A retractable needle device selectively attachable to a fluid collection or infusion device having a forwardly facing connector (22, 23), the retractable needle device comprising: a housing having a rearwardly facing engagement member attachable to the forwardly facing connector (22, 23), a forwardly facing slide support surface having a first opening in fluid communication with the engagement member and a second opening laterally spaced apart from the first opening, the second opening communicating with a rearwardly projecting needle retraction cavity, a first pinch surface at the housing, and a fluid path between the engagement member and the first opening; the retractable needle device comprising: a needle; a needle alignment member comprising a needle tube and a second pinch surface; a needle retraction mechanism comprising a needle holder, the needle holder positioned within the needle tube and configured to bias the needle rearwardly; and an annular fluid seal seated in the first opening and providing fluid communication between the housing and the needle holder; wherein the first and second pinch surfaces (35, 56) are configured so that a pinching force applied between them will cause the housing to move laterally in relation to the needle alignment member from a first position, wherein the needle is aligned with and coaxial to the first opening, to a second position, wherein the needle is aligned with and coaxial to the second opening so that the needle retraction mechanism biases the needle into the retraction cavity. a housing having a rearwardly facing engagement member attachable to the forwardly facing connector (22, 23), a forwardly facing slide support surface having a first opening in fluid communication with the engagement member and a second opening laterally spaced apart from the first opening, the second opening communicating with a rearwardly projecting needle retraction cavity, a first pinch surface at the housing, and a fluid path between the engagement member and the first opening; the retractable needle device comprising: a needle; a needle alignment member comprising a needle tube and a second pinch surface; a needle retraction mechanism comprising a needle holder, the needle holder positioned within the needle tube and configured to bias the needle rearwardly; and an annular fluid seal seated in the first opening and providing fluid communication between the housing and the needle holder; wherein the first and second pinch surfaces (35, 56) are configured so that a pinching force applied between them will cause the housing to move laterally in relation to the needle alignment member from a first position, wherein the needle is aligned with and coaxial to the first opening, to a second position, wherein the needle is aligned with and coaxial to the second opening so that the needle retraction mechanism biases the needle into the retraction cavity. a needle; a needle alignment member comprising a needle tube and a second pinch surface; a needle retraction mechanism comprising a needle holder, the needle holder positioned within the needle tube and configured to bias the needle rearwardly; and an annular fluid seal seated in the first opening and providing fluid communication between the housing and the needle holder; wherein the first and second pinch surfaces (35, 56) are configured so that a pinching force applied between them will cause the housing to move laterally in relation to the needle alignment member from a first position, wherein the needle is aligned with and coaxial to the first opening, to a second position, wherein the needle is aligned with and coaxial to the second opening so that the needle retraction mechanism biases the needle into the retraction cavity.