In September 2013, Google announced Hummingbird the new revised engine that powers Google's search algorithm. It made search faster and more efficient - but it isn't a spam algorithm. Spam algorithms may plug into the overall algorithm, but Hummingbird is not a spam algorithm.
John Mueller of Google reiterated that the other day on Twitter saying "all our algorithms have to deal with spam, but Hummingbird isn't specifically for spam."
Google actually said something similar back in January 2014, that Hummingbird isn't to blame for your rankings drop. But Google also said Hummingbird did impact 90% of searches - so not sure many believed it had no impact.
Forum discussion at Twitter.