Hunting down the HIV virus

Case

Hunting down the HIV virus

New test makes identifying the type of virus cheaper and simpler

Increasing numbers of people in developing countries are becoming infected by a type of HIV virus that is resistant to one or more AIDS inhibitors. Identifying which type of HIV a person is infected with is therefore the first step towards successful treatment. Many developing countries cannot afford to pay for the tests required for this, however. Dutch and African scientists have therefore collaborated with a number of companies in a research project called ART-A to develop a resistance test based on dried blood instead of blood plasma. The new test is much cheaper and, what is more, can be easily carried out under any conditions.

The price of AIDS inhibitors has fallen drastically since the beginning of this century under pressure from political and civil society organisations. This has given millions of people in low and middle-income countries access to treatment and medication. Unfortunately it has also created a new problem: increased use of medicines has led to a surge in the number of people infected with a type of virus that is immune to regular AIDS inhibitors. ‘That is a consequence of the treatment, but also of the specific nature of the AIDS virus,' explains Susan Aitken. She is one of the researchers who worked on the ART-A research project, which stands for Developing an Affordable Resistance Test for Africa.

Drugs for life

'Anyone with HIV or AIDS has to take medication for the rest of their lives. Several pills a day, every day, year in, year out. That's the only way of suppressing the virus,' Aitken explained. 'The often very unpleasant side effects make this treatment difficult to sustain. In Africa, you also have the problem that patients cannot always get hold of a new supply of medicine in time. And sometimes people just forget to take their pills. The HIV virus rapidly starts multiplying and mutating after a few days with no medication. If the mutated virus is passed on to another person, it can spread very quickly because it no longer responds to the old drugs. And new medicines specially designed to combat a mutated variant of the virus are many times more expensive.'

Simplifying the resistance test

Authorities need to keep a close eye on changes in resistance of the virus in order to be able to set up effective treatment programmes to combat HIV and AIDS. And many African countries are at the limits of their capabilities in that respect. Standard resistance tests are not only expensive, but are also technically very complex. It is the test process that chiefly makes existing tests unsuitable for use in developing countries. 'You need blood plasma to do these tests,' Aitken explains. 'Taking blood samples is already a high-risk undertaking for which you need trained staff. After that, the plasma has to be kept at a constant temperature of -80 degrees Celsius while being transported to a central lab. Once there, it is spun in huge centrifuges and only then is it suitable to undergo the resistance test. Every one of these steps is difficult to achieve in many African countries.'

Dried blood can be kept for two weeks without being cooled
- Susan Aitken

The ART-A research project therefore had two goals: to develop a much cheaper resistance test and at the same time one that is appropriate for conditions in Africa. Researchers from institutes including the University Medical Center Utrecht, the South African University of the Witwatersrand and the biotech company Virco have jointly developed a method for which a few drops of dried blood suffice. Aitken: 'Enough material can be obtained from a tiny prick of the patient’s finger. This is a very simple procedure that can also be conducted without much risk in even the most remote areas.'

Dried blood in standard freezer

Did you know? The blood sample is collected on special filter paper. The dried blood is still suitable for being tested after being kept out of the fridge for two weeks.

The use of dried blood for analysis is not new, but little research has been done into it. 'One of the things we wanted to know was what the ideal conditions for storing dried blood were, without affecting the reliability of the test.'

The new method makes the use of expensive super-freezers and centrifuges redundant. Aitken: 'We discovered that dried blood can be kept for two weeks without being cooled. It only starts to become less useful after that. Once these two weeks have elapsed, it has to be stored at -20 degrees Celsius. That can be done in a standard freezer and so is perfectly feasible in Africa, even in the most remote areas.' Once the blood sample has been taken it can be sent by post to a central lab. Because there is no longer a need for centrifuges, the test to be carried out in the lab is much simpler and cheaper.

 

Locally produced

The next step is to convert the research results into organising a practical production and logistics programme. ART-A has received additional funding to do this. The money will be used to set up facilities in Africa where the test can be produced by local companies. From there, the test can be distributed throughout the African continent.

The ART-A research project is part of the NACCAP programme: Netherlands-African partnership for Capacity development programme and Clinical interventions against Poverty-related diseases. This programme is funded by the Dutch Ministry of Foreign Affairs and coordinated by NWO-WOTRO.

The research into the development of the resistance test was completed in 2012.