Featured Research

from universities, journals, and other organizations

New Species Of Infectious Disease Found In Amazon

Date:
April 6, 2008
Source:
University of California, San Diego Health Sciences
Summary:
While investigating the tropical disease leptospirosis in the Peruvian Amazon, an infectious disease specialist has uncovered new, emerging bacteria that may be responsible for up to 40 percent of cases of the disease. Patients with severe forms of leptospirosis have jaundice, renal failure and lung hemorrhage, with high fatality rates.

While investigating the tropical disease leptospirosis in the Peruvian Amazon, an infectious disease specialist from the University of California, San Diego School of Medicine has uncovered new, emerging bacteria that may be responsible for up to 40 percent of cases of the disease. Patients with severe forms of leptospirosis have jaundice, renal failure and lung hemorrhage, with high fatality rates.

Related Articles


Joseph Vinetz, M.D., professor of medicine in UC San Diego’s Division of Infectious Diseases – working in collaboration with colleagues from Universidad Peruana Cayetano Heredia in Lima, Peru, and others – headed the study that led to discovery of the new species in the family of pathogens, Leptospira, which is spread from animals to humans.

Leptospirosis is a severe, water-borne disease transmitted from animals to humans, with tens of millions of human cases worldwide each year. Fatality rates can range as high as 20 to 25 percent in some regions, and it is particularly prevalent in tropical countries where poor people live under highly crowded condition, or in rural areas where people are exposed to water contaminated by the urine of Leptospira-infected animals such as rats.

The new species reflects Amazonian biodiversity, according to Vinetz, and the pathogen has apparently evolved to become an important cause of leptospirosis in the Peruvian Amazon region of Iquitos. There, Vinetz leads an international team of physicians from the U.S. and Peru in an NIH-funded training program studying malaria, leptospirosis and other infectious diseases that impact disadvantaged populations in developing countries.

The researchers found that the new species, Leptospira licerasiae – cultured from a very small number of patients, as well as eight rats – is significantly different from other forms of the bacteria at a genomic level and has novel biological features.

“This strain has fundamentally different characteristics,” said Vinetz, adding that the next step is to sequence its genome. “We think that hundreds of patients are infected with this pathogen, which is so unique that antibodies for the disease don’t react to the regular tests for leptospirosis.”

In testing 881 patients in a prospective clinical study of fever, the researchers found that 41 percent of them had antibodies that reacted only to this new strain of the bacteria, showing a much higher incidence of leptospirosis than previously suspected.

“This observation is relevant to other regions of the world where leptospirosis is likely to be common, because it’s necessary to identify the right strain of the Lepstospira in order to make the correct diagnosis,” Vinetz said.

Since isolation of the new Leptospira in people was rare despite the high prevalence of antibodies to this strain of the bacteria in the Amazonian population, Vinetz theorizes that the individuals with positive cultures may have a previously undiscovered immune system defect, making them more susceptible to the disease.

Journal reference: Matthias MA, Ricaldi JN, Cespedes M, Diaz MM, Galloway RL, et al. (2008) Human Leptospirosis Caused by a New, Antigenically Unique Leptospira Associated with a Rattus Species Reservoir in the Peruvian Amazon. PLoS Negl Trop Dis 2(4): e213. doi:10.1371/journal.pntd.0000213

Additional contributors to the paper include Michael A. Matthias, Jessica N. Ricaldi, Kailash Patra, and Mayuko Saito of UCSD, Manuel Cespedes of the National Institute of Health in Lima, Peru, M. Monica Diaz of the University of Tucuman, Argentina, Renee Paul N. Levett, ReneeL. Galloway and Arnold G. Steigerwalt of the Centers for Disease Control and Prevention, Atlanta , Carlos Vidal Ore of the Peruvian Ministry of Health, Loreto, Peru, Eduardo Gotuzzo of Universidad Peruana Cayetano Heredia, Lima, Peru, and Robert H. Gilman of Johns Hopkins School of Public Health. The study was supported by U.S. Public Health Service grants from the National Institutes of Health.


Story Source:

The above story is based on materials provided by University of California, San Diego Health Sciences. Note: Materials may be edited for content and length.


Cite This Page:

University of California, San Diego Health Sciences. "New Species Of Infectious Disease Found In Amazon." ScienceDaily. ScienceDaily, 6 April 2008. <www.sciencedaily.com/releases/2008/04/080401225633.htm>.
University of California, San Diego Health Sciences. (2008, April 6). New Species Of Infectious Disease Found In Amazon. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2008/04/080401225633.htm
University of California, San Diego Health Sciences. "New Species Of Infectious Disease Found In Amazon." ScienceDaily. www.sciencedaily.com/releases/2008/04/080401225633.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Nurse Nina Pham Cured of Ebola

Texas Nurse Nina Pham Cured of Ebola

AFP (Oct. 25, 2014) — An American nurse who contracted Ebola while caring for a Liberian patient in Texas has been declared free of the virus and will leave the hospital. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) — The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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