Can there be a world without antibiotics?

Medical experts around the globe are worried that more and more viruses and bacteria are becoming resistant to today’s medicine. They are afraid that in a few generations antibiotics may become useless. Scientists have already discovered bacteria that do not react if treated with antibiotics. As a result medical treatment will become more expensive as new drugs have to be developed.

Doctors and other health experts criticize the fact that antibiotics are being used in a wrong way. They are often prescribed in cases in which they do not work. In some areas, especially Third World countries and densely populated areas in India, Pakistan or Bangladesh doctors have already run out of antibiotics. Prescribing wrong antibiotics or taking them for too short a time will not kill off bacteria. Some doctors prescribe antibiotics for the common flu, making it ineffective for later illnesses. The World Health Organization claims that many infectious diseases are becoming untreatable and cannot be controlled. Many patients who become resistant to drugs even die.

Another problem is that farmers in the United States and Europe are adding antibiotics to feed cattle and other animals, in order to make them grow faster and produce more meat. Also, through increased global travel, bacteria are spreading faster than ever before.

Since Alexander Fleming discovered penicillin in the early 20th century antibiotics have saved hundreds of millions of lives. Many operations cannot be carried out if we are unable to treat infections. The transplantation of organs can become very risky if patients do not get medication to strengthen their immune system. Routine operations like removing an appendix or replacing a bad hip could become fatal. Childbirth may once again threaten a woman’s life and raise child mortality. Even illnesses like pneumonia, which today can be treated effectively with antibiotics, might once again turn into a mass killer. Antibiotics have made infections like tuberculosis treatable. Cancer treatment would be unthinkable without the proper treatment of the immune system to accompany it.

Health experts call for increased action to fight off diseases. Most common is the call to improve hospital hygiene, where infectious diseases start out. Especially in Third World countries, bacteria spread through dirty water and the sewage system. Even making people aware of washing their hands more often can stop the spread of infectious diseases.

(www.english-online.at. Adaptado.)

RADIATION AND EVOLUTION

1 THE disaster last year at the Fukushima Dai-ichi nuclear power plant, caused by an earthquake and tsunami, scored seven on the International Nuclear and Radiological Event Scale (INES). No worse rating exists. Radiation is harmful to living things, yet the long-term effects of persistently high levels of background radiation on ecosystems are poorly understood. With this in mind, a team led by Timothy Mousseau of the University of South Carolina and Anders Moller of the University of Paris-Sud set out to compare bird species dwelling near the Fukushima plant with those living at the site of another nuclear incident that scored a seven on the INES: the Ukrainian town of Chernobyl, where disaster struck in 1986. Remarkably, they found that some species seem to develop a tolerance for radioactivity over time.

2 Fukushima and Chernobyl are more than 7,000km (4,350 miles) apart, but Dr Mousseau and his colleagues soon realised that the two sites had much in common. Both are in areas that have a temperate climate with species that have similar habits and needs. And both are surrounded by a mixture of farmland and forest. Upon closer examination the researchers found that 14 species of bird lived in both regions, including the barn swallow, great tit, great reed warbler, buzzard and Eurasian jay. With so many similarities between the two places, a comparison of the biological responses to radiation in each (recent in Fukushima; long-term in Chernobyl) would surely be illuminating.

3 To do this, during July 2011, the researchers counted and identified birds at 300 locations near Fukushima that had radiation levels as low as 0.5 microsieverts per hour and as high as 35 (for comparison, dental X-rays rarely expose patients to more than 0.05 microsieverts). Then they compared these results to bird data collected in areas that had the same range of radiation levels near Chernobyl between 2006 and 2009.

4 Their results show that as radiation levels in an area rose to 35 microsieverts per hour, the average number of birds dropped by almost a third compared with the areas where radiation levels were only 0.5 microsieverts per hour. This makes sense: in those areas with a high  level of radiation, living things would tend to die or sicken and fail to reproduce. However, when researchers looked at the 14 bird species that lived in both regions, they found that the same level of radiation was associated with twice as large a drop in bird numbers in Fukushima as in Chernobyl.

5 The reasons for this are not clear. It is possible that the composition of the radionuclides are proving more dangerous to the Fukushima birds than they are to the birds near Chernobyl. But Dr Mousseau suggests a more likely explanation is that evolution has already been at work near Chernobyl, killing off individual birds that cannot cope with the background radiation and allowing the genes of those that have some tolerance to be passed on. The birds at Fukushima are only beginning to face the evolutionary challenge of living in a radioactive world.

Adapted from The Economist, March 3, 2012