Zika Infection Spread By Sex In Dallas – Earlier Sexual Transmission In Colorado – Detailed Symptoms News came out of Dallas yesterday of a case of the Zika virus being spread by sexual intercourse. This is however not the first US example of this virus, linked to brain deformities in children, being passed on to a partner through sex. An earlier case in Colorado made history as the first example of sexual transmission of an insect borne virus (arbovirus).
Yesterday the US CDC (Centres For Disease Control and Prevention) rapidly issued recommendations urging the use of condoms to prevent the spread of the Zika virus through sexual intercourse. This followed a report from the Dallas Health Authorities who had been tracking the case of a person having returned from Venezuela a couple of weeks ago. They believe the person was infected with Zika by a mosquito while staying in Venezuela. Following their return to Dallas the person had sex with a second person who soon started to show ‘flu like’ symptoms.
This second person, who had not been outside of the Dallas area, went to their doctor who decided to have blood samples checked for possible causes. After two weeks of testing the CDC were able to rule out other possible viruses, including dengue and chikungunya. They confirmed however that Zika was present in samples from both individuals. Mosquito testing around the couple’s home confirmed that there were no mosquitoes of the type that transmits Zika (Aedes). In addition there are very few mosquitos at this time of year in the vicinity of the residence.
As I reported in my article about Zika on January 19th 2016 (link below)….
19th Jan 2016 ZIKA – Which Countries to Avoid? – Where is Risk highest in USA? – Microcephaly link
….there have been earlier reports of sexual transmission of the Zika virus in the USA.
In this earlier case the victims were a professional biologist and his wife who wrote up their experiences in a scientific paper in May 2011. The biologist, Brian Foy of Colorado State University in Fort Collins, had been working in Senegal in 2008 at the same time that the (then) rather obscure Zika pathogen was also present. Upon his return home to Dallas he engaged in sexual intercourse with his wife Joy Chilson Foy. Joy Chilson Foy a local nurse, was also a co-author in the scientific paper published 3 years later, and had not left the USA since 2007 (and had never been to Africa or Asia where Zika was then known to be present).
Brian Foy was involved in a mosquito gathering project in Senegal and was bitten several times in his short stay by the Aedes mosquito which is the main vector of the Zika virus. He returned home to Northern Colorado on August 24th 2008. Within 5 days of his return he and a colleague developed symptoms typical of a Zika infection but not until after he had engaged in sex with his wife. The report describes that the ‘vaginal sexual intercourse’ took place before he had symptoms of the disease.
The symptoms Brian Foy exhibited from August 30th were a rash on his torso, extreme fatigue, headaches, and swollen and painful wrists, knees, and ankles. He did not have fever. He also had symptoms of prostatitis: painful urination and blood in his semen (called hematospermia – a red–brown fluid in the ejaculate that came out of his penis). His wife developed symptoms from September 3rd including malaise, chills, extreme headache, photophobia, and muscle pain that continued until September 6. She also did not have fever but developed a rash on her back from September 7th (see picture above).
In addition Brian Foy developed two aphthous ulcers on his lips on September 2nd and his wife developed a similar ulcer on the inside of her lip on September 7th. Both patients also exhibited joint pains and Joy Chilson Foy had conjunctivitis (see picture below) from September 8th. None of their four children exhibited any of the syptoms typical of a Zika infection during this period.
One of the reasons it took until 2011 to publish the results of this sexual activity in 2008 was the uncertainty about the cause of the symptoms. It was a chance meeting of Foy’s PhD student Kevin Kobylinski (on the left in the picture above) with entomologist Andrew Haddow on another trip to Senegal that set the scientists on the scent of Zika. Haddow’s grandfather was one of the scientists that isolated the virus in the Zika forest of Uganda in 1947 and he pointed out that the symptoms described above were typical of this disease.
Kobylinski who had had similar symptoms to Foy when they both returned from Senegal explained Haddow’s suggestion to him and they sent the samples they had kept since September 2008 (in the freezer) to Haddow for testing. He was able to confirm the presence of Zika.
Although the evidence that Foy transmitted the virus to his wife through sex was not direct the circumstantial evidence was very strong. She was unlikely to have been infected by an aedes mosquito because they were not present on Northern Colorado. In addition it takes the virus two weeks to complete its life cycle in a mosquito before it can reinfect another human being. However Foy’s wife showed symptoms just 9 days after those of her husband..The fact ttat they had sex together is clearly documented in the 2011 research paper (the link to the original paper by is here – Foy BD, Kobylinski KC, Foy JLC, Blitvich BJ, Travassos da Rosa A, Haddow AD, et al. Probable non–vector-borne transmission of Zika virus, Colorado, USA. Emerg Infect Dis 2011 May; 17(5): 880–882).
Together with its growing link to microcephaly (reduced skull and brain size in newborns) I think we will be hearing a lot more about the risks of sex with people from Zika areas in the near future. Here is a current map of those area were Zika is present:
This development shows how important it is to think outside of the box when trying to combat dangerous infectious disease epidemics. The story above details the first published example of an insect born arbovirus being transmitted between humans by sex. With this in mind you might also be interested in my article about the importance of identifying whether bed bugs could also have a role in the transmission of arboviruses like Zika. Here‘s the link:
Bed Bugs – Insecticide Resistance – Arbovirus Transmission – Zika and Microcephaly
One final comment – Yesterday the American Red Cross appealed to prospective donors who have visited Zika outbreak zones to wait at least 28 days before giving blood. It said risks of transmitting the virus through blood donations remained “extremely” low in the continental United States (info from Reuters).
Chris Duggleby
If you are interested in reading my other health focused articles try the following
Torture In The Shower – Face and Body Soap Allergies – Main Suspect: Pears Transparent Soap
Toxic Chemicals in Sex Toys – 18 Vibrators, Cock Rings, Love Balls Tested – Only 3 Get All Clear
My T-shirt Made Me Sick – Textile Allergies – Sinusitis From Your Underwear
Chris Duggleby 