Cholera remains a public health problem in countries without access to safe drinking water and adequate sanitation. Researchers are trying to come up with theoretical models for cholera that allow them to understand how an outbreak happens, how it can best be contained, and how it might be prevented. Until now, the existing cholera models have not been able to describe and explain actual outbreaks very well. Taking new experimental data into account, David Hartley and colleagues (of the University of Maryland) now report a major advance in cholera modelling in the international open-access medical journal PLoS Medicine.

In 2002, Andrew Camilli and colleagues reported that cholera bacteria isolated from the stools of sick patients were much more infectious than those found in contaminated water. (They compared the two by exposing mice to a mix and determining which bacteria made the mice sick.) Those researchers proposed that the infection of a human patient (i.e., the exposure to an environment that is quite different from their regular freshwater ponds) changes the cholera bacteria. As a result, for a short period of time, the bacteria become more infectious.

The study caught the attention of David Hartley and colleagues, who saw a chance to improve the modeling of cholera epidemics. Hartley was interested because Camilli's results shed new light on a fundamental question in cholera epidemiology: what is the relative importance of human-to-human infection(i.e. fecal to oral) versus environment-to-human infection (through contaminated food or water)? If the infective dose of bacteria that have become hyperinfectious because of recent passage through a human host is much lower than that of bacteria from the environment, this would support a crucial role of human-to-human transmission in cholera epidemics.

Hartley and colleagues found that incorporation of the existence of a hyperinfectious state into their models resulted in a much bett
'"/>

Contact: Paul Ocampo
press@plos.org
415-624-1224
Public Library of Science
5-Dec-2005

Page: 1 2
Related medicine news :

1. Mayo Clinic -- Collaborating to move treatment research forward
2. A step forward in stem cell research
3. Sleep Slide-Rule improves childrens understanding of the importance of sleep
4. Advances in understanding bipolar disorder topics of press briefings June 7, 8
5. Hepatitis B patients understanding of infection and treatment deficient
6. Transplanting human gut bugs into mice helps understanding of metabolic system
7. Study puts us one step closer to understanding the function of sleep
8. New amfAR research grants aim to advance understanding and prevention of rectal HIV transmission
9. New study on relationship between literacy and understanding of prescription labels
10. Sound understanding of indoor acoustics could make hearing easier
11. Low literacy increases risk of death and misunderstanding of medical consent forms