Background Hepatitis C virus (HCV) testing and counseling have the potential for impacting individual behaviour and transmission dynamics at the population level. Evidence of the impact of HCV-positive status notification on injection risk reduction is limited. The objective of our study was to (1) assess drug and alcohol use and injection risk behaviors following notification; (2) to compare behaviour change in people who inject drugs (PWID) who received a positive test result and those who remained negative; and (3) to assess the effect of age on risk behavior. Methods Data from the InC3 Study were analyzed. Participants initially HCV seronegative were followed prospectively with periodic HCV blood testing and post-test disclosure and interview-administered questionnaires assessing drug use and injection behaviours. Multivariable generalized estimating equations were used to assess behavioral changes over time. Results Notification of a HCV positive test was independently associated with a small increase in alcohol use relative to notification of a negative test. No significant differences in post-notification injection drug use, receptive sharing of ancillary injecting equipment and syringe borrowing post-notification were observed between diagnosis groups. Younger PWID receiving a positive HCV test notification demonstrated a significant increase in subsequent alcohol use compared with younger HCV negative. Conclusion PWID receiving a HCV positive notification increased frequency of alcohol use post-notification, whilst no reduction in injection drug use behaviors was observed between notification groups. These findings underscore the need to develop novel communication strategies during post-test notification to improve their impact on subsequent alcohol use and risk behaviors.

Infection of molluscs by digenean trematode parasites typically results in the repression of reproduction -the so-called parasitic castration. This is known to occur by altering the expression of a range of host neuropeptide genes. Here we analyse the expression levels of 10 members of POU, Pax, Sox and Hox transcription factor gene families, along with genes encoding FMRFamide, prohormone convertase and b-tubulin, in the brain ganglia of actively reproducing (summer), non-reproducing (winter) and infected Haliotis asinina (a vetigastropod mollusc). A number of the regulatory genes are differentially expressed in parasitised H. asinina, but in only a few cases do expression patterns in infected animals match those occurring in animals where reproduction is normally repressed.