SARS-CoV-2 may persist in semen for months after infection

Researchers from the University of São Paulo (USP) in Brazil have shown for the first time that SARS-CoV-2, the virus that causes COVID-19, can remain in the semen of patients for up to 90 days after their discharge from hospital. to 110 days after initial infection, thereby reducing sperm quality. The study is reported in an article published in the journal Andrology. The authors suggest that people who are planning to have children should observe a period of “quarantine” after recovering from COVID-19.

More than four years after the start of the pandemic, we know that SARS-CoV-2 is capable of invading and destroying several types of human cells and tissues, including the reproductive system, where the testes serve as a “gateway”. ‘entrance “. Although scientists have noted that the virus is more aggressive than other viruses toward the male genital tract and autopsies have found it in the testes, it has rarely been detected in semen by polymerase chain reaction analysis ( PCR), which focuses on viral DNA.

To address this knowledge gap, the study – supported by FAPESP – used real-time PCR and transmission electron microscopy (TEM) to detect viral RNA in semen and sperm donated by recovering men of COVID-19.

The semen samples were collected from 13 patients aged 21 to 50 who had mild, moderate and severe COVID-19 and were admitted to Hospital das Clínicas (HC), the hospital complex run by the Faculty of University Medicine (FM-USP). . Analysis was performed up to 90 days after discharge and 110 days after diagnosis. Although PCR test results were negative for SARS-CoV-2 in semen in all cases, the virus was detected in the semen of eight of 11 patients with moderate to severe COVID-19 (72.7 %) within 90 days of their release, which does not mean he was no longer present any longer, according to the authors.

SARS-CoV-2 was also detected in one of the patients with mild COVID-19. In total, the virus was detected in the semen of nine of 13 patients (69.2%). Two others had ultrastructural gamete deficiency similar to that seen in patients diagnosed with COVID-19. The authors therefore concluded that 11 of the patients had the virus in their semen.

Additionally, we discovered that sperm produce “extracellular traps” based on nuclear DNA. In other words, the genetic material in the nucleus decondensed, the sperm cell membranes ruptured, and the DNA was expelled into the extracellular medium, forming networks similar to those previously described in the systemic inflammatory response to SARS-CoV-2. »

Jorge Hallak, professor at FM-USP and corresponding author of the article

The networks in question are neutrophil extracellular traps (NETs). Neutrophils, a type of white blood cell, form the front line of the immune system, immobilizing and killing disease-causing bacteria, fungi and viruses. However, when overactive, NETs can damage tissues elsewhere in the body (to find out more: agencia.fapesp.br/33523).

TEM analysis showed that sperm produced nuclear DNA-based extracellular traps to neutralize the pathogen, “sacrificing themselves” to contain the pathogen in a mechanism known as the ETosis-like suicidal response ( ETosis meaning death via extracellular traps).

“The discovery that sperm are part of the innate immune system and help defend the body against attack by pathogens is unique in the literature and makes the study very important. It can be considered a scientific paradigm shift “Hallak said.

Until now, he adds, sperm were known to have four functions: link the genetic content of male gametes to female gametes, fertilize the female gametes, promote the development of the embryo until the twelfth week of pregnancy and co-determine the development of certain chronic diseases in children. adulthood, such as infertility, hypogonadism, diabetes, hypertension, certain types of cancer and cardiovascular disorders, among others.

The discovery described in the study adds a new function to their role in reproduction. “The possible implications of our findings on the use of sperm in assisted reproduction should be urgently examined by doctors and regulators, particularly with regard to the technique used by Brazilian laboratories that carry out gamete micromanipulation in more 90% of cases of marital infertility, which involves the injection of a single sperm into the egg and is known as intracytoplasmic sperm injection, or ICSI,” Hallak said.

Hallak advocates postponing natural conception and especially assisted reproduction for at least six months after SARS-CoV-2 infection, even if mild COVID-19 ensues.

Previous discoveries

Hallak was one of the first members of the scientific and medical communities to suggest more caution in reproductive protocols during the pandemic. He has been studying the impact of COVID-19 on reproductive and sexual health since 2020, when he volunteered on the front lines as an emergency physician at HC-FM-USP.

His research group, which includes colleagues from the FM-USP Department of Pathology, has already made important discoveries in the field, such as the higher risk of severe COVID-19 infection and death from the disease for men simply because of their sex, perhaps because of the abundance of ACE2 and TMPRSS2 receptors in the testes, while the ovaries only have ACE2 receptors. The virus uses ACE2 to invade cells; TMPRSS2 is a protein that allows the virus to bind to ACE2 on the surface of cells.

In a study conducted with members of the Division of Clinical Urology at HC-FM-USP, the group found that health care workers experienced sharp declines in libido and sexual satisfaction, as well as increased consumption of pornography and more frequent masturbation, due to the pandemic.

The group also discovered that the testes are potential targets for infection by the virus, which causes subclinical epididymitis (inflammation of the epididymis, a narrow tube attached to each testicle that stores, matures and transports sperm), and showed for the first time the severity of testicular damage associated with COVID-19.

The group of doctors and scientists at HC-FM-USP, led by Professor Carlos Carvalho, is currently studying the delayed effects of SARS-CoV-2 infection in more than 700 patients initially evaluated for a thematic project funded by FAPESP.