Each year 1.4 million people die from tuberculosis, many of them in poor countries. South Africa wants to curb the spread of the disease, especially its resistant forms by extremely rapid diagnostic device. It shortens the testing time from weeks to two hours.
The Township KwaMsane is a beautiful place. It is surrounded by hills in the South African province of KwaZulu-Natal. 30 minutes west of here are often elephants, giraffes, zebras and rhinos visible at the edge of a highway that runs through the middle of a national park. A few kilometers east shine sugar cane fields in the subtropical sun and seem to pour into the Indian Ocean. But KwaMsane is a sick place. Many people in the area suffering from tuberculosis, and that the often fatal form of MDR (multi-drug resistant) against which hardly affects a drug
In November 2011 felt the 25-year-old Jabu Ngcobo suddenly a stinging in her side and settled in the clinic of KwaMsane investigate. This is similar to a caravan park where the cars – called Home Park in South Africa – act as a treatment room. A small paved courtyard serves as a waiting room, he is surrounded with plastic chairs. “I thought so, that I have MDR-TB, as well as my two brothers and my sister had the same thing,” said Ngcobo. In fact, she was diagnosed with the resistant form. But unlike her siblings could very next day start therapy.
The rapid diagnosis and healing Ngcobos enabled a machine called the GeneXpert. A few years ago would be the progressive molecular tricks that they identified the DNA of the pathogen Mycobacterium tuberculosis, have been possible only in a highly modern biotech laboratory with expensive diagnostic equipment. In the hospital of KwaMsane she stands on a counter and looks at first glance like a high quality espresso machineThe GeneXpert machine is easy to use. A technician injects a coughed up mucus sample from a patient in a small container that looks like a printer cartridge and puts it into the machine. There is then automatically plays a reaction from, recognize the characteristic pieces of the pathogen DNA and amplified to obtain a sufficient quantity for the investigation. If fluorescent molecules with the target DNA come into contact, they begin to glow. The meter detects and reports it to a computer. In less than two hours can GeneXpert tuberculosis causing bacteria not only prove -., But also accurately determine whether bacteria are present in the DNA that mutations that make them resistant to the most common antidote
Ngcobos of their siblings had only experienced dangerous disease several months after the release of their mucus samples, because they had to be taken to start the next analysis laboratory. But that was in Durban 275 km away. There a so-called bacterial culture was created – this is called the breeding of pathogens in plastic trays that are filled with a nutrient gel. Only when a sufficient amount of bacteria was grown, their susceptibility to drugs was tested. In the best case takes the six weeks in reality often takes three months until the samples arrive at the laboratory, there is time for the analysis and the results are reported.
Only then learn how residents of rural places So KwaMsane whether they will help more than six months a simple antibiotic treatment or if they need a 18-month bombardment with heavy medications. Jabu Ngcobo immediately began taking 22 pills a day and was treated with anti-tuberculosis injections. With her though no more bacteria were already a month later demonstrated. For others, however, the long wait on the diagnosis can have serious consequences. Ngcobos One of brothers who suffered a severe lung injury that will never heal moretuberculosis bacteria enter through coughed-up mucus from the lungs into the air . Who has longer time in close contact with an infectious patient may be infected. One-third of the human population is infected. In the overwhelming majority of the immune system, the infection largely under control, they do not even notice most. But in many poor countries, especially in large parts of central and southern Africa, tuberculosis has continued almost epidemic proportions. 2011 affected an estimated 8.7 million people from the number of deaths reached about 1.4 million per year. Thus, tuberculosis is by the HIV virus to the second deadliest pathogens
One of the main reasons for the persistence of the tuberculosis epidemic is that there is no simple and affordable way to diagnose the infection -. Approximately three million cases per year are not recognized. Many sufferers are not even tested for tuberculosis, with other diagnostic techniques obsolete give falsely clear. Fastest works of “Grease” developed 125 years ago-test, in which colored a mucus sample and is examined under a microscope for the bacteria out
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This text magazine issue 03/2013 is taken from Technology Review. The booklet can, just like the current issue, be ordered online here.
