Can genetically modified mosquitoes eradicate Malaria, Zika, Chikungunya and Dengue?

By: | Muhammad Ali Azlan |

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Web Desk: The small, dark female mosquito transmits deadly viruses, like dengue fever, chikungunya, malaria and the Zika virus.

The Aedus aegypti can be termed the ‘Ultimate Pest’.

Aedes aegypti, the yellow fever mosquito, is a mosquito that can spread dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents. The mosquito can be recognized by white markings on its legs and a marking in the form of a lyre on the upper surface of its thorax. This mosquito originated in Africa, but is now found in tropical, subtropical and temperate regions throughout the world.

Their eggs can last up to a year without water and they can “travel” on planes, trains, and automobiles. That’s how these insects have infested global populations.

Pakistan, along with other Asian countries, is undergoing substantial climate changes. The summers are getting harsher, whereas the winters are getting milder with every passing year. The rising temperature has nurtured the outbreak of many arboviral illnesses in the region, including malaria and dengue. The deplorable sanitary conditions of most Asian countries further adds fuel to the fire

An arbovirus is angent that is maintained in nature primarily “through biological transmission between susceptible vertebrate hosts by hemato-phagous (blood-feeding) arthropods” (WHO Scientific Group, 1969). Two important processes are implied in this definition. The first is that in general, before an arthropod vector can become infected it has to feed on a vertebrate host which has circulating virus in its blood. Secondly, the virus ingested by the vector must undergo a period of replication in the arthropod before transmission to another host can occur. For example, when a vector feeds on a viremic host the virus is deposited in the vector’s midgut where infection of the cells lining the midgut occurs. After a period of replication, virus particles are shed into the body cavity where various tissues become infected. Eventually, the virus reaches the salivary glands, and following a phase of virus replication in these organs, the arthropod can transmit virus to a susceptible vertebrate. This period of virus replication in the vector from the time the virus is initially ingested with a blood meal until the ability to transmit is acquired is termed the extrinsic incubation period and is dependent, within limits, directly on the ambient temperature (Chamberlain and Sudia, 1961; Murphy et al., 1975).

“Dengue fever has been increasing almost 30 times in the past 30 years. It’s increasing all around the world and it’s spreading fast,” says Derric Nimmo, product development manager at Oxitec, a British biotechnology company.

Currently, there is no vaccine or treatment for either Zika or dengue. The only way to fight the spread of the disease is to limit the insect population.

“As scientists, we’ve been fighting a losing battle against mosquitoes. They kill one person every 12 seconds. There’s a desperate need for new technology,” says Andrew McKemey, field operations, Oxitec.

British biotechnology company Oxitec has engineered male mosquitoes to pass a fatal gene on to their offspring, which kills them before they reach adulthood. When released into the environment, Oxitec’s mosquitoes can, in ideal circumstances, suppress the proliferation of mosquitoes and ultimately cut down on the mosquito-borne diseases.

The hope is that if the deadly male mates with wild females, the population will thin. This could potentially save hundreds of thousands of human lives.

However, not everyone is convinced.

According to Oxitec, field trials in the Cayman Islands, Panama and Brazil reduced the mosquito population by 90 percent. In fact, in 2015, a scientific advisory panel to the government of Brazil approved the release of the Oxitec mosquitoes to control a dengue outbreak.

The questions still remain, The mosquito created for ‘good’ today, In the wrong hands can wreak havoc.

In this rapidly advancing and changing society, only time will answer the queries of the curious mind.

For now, It’s man vs nature and that is how it’s always been, unfortunately.

 

 

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