Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Smithsonian Scientist Uncovers New Links Connecting Environmental Changes with Spike in Infectious Disease

22.05.2014

Human Activities Near Lake Malaŵi Lead to Rise in Parasitic Infections

National Museum of Natural History scientist Bert Van Bocxlaer and an international team of researchers revealed that anthropogenic changes in Africa’s Lake Malaŵi are a driving force behind the increase of urogenital schistosomiasis, a debilitating tropical disease caused by parasitic flatworms.


Schistosomiasis: B. nyassanus

Courtesy of Ad Konings, Cichlid Press


Schistosomiasis: Schistosoma parasite

Courtesy of Beltran et al. (2008), PlosOne 3(10): e3328.

Scientists estimate that 250 million people are affected by schistosomiasis worldwide, and 600 million more are at risk of contracting it. In some villages along the shorelines of Lake Malaŵi, 73 percent of the people and up to 94 percent of the schoolchildren are infected with urogenital schistosomiasis, one of several forms of the disease.

Van Bocxlaer’s research suggests that this spike in infection is directly linked to an increase in human populations and agricultural activities near Lake Malaŵi, and may include a change in the dietary preferences of mollusk-eating fishes. Details from this study and recommendations to reduce the prevalence of urogenital schistosomiasis are published in the May 2014 issue of Trends in Parasitology.

Human population densities in Malaŵi have more than doubled during the past 30 years, resulting in increased land use, overfishing and ecological changes that create a favorable environment for Bulinus nyassanus, a small freshwater snail that acts as an intermediate host of the disease-causing parasite.

Infected snails release larval flatworms that can penetrate human skin upon contact with water. Humans are the definitive host and, upon infection, excrete eggs that hatch in water and infect snails such as B. nyassanus.

“Scientists have long known that environmental changes can affect public health, but our research reveals that human impact on the environment plays a larger role in the spread of schistosomiasis than previously thought,” said Van Bocxlaer. “Decreasing the transmission of this infectious disease will require an integrated control program for schistosomiasis, including community-based health education with efforts toward more sustainable resource use.”

Van Bocxlaer and his team discovered that human activities surrounding Lake Malaŵi have led to drastic biotic and abiotic changes in the lake’s ecosystem. Observed changes include an increase in sedimentation and nutrient influx due to agricultural initiatives and soil erosion.

B. nyassanus thrives in the shallow, nutrient-rich sandy sediments along shorelines that humans frequent, and it faces few natural predators because populations of fish that feed on this snail have greatly declined due to overfishing. Scientists also suspect that the fish have a decreased affinity for eating B. nyassanus, favoring instead a recently introduced non-native form of the snail Melanoides tuberculata.

The research team examined sediment archives and compared historical and modern populations of B. nyassanus to determine ecological changes in Lake Malaŵi over time. The scientists relied on historical data, such as those preserved in museum collections, to determine that changes in snail populations in southern Malaŵi that, in conjunction with the impacts of human activities in this region, have contributed to an increase of schistosomiasis during the past several decades.

Symptoms of schistosomiasis generally originate in the urogenital organs and the intestines and can lead to life-threatening complications. Estimates from the World Health Organization suggest that more than 200,000 deaths per year are due to schistosomiasis in sub-Saharan Africa alone; approximately one-third of the total deaths caused by malaria worldwide.

Kathryn Sabella | Eurek Alert!
Further information:
http://newsdesk.si.edu/releases/smithsonian-scientist-uncovers-new-links-connecting-environmental-changes-spike-infectious-

Further reports about: Disease Environmental Infectious ecosystem eggs environment freshwater schistosomiasis skin spread

More articles from Health and Medicine:

nachricht Mobile phone test can reveal vision problems in time
11.02.2016 | University of Gothenburg

nachricht Proteomics and precision medicine
08.02.2016 | University of Iowa Health Care

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: Production of an AIDS vaccine in algae

Today, plants and microorganisms are heavily used for the production of medicinal products. The production of biopharmaceuticals in plants, also referred to as “Molecular Pharming”, represents a continuously growing field of plant biotechnology. Preferred host organisms include yeast and crop plants, such as maize and potato – plants with high demands. With the help of a special algal strain, the research team of Prof. Ralph Bock at the Max Planck Institute of Molecular Plant Physiology in Potsdam strives to develop a more efficient and resource-saving system for the production of medicines and vaccines. They tested its practicality by synthesizing a component of a potential AIDS vaccine.

The use of plants and microorganisms to produce pharmaceuticals is nothing new. In 1982, bacteria were genetically modified to produce human insulin, a drug...

Im Focus: The most accurate optical single-ion clock worldwide

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...

Im Focus: Goodbye ground control: autonomous nanosatellites

The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.

Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...

Im Focus: Flow phenomena on solid surfaces: Physicists highlight key role played by boundary layer velocity

Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.

The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).

Im Focus: New study: How stable is the West Antarctic Ice Sheet?

Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels

A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Symposium on Climate Change Adaptation in Africa 2016

12.02.2016 | Event News

Travel grants available: Meet the world’s most proficient mathematicians and computer scientists

09.02.2016 | Event News

AKL’16: Experience Laser Technology Live in Europe´s Largest Laser Application Center!

02.02.2016 | Event News

 
Latest News

LIGO confirms RIT's breakthrough prediction of gravitational waves

12.02.2016 | Physics and Astronomy

Gene switch may repair DNA and prevent cancer

12.02.2016 | Life Sciences

Using 'Pacemakers' in spinal cord injuries

12.02.2016 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>