The ability of sperm to move and fertilize eggs has a normal rate of 50%. In men infected with the new coronavirus and who have developed Covid-19, however, this sperm motility is reduced to levels between 8% and 12%, according to studies conducted at the University of São Paulo.
Even a year after illness, previously infected men maintained this low motility. Another change noticed was related to hormone levels. Although the normal level of testosterone in humans is 300 to 500 nanograms per deciliter of blood (ng / dL), in men who have had Covid-19, the hormone reached values ??below 200 and often between 70 to 80 ng / dL.
According to Jorge Hallak, a professor at the USP School of Medicine, and one of the researchers, they have seen increasingly prolonged changes in the quality of sperm and hormones in patients with Covid-19. “(…) even in those who presented a benign or asymptomatic state”, explains Hallak, in an interview with Agência FAPESP.
Testes and epididymis
Studies carried out in collaboration with the Faculty’s pathology department have revealed that SARS-CoV-2 is also capable of infecting the testes. As a result, they impair the ability of the male gonads to produce sperm and hormones.
According to Hallak, this happens even in asymptomatic cases or with few symptoms. “Of all the testicular harmful agents that I have studied so far, SARS-CoV-2 seems to be very active,” he says.
“Each pathology has particularities that practice and experience show us. SARS-CoV-2 has the characteristic of affecting spermatogenesis in a way that we are now finding, such as very low persistent progressive motility, without significant change. sperm concentration, “he explains. at the FAPESP Agency.
The results come from an analysis of 26 patients who have undergone Covid-19. From ultrasound examinations, the researchers found that more than half suffered from severe inflammation of the epididymis, the structure responsible for storing sperm, in which they acquire the ability to move. The results were published in the scientific journal Andrology.
“Unlike a classic bacterial infection or with other viruses, such as mumps, which causes swelling and pain in the testicles in a third of those affected, the epididymitis caused by the new coronavirus is painless and cannot be diagnosed. by palpation [exame físico] or with the naked eye, ”Hallak warns.
Given the results, the specialist points out that adolescents and young adults or men of childbearing age, if they are infected with the new coronavirus, should consult a urologist or an andrologist, after the disease, to be evaluated.
During the consultation, the following should be assessed:
Measurement of testicular volume; Dosage of testosterone and other hormones; Semen analysis with sperm function tests; Color Doppler ultrasound examination to assess possible testicular damage that could affect fertility and hormone production.
“These people need to be followed for at least one to two years after infection, because we still don’t know how the disease progresses,” says Hallak.
Coronavirus in testicular cells
The same group of researchers also developed another study, published in the same scientific journal, which indicates that the new coronavirus is able to invade all types of cells in the testis. This invasion can alter hormonal function and male fertility.
To arrive at the results, the researchers used minimally invasive autopsy techniques to take testicular tissue samples from 11 men, aged 32 to 88, who died from severe Covid-19.
In an interview with Agência FAPESP, Amaro Nunes Duarte Neto, infectious disease specialist and pathologist at FM-USP and the Adolfo Lutz Institute, and study coordinator, points out that, even in younger patients, the amount of semen was quite limited. “What immediately caught our attention in these patients who died from Covid-19 was the drastic reduction in spermatogenesis. Even the youngest, of childbearing age, had practically no sperm,” explains- he does.