HIV tests important in preventing the spreading of the virus
HI virus has spread to every corner of the world. Luckily, the virus has been studied thoroughly, and also the developing countries benefit from the new treatments and diagnostics. But how could the spreading of the disease be prevented?
Senior Researcher Henrikki Brummer-Korvenkontio in the laboratory. Photo: Jan Jansson.
HIV is in the media regularly. In Finland, the cases where someone has been suspected to spread the virus intentionally or knowingly have filled the headlines for days. However, the number of infected and the mortality rate due the virus is the highest in Africa.
Everyone should know the facts by now; HIV spreads through the transfer of blood, or bodily fluids involved in sexual interaction. There is no cure for HIV and untreated virus leads to AIDS, which is fatal. Still, in Finland almost two hundred new infections are found every year.
Preventing the spreading of HIV requires easily accessible services
The two major routes of HIV transmission are unsafe sex, and contaminated needles. The most common ways of preventing the spreading of the virus are giving information and advice on the matter, and giving away free condoms. The HIV epidemic among intravenous drug users in Finland has subsided since the 1990s, due to distribution of needles. However, the number of sexually transmitted infections has increased during this decade.
According to Senior Researcher Henrikki Brummer-Korvenkontio from the National Institute for Health and Welfare, most infected people try avoid spreading the virus, if they are aware of it. For that reason many countries, including Finland, offer free, anonymous and quick HIV tests.
Finnish HIV Foundation and AIDS Council offer rapid tests that give the result in 15 minutes. In addition to the AIDS Councils testing facilities in Helsinki and Oulu, the tests are also done in prisons and needle exchange points.
Rapid test ideal in developing countries
The treatment for HIV is expensive. If you compare the price of one rapid test, 10 euros, to the annual cost of HIV treatment per person, 10 000 euros, it easily justified to conduct HIV tests to everyone in the risk group in order to prevent the spreading of the disease. The rather inexpensive rapid test is especially ideal in rural locations where there are no fridges, centrifuges, and other laboratory equipment.
For example Determine HIV 1/2 can be done in humble surroundings. You can watch an animated introduction on how a Determine HIV 1/2 test is done.
The spreading of HIV across the globe. Picture: Wikimedia commons.
False positives are the necessary evil
The HIV test is simple, but the human biology makes testing less straightforward. The test detects antibodies for the virus from a blood sample. Most people develop detectable antibodies approximately three weeks after the infection. But differences between individuals are great, and therefore one has to wait for three months to get the absolutely right result. After three months all infected develop the high enough amount of antibodies that it shows in the test.
A negative result after three months is certain. However, the test may detect also other than HIV spesific antibodies and thus give a false positive result, even though there is no actual HIV infection.
The positive result is the most unreliable in countries like Finland, where the amount of actual HIV infections is low. Therefore all primary positive results have to be verified from blood sample in laboratory. But for example in an African country where 10% of the people are HIV positive, only one in every 50 positive results is false.
Changing the rapid test could lead to the situation, where the test would give false negative results. Therefore the false positives are the necessary evil.
Brummer-Korvenkontio would not like to see HIV tests next to preagnancy tests at the supermarket counters. The main reason is the possibility of false positive results that cause anxiety in people. In addition, the tests are easily accessible in Finland as it is, and this has to be ensured in he future as well.
Translation: Elisa Lautala.
Jan Jansson is a chemistry teacher that spends his little free time doing molecular gastronomic experiments.