HIV – an overview

Human Immunodeficiency Virus (HIV) is a virus that attacks the immune system and gradually weakens it over time.


How is it spread?

Typically HIV is spread through sexual contact or the sharing of infected drug needles. Previously unscreened blood donations were a potential cause but in developed countries this is almost non-existent because of new stringent screening processes.

Sexual intercourse remains the most common way that HIV is spread.

The table below shows relative risks for unprotected exposure:


All bodily fluids can contain varying amounts of the virus but by far the most potent fluids are blood and semen, hence the risks highlighted in the above table. Vaginal fluid and saliva can contain the virus but at much lower levels.

For more information on how HIV can spread please see here.

HIV - overview


What does it do?

HIV enters the body and binds onto a specific white blood cell known as CD4 cells. Once bound the virus enters the cell, uses the cell to replicate further virus numbers and eventually kills the cell, which releases more virus ready to infect further CD4 cells. If left unchecked and untreated the CD4 count will drop very low and cause problems with your immune system. If left long term this will eventually lead to Acquired Immunodeficiency Disorder (AIDS).


HIV Symptoms?

Symptoms are not specific in HIV meaning that it can mimic many other common conditions. Some people may experience severe flu like symptoms, known as Acute Retroviral Syndrome (ARS) but symptoms alone are not enough to diagnose HIV.

Videos on HIV signs and symptoms:


The only way to be sure for HIV is to get tested. Full laboratory blood tests as well as rapid tests are available that are conclusive at different window periods.

Videos on HIV window period and test accuracy :

Rapid tests – ready in 15 – 20 mins

  • 4th generation combo test – conclusive 28 days or more from exposure.
  • 3rd generation determine test – conclusive 3 months or more from exposure
  • 3rd generation oral swab test – conclusive 3 months or more from exposure
3rd gen
3rd generation test


4th gen
4th generation test


Oral swab test

Laboratory tests

  • 4th generation combo test – conclusive 28 days or more from exposure.
  • 3rd generation determine test – conclusive 3 months or more from exposure.
  • HIV PCR RNA test – conclusive 10 days or more from exposure.

Unfortunately no test is available before 10 days. However, if your exposure happened within the last 72 hours then you can take Post Exposure Prophylaxis (PEP) medication to reduce the risk of HIV transmission.

Video on HIV Post-exposure prophylaxis (PEP)

*Post-exposure prophylaxis (PEP) is short-term antiretroviral treatment to reduce the likelihood of HIV infection after potential exposure.

What if my HIV test is positive?

HIV diagnosis needs to be exact because of the repercussions, particularly in Singapore. Firstly a single ‘reactive’ result must be followed up with a Western Blot laboratory blood test for confirmation. Only after this test is done can we say that a person is ‘positive’ for HIV.

Once this confirmatory blood test is completed doctors are bound by law to inform the ministry of health of the patient’s positive status. Should the patient be on a work pass or PR, they will have this revoked and they will be asked to leave the country.

Seeking treatment as soon as possible after confirmation of a positive status will greatly improve long term outcomes.

Video on HIV Treatment: Highly active antiretroviral therapy (HAART)

Anonymous testing is also available at our Robertson clinic. Here we can only do the in house rapid tests since laboratory tests are not anonymous.



With Anonymous HIV testing, no personal details are needed, and a positive result will not be informed to the Ministry of Health.



Related Topics:

Anonymous HIV testing at our Clinics – here
HIV – Understanding the Window Period – here
Cost of HIV/STD tests at our Clinics
Condom Broke
Getting HIV from Oral Sex
More on HIV symptoms
How long can HIV live outside the body?
Learn more about HIV Testing (F.A.Q) – here


1.) Dr. Tan and Partners @Novena

Men’s Health & Sexual Health Clinic

Dr. Tan Kok Kuan is currently practising in Men’s Health & Sexual Clinic @Novena Medical Centre

Novena Medial Centre
#08-31, 10 Sinaran Drive
Singapore 307506

+65 6397 2095


Operating Hours:
Monday to Friday
8.30 a.m to 5.30 p.m.

9.00 a.m. to 1.00 p.m

Sunday and Public Holiday

2.) Dr. Tan and Partners @Somerset

Men’s Lifestyle Clinic

Dr. Taufiq is currently practising in Men’s Lifestyle Clinic @Somerset (Orchard Building) 

Orchard Building
#10-08, 1 Grange Road
Singapore 239693

+65 6262 0762


Operating Hours:
Monday to Thursday
10.00 a.m to 2.00 p.m. and
3.00 p.m. to 7:00 p.m.

10.00 a.m to 1.00 p.m. and
2.00 p.m. to 7:00 p.m.

9.00 a.m. to 1.00 p.m

Sunday and Public Holiday

3.) Dr. Tan and Partners @Robertson

Men’s Health & Anonymous HIV Testing Clinic

Anonymous HIV Testing in Singapore:
(Don’t require any identification, such as passport, NRIC or contact details during registration. )

Dr Jonathon Ti is currently practising at @Robertson Branch

11 Unity Street
#02-07, Robertson Walk
Singapore 237995

+65 6238 7810


Operating Hours:
Monday to Friday
8.00 a.m to 9.00 p.m.

9.00 p.m. – 9.00 p.m.

9.00 p.m. – 2.00 p.m.

Public Holiday Closed