One way that Senegal maintains a low HIV prevalence is through conservative cultural norms that discourage sex outside of marriage[citation needed], limiting the number of sexual partners an average Senegalese person will have and thus limiting their chance of coming into contact with the virus. The government also passed legislation to make working closely with sex workers to ensure they get regular STI and HIV tests and treatment possible.[3] Senegal also has had huge public health campaigns to promote condom usage. Senegalese hospitals have also had their blood supplies screened for syphilis and hepatitis since 1970, leading to the removal of some blood contaminated with HIV before an HIV antibody test was created.