Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New tools used to control foodborne hepatitis A outbreaks related to green onions

22.09.2005


Novel use of genetic testing methods helped public health officials control and limit the further spread of four outbreaks of foodborne hepatitis A virus in 2003 related to the consumption of green onions, according to a detailed analysis published in the October 15 issue of The Journal of Infectious Diseases, now available online.



The authors of the study, Joseph J. Amon, PhD, MSPH, and colleagues at the Centers for Disease Control and Prevention (CDC), explained that these molecular epidemiologic methods had not previously been used in an ongoing investigation of a hepatitis A virus outbreak. The methods, involving genetic sequencing analysis of virus found in blood samples from infected individuals, have greatly improved understanding of outbreaks of other foodborne pathogens, but are time-consuming and not widely available.

In September 2003, Tennessee, North Carolina, and Georgia reported a total of 422 cases of foodborne hepatitis A virus infection to CDC. Preliminary investigations suggested clustering of reported cases among patrons of three unrelated restaurants. Investigators identified green onions as the likely culprit in the outbreak by interviewing infected and uninfected restaurant patrons. In addition to these standard techniques, the researchers also compared viral RNA sequences from case patients and individuals concurrently ill with hepatitis A virus infection in non-outbreak settings in the United States and Mexico.


Viral RNA sequences from patients in the three states, plus patients involved in a subsequent outbreak in Pennsylvania in October 2003 (the latter recently described in the Sept. 1 issue of the New England Journal of Medicine), were slightly different from each other. The viral sequence from each outbreak, however, was identical to one or more sequences isolated from northern Mexican residents infected with hepatitis A virus. The researchers concluded that the sources of the green onions served in restaurants in Tennessee and Georgia were three farms in northern Mexico.

Dr. Amon and colleagues credited the viral sequencing techniques with helping them to identify the relationships between the outbreaks in four separate locations, and to define the scope of the outbreaks quickly. The sequencing allowed them to determine if cases reported in other states were related to the four original outbreaks and provided reassurance that a larger outbreak was not occurring. The molecular epidemiologic methods also enabled public health officials to respond quickly to the later Pennsylvania outbreak. As a result, consumers were warned of the potential risk, and entry of green onions from four Mexican farms into the state was banned.

"This research highlights the role of viral sequence analysis in improving our overall understanding of the roughly 50 percent of hepatitis A cases in the U.S. that are from an unknown source," Dr. Amon said. "Just as the E. coli-contaminated beef outbreaks in the early 1990s prompted changes in epidemiological surveillance that have increased our knowledge of foodborne bacteria, the 2003 hepatitis A outbreaks demonstrated the potential for integrated molecular surveillance to provide a better understanding of the epidemiology of hepatitis A and facilitate rapid responses to outbreaks."

Steve Baragona | EurekAlert!
Further information:
http://www.idsociety.org

More articles from Life Sciences:

nachricht A novel synthetic antibody enables conditional “protein knockdown” in vertebrates
