Covid -19 – impact on sperm DNA fragmentation
Covid-19, caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2), has impacted the lives of almost every single person. It is one of the RNA (ribonucleic acid) viruses which cause human diseases such as flu, colds, Dengue, Ebola etc. Some reports have shown that men are more prone to being infected by Covid. As a consequence, research is ongoing to determine whether the Covid infection can affect male fertility – immediately after contracting it or as a long-term issue.
Sperm DNA fragmentation means that there is abnormal genetic material within the sperm. It is the breaking or separation of DNA strands. Men with high levels of sperm DNA fragmentation often have defects in sperm motility which may lead to male subfertility or IVF failure.
Oxidative stress is an imbalance between antioxidants and free radicals (molecules containing oxygen with an uneven number of electrons). This uneven number allows easy reaction with other molecules which can cause chemical reactions in the body. These reactions are known as oxidation. Oxidative stress can lead to sperm damage and possible infertility. It is the major cause of DNA fragmentation.
ACE2 (Angiotensin-converting enzyme) is a protein on the surface of many types of cells. It functions in the male reproductive system as well. According to some data available, the ACE2 receptor helps the Covid19 virus enter host cells, some of which are the testicular cells. Enhanced testosterone levels may assist with the onset of Covid19. However, on the contrary, hypogonadism (low testosterone level) is associated with increasing pro-inflammatory cytokines and testosterone treatment can help reduce the inflammation. Uncontrolled inflammatory responses can lead to oxidative stress which, in turn, can cause DNA fragmentation.
Although the male testes are strongly protected, some viruses, like Covid19, can still break the barrier and appear in the semen. They induce inflammation, orchitis and oxidative stress which can affect male fertility. They can increase vulnerability and risk of infection of the male gonads which, in turn, can affect testicular functionality. The Covid19 infection has shown an increase in cellular inflammation correlated with cell and organ damage, which could result in testicular dysfunction.
Due to the effects of Covid19 being similar to other viruses like Hepatitis and HIV, it is presumed to have like effects on male reproductivity, especially in patients of reproductive age. Such viral infections affect the production of mature spermatozoa and male reproductive hormones.
Autopsies on deceased Covid19 patients showed inflammation in one or both testes as a result of the infection with destruction and death of the sperm cells. Contrariwise, some studies showed that there was no trace of the virus in the semen of Covid19 recovered patients.
Reports suggest that Covid19 could reduce male fertility by testicular inflammation, alteration in gonadal function and injury to the seminiferous tubules (where sperm cells are produced in the testes).
However, research is still ongoing and there is no definite Yes or No as to whether Covid19 may affect male fertility. Detailed studies are being conducted to evaluate the effect on sperm count, motility, hormones, semen quality and possible formation of antisperm antibodies. To try and prevent the transmission of Covid19, people who have been infected by this virus, especially males of reproductive age, should have their fertility tested by having a sperm DFI Test (sperm DNA fragmentation index) and semen analysis.