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 New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>