Back grey arrow rt.gif
Evidence of Sexual Transmission of Zika Virus; oral sex?
  Download the PDF here
Zika Death in PR / HIV Infection & Zika Virus / 1st case of Zika in HIV+ - (05/09/16)
NEJM June 2 2016 - "Two studies have shown the presence of infectious ZIKV in semen╔..The sexual contact involved seven episodes of both vaginal sexual intercourse, without ejaculation and without the use of a condom, and oral sex with ejaculation."╔..was it through oral sex??
Evidence of Sexual Transmission of Zika Virus
N Engl J Med June 2 2016
To the Editor:
Zika virus (ZIKV), an emerging flavivirus, generally causes mild infection in humans but is associated with severe neurologic complications and adverse fetal outcomes. ZIKV is transmitted to humans primarily by aedes mosquitoes. However, there is some evidence of sexual transmission.1,2 Two studies have shown the presence of infectious ZIKV in semen.3 A recent article described detection of ZIKV RNA in semen 62 days after the onset of illness, but infectious virus was not cultured.4
We report a case of ZIKV infection in a previously healthy 24-year-old woman (Patient 1) who was living in Paris and in whom acute fever, myalgia, arthralgia, and pruritic rash developed on February 20, 2016. She was not receiving any medication, had not received any blood transfusions, and had never traveled to a region where Zika was epidemic or to tropical or subtropical areas. Her last trip outside France was to Okinawa, Japan, from December 21, 2015, to January 1, 2016. A clinical examination on February 23 showed a maculopapular rash on the patient's abdomen, arms, and legs and a temperature of 36.6íC. The illness lasted approximately 7 days.
Patient 1 reported sexual contact between February 11 and February 20, 2016, with a man (Patient 2, the index patient) who had stayed in Brazil from December 11, 2015, through February 9, 2016. The sexual contact involved seven episodes of both vaginal sexual intercourse, without ejaculation and without the use of a condom, and oral sex with ejaculation.
Patient 2, a 46-year-old man, reported fever, asthenia, myalgia, chills, and a cutaneous rash that began on February 7, while he was in Rio de Janeiro. The symptoms had resolved on the day he arrived in France on February 10. The clinical examination of Patient 2 was normal on February 23 (details are provided in the Supplementary Appendix, available with the full text of this letter at
Populations of Aedes aegypti and A. albopictus mosquitoes are not established in the city of Paris. Moreover, in France, the diapause period of aedes species extends from December to May.
Three days after the onset of her symptoms, on February 23, samples of urine and saliva were obtained from Patient 1. The urine sample tested positive for ZIKV RNA by reverse-transcriptase polymerase chain reaction (RT-PCR) at a viral count of 3.5x103 copies per milliliter, and the saliva tested positive at a viral count of 2.1x104 copies per milliliter. A plasma sample tested negative for ZIKV RNA by RT-PCR, but serum IgM antibodies to ZIKV were detected (see the Supplementary Appendix). A vaginal swab obtained on March 1 was negative for ZIKV RNA by RT-PCR.
In Patient 2, a urine sample obtained 16 days after the onset of symptoms tested positive for ZIKV RNA by RT-PCR with a viral count of 4x103 copies per milliliter, but plasma and saliva samples tested negative. The first and second urine stream samples obtained on day 24 were positive for ZIKV RNA with a viral count of 2.1x104 copies per milliliter. Semen samples tested positive for ZIKV RNA by RT-PCR with a high viral load of 2.9x108 copies per milliliter in the sample obtained on day 18 and 3.5x107 copies per milliliter in the sample obtained on day 24. ZIKV was isolated by means of culture from semen samples on days 18 and 24. Timelines are shown in Figure 1A.
A complete ZIKV genome was sequenced from saliva samples obtained from Patient 1 and semen samples obtained from Patient 2 (see the Supplementary Appendix). Only four mutations, all of them synonymous, differentiate the sequences of the two patients. The complete nucleotide coding sequences of ZIKV identified in these semen and saliva samples cluster together within the phylogenetic tree (Figure 1B).
These data support the hypothesis of sexual transmission (either oral or vaginal) of ZIKV from Patient 2 to Patient 1. We cannot rule out the possibility that transmission occurred not through semen but through other biologic fluids, such as pre-ejaculate secretions or saliva exchanged through deep kissing. The saliva of Patient 2 tested negative on day 10 after the onset of his symptoms, but it was not tested earlier. ZIKV has been detected in saliva,5 but, to our knowledge, no cases of transmission through saliva have been documented.
The current outbreaks of ZIKV infection should be an opportunity to conduct studies to understand the natural history of ZIKV. We need to better define recommendations to prevent transmission of the virus. In particular, guidelines regarding how long men who are returning from an area where active ZIKV transmission is occurring should continue to use condoms during sexual contact with pregnant women and those of child-bearing age are lacking. In addition, recommendations regarding the possibility of oral transmission of the virus through semen are needed.
Zika May Be Transmitted by Oral Sex, Scientists
NY Times
June 2, 2016
Scientists raised the possibility that the Zika virus can be transmitted by oral sex - perhaps even by kissing - on Friday in a letter to The New England Journal of Medicine describing one such case in France.
A single incident may seem trivial. But until early this year, there was only one known instance of sexual transmission of the Zika virus - a 2008 case in which a mosquito researcher just back from Africa infected his wife in Colorado.
Now scientists believe that sexual transmission is an important driver of the Zika epidemic in the Americas. Cases have been reported in 10 countries where no mosquitoes carry the virus, including France, Germany, Italy, Portugal and New Zealand. In the French case, a 46-year-old man returned to Paris from Rio de Janeiro on Feb. 10, shortly after experiencing Zika symptoms in Brazil - fever, headache and a rash - that had just ended when he reached France.
He and a 24-year-old partner had sex seven times between Feb. 11 and Feb. 20, each involving vaginal sex without ejaculation and oral sex with ejaculation.
The woman fell ill on Feb. 20. Both were tested for Zika infection on Feb. 23. The man had high levels of the virus in his semen and urine, but none in his blood or saliva. The woman had the virus in her urine and saliva, and antibodies to the virus in her blood. But a vaginal swab was negative for the infection.
The two were using oral sex as a form of birth control, said Dr. Yazdan Yazdanpanah, an infectious disease specialist at the National Institute of Health and Medical Research in Paris and one of the report's authors.
"I don't think this changes anything, but it shows you how elaborate the number of avenues of possible transmission can be," said Dr. William Schaffner, head of preventive medicine at Vanderbilt University Medical School.
He agreed that the most likely transmission route was oral sex, although he said it was possible that the woman was infected by pre-ejaculate during vaginal sex, or that the couple's recollections of each sex act were imperfect.
"It could be that it's a moment of passion, it's late at night and everyone's had a few liqueurs," he said.
Dr. Yazdanpanah said the two were interviewed separately and their descriptions matched. Dr. John T. Brooks, an epidemiologist at the Centers for Disease Control and Prevention studying sexual transmission of the Zika virus, said he was "not particularly surprised" to see transmission that was probably by oral sex.
Transmission through kissing is unlikely, Dr. Brooks said.
"Casual kissing has got to be safe because, if it weren't, don't you think we'd see a lot more Zika? Every mom who kissed her baby would pass it on," he said. "To be sure, we'd have to look for deep kissing in the absence of sexual contact, and that's hard to find."

  iconpaperstack View Older Articles   Back to Top