Dr. Tan and Partners is one of the few approved Anonymous HIV Testing Centres in Singapore. A detailed write up on our service is available here.

Other STD services: Early STD Screening, Rapid Hepatitis B Blood Test, Swab for Gonorrhea and many more... contact us to make an appointment now!

A quick breakdown on how HIV can be transmitted.

This topic aims to show ways in which HIV can and cannot be transmitted. It ties in with a recently published topic found here http://www.drtanandpartners.com/how-does-hiv-enter-the-body/.

 

This topic will be split into 3 parts; Definite ways of HIV transmission, theoretical ways of transmission, and no way of transmission.

 

Bear in mind that in order for HIV to be transmitted fluid from a positive person has to come into contact with the negative person. Semen and blood hold high loads of the virus but saliva and vaginal fluid hold very little.

HIV-modes-of-transmission

According to Singapore Ministry of Health UPDATE ON THE HIV/AIDS SITUATION IN SINGAPORE 2014.

Definite ways of HIV transmission (risk will be listed as risk per 10000 – so 1/10000 means that for every 10000 people who engage in that activity, 1 person will become infected.

  • Blood transfusion – 9250/10000 (this is only with HIV infected blood which is very rare nowadays as every donor blood sample is screened before use).
  • Needle sharing in intravenous drug use – 63/10000.
  • Needlestick injury – 23/10000.
  • Receptive anal sexual intercourse – 138/10000.
  • Insertive anal sexual intercourse – 11/10000
  • Receptive penile-vaginal sexual intercourse – 8/10000
  • Insertive penile-vaginal sexual intercourse – 4/10000
  • Receptive and insertive oral sexual intercourse – low (too low for accurate numbers).

 

HIV_transmission-risk

Estimated risk per exposure to HIV transmission: assume that the ‘source partner’ is always HIV-positive. For a partner of unknown status, the risk is affected by the prevalence of HIV in the relevant community – i.e., the chance that the partner does in fact have HIV. Unless otherwise stated, the sexual acts are always without a condom.

 

Theoretical ways of HIV transmission:

  • Blood contact onto an open wound – possible but an unlikely scenario as open wounds should be tended immediately in order to reduce the risk of other infections. The risk of a bacterial infection would be higher than an HIV infection.
  • Blood contact onto mouth or eyes – again possible but extremely unlikely unless you happen to be in a horror movie.
  • Dried blood – although HIV can survive in dried blood for several days, the environment has to be favourable and transfer this way is very very unlikely.

 

No risk of HIV transmission:

  • Breathing the same air as someone.
  • Touching a toilet seat or door knob.
  • Drinking from a water fountain.
  • Hugging, kissing or shaking hands (although kissing may transfer fluids the level of virus in saliva is so low as to make the risk negligible).
  • Sharing utensils.
  • Sharing gym equipment.
  • Skin to skin contact with an HIV positive person even if they happen to have fluid of unknown origin on them (particularly applies to commercial sex workers).
  • Biting or scratching that does not break the skin or draw blood.
  • Essentially, as mentioned above, fluid-fluid contact is necessary for transmission – if this hasn’t happened then there is no risk for HIV.

 

I hope this helps answer most questions that concern people over possible ways of HIV transmission – if new questions pop up I will try and add to this topic to help allay people’s fears.

 

 

Feel free to email your queries, feedback and suggestions on what other topics you want to see in the comments section below.

For lady patients who prefer female doctors, we have professional certified female Doctors to attend to your medical needs.

We are Open on Saturdays and Sundays.

Click Here for Contact Details, Address and Opening Times.

We are now Open on Weekends.

HIV_banner

 

Women’s Health Forum

Hey Gal friends! Our lady doctors have launched a health forum specially for women only!

If you have health tips or you need health advices, join us.

For Women. From Women

Join in the discussion!

 

 

333 Comments

  1. Russell uyeh

    Hello Doctor
    I had a little fling with a lady I am not sure of her status.we kissed deeply,I fingered her and she gave me a blow job.didn’t penetrate her but after a few week I fell ill and got strange symptoms like swollen lymph nodes and others.did a HIV test twice in a space of two months and it was negative…..what are my chances of not being infected

    • Your chances of NOT being infected are 100%, as your tests are negative and the initial risk was essentially zero anyway.

