Viruses have evolved to spare women, who are more “precious” than men

According to a recent study, we are not all in the same boat when it comes to viruses. The latter would have evolved to affect the sexes differently, sparing women more than men.

One of the most enduring mysteries of medical science is that certain infectious diseases affect men more severely than women. For example, men infected with tuberculosis are 1.5 times more likely to die than women. They are also five times more likely to develop cancer when infected with the human papillomavirus (HPV). According to a recent study published in the journal Nature Communications, this inequality of treatment is due not to a difference in the immune system, but to a strategic evolution of viruses. Women would be more « precious » hosts for the viruses which would then have evolved to keep them alive longer than men.

To reach such conclusions, a team of researchers led by Francisco Ubeda of the Royal Holloway University in London looked into the case of the HTLV-1 virus (for human T-1 lymphotropic virus), a virus which can be cause of leukemia-like cancers. It appears that this infectious disease is five times more deadly in men than in women. A sneaky behavior since according to the researchers, it would be precisely to be able to transmit this virus to children during childbirth or breastfeeding that women would be less severely affected by the virus.

As summarized by Dr. Ubeda, quoted by The Sun: “ Pathogenic viruses adapt to be less virulent in women and increase their chances of being transmitted to next generations during pregnancy, childbirth or breastfeeding « . The objective of the virus here being to proliferate and spread and not necessarily to cause death, because if the host is bedridden or dies, the viruses can no longer spread. An evolutionary choice which is illustrated in particular in Japan. In this country, leukemia affects men more than women, even though the breastfeeding rate is quite high. In fact, the infection is 2 to 3.5 times more likely to become fatal among Japanese men than among Japanese women.

There are also many examples that support this hypothesis. Men infected with the Epstein-Barr virus are twice as likely to develop Hodgkin’s lymphoma as women, just as men have a higher risk of contracting a severe case of chickenpox. Both viruses are transmitted from mother to child. Thus, women are more spared, the pathogens having evolved to keep them alive longer than men.


Laisser un commentaire