Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Multiple malaria infection inhibits spread of parasite

27.03.2007
People who are frequently infected with malaria parasites can develop immunity against the gametocyte, the infectious stage. This immunity inhibits the spread of the parasite. Dutch researcher Mike van der Kolk discovered this during his research into malaria transmission under the inhabitants of Cameroon, Senegal and Indonesia. After just a few infections, people can develop immunity that inhibits transmission.

Malaria is not caused by a mosquito but by a parasite in the mosquito. The malaria parasite needs the mosquito to reproduce and spread. The gametocyte is the developmental stage of the parasite that can be transmitted from people to the mosquito. In the mosquito's stomach the gametes are released and fertilisation takes place. The parasite develops further until the final stage (the sporozoite) in the salivary gland. The sporozoite can be transmitted with the saliva to a person if he/she is bitten by this mosquito. There the parasite reproduces rapidly and the person becomes ill.

Immunity
People who live in areas where malaria is prevalent, can develop a natural immunity that stops the development of the parasite in the mosquito. This prevents the parasite from spreading further. The presence of this immunity, the so-called transmission-reducing activity, is determined using a laboratory test. Van der Kolk discovered that people who are often infected with malaria could quickly acquire this immunity. He also found that people with higher numbers of gametocytes are more frequently immune.
Infectious bites
Each year more than 200 million people develop malaria. More than one million people die from malaria each year. In Cameroon, the researchers recorded how often people were bitten by a mosquito that carried malaria parasites. They also examined the number of transmittable parasites in the blood of infected persons. In a neighbourhood of the capital Yaoundé, 34 infectious bites per person per year were found to occur. The number of gametocytes per person was season and age dependent. Children were found to be by far the most important source of malaria transmission in the area. In the village Koundou, the number of infectious bites was about five times as high as in the capital. There previous research had revealed 177 infectious bites.
Test
The existing laboratory test for malaria immunity did not yet work optimally. Therefore the researchers first modified this method before starting the research on immunity. With the improved test, the researchers studied how people not previously exposed to malaria become infected or immune. Migrants in the province of Papua in Indonesia, who had not previously been exposed to malaria were investigated for this purpose. Malaria is highly prevalent in Papua. After just one to four malaria infections the immunity against the infectious gametocytes increased. Immunity therefore develops quickly after exposure to an infection. The researchers expect that the modified methods will make it possible to carry out more detailed studies into the development and maintenance of immunity within the population.

Mike van der Kolk's research was funded by NWO.

Mike van der Kolk | alfa
Further information:
http://www.nwo.nl/nwohome.nsf/pages/NWOA_6YPL79_Eng

More articles from Health and Medicine:

nachricht Antibiotic effective against drug-resistant bacteria in pediatric skin infections
17.02.2017 | University of California - San Diego

nachricht Tiny magnetic implant offers new drug delivery method
14.02.2017 | University of British Columbia

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>