  2. A razor cut a person with HIV in the evening, in the morning of the next day, that razor cut another person, and blood is involve in both cases. Please Doctor, what is the risk of the person being infected?

    • There are many factors that would influence infection risk, including viral load and amount of blood present. Overall risk is likely very low given the amount of time between cuts.

  3. JUSTICE

    somebody use his finger to remove pimples from the skin of HIV infected person and after about 10 hours he use the same finger to removes pimples from another person. Can the second person be infected?

    • I would say the risk is extremely low. There has never been any similar case reported before.

      • JUSTICE

        Please Doctor, what if the pimples were removed from the second person immediately after the infected person, that is within 10 minutes

  4. ConcernedTony

    Hi Doctors

    I had a risky exposure 35 days ago, took PEP after 55 hours and just completed it yesterday.

    Here are my results so far:

    Day 15,5: RNA PCR: Negative
    Day 15,5: Ab (3rd Gen): Negative
    Day 21: Core Rapid: Negative
    Day 22,5: RNA PCR: Negative
    Day 22,5: Ab (3rd Gen): Negative
    Day 32: Core Rapid: Negative
    Day 33: 1st Day After PEP – Ab (3rd Gen): Negative
    Day 33: 1st Day After PEP – P24 Ag: Negative
    Day 35: 3rd Day After PEP – Rapid: Negative

    I am planning to test after another 2 weeks with the PCR test (2 weeks after PEP) however have three questions for now:

    1) What is your opinion of these results so far?

    2) Have you seen anyone test negative with the Duo Test immediately after PEP who then goes on to turn positive?

    3) What is the difference between a third generation antibody test and a fourth generation antibody test? (The information via Google is lacking with this)

    Thank you in advance.
    Keep up the great work!

    Tony

    • I would consider your tests essentially conclusive and to be honest extremely excessive. I have not seen anyone test negative post-PEP subsequently turn positive (provided there were no other high risk exposures within the window period). The 3rd generation antibody test only checks for HIV antibody, while 4th generation tests check for both antigen and antibody.

  5. Ajay Nair

    Hi Doctor,

    I have been having an irritation of the penis tip and foreskin and was being treated by a dermatologist with Elidil and Nizoral creams. I still have some sores and redness. I had a sexual encounter with a girl I don’t know well. I fingered her for a while and them had protected sex. After sex, while removing the condom and cleaning, I suspect that the vaginal fluid on my finger and outside of the condom would have definitely come in contact with the open sores on my penis. Is there a risk of HIV infection in this case?

    Regards, Ajay

    • There is a low risk even with protected intercourse. Please speak to your doctor or visit us for consult and evaluation.

      • Ajay Nair

        Thanks Dr. I will try to consult youASAP. But I understand that i may have to wait for some time for the blood test to show the correct result. Meanwhile, just to understand- you said there is a low risk – is it because of the sores or the medication that i am applying? Otherwise i was under the impression that protected sex is generally safe. Regards. Ajay

        • Condoms will be up to 98% protective. So yes, protected sex is generally safe, just not 100%. We can have a conclusive HIV result with rapid testing 28 days post-exposure. However, if you have symptoms of concern, do come by earlier for evaluation (there are many other STDs which are much more common than HIV).

  6. Hi
    Sorry for my bad english.

    Dr iam very confused last 8 months before i tested hiv and std. Chlamydia is positive i take medicine.then 45 day before i had protected sex for 1min with call girl in malaysia. Afterthat i test for uti is positive then i take medicine for uti after some days i had sores in my face and body. I am very afraid now this is due to hsv. by this 1min exposure hsv will transmit or it is due to side effect of uti medicine.kindly send reply as soon as possible.iam very depressed.

  7. Hello, I have a neighbor who I try to avoid, but run into outside from time to time. She disclosed information to me in passing that I’d rather not know. For instance I know the she continuously sleeps with men and never uses protection, I am a full blown hypochondriac so that alone makes me want to avoid contact. My anxiety always gets the best of me. Anyways, this evening I was walking my dog outside with my toddler when the neighbor and her son came out and my toddler ran ahead and the neighbor picked her up before I could get to them, I went to grab my kiddo and she initiated an awkward side hug with me. I noticed her shirt was wet and asked if she had been swimming, she replied that her nipple piercing was infected and had oozed pus so she washed it then put a wet wash clothe in her thin sports bra to keep it moist. My toddler nor I have broken skin that I could find, but I do have a lot of acne on my shoulder and arms. My thoughts are what if her pus seeped through that wash rag and was wet on her shirt. I am pregnant and so overprotective of my daughter, what are the chances that she could have transmitted hiv through her wet shirt, or other stds? I took us inside and bathed us both immediately but am freaking out. I am also pregnant. Please help, do we need to consult our doctors?

    • There is zero risk of HIV transmission from this encounter, and I do not believe you need to see a doctor for this. However, it sounds like you may have underlying anxiety issues – I would recommend you seek some evaluation and possible treatment for this.

  8. I work in Blood serum manufacturing plant. last week i have a cut in my hand through paper file little blood oozes out from that cut. then i touched the blood sample which was in falcon tube and after few minute i touched the cut area with the same hand in which i hold the blood sample.

    is there any chance of getting HIV ?

  9. Massmor

    is it not possible for infected blood in the mouth to find its way to the blood stream through the mucous membrane or the points which provide opening for the bleeding in gums?

  10. Massmor

    Hi doctor. I am a 22 year old guy leaving in Canada, about 2 weeks ago I was at a night club and I met this girl…we had an open mouth kiss for about 3 minutes, from there I went to the washroom, and when I spit my saliva had traces of blood, am not sure if it was mine or hers. If it was hers and I also had bleeding gums at the time, how are the risks of contracting HIV?

  11. Hi doctor​I am HIV positive and my boyfriend he’s negative so today he putted his penis on my Virgin mouth he didn’t put inside then I stopped his could he be infected

  12. abcdabcd

    Dear Doctor,

    You say in this page that skin to skin contact with HIV positive person even if they have fluid of unknown origin is NO risk.
    1. Does that mean that a HIV positive person with bleeding cut in the hand giving handjob is no risk activity?
    2. What is the blood touches glans area?
    3. What is the cut was healing?

    Thank you.

    • There have been absolutely zero cases of this type of transmission ever reported. We can thus conclude the risk is effectively zero.

      • abcdabcd

        Thank you doctor.
        1. Whenever experts say that there is zero risk with handjob for HIV, do they already accout for the fact that blood or genetical fluids may touch penis glans?
        2. Could you please briefly explain how exposure with handjob is zero risk even with bodily fluids, but with insertive sex it is not zero risk although the same fluid touches the penis head?

  13. George

    I work in a printing press. Last week I have a cut on my thumb that is nearly healed. Yesterday while cutting fired I accident opened the cut and bled a bit then after finishing with the firewood, the bleeding had stopped. So I went to the office sink and I washed off the blood with water, then I dried the cut area with a shared towel that hung near the sink for drying hands. My worry is that the towel was already wet from being used by other people in tye office.

    1. Suppose an HIV+ person used the towel and left sme blood there, can I get HIV from that
    2. What is the chance of contracting hiv through cuts?

  14. Concerned Gerald

    dear doctors

    i write u from cambodia. i am an exchange student from greenland here for work to teach english to local kids. four days ago i engaged in anal fingering with a hiv + young adult. he undoubtedly fingered himself then fingered me. he didn’t know he was hiv + until i asked him to take a test which was roughly just under 60 hours from our time together (56 hours to be exact). he is not on any medication or arvs as he didn’t know he was +. my concern for your advice. i was put on Tribuss while at the doctor – this is the only PEP available to me here now, I took the first dose 56 hours after the episode while at the doctor. the doctor put me on this because he fingered his anus before fingering me however he was a young and seems liked an inexperienced doctor. healthcare here is limited so i come to this site as i need to know your professional opinion from your experiences with this subject.

    i) was PEP needed for this?
    ii) in your experience is 56 hours too late for PEP?
    iii) people who start PEP at this time, what is the percentage that will have seroconversion occur and make them +?

    yours hopefully in good health.
    gerald

    • If it was just anal fingering, then I do not believe you are at significant risk to warrant PEP. 56 hours is not too late for PEP, it is still very effective up to 72 hours post-exposure, although earlier is better.

