Dengue fever With bacteria against viruses

Australian researchers have infected and exposed about 300,000 mosquitoes to the fruit fly bacterium Wolbachia. The bacteria should actively fight against dengue fever viruses

25/08/2011

An unusual but apparently effective method has been developed by Australian scientists to stem the spread of dengue fever. To fight the virus, researchers at the University of Melbourne have infested mosquitoes with bacteria that are believed to help control the pathogens of dengue fever. The mosquitoes have already been widely exposed after initial experiments in the laboratory were successful. There is no danger for man, as the scientists emphasized.

In Australia, researchers have launched a major experiment. For this they infected Egyptian tiger mosquitoes (Aedes aegypti mosquitoes) - which are considered the main vectors of dengue fever - with the bacterium of the genus Wolbachia. These bacteria are considered to be harmless to humans and are native to numerous species of insects. If a mating occurs between a non-infected female mosquito and an infected mosquito male, the larvae die off. If both parent mosquitoes were infected, the offspring of the mosquitoes usually survive. The hope of the researchers is that after a certain period of time the proportion of Wolbachia bacteria infected insects increases and the causative agent of the dangerous fever disease can not spread further. At least in the previous laboratory tests, initial successes were achieved, as the research team led by Ary Hoffmann of the University of Melbourne in the journal „Nature“ to report.

In a total of ten weeks, scientists are exposing the germ-infected mosquitoes in two North Australian communities. According to initial analyzes, the proportion of infected mosquitoes - in whose saliva there was no dengue virus - increased continuously in the first few weeks. After completion of the study, the proportion of bacterial insects was over 80 percent and in some test areas even almost 100 percent. "We are very proud of this success," said Scott Ritchie of James Cook University.

The researchers have already received high praise from experts. Jason Rasgon from the Johns Hopkins Malaria Research Institute in Baltimore wrote in an adjunct to the findings of the study that now one „new era in the control of mosquito-borne diseases“ started. The first milestone has now been reached. In subsequent studies, it must now be checked whether the number of dengue patients in the test areas actually decreases significantly. So far, physicians and researchers have not been able to develop an effective strategy to stop the spread of the disease. More than 100 million people fall ill each year, especially in tropical and subtropical regions. More than 40,000 patients die every year from the infectious disease. Europe and Germany have also seen a rapid increase in new infections in recent years. Researchers are responsible for the steadily increasing climate change.

The viral infectious disease is the world's most common and fastest-spreading mosquito-borne disease. According to the World Health Organization (WHO), around 50 to 100 million people worldwide are infected with it each year. With around half a million infected people, the dengue fever takes a serious course. Especially children and immunocompromised patients are at risk of a deadly end. While in the subtropical regions, the number of cases skyrocket astronomically, in the year 2010, 290 people in Germany fell ill with the fever. All German patients, however, had introduced the illness from their holidays. In addition to flu-like symptoms, internal bleeding and, in the case of a severe course, the life-threatening "dengue hemorrhagic fever" can occur. (Sb)

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Picture: Depeche