Zika virus is a member of the Flaviviridae virus family and the Flavivirus genus. It causes a mild illness known as Zika fever. Symptoms are similar to other Flaviviruses such as Dengue fever or the Alphavirus Chikungunya. While symptoms do not manifest in all individuals (fever) and the effects are relatively mild, the medical concern is with lasting physiological changes.
New research has shown that Zika virus can get into the testes of mice, causing them to shrink and leading to damage so bad that sperm production drops. This is based on a study in mice and, as yet, there is no evidence that the same issue arises with human males who become infected. It is also important to note that the mice used in the study deliberately had their immune system suppressed before they were infected with Zika virus. Nevertheless, the animal model findings warrant further investigation.
With the study, it was observed that Zika virus preferentially infected spermatogonia, primary spermatocytes, and Sertoli cells in the testis, resulting in cell death, and thus, a loss of fertility.
Talking with NBC News, Dr. Kelle Moley, a fertility specialist at Washington University in St. Louis and who led the study said: “This is the only virus I know of that causes such severe symptoms of infertility. There are very few microbes that can cross the barrier that separates the testes from the bloodstream to infect the testes directly.”
The research has been published in the journal Nature, with the paper headed “Zika virus infection damages the testes in mice.”
The latest findings add to the risks already recorded in relation to pregnant women (or women hoping to become pregnant in the near future). This risk relates to the unborn child, a condition called microcephaly (a birth defect marked by a small, misshapen head.)
