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Female to Female Sexual Transmission of HIV

Let me tell you a story of a lady. Let’s call her Ms. T.

Ms. T was 46 years old. She has not had a heterosexual relationship in the past 10 years. In the past 5 years, she has had 3 female sexual partners. She does not do drugs, no tattoos, never been for acupuncture and has never had the need for blood transfusions or organ transplants.

Ms. T was not too well to do so she supplemented her income by selling blood to the local blood bank. In March 2012, she donated blood again and was told everything was fine. Most importantly, her HIV test was clear.

10 days after donating blood, she developed a sore throat, fever, vomiting, diarrhea and muscle cramps. She was seen at the emergency department and again tested negative for HIV. She was given some antibiotics and discharged.

18 days later, Ms. T again went to try to sell blood. This time, she was told her blood could not be accepted because she tested positive for HIV. On 5th July 2012, repeat HIV tests were positive and she was confirmed to be infected with HIV.

She revealed that her current 43 years old female sex partner was diagnosed with HIV in 2008. She had been on anti-retroviral medication but stopped since 2010.

They have been having unprotected sex with oral and vaginal contact and sharing insertive sex toys. They described their sexual contact as at times rough to the point of causing bleeding. They also have had unprotected sex during their menses.

Genetic studies found that the HIV that infected both women was 98% identical in genetic sequence. Furthermore, Ms. T reported no other sexual partners in the 6 months leading up to her diagnosis of HIV. The conclusion was therefore it was extremely likely that Ms. T was infected with HIV from her female sexual partner.

This was an actual case that happened in Texas in 2012. It was reported in the US CDC Morbidity and Mortality Weekly Report Vol. 63 No. 10 dated 14th March 2014.

This is not the first time HIV transmission between women who have sex with women (WSW) has been reported. However, it is the first time the evidence has been so compelling.

In many previous studies, there were other risk factors for the infected women such as injection drug abuse or having male sexual partners at the same time. In fact, there was a study that followed 18 sero-discordant WSWs for 6 months and found not HIV transmission.

However, the evidence from this case is compelling enough for us to conclude that although rare, female-to-female sexual transmission of HIV can occur. The risk is presumably higher when there is exposure to menstrual blood or blood from trauma during rough sex. The risk is lowered if the HIV +ve partner is under medication and the HIV viral load is controlled.

About Dr. Tan
Dr. Tan graduated from the National University of Singapore in 2001. His residency was in the two largest public hospitals in Singapore; Tan Tock Seng Hospital and Singapore General Hospital.

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  1. Smitmonter

    I had unprotected sex with sex worker and I took PEP within 48 hrs.

    I took rapid (ag / ab ) test on 87th and 146th days (CMIA) method )of after exposure.
    Result is non reactive.
    but I took rapid hiv (ab) test on 151rd(gen 2)of after exposure.
    result is reactive

    Again I took Hiv test on 158rd day of after exposure (HIV RNA viral load <20 cps/ml ) also non reactive.

    Again I took blood test on 190th day (ELISA combo).
    All above results are non reactive.

    is it my result is confirmed. or still do I need to take any other test to conform the my status.
    doctor help me me very thank

  2. There are 3 possible explanations. 1. Her symptoms were not due to HIV ARS but to some other viral infection. 2. She developed HIV ARS at 2 weeks post infection when the 4th Gen test is not yet 100% sensitive. 3. They did not use the 4th Gen test. The report did not detail which test was used.

  3. Anxious

    Dear Dr.Tan, why this women were tested negetive even she is showing seroconversion symtoms? This case happened in 2012 but 4th gen hiv test is already a standard recommended 1st line test in 2008 in US. I suppose the hospital will know what is the right test to use.