High-risk sexual behaviour is that which puts the donor at risk of infectious diseases which may then be transmitted to the recipient/patient. This risk occurs because the donor themselves currently participate in high-risk behaviour, or currently have sex with someone from a high-risk background.
The aim is to reduce the risk of 'window period' transmissions, where a donor is infected with (for example) HIV, but the infection is too recent to be picked up by screening tests and the infection is passed to the patient. For this reason, donors who have participated in high risk sexual behaviour say over one year ago, but do not do so currently, should be allowed to donate.
There is no strict definition of what high-risk behaviour/background is, but it would include those who have unprotected vaginal or anal sex with multiple partners (with a higher risk in men who have sex with men), those who pay (or are paid) for sex, those from an geographical area with a very high prevalence of HIV, and those with other sexually transmitted diseases.
Unprotected sex within a monogamous relationship is not necessarily seen as high-risk behaviour, regardless of whether it is a male homosexual relationship or not, if both partners remain monogamous during a set time-frame.
Individual at Risk
Guidance at RECRUITMENT
Guidance at CT/WORK-UP
However, a donor identified to be engaging in high-risk sexual behaviour may be acceptable at the discretion of the requesting transplant centre.
Justification for guidance
With use of modern screening techniques, the risk of unintended transmission of an infectious disease is very small. Stem cell donors undergo in-depth medical and sexual health questionnaires, and will have a face-to-face interview with donor centre staff, allowing ample oppotunity to identify those donors at increased risk of contracting a window-period infection.
In many cases, the benefit to the recipient of receiving a donation with vastly outweigh the risk of transmission of an infectious agent.
For these reasons, the employment of fixed deferral periods for certain groups deemed to be at a higher risk of developing window period infection, particularly men who have had sex with men, is not recommended by the WMDA. However, many countries will have legislation governing such issues, and these must take precedent.