Testing options

Conventional test

Conventional test refers to taking blood from a vein and sending the specimen to a laboratory where trained technicians perform the test, followed by confirmatory tests if necessary.

Rapid test

Rapid test refers to obtaining a blood drop from a finger-prick (or oral fluid by swabbing the gums), performing the test on-site and reading the result in about 20 minutes by a healthcare worker or community worker.

How is HIV rapid test performed?

  • Clean fingertip with alcohol and prick with a lancet. Get a small drop of blood with EDTA capillary tube. Transfer the sample to the test strip and apply one drop of Chase Buffer. Result of the test can be read after 20 minutes.
  • Please note: Rapid test is only a screening test. Any positive rapid test result should be followed by confirmatory test of venous blood conducted by a laboratory.

HIV self-testing

HIV self‑testing refers to the process by which a person collects a specimen, performs a test and interprets the test result by oneself to check his/her HIV status. The procedure of HIV self-testing and rapid test is the same. The only difference is that self-testing requires the users to read and interpret the results by themselves.

HIV self-testing is used for preliminary screening. Any positive HIV self-test result must be confirmed by laboratory-based testing with a venous blood sample.

Suggested user

HIV self-testing is suitable for most people, however the following person is not recommended to use:

  • already been diagnosed with HIV infection in other clinics/ laboratories
  • already been tested with HIV positive by rapid test in non-governmental organisations
  • feeling very nervous about getting an HIV self-test
  • unable to follow the instructions of using the HIV self-test kit
  • do not have confidence to interpret the test result on your own
  • currently on HIV Pre-exposure Prophylaxis (PrEP), HIV Post-exposure Prophylaxis (PEP) or HIV antiretroviral treatment

For the above conditions, you are advised to approach the AIDS Counselling and Testing Service or other services providing HIV testing in Hong Kong.

Comparison of conventional test, rapid test, and self-testing

The following table shows the advantages and disadvantages of these methods:

Conventional test Rapid test Self-testing
Cost
  • Government service (AIDS Hotline) and some of the local AIDS NGOs provide free services
  • Free in Government service (AIDS Hotline) and local AIDS NGOs
  • Order free HIV self-test kit (Press here)
  • Or purchase a testing kit by themselves
Privacy and confidentiality
  • Anonymous and confidential in AIDS Hotline of Department of Health and local AIDS NGOs
  • Requires personal information if done in hospitals or clinics other than the above
  • Anonymous and confidential in AIDS Hotline of Department of Health and local AIDS NGOs
  • Greater privacy with total self-control
Turnover time and accuracy of result
  • Confirmatory result available in 5-7 days and it is a definitive diagnosis
  • Result available in 20-30 minutes. Positive results require another confirmatory test
  • Misinterpretation is not common as test performers are trained to provide the testing service
  • Self-testing result available in 20-30 minutes. Positive results require another confirmatory test
  • Risk of misinterpretation of results by users themselves
Accuracy (Sensitivity and specificity)
  • Very high accuracy, gold-standard
  • High accuracy in trained hands
  • Accuracy slightly reduced in untrained hands
  • Risk of procedure error
Window period
  • shorter window period as 4th generation technique is currently used in Hong Kong government laboratory
  • Shorter window period especially when 4th generation kits are used
  • Longer window period if lower generation kits are used
Counselling, support service and linkage to care
  • Good
  • Good
  • Risk of insufficient counselling and support service
  • Lack of / delayed linkage to care
Other advantages and disadvantages
  • Greater convenience in time and space