Virus mini lab in a suitcase
March 3, 2015
When a patient shows up at the doctor's office with fever, the first assumption in countries with colder climates usually is: "another case of the flu." In tropical regions, however, doctors are likely to offer "malaria" as a first ad hoc diagnosis. But this first assumption can be dangerously misleading. The fever could also have been triggered by a much more dangerous infection, such as the Dengue, Marburg or Chikungunya virus, or even - in the worst scenario - by Ebola.
It is critical that medics obtain clarity about the origin of symptoms as early as possible. With this in mind, virologist Ahmed Abd El Wahed thought it would be good to have a small, mobile laboratory. He pursued his idea together with a colleague, Frank Torsten Hufert, at the University of Göttingen, where Abd El Wahed was researching at the time. Initially, his aim was to offer doctors in Mecca a device they could use to test pilgrims of the Hajj for the MERS-Corona-virus.
Back then, nobody in Saudi Arabia was interested in his suitcase. However, Abd El Wahed now hopes that the invention could be of use in Africa: a mobile laboratory, which fits into a suitcase, can run full-fledged genetic analyses on a number of different viruses. Moreover, the tests reach a degree of reliability that was so far unthinkable outside well-equipped classical medical laboratories. So the mini-lab is well suited for use in clinics in the Ebola-affected regions of West-Africa. And it is already in use there.
Not a rapid test
An Ebola rapid test - similar to a pregnancy test - has been on the market since January. However, the suitcase-lab is not supposed to replace that option.
But, while every physician can carry the rapid test at all times and identify an Ebola-infection with a high degree of certainty, the method is not fool-proof. There is still the possibility that an Ebola-infection remains undetected. Therefore, in case of suspicion, blood-tests will always have to be taken and sent to a proper laboratory for DNA-testing.
And this is where the suitcase lab comes into play: Abd El Wahed's brain child can perform in-depth DNA-analysis right on the spot - a great advantage in underdeveloped countries where bad roads can make transportation difficult. Furthermore, the lab can test blood samples for as many as eight different viruses, including all three known varieties of Ebola - something the instant test can't do.
Multiplying genetic information
To conduct DNA-analyses, researchers need to multiply specific sections of genetic information. Traditionally, this is done using a method called polymerase chain reaction (PCR).
This method is used when forensic investigators take genetic fingerprints, or when medics conduct a paternity test or food controllers want to find out the origins of meat.
But PCR requires a complex laboratory with extensive equipment. Test tubes with the genetic material must be heated and cooled repeatedly: first to 96 degrees, then to 50-60 degrees and again to 72 degrees Celsius. This procedure must be repeated numerous times, which can take hours. Also, some ingredients must be continuously cooled to minus 20 degrees Celsius during transport.
Breakthrough with a new method
This changed in 2006 when a team of researchers under biochemists Olaf Piepenburg and Niall Armes invented a new DNA multiplication procedure called recombinase polymerase amplification (RPA).
RPA multiplies the required genetic information of the viruses faster than PCR - within ten to fifteen minutes. In addition, RPA works at a continuous temperature of 37 degrees, which means no cooling is needed in the process or transport of ingredients.
In June 2014, Abd El Wahed, who works at the German Primate Center in Göttingen, had his suitcase ready for use. Piepenburg and Armes contributed necessary equipment and ingredients, which they have now converted into a start-up enterprise.
Abd El Wahed's former boss, the virologist Manfred Weidmann - now teaching at the University of Sterling - contributed the specific RPA test for the Ebola virus.
The device receives its electric power from a solar panel. At the moment, it is being tested with cooperation partners of theInstitut Pasteur in Dakar/Senegal and with the Institute of Public Health in Guinea.
Besides hospitals, Abd El Wahed also thinks the suitcase could be useful at airports. "If someone arrives at an airport with symptoms, you can find out what he has in 15 Minutes," Abd El Wahed boasts. The estimated costs for the mini-lab is currently around 5000 euros. Each test costs about four euros.