Current research effort to control dengue

 

 Vectors for transmitting dengue

Photograph taken during the 1965 Aedes aegypti...

Photograph taken during the 1965 Aedes aegypti eradication program in Miami, Florida (Photo credit: Wikipedia)

Dengue is a disease transmitted between people  by Aedes aegypti and Aedes albopictus, which are called- including other insects- vectors for transmitting diseases.  For transmission to effect, a mosquito must feed on an infected person within a 5-day period when sufficient amount of virus are in the blood  This period usually commences before dengue symptoms appear. Symptoms of infection usually begin 4 – 7 days after the mosquito bite and may last 3 – 10 days.

8-12 days incubation period

Granting a vector mosquito bites a dengue-infected person, it’s  now the opportune time for the virus to enter the mosquito in the bloodmeal, but it will need another 8-12 days incubation before it can be transmitted to another person.   The mosquito remains infected for the remainder of its life, which might be days or weeks. When an infected female Aedes aegypti mosquito bites a person, especially a child who is most vulnerable to this disease, it leaves a virus that causes serious illness and even death if not treated well.

Infected humans are sources of dengue virus

Patients who are already sick and infected with the dengue virus can pass the infection on to other people who aren’t sick through mosquito vectors. In other words, infected humans act as source of the dengue virus for uninfected mosquitoes.  Infected persons facilitate the transfer and spread of the dengue virus from person to person via the vector mosquitoes. This explains why patients in medical rooms or hospitals are closely monitored from getting bitten by mosquitoes.

Origin of Dengue

According to CDC (Center for Disease Control and Prevention), the four dengue viruses originated in monkeys and made their way independently toward humans in Africa or Southeast Asia between 100 and 800 years ago. 

Countries with dengue in 2013 and 2014

Dengue fever got a foothold last year 2013 in Florida, USA, and in Yunan, China as well. In the same year, dengue continue to plague Mexico, Costa Rica and Honduras.  Singapore reported an increase in cases. Outbreaks has likewise been noted in Laos. This year 2014 Cook Islands, Malaysia, Fiji, Vanuato and Pacific Islands have reported an increasing number of cases. WHO said about 500 thousand patients with severe dengue, a majority of them children, need to be brought to hospital each year.  About 2.5% of those affected die.

Wolbachia, a bacterium to control dengue

Researchers worldwide are joining hands to combat and check the spread of the dengue virus. They are convinced that Wolbachia, a bacterium can be used to control dengue. Found in 60% of all insects and harmless to humans, wolbachia was thoroughly studied by scientists through laboratory tests and came up with a promising result that it can effectively block  the transmission  of dengue by mosquitoes. However, the  vector Aedes aegypti that carries the dengue virus is one of the insects which carry  no wolbachia naturally,  but the problem was solved by the same scientists, who have learned through research how to infect them with it. In other words, they were able to successfully place wolbachia in the system of the female Aedes aegypti, and at the same successfully prove that the bacterium wolbachia prevented the transfer or spread of dengue virus.

Wolbachia research center

Gadjah Mada University in Yogyakarta, Indonesia is one of the research centers which is dedicated to the cause of eradicating dengue. It collaborates with other researchers the world over. Their current goal is to raise colonies of wolbachia mosquitoes for release in the wild in hopes that they will breed with wild mosquitoes  to check the spread of dengue. First release of wolbachia mosquitoes in the wild was done in Australia in 2011. In January, the Indonesian team began releasing Wolbachia mosquitoes in Yogyakarta and its surroundings.  During his visit, Bill Gates, a philanthropist and main financial supporter of this program, had his hands full in releasing  dozens of the Wolbachia mosquitoes into the wilderness.

Bill Gates, main financial supporter of the research program

Bill Gates spoke to residents in the dengue-affected area, and learned that some have been seriously ill with the virus. The people are expressing hopes that the released wolbachia-treated mosquitoes will bring positive results to the dengue problem that have long plagued their city. Evaluation is far from over. The research team aims to breed and raise thousands of Wolbachia mosquitoes more in the coming days ahead. The research team dedication to their work, given that they have to let the hungry female mosquitoes – several hundreds of them- bite their arms to supply human blood for the mosquito eggs to develop, earned Gates respect and admiration for them.  Gates,  when requested to have his arm be bitten by the mosquitoes happily complied. In a few minutes, his arm swelled up with bites: …” It was a small price to pay for an amazing project that has the potential to turn the tide against a terrible disease.” he said.

CREDIT: You tube video 1ErcwogWbIA; all pictures courtesy of Wikipedia through Zemanta.

Aedes aegypti Image source: Centers for Diseas...

Aedes aegypti Image source: Centers for Disease Control and Prevention Publich Health Image Library. (Photo credit: Wikipedia

 

English: A typical rash as seen in dengue fever.

English: A typical rash as seen in dengue fever. (Photo credit: Wikipedia 

 

 

 

 

 

 

 

 

 

 

 

 

 

A 1920s photograph of efforts to disperse stan...

A 1920s photograph of efforts to disperse standing water and thus decrease mosquito populations (Photo credit: Wikipedia)

 

 

 

 

 

 

 

 

 

 


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