There are two main forms of the human immunodeficiency virus, HIV-1 and HIV-2. HIV-1 was discovered in 1983 at the Institute Pasteur in Paris, and HIV-2 was first identified among patients in Cameroon in 1985. HIV-2 is less virulent than HIV-1, and does not usually result in full-blown acquired immune deficiency syndrome (AIDS); nonetheless, ultimately it is still fatal.
By infecting and gradually destroying the immune system, HIV reduces the body’s protection against cancers, pneumonia and other infections that can take hold and lead to death. Initially, someone living with HIV may not display symptoms of the infection because their immune system can keep it under control, but ultimately drug support will be required. Anti-HIV drugs can help the immune system and keep the HIV infection under control, but it cannot completely rid the body of HIV infection.
Global perspective
Sub-Saharan Africa, is home to just over 10% of the world’s population but to over 60% of all people (25.8 million) living with HIV. In 2005, an estimated 3.2 million people in the region became newly infected, while 2.4 million adults and children died of AIDS. By 2010, an estimated 18 million children in sub-Saharan Africa alone will be orphaned by HIV/AIDS.
In 2005, approximately 8.3 million people in Asia were living with HIV, including 1.1 million who became newly infected in the previous 12 months. Over 500,000 people died from the disease in 2005.
Across Eastern Europe and central Asia, the number of people living with HIV was estimated at 1.6 million in 2005. Around three quarters of new infections reported between 2000 and 2004 were in people under 30 (compared to 33% in Western Europe). In Latin America the number of people living with HIV was estimated at 1.8 million in 2005.
Clearly, more rapid testing and diagnosis of HIV will help patients access life-saving medication and treatment.
Testing on the Tyne
Following a successful 12-month pilot project, the sexual health team from Newcastle Primary Care Trust has implemented HIV FASTEST, an innovative community service that provides HIV test results in one hour. Staffed by experienced sexual health professionals, the service encourages gay and bisexual men to take a free, confidential HIV test. No appointment is necessary at the city centre ‘drop in’ facility and results are available in 15 minutes, eliminating the worrying wait. Clients with HIV-reactive tests are referred immediately to genitourinary medicine (GUM) services for specialist care and support.
Undiagnosed HIV continues to represent a major public health issue, and Kathryn Kain, senior health advisor for Newcastle PCT’s GUM department, explained how HIV FASTEST helps to address the problem: “Our intention is to get more patients with HIV infection diagnosed earlier and fast-tracked into treatment and care services, improving outcomes and reducing onward transmission. We are removing the barriers to testing by improving access, reducing waiting times and providing professional advice and support.”
The team evaluated several HIV test kits and selected Determine HIV from Inverness Medical on the basis of ease of use, safety, reliability and cost. Performed on fingerprick samples, the test detects HIV-1 and HIV-2 with 100% sensitivity and 99.75% specificity. Clear results are available in 15 minutes, and, with no need for equipment or refrigeration, the kits are easy to transport and store.
User feedback on the FASTEST service has been very positive, being described as “much needed, friendly, confidential and professional”.
Determined detection
Determine HIV-1/2 is a visually read in vitro qualitative immunoassay for the detection of antibodies to HIV-1 and HIV-2 in human serum, plasma and whole blood. With its simple one-step procedure for serum/plasma, and two-step procedure for whole blood, Determine HIV-1/2 is quick and easy to use, delivering clear, dependable results in just 15 minutes. By detecting all known subtypes of HIV, Determine HIV-1/2 will help healthcare workers across the world diagnose individual infection, prevent mother-to-child transmission, monitor HIV prevalence and screen blood donations.
As with many in vitro diagnostic tests, however, a negative result with Determine HIV does not exclude the possibility of infection with HIV. A false-negative result can occur in certain circumstances:
* when only low levels of antibody (eg in early seroconversion specimens) are present which are below the detection limit of the test
* in infection with a variant of the virus that is less detectable by the Determine HIV assay configuration
* in exceptional cases where the HIV antibodies in the patient do not react with specific antigens utilised in the assay configuration
* in specimen handling conditions that result in loss of HIV antibody multivalency.
Scientifically engineered to provide dynamic performance in a rugged and robust format, Determine HIV-1/2 can be shipped, stored and used in nearly any environmental condition (2–30ºC), even where there is no power or water. Easy to use and highly flexible, Determine HIV-1/2 requires minimal training, no equipment and can be relied upon for fast and accurate diagnosis in the most basic of healthcare settings. Refrigerated storage is not required with Determine HIV-1/2 and it has in-built flexibility to be used with whole blood or serum/plasma, collected either by fingerprick or venipuncture.