Featured Research

from universities, journals, and other organizations

Multiple Malaria Infection Inhibits Spread Of Parasite

Date:
March 27, 2007
Source:
Netherlands Organization for Scientific Research
Summary:
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. Researchers discovered this during research into malaria transmission with the inhabitants of Cameroon, Senegal and Indonesia. After just a few infections, people can develop immunity that inhibits transmission.

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 Yaoundι, 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.


Story Source:

The above story is based on materials provided by Netherlands Organization for Scientific Research. Note: Materials may be edited for content and length.


Cite This Page:

Netherlands Organization for Scientific Research. "Multiple Malaria Infection Inhibits Spread Of Parasite." ScienceDaily. ScienceDaily, 27 March 2007. <www.sciencedaily.com/releases/2007/03/070326121148.htm>.
Netherlands Organization for Scientific Research. (2007, March 27). Multiple Malaria Infection Inhibits Spread Of Parasite. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2007/03/070326121148.htm
Netherlands Organization for Scientific Research. "Multiple Malaria Infection Inhibits Spread Of Parasite." ScienceDaily. www.sciencedaily.com/releases/2007/03/070326121148.htm (accessed April 18, 2014).

Share This



More Health & Medicine News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) — President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) — A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) — A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Thousands Of Vials Of SARS Virus Go Missing

Thousands Of Vials Of SARS Virus Go Missing

Newsy (Apr. 16, 2014) — A research institute in Paris somehow misplaced more than 2,000 vials of the deadly SARS virus. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins