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:6/26/2017)... ... 2017 , ... Maryland’s soybean farmers have improved the sustainability ... the United Soybean Board. , Thanks to the responsible use of technology ... on less land per bushel, the report says. The United Soybean Board’s “Soy ...
(Date:6/26/2017)... ... June 26, 2017 , ... New patients with missing ... Cotey, with or without a referral. Dr. Cotey is a trusted dentist who has ... tooth replacement option. , Patients with missing teeth in Fitchburg, WI, are encouraged to ...
(Date:6/25/2017)... ... ... CareSet Labs released the Root NPI Graph today at the 2017 Academy ... of the Doctor Referral teaming dataset commonly available from Medicare. , Originally created through ... “Doctor Referral Dataset” as released by Medicare and “DocGraph” as released by Trotter, the ...
(Date:6/24/2017)... ... June 24, 2017 , ... Dr. Mitchell Mehlman ... Road in Lake Ronkonkoma, Dental365 offers patients high-quality and affordable routine and emergency ... the dentist fit into their patients’ busy lifestyles. Dental365 also gladly work with ...
(Date:6/23/2017)... ... ... By scoring 100% for fiscal management and accountability, the Arthritis National Research ... Charity Navigator, validating ANRF's work as a top charity in America. , This achievement ... earns ANRF a spot on their “ 10 Charities Worth Watching ” list as ...
Breaking Medicine News(10 mins):
(Date:6/20/2017)... CHICAGO , June 19, 2017  Hill-Rom Holdings, Inc. ... conference call and webcast on Friday, July 28, 2017, beginning ... Conference Call Audio Only Dial-in information: To participate in the ... Please dial into the call at least 10 minutes prior ... Code is 34090339.  ...
(Date:6/16/2017)... -- Datascope Corp. is voluntarily performing a worldwide field correction of certain Intra-Aortic ... code.     ... NUMBER ... 0998-UC-0446HXX; 0998-UC-0479HXX 0998-00-3013-XX;  0998-UC-3013-XX ... This field correction also applies to any System ...
(Date:6/14/2017)... , June 14, 2017  ivWatch LLC, a medical ... of intravenous (IV) therapy, is pleased to announce it ... of Nonsurgical Hospital Supplies and Equipment at the 2017 ... for the medtech industry. The award was presented by ... K. Javits Center in New York ...
Breaking Medicine Technology: