection drug use patterns and among women who inject drugs in Tijuana, Mexico, 2019 (N = 30)

Injection initiation

Influenced by others

Injection initiation was influenced by someone else, either by direct injection or exposure to others’ drug use

21 (70.0)

Not influenced by others

Injection initiation was not influenced by anyone else. Other factors such as the use of other drugs or key life events may instead play a larger role

9 (30.0)

Use of other drugs

Previous use of other drugs was mentioned in relation to the participants’ experience of beginning to inject drugs

10 (33.3)

Influenced by key life event/experience

Key life events or experiences, such as deportation, medical concerns, or the death of a family member, contributed to the participants’ initiation into injection drug use

10 (33.3)

Learned to inject by watching others

In order to learn to inject themselves, the participants watched and learned others’ injection techniques

14 (46.7)

Participants who know how to inject themselves

Inject themselves and are street-hit doctors

The participant describes themselves as a “street-hit doctor” (i.e., someone who assists others with injection on a regular basis, usually in exchange for money, drugs, or other compensation)

1 (3.3)

Inject themselves and occasionally help others

The participant helps others to inject, sometimes for compensation such as drugs or money

16 (53.3)

Inject themselves but do not help others

The participant injects themselves but not does help others to inject

7 (23.3)

Never have initiated someone

Of those that know how to inject themselves and others, the participant has never helped someone else to inject for the first time

12 (40.0)

Have initiated someone

The participant has helped someone else to inject for the first time

4 (13.3)

Participants who rely/get help from someone to inject

Have someone close and whom they trust to help them

The participant gets help from someone close to them, whom they trust, such as a friend, roommate, or intimate partner helps them to inject

10 (33.3)

Asks other PWID

The participant receives help from other PWID, for example, acquaintances but not necessarily someone they know well or trust

8 (26.7)

Ask anyone who is around

The participant asks for help from anyone who is around and might not know to inject drugs

1 (3.3)

Knows how to inject themselves but currently needs help occasionally

The participant knows how to inject and may have in the past injected themselves, but they currently rely on others for help injecting due to difficulties finding their veins, fear of getting wounds, or other health concerns

4 (13.3)

Relies on others to inject them but they help others

The participant relies on someone else to help them inject, often due to difficulties finding their own veins, and they also help others inject drugs

2 (6.7)