Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Insight into Predicting Cholera in the Bengal Delta

06.11.2009
Cholera, an acute diarrheal disease caused by the bacterium Vibrio cholerae, has reemerged as a global killer. Outbreaks typically occur once a year in Africa and Latin America. But in Bangladesh the epidemics occur twice a year – in the spring and again in the fall.

Scientists have tried, without much success, to determine the cause of these unique dual outbreaks – and advance early detection and prevention efforts – by analyzing such variables as precipitation, water temperature, fecal contamination and coastal salinity.

Now, researchers from Tufts University, led by Professor of Civil and Environmental Engineering Shafiqul Islam, have proposed a link between cholera and fluctuating water levels in the region's three principal rivers – the Ganges, Brahmaputra and Meghna.

"What we are establishing is a way to predict cholera outbreaks two to three months in advance," says Islam, who also holds an appointment as professor of water and diplomacy at The Fletcher School at Tufts. "It's not a microbiological explanation. The key is the river discharge and regional climate."

The Tufts researchers' findings were reported in the latest issue of Geophysical Research Letters, published October 10, 2009.

Understanding cholera's environmental catalysts

Vibrio cholerae lives and thrives among phytoplankton and zooplankton in brackish estuaries where rivers come into contact with the sea. The Bengal Delta, which scientists have considered the native land of cholera, is fed by three rivers.

Almost all of the rainfall in the region occurs during the four-month monsoon season between June and September. Water levels in the river system rise, causing floods that cover 20 percent of the land in an average year. Water levels then fall rapidly, though low-lying, depressed areas remain submerged for weeks.

The Tufts team tracked the month-by-month incidence of cholera using data from the International Center for Diarrhoeal Disease Research, a treatment center that recorded incidences of cholera for the biggest population center of Bangladesh from 1980 to 2000.

The Tufts team correlated these cholera incidence statistics with an analysis of water discharges from the three rivers. Their findings suggested two distinctive epidemic patterns that are associated with the seasonal cycles of low river flows and floods.

A spring outbreak occurs in March, during the period of low river flow in Bangladesh. The low river flow allows seawater from the Bay of Bengal to move inland, transporting bacteria-carrying plankton.

A second epidemic occurs in September and October, after monsoon rains have raised water levels. Here, a different dynamic takes place. Floodwaters have mixed water from sewers, reservoirs and rivers. As the floods recede, contamination is left behind..

Predicting cholera before it happens

Islam and his team linked the incidence of cholera cases to the level of water flow in the rivers. In order to confirm their findings, the researchers looked for a consistent pattern. They analyzed the incidence of cholera in five years of severely low river flow from 1980 to 2000 and compared it with five years of average and below average river flow. The same analysis was done for extreme, average and below average floods to study the fall epidemic.

The researchers found a relationship between the magnitude of cholera outbreaks and the severity of the region's seasonal low river flow and floods. "The more severe the low river flow, the larger the spring epidemic," says Islam. "The same thing is true with flooding during the fall." Islam says that the findings will contribute to the development of systems to anticipate and predict cholera outbreaks based on the hydroclimate of the region.

This research was funded in part by the National Science Foundation and a National Institutes of Health Fellowship. Researchers included engineering doctoral students Ali S. Akanda and Antarpreet S. Jutla.

Akanda, A. S., A. S. Jutla, and S. Islam (2009), "Dual peak cholera transmission in Bengal Delta: A hydroclimatological explanation," Geophys. Res. Lett., 36, L19401, doi: 10.1029/2009GL039312.

Tufts University, located on three Massachusetts campuses in Boston, Medford/Somerville, and Grafton, and in Talloires, France, is recognized among the premier research universities in the United States. Tufts enjoys a global reputation for academic excellence and for the preparation of students as leaders in a wide range of professions. A growing number of innovative teaching and research initiatives span all Tufts campuses, and collaboration among the faculty and students in the undergraduate, graduate and professional programs across the university's schools is widely encouraged.

Tufts University School of Engineering is dedicated to educating the technological leaders of tomorrow. Located on Tufts' Medford/Somerville campus, the School of Engineering offers a rigorous engineering education in an environment characterized by the best blending of a liberal arts college atmosphere with the intellectual and technological resources of a world-class research university. Close collaboration with the School of Arts and Sciences and the university's extraordinary collection of excellent professional schools creates a wealth of educational and research opportunities. The School of Engineering's primary goal is to educate engineers committed to the innovative and ethical application of technology in the solution of societal problems. It also seeks to be a leader among peer institutions in targeted areas of interdisciplinary research and education that impact the well-being and sustainability of society, including bioengineering, sustainability and innovation in engineering education.

Alexander Reid | Newswise Science News
Further information:
http://www.tufts.edu

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>