"Trich," caused by the parasite Trichomonas vaginalis, affects some 3.7 million Americans, but 70 percent of people infected with it never show any symptoms of the disease, according to the Centers for Disease Control and Prevention.
 

Researchers from the University of California-Los Angeles and the University of Sassari in Italy found that the T. vaginalis parasite secretes a protein that promotes inflammation in the prostate and the growth of cancerous prostate cells, the LiveScience Website reports.
 

"This study suggests a possible way the parasite Trichomonas vaginalis could encourage prostate cancer cells to grow and develop more quickly," said Nicola Smith, health information officer at Cancer Research UK, told the BBC.

Editor's Note: The One Thing You Should Do for Your Prostate Every Morning
 

The new study, published in the Proceedings of the National Academy of Sciences, backs an earlier study from 2009 that found that men with antibodies to T. vaginalis were twice as likely to develop an aggressive form of prostate cancer that spread outside the prostate.
 

"Together, these data indicate that chronic T. vaginalis infections may result in … inflammation and cell proliferation, thus triggering pathways that contribute to the promotion and progression of prostate cancer," said the researchers who conducted the latest study, which involved laboratory research.
 

Trichomoniasis is easily cured with antibiotics, but many infected people never get treatment. Some men with trich feel an itching or irritation inside the penis, a burning sensation after urination or ejaculation, or some discharge, according to the CDC. Women with the infection may notice itching, burning, redness, soreness, discomfort with urination, or a discharge.
 

Prostate cancer is the second-most common cancer among men in the United States, according to the American Cancer Society, and almost 30,000 American men die each year from the disease.