Human immunodeficiency virus (HIV)

Human Immunodeficiency Virus (HIV) remains a significant public health focus in Hong Kong. While the current prevalence of HIV infection in the general population is 0.1%—well below the global average—understanding the local landscape of the virus is crucial for continued prevention and care . The Hong Kong Department of Health maintains a robust surveillance system, and recent data shows encouraging trends, including a ninth consecutive year of decline in new infections . This article provides a comprehensive overview of the HIV situation in Hong Kong, including the latest statistics, transmission routes, prevention strategies, and where to get tested.

◈ Latest HIV/AIDS Statistics in Hong Kong (First Half of 2025)

Staying informed with the most recent data is key to understanding the epidemic's trajectory. The following table summarizes the key figures for the first half of 2025, as reported by the Centre for Health Protection (CHP) .

Life cycle of HIV

The life cycle of the human immunodeficiency virus (HIV) is a complex 7-step process which involves invasion and destruction of the CD4 cells (a type of white blood cells that forms the body’s natural defense system), therefore destroying the immune system as the virus replicates. There are two types of HIV virus

• HIV-1, which accounts for almost all HIV infection worldwide, and
• HIV-2, which is mostly confined to west Africa, is less infectious and is associated with slower decline in CD4 cells and progression of disease.

There are 3 stages of HIV infection, acute HIV infection, chronic HIV infection and AIDS.

Acute HIV infection - Stage 1 

During acute HIV infection, which is defined by the period between the presence of HIV RNA and detectable antibodies level (REF1), the HIV virus multiplies rapidly and is found in high concentration in the blood and bodily fluids for about 10-12 weeks (REF2). It has been reported that patients during the acute HIV infection state is 26 times more infectious than those during chronic HIV infection. It is suggested to get HIV test and start the HIV treatment. Approximately 10-50% of new HIV infections is believed to occur during the acute infection period, especially in relationships involving multiple or frequent change of sexual partner (REF3).

Chronic HIV infection - Stage 2

After the symptoms subsided, patients can remain asymptomatic but infectious for years while the virus continues to multiply at low levels. Without treatment, most patients will progress to AIDS.

AIDS - Stage 3

AIDS (acquired immunodeficiency syndrome) is the final stage of HIV infection, which is characterized by low CD4 count (less than 200 cells/mm3), as a result of prolonged untreated HIV infection, or the development of opportunistic infections (infections that usually pose little to no harm in healthy individuals) (REF4). Patients with AIDS have a high viral load and are very infectious.

◈ Key Trends and Public Health Challenges

↘ A Persistent Challenge: Late Presentation

Despite positive trends, a significant challenge is the high rate of "late presenters." This refers to individuals diagnosed with HIV when their CD4 immune cell count is already very low (below 200 cells/mm³) or when they have already developed an AIDS-defining illness . In the first half of 2025, the proportion of late presenters rose to 58% . Late diagnosis leads to a higher risk of opportunistic infections and a tenfold increase in mortality rate compared to those diagnosed early .

↘ Transmission and At-Risk Populations

Sexual contact continues to be the dominant mode of HIV transmission in Hong Kong, accounting for over 95% of new cases . The data indicates that more than half of the sexually acquired infections in 2025 were through homosexual or bisexual contact . It is also important to note that individuals who do not consider themselves part of a high-risk population may still be vulnerable, as this group accounts for 60-70% of late presenters .

Prevalence of worldwide HIV infection

According to UNAIDS, in 2023,

Worldwide:

• 39.9 million [36.1 million–44.6 million] people globally were living with HIV
• 1.3 million [1 million–1.7 million] people became newly infected with HIV
• 630 000 [500 000–820 000] people died from AIDS-related illnesses
• 30.7 million people [27–31.9 million] were accessing antiretroviral therapy
• 88.4 million [71.3 million–112.8 million] people have become infected with HIV since the start of the epidemic.
• 42.3 million [35.7 million–51.1 million] people have died from AIDS-related illnesses since the start of the epidemic

Asia and the Pacific region:

• 6.7 million people were living with HIV
• 13% decrease in new HIV infections since 2010
• 51% decrease in AIDS-related deaths since 2010
• 67% were on anti-retroviral therapy (ART)
• 300,000 newly infected cases were reported
• 150,000 deaths were reported due to AIDS-related illnesses

HIV Prevention and Testing in Hong Kong

Consistent and correct condom use remains the cornerstone of HIV prevention through sexual transmission . Alongside prevention, regular testing is essential for control.

↘ Where to Get Tested in Hong Kong

Hong Kong offers multiple accessible and confidential testing channels :

Free Anonymous Testing: The Department of Health provides free, anonymous, and confidential HIV antibody quick tests ( 90 days window period is required). Appointments can be made via the HIV Testing Service website (www.hivtest.gov.hk) 

Self-Testing Kits: Oral fluid-based or blood-based (finger-prick) self-test kits can be ordered online and collected at designated pick-up locations across Hong Kong .

Urban Medical provides all-rounded HIV tests, such as HIV RNA Test, HIV p24 antigen/antibody test, HIV quick test, which required 7, 14, 90 days respectively, with extremely fast report.

Treatment and the Path to a Functional Cure

↘ Effective Management with ART

HIV is now a manageable chronic disease . With early and consistent antiretroviral therapy (ART), people living with HIV can achieve an undetectable viral load, which not only preserves their health but also prevents transmission to sexual partners. This concept, known as Undetectable = Untransmittable (U=U), is a critical public health message

◈ Conclusion: A Shared Responsibility

Hong Kong has made significant strides in controlling its HIV epidemic, as evidenced by the declining number of new infections. However, the high rate of late presentation highlights an urgent need for increased public awareness and more frequent testing, even among those who do not perceive themselves to be at high risk. By combining consistent condom use, regular testing, immediate treatment, and supporting local innovations in research, Hong Kong can continue its progress toward ending the AIDS epidemic as a public health threat.