Mutant mosquitoes may prevent dengue

There is treatment for dengue, but no vaccine to prevent the disease. No one even knows how to control the Aedes mosquito which carries the disease.

Scientists are experimenting on transformation of the Aedes mosquitoes in an attempt to halt the spread of dengue.

Entomologists and pathologists said dengue will not be eliminated until the Aedes mosquito is destroyed. Though it may not be possible to destroy Aedes mosquito absolutely, dengue can be reduced to a minimum if the insect is unable to carry the virus. However, it is still not clear how the transformed mosquito will affect the animal world.

Scientists of Bangladesh Atomic Energy Commission (BAEC) said the dengue virus will not spread if the female Aedes mosquito is rendered infertile. The experiment on this has started in Savar. Members of International Atomic Energy Commission came to Dhaka in this regard.

Australian scientists meanwhile said the dengue virus will not spread if Aedes is intentionally infected with the Olbakia bacteria.

The number of dengue patients in the country this year reached 61,039. According to the information of the control room and health emergency centre of the Directorate General of Health Services (DGHS), 1,446 new dengue patients were admitted to the hospitals on Friday. Among them, 689 patients were admitted in Dhaka and 757 patients were admitted outside Dhaka.

Infertile mosquitoes

Government’s atomic energy research centre has taken up a project to render infertile the male Aedes mosquitoes to control the dengue situation. The government officials said the experiment of ‘Sterile Insect Technique’ (SIT) was successful in the laboratory.

The male mosquitoes are released into the environment after making them infertile using gamma rays. These mosquitoes will be unable to produce larvae and thus the production of Aedes mosquitoes can be controlled. This way the spreading of dengue will be controlled.

According to the Institute of Epidemiology, Disease Control and Research (IEDCR), male Aedes mosquitoes do not bite people and also not carry the dengue virus. This is why they are not harmful for the environment. It will help control the dengue outbreak. The members of international atomic commission are currently in Dhaka to provide technical support to the atomic energy commission for the field test of the method.

Bacteria infected mosquito

Scientists said Aedes mosquitoes can be infected through bacteria also as it is infected with virus. The spreading of dengue virus can be disrupted if the Olbakia bacteria is injected into the body of Aedes mosquito. The method was successful in Australia in 2004. IEDCR said the method is effective in 12 countries worldwide under the project named World Mosquito Programme.

A number of sources of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) said the organisation is ready to test run the project.

Consultant professor of icddr,b, Mahmudur Rahman, said the Aedes mosquito first gets infected with Olbakia bacteria. The Olbakia infected male mosquitoes are unable to fertilise the eggs while mating with the female mosquitoes. On the other hand, the female mosquitoes carrying Olbakia bacteria will be giving birth to mosquitoes with the same bacteria. Thus the Aedes mosquitoes will be replaced by the bacteria infected mosquitoes.

According to icddr,b, said this is a way to control the mosquito-borne diseases like dengue and chikungunya without hampering the natural ecosystem.
During a press briefing on his recent visit to Dhaka, senior entomologist of World Health Organisation (WHO), BN Nagpal said the technology is on test run. He also added that expert people and efficient laboratories are needed for a successful test of the technique.

Entomologist and professor of zoology at Jahangirnagar University, Kabirul Bashar said people should know the side effects before using any new technology, medicine or ointment. He also said that use of mosquito repellents should be continued. No one can ensure the success of the mosquito mutating projects, he added.

* This report appeared in the print edition of Prothom Alo and has been rewritten in English by Saimul Huda