  15. Beyers

    Hi Doctors

    I sure you receive this daily from thousand people across the globe and I say thank you for your time and patient for it. You guys do a great job to keep people who make silly mistake in check with the reality of possible outcome. I’m sorry in advance for not so good English as I try my best.

    I know I’m human and we all make mistake but I made one that is eat me up. I come to you and this forum as I had an experience a week ago which I need your advise. I currently work and live in Cairo, Egypt and had a weekend visit with friends to a nearby town last Thursday to Sunday 23 June to 25 June. On Saturday morning the 24th June, I met a Transgender Thai CSW as I was curious about the experience for my first time. I got her detail from the Google and I visit her. In there I didn’t plan on being a risk and we begin session with me protecting both her penis and mine with condoms I buy before going to see her. I began oral on her then she asked if I wanted to insert her. She apply a lubricant which I not sure what type and brands. I then insert her for a few strokes but then I got scare and pul out (so protected insertive anal here). She was then masturbating with my penis (with the condom on). We stop for like five second cause she then ask me if she can insert me and I was okay to just try for it. She then use the lubricant to touching my bum to put around, then she penetrate me for two strokes for about three second and I say stop because it hurt too much. I’m sure she could have her rectal fluid secretion from my covered penis on her hand which was applied against my bum with the lube and then penetrated me. A week later my bum hurts from it as I clench when there was insertion at the time although I am really hoping it is not a STD. I have no discharge but just pain. This time with her was obviously protected receptive anal however with the extreme high chance of her anal fluid secretions being mixed with the lubricant which enter me is make me worry bad. We then play around and the time was over. After the time I found out that she was recently diagnosed as HIV+ which I know her viral load must be very high. I only find out her status on the Monday morning. I go to pharmacy and taken Trivenz (Atripla) PEP as that is all available here PEP at 55 hour delay post exposure. I will to complete this PEP every day on time even if I get very sick. I saw a doctor two days ago for my bum and he gave me antibiotics and injection in case of Gnorrea and Chlymadia. I feel this is similar to a case of anal fingerings with fluids but not really that is why I come to for, for your opinion and to make easy for my worry.

    My questions are for you:

    1) What are is the likely hood I was infected from this episode?

    2) Did I start PEP too late? (I know the cut off time is 72 hour but read many posts about the studys suggest any PEP taken past 36-48 hours is already to late. What is your opinion or experiences with this?

    3) Have you seen someone or peoples taking the PEP at 55+ hours and remain negative?

    4) What is your opinion of Atripla as the only PEP regimen, have you seen or heard of anyone taking this as PEP and remaining negative?

    5) Have you seen a case like this previously and what was the outcome?

    I am a married man with a child on the way. I am lose my mind with a worry and need to know without there being any optimism for truths what’s the reality of my situation. I come from a conservative family and I can’t level with my wife and my family because they will throw me out to the streets me for a mistake. I have a no place to turn to and and this is the only place I can turn to during this very bad space and times in my once very happy life. I am 10 days in to the PEP treatment and taking it like clock work and need to know what are the odds here with the questions I asked answered in as much a detail as possibly could be.

    Please help me.
    I am desperate, sorry for my long message.

    Thank you.
    Beyers

    • Hi. Overall risk for insertive and receptive unprotected anal with an HIV positive partner would range between approximately 0.1-1.5% per act. PEP is definitely still considered effective within 72 hours, and I have seen many patients remain negative after PEP despite starting >48 hours post-exposure. Atripla is effective as PEP. I believe you have done what you can to minimize your risk and I’m confident you will be fine at the end of your PEP.

      • Beyers

        Hi Dr. Jonathan.

        Thank you for the fast reply.
        I have only one more question, You say you have seen many patients remain negative, for those that don’t remain negative, what is the percentage as this would be PEP failure? I just want to know my realistic odds.

        Thank you.

Leave a Comment

error: Content is protected
Copy Protected by Chetan's WP-Copyprotect.