Zika Current Affairs

Scientist develop rapid test to diagnose Zika and dengue

Researchers including from India have developed low-cost, rapid diagnostic test consisting of pan-dengue strip for diagnosing Zika and dengue viruses and differentiating four serotypes of dengue virus.

Zika and dengue both belong to same viral family, which are called flaviviruses. They are two closely related viruses spread by the same mosquito

Key Facts

The test resembles pregnancy test strip and contains antibodies that react to presence of Zika or dengue virus, and also contains gold nanoparticles that respond to antibody reaction. It does not have cross-reactivity leading to wrong diagnosis as antigens specific to dengue and Zika viruses were identified.

To use the test, medical professional dipped strip into a tube of either blood serum or whole blood of patient. If the test is positive, then dot or line was seen on the strip that results from seeing gold nanoparticles that signal antibodies recognising viral protein.

The diagnostic test has nearly 100% ability to distinguish between two virus infections. It has nearly 76-100% sensitivity and specificity in case of dengue and in case of Zika, it has 81% sensitivity and 86% specificity.

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Genetically Modified mosquito trials launched to control dengue, chikungunya and zika

Outdoor caged trials of genetically modified mosquitoes waere launched in Dawalwadi, Badnapur in Jalna district of Maharashtra to demonstrate the efficiency this technique to suppress wild female mosquito populations that transmit dengue, chikungunya and Zika.

The trials are conducted by Oxitec and uses the Release of Insects carrying Dominant Lethal genes (RIDL) technology.

Key Facts
  • Oxitec’s technology uses GM male Aedes aegypti mosquitoes that carry a dominant lethal gene. This gene is passed on to offspring after male GM mosquitoes mate with wild female mosquitoes.
  • The lethal gene in the offspring kills the larvae before they reach adulthood. Since male mosquitoes do not bite humans, the release of these GM mosquitoes will not increase the risk of dengue, chikungunya and Zika.
  • Oxitec’s mosquitoes were first released in Brazil were they have successfully reduced the local populations of mosquitoes by more than 90%, whereas insecticides only affect 30%.
  • Advantages: This strategy is considered as most eco-friendly solution so far to control the spread of infectious diseases as it only targets a specific mosquito strain and does not produce any toxic compounds. It has 99% efficiency to kill offspring.
Background

Dengue is estimated to infect 5.8 million people in India every year, costing the country over $1 billion annually. In recent times, outbreaks of Chikungunya, a mosquito borne viral disease have been increasingly reported in India. Both viral diseases are transmitted by female Aedes aegypti mosquitoes. The World Health Organization (WHO) has fully supported the genetically engineered mosquitoes during last year’s Zika outbreak.

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