Navigation Links
Study suggests surface water contaminated with salmonella more common than thought
Date:2/27/2009

Athens, Ga. A new University of Georgia study suggests that health agencies investigating Salmonella illnesses should consider untreated surface water as a possible source of contamination.

Researchers, whose results appear in the March issue of the journal Applied and Environmental Microbiology, tested water over a one-year period in rivers and streams in a region of south Georgia known for its high rate of sporadic salmonella cases. The team found Salmonella in 79 percent of water samples, with the highest concentrations and the greatest diversity of strains in the summer and after rainfall.

"Streams are not routinely tested for Salmonella, and our finding is an indication that many more could be contaminated than people realize," said Erin Lipp, associate professor in the UGA College of Public Health. "We found our highest numbers in the summer months, and this is also the time when most people get sick."

Lipp, who co-authored the study with former UGA graduate student Bradd Haley and Dana Cole in the Georgia Division of Public Health, said that although contaminated water used to irrigate or wash produce has been linked to several well-publicized outbreaks of salmonellosis in recent years, the environmental factors that influence Salmonella levels in natural waters are not well understood. She said understanding how Salmonella levels change in response to variables such as temperature and rainfall are critical to predictingand ultimately preventingthe waterborne transmission of the bacteria.

The team studied streams in the upper reaches of the Suwannee River Basin, which begins in south Georgia and flows into central Florida. The study area contains a mix of forested lands, row crops, pasturelands, wetlands and small cities. The researchers chose sampling sites near a variety of those environments but found little variation in Salmonella concentrations by location. The diversity of Salmonella strains, however, was highest near a farm containing cattle and a pivot irrigation system, suggesting that close proximity to livestock and agriculture increase the risk of contamination. The researchers also found a strong and direct correlation between rainfall for the two days preceding sample collection and the concentration of Salmonella, suggesting that runoff contributes to the contamination.

Salmonella can be found in the intestinal tracts of several species of animals and in humans. The bacteria are shed in feces, but Lipp said recent data suggest that they can persist and possibly grow in water if given the right conditions. Her study found that the diversity and concentration of Salmonella increased as temperatures increased. The highest concentrations and greatest diversity of strains were found in August, the warmest month of the year. Lipp adds that her study, which was funded by the National Oceanic and Atmospheric Administration Joint Program on Climate Variability and Human Health, lends support to the idea that Salmonella illnesses could increase as a result of global warming.

Lipp notes that her study area had 58 cases of Salmonella illness per 100,000 people in 2007, the last year for which figures are available, compared to a state average of 22 cases per 100,000 people and a national average of 15 cases per 100,000 people. She said the exact mechanisms by which people in her study area are being exposed to environmental Salmonella are unclear, but the most commonly detected strain in the studied streams was among the top ten associated with human infections in the health district. The porous nature of the soil in the study area means that surface water and groundwater are prone to mixing, especially after rainfalls, and Lipp said that poorly sited wells might be a factor in many illnesses. Another possibility, especially common among children, is so called incidental exposure by which people become infected with the bacteria when playing in or near contaminated waterways.

"Understanding the environmental factors that contribute to salmonella illnesses can guide our efforts to educate people about how they can avoid being sickened through the proper construction and maintenance of wells, basic hygiene such as hand washing and good food safety practices," Lipp said. "We also have the potential to decrease the likelihood of larger outbreaks related to produce, because in many cases contaminated irrigation water, and not the produce itself, may be the cause of the outbreak."


'/>"/>

Contact: Sam Fahmy
sfahmy@uga.edu
706-542-5361
University of Georgia
Source:Eurekalert

Related medicine news :

1. Penn study finds pro-death proteins required to regulate healthy immune function
2. New study shows promise in reducing surgical risks associated with surgical bleeding
3. Study, meta-analysis examine factors associated with death from heatstroke
4. Study suggests loss of 2 types of neurons -- not just 1 -- triggers Parkinsons symptoms
5. Study says COPD testing is not measuring up
6. Preclinical study suggests organ-transplant drug may aid in lupus fight
7. Ability to cope with stress can increase good cholesterol in older white men, study finds
8. High alcohol consumption increases stroke risk, Tulane study says
9. Mailman School of Public Health study examines link between racial discrimination and substance use
10. Pitt study finds inequality in tobacco advertising
11. Stanford study highlights cost-effective method of lowering heart disease risks
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/24/2017)... ... ... “End Time GPS”: a dauntless and enlightened study of the second-coming of ... creation of published author, Wesley Gerboth, a World War II veteran, with a highly-regarded ... at age ninety-one, he shares the Wisdom God bestowed upon him in this publication. ...
(Date:3/24/2017)... ... March 24, 2017 , ... “The Communion of Saints: A ... God in congregations across the United States. “The Communion of Saints” is ... who has served congregations in seven states throughout his long career of devotion ...
(Date:3/23/2017)... ... March 23, 2017 , ... In 2016 the World Health Organization ... could be four million Zika-related cases in the Americas within the next year. Lyme ... cases reported per year skyrocketing to an estimated 329,000. Yet, Zika, Lyme and other ...
(Date:3/23/2017)... ... , ... The physicians of KSF Orthopaedic Center PA are proud to announce ... is located at 2255 E. Mossy Oaks Rd., Suite 440, Spring, Texas 77389 inside ... patients living in the north Houston area (The Woodlands, Conroe, Magnolia, Kingwood, Humble) with ...
(Date:3/23/2017)... (PRWEB) , ... March 23, 2017 , ... Texas ... located at 960 Gruene Road in Building 2. The clinic is the group’s second ... Bennett, PT, says opening the company’s second New Braunfels location brings things full circle ...
Breaking Medicine News(10 mins):
(Date:3/23/2017)... Executive Summary ... primary research (inputs from industry experts, companies, stakeholders) ... the analysis of global heart valve devices market ... Replacement Procedure By Technique (Mechanical, Bioprosthetic, Transcatheter Aortic ... Balloon Valvuloplasty, Transcatheter Mitral Valve Repair (TMVR)), By ...
(Date:3/23/2017)... As a result of diagnostic technology ... of allergic diseases, cutting edge developments in targeted ... ways in which pharmaceutical and biotech companies are ... be both a high quality meeting and a ... immunologists, research scholars and doctors. The event will ...
(Date:3/23/2017)... LONDON , March 23, 2017 ... latest Pharmaceutical and Healthcare disease pipeline guide Primary ... overview of the Primary Hyperoxaluria (Genito Urinary System ... is a rare condition characterized by recurrent kidney ... of a substance called oxalate. Symptoms include blood ...
Breaking Medicine Technology: