Tsai notes that while "some drug addicts are really particular about the length or flexibility of needles, and there is even brand loyalty--they won't use any other hypodermic gear if it's not that brand--many addicts know pathetically little about avoiding HIV infection.
因此，「不同長短、不同柔軟度的針頭，對於毒癮患者來說，其實是相當講究的，甚至產生了針具的品牌忠誠，非特定牌子的針具不用，」蔡佩玲說，「但相對於這種講究，部份毒癮患者對於避免愛滋病感染的知識卻貧乏的可憐。