1 / 10A scientific research paper published in the World Journal of Men's Health observed the difference in tissue composition between men who had contracted the disease and men who had not.2 / 10COVID can cause damage to blood vessels, which in turn can damage parts of the body the vessels supply, including the sponge-like tissue in the penis.3 / 10Ranjith Ramasamy, associate professor and director of the University of Miami Miller School of Medicine's reproductive urology programme, led the study.4 / 10He said that erectile dysfunction 'could be an adverse effect of the virus'.5 / 10The study focused on four men who were having penile prosthesis surgery for erectile dysfunction.6 / 10Two had suffered with COVID-19, and two had not. They were all aged between 65 and 71 and of Hispanic ethnicity.7 / 10The pair who had the coronavirus were infected six and eight months before the observations, with one hospitalised for the virus and the other not.8 / 10Neither had a history of erectile dysfunction. Remnants of the virus were observed in the penis tissue of the two COVID-positive men.9 / 10The damage COVID causes to blood vessels is known as endothelial dysfunction. Dr Ramasamy said: 'In our pilot study, we found that men who previously did not complain of ED [erectile dysfunction] developed pretty severe ED after the onset of COVID-19 infection.'10 / 10He added: 'Our research shows that COVID-19 can cause widespread endothelial dysfunction in organ systems beyond the lungs and kidneys. 'The underlying endothelial dysfunction that happens because of COVID-19 can enter the endothelial cells and affect many organs, including the penis.'