Navigation Links
Scientists crack dengue fever puzzle

Experts may have solved the mystery of why dengue fever, unlike other infections, is usually more severe the second time around. Dengue is a debilitating, sometimes fatal illness endemic to much of the tropics. Caused by a virus, it is characterized by high fever, bone and muscle pain and -- in the most serious cases -- hemorrhage and fatal shock.
Dengue is also unusual in that //symptoms are more severe during a second or third infection compared to first-time infection.Experts estimate that over 50 million people are affected by dengue each year, with about five percent of patients dying of the illness.

The findings may complicate the search for a vaccine against the deadly mosquito-borne illness, according to British and Thai scientists. Now scientists believe they have solved the dengue paradox. The key to the puzzle, say researchers is the fact that the dengue virus falls into four distinct subtypes. Initial infection with one subtype causes the immune system to direct its response to that specific variant. But if an individual later contracts any of the three other variants, he or she is left virtually defenseless against the virus.

The scientists evaluated the immune cell response of 73 Thai children hospitalized with dengue fever and found that all but two had been infected at least once before.

What's more, these children had relatively low levels of infection-fighting T cells specific for the new virus. Normally infection with viruses such as hepatitis C or Epstein-Barr result in high levels of such T cells. The researchers think a second infection triggers the immune system to frantically hunt for the wrong subtype of the virus, causing painful inflammatory symptoms such as aching and fever.

However, this second immune response generates immune cells that only react weakly to the new virus. And the duration of the disease is also much longer because the body fails to clear the infection quickly.

The discovery could hamper efforts to find an effective dengue vaccine. The risk, is that if the vaccine does not "hit" all four types of the virus, the vaccine may end up mimicking a second natural infection. For example, the vaccine may "prime" the immune system to attack only one or two types, leaving the patient with increased susceptibility to other types.

According to researchers, this danger was first identified after the development in the 1960s of a vaccine to the common respiratory syncytial virus "that made the natural disease worse." After vaccination with a harmless, inactivated form of the virus, children who were subsequently infected with respiratory syncytial virus -- the leading cause of lower respiratory tract infections in children -- suffered more severe lung symptoms than did unvaccinated children.
'"/>




Related medicine news :

1. Scientists plan human cloning clinic in the United States
2. Scientists found ancient Human Germ Killer
3. Scientists locate key hormone involved in appetite control
4. Scientists open the book of life
5. Scientists review SARS
6. Scientists push to lower hidden sodium in food
7. Indian Scientists Make Wide-Ranging Analysis And Annotation Of X Chromosome
8. Scientists have found effective brain regions for deep brain stimulation for Parkinson’s
9. Scientists reveal the secrets of sarcasm
10. Scientists Unveil Mechanism Behind Resistance to Severe Malaria
11. Scientists Warn Against Food Borne Illnesses
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/25/2016)... ... June 25, 2016 , ... First Choice Emergency Room , the largest ... as the Medical Director of its new Mesquite-Samuell Farm facility. , “We are ... Mesquite location,” said Dr. James M. Muzzarelli, Executive Medical Director of First Choice Emergency ...
(Date:6/25/2016)... ... June 25, 2016 , ... Conventional wisdom preaches the ... In terms of the latter, setting the bar too high can result in disappointment, ... just slow progress toward their goal. , Research from PsychTests.com reveals ...
(Date:6/24/2016)... , ... June 24, 2016 , ... Marcy was in a crisis. Her son James, ... out at his family verbally and physically. , “When something upset him, he couldn’t control ... use it. He would throw rocks at my other children and say he was going ...
(Date:6/24/2016)... (PRWEB) , ... June 24, 2016 , ... Comfort Keepers® ... American Cancer Society and the Road To Recovery® program to drive cancer patients to ... and other adults to ensure the highest quality of life and ongoing independence. ...
(Date:6/24/2016)... ... June 24, 2016 , ... The Haute ... Dr. Barry M. Weintraub as a prominent plastic surgeon and the network’s newest ... world, and the most handsome men, look naturally attractive. Plastic surgery should be ...
Breaking Medicine News(10 mins):
(Date:6/26/2016)... Story Highlights: ... the health care industry is causing providers to review ... Deloitte offers a suite of solutions for health care ... cost optimization: labor resource analysis, revenue cycle optimization and ... outcomes and better economics ...
(Date:6/24/2016)... , June 24, 2016 ... has announced the addition of the " Global ... This report ... provides an updated review, including its applications in various ... total market, which includes three main industries: pharmaceutical and ...
(Date:6/24/2016)... 2016 Research and Markets has announced ... Diagnostic Tests" report to their offering. ... The World Market for Companion Diagnostics covers ... Market analysis in the report includes the following: ... Diagnostic Kits) by Region (N. America, EU, ROW), 2015-2020 ...
Breaking Medicine Technology: