Researchers at the Paris, France-based French National Institute of Health and Medical Research (Inserm), Paris-based Centre National de la Recherche Scientifique (CNRS), and academic practitioners from University Toulouse III- Paul Sabatier and Toulouse University Hospital have shown that the Zika virus, which can persist in semen for over 130 days or over four months, show the presence of the virus even within spermatozoa.
The researchers analyzed 11 samples of semen, five samples of urine, and 10 samples of blood with Zika virus over a total period of 141 days. The virus was present in all samples up to the 37th day, from which point on the virus only persisted in the semen, where it stayed for more than 130 days, even while the male patient was in good health. The same results were seen in two other patients, in whom the virus persisted for over 69 and 119 days in the semen.
“We detected the presence of Zika virus inside approximately 3.5 percent of the patients' spermatozoa,” says Guillaume Martin-Blondel, Inserm researcher at the Toulouse Purpan Pathophysiology Centre and physician at the Infectious and Tropical Diseases Department of Toulouse University Hospital.
Scientists have yet to determine the factors responsible for this variation in persistence. From the point of diagnosis, these patients are advised to use protection during sexual contact. (Related: Zika virus and depopulation: Rising number of miscarriages, birth defects blamed on virus as governments urge women not to reproduce.)
According to the researchers, for other sexually transmitted viruses, such as human immunodeficiency virus (HIV), the virus is kept “stuck” at the surface of spermatozoa. It is therefore possible to “wash” the spermatozoa from HIV-infected patients for purposes of an in vitro fertilization. It is not possible, however, for male patients with Zika virus, since the virus can also be found outside the sperm, in the seminal fluid.
Advisers to the United States Food and Drug Administration on Friday, December 1 have suggested that the requirements for screening blood donations for the patients who have been infected with Zika virus should be relaxed due to supposed lessened risk of transfusion-transmitted infection.
The panel suggested that instead of requiring Zika virus testing on each individual blood donation, tests could be done on “mini-pools”, meaning, blood samples would be grouped together before testing.
The FDA in 2016 has recommended blood centers in America to screen all blood donations for Zika virus, amidst a Zika outbreak that contaminated over 30 countries in Latin America and the Caribbean and parts of the U.S.
The virus, which is mainly carried by mosquitoes, has been associated with a rare birth defect known as microcephaly, prompting federal health officials to declare a global health emergency.
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