According to a pre-published study, men are more susceptible to Covid-19 because of their testicles where the virus finds refuge. However, these results have been disputed by several scientists.
- Nearly 3 out of 4 serious cases of Covid-19 are men
- Some scientists believe that the virus could find refuge in the testicles of men and the infection last longer in their organism
Men more affected by Covid-19 than women. Thanks to a Chinese study published on February 24 in the journal jama and covering 44,672 confirmed cases in the country, we had for the first time visibility on the profile of the people most vulnerable to this new virus. The latter showed in particular that men would be more sensitive to it. Since then, a lot of data has accumulated, confirming this trend. Thus, according to the latest weekly epidemiological bulletin from Public Health France, out of 2,806 serious cases of Covid-19 recorded since March 16, 73% of them were men. According to a new study pre-published on the medical site MedRxiv, this could be explained by their testicles. However, these results have been disputed by several scientists.
To reach this astonishing conclusion, Doctor Aditi Shastri, oncologist at Montefiore Medical Center in New York (USA) and her mother, Doctor Jayanthi Shastri, microbiologist at Kasturba Hospital for Infectious Diseases in Mumbai (India), followed 48 men and 20 women infected with the coronavirus. The subjects ranged in age from 3 to 75 years old and lived in Mumbai. The researchers then noticed that while women took four days to get rid of the infection, it took six for men. In three families who participated in the study, the men also needed longer than the women to recover from the disease.
According to scientists, this could be because the coronavirus could attach to cells expressing the protein ACE2 or angiotensin converting enzyme 2, which is found in the lungs, heart, intestines, and in large quantities in the testicles. On the contrary, the ovarian tissue contains almost none. Thus, SARS-CoV-2 could find refuge in the testicles of men and the infection last longer in their body.
Disputed results
However, some English scientists have some reservations about these results, which have not yet been peer-reviewed. For virology professor Ian Jones, from the University of Reading (UK), for the virus to reach the testicles, “it would first have to travel through the bloodstream”. If it has already been indicated for the Covid-19, “this is not usually what coronaviruses do”, which are located mainly in the respiratory tract. According to him, if men resist the virus less well than women, it is “maybe because they have only one X chromosome”.
Jonathan Ball, professor of molecular virology at the University of Nottingham (United Kingdom), highlights another study which found no trace of coronavirus in the semen of patients. So that would suggest that “the male genital tract is not a significant reservoir for the virus”. However, this study has not yet been re-read, nor does it, he adds.
Finally, for Derek Hill, professor of medical imaging at University College London, much more data is needed to be able to draw concrete conclusions from this study.
Previous coronaviruses were also more dangerous for men
This new coronavirus is not the first to be more complicated for men. Three years ago an American study on SARS and MERS, the previous pathogenic coronaviruses for humans, already showed strong gender disparities. The work, carried out on mice, suggested that cellular receptors for estrogens (female hormones) played a role in the immune response.
Today, in France, Jean-Charles Guéry, researcher at the Purpan physiopathology center (Toulouse), is mainly interested in the inflammatory response according to gender.
“For Covid-19, the hypothesis is that biological factors act on the modulation of the immune response and therefore on the severity of the inflammation”he explains to West France. This excessive inflammation is the cause of severe acute respiratory syndromes requiring hospitalization in intensive care. Another possibility:Variations in the composition of the intestinal microbiota, which differs according to the sexes, and which plays a role in the control of inflammation.”
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