They don't have the nofollow tag on them. And yes they do affect rankings. They are outbound affiliate links and Google sniffs them instantly. Outbound links are valuable in terms of SEO but not the affiliate links.
Don't worry about them so much. Just build some quality backlinks to your website. Those hoplinks don't do much harm.
Keep nofollow tag to that affiliate link. Then the search engines will not follow them. Don't just fill your web page with affiliate links. Have a control over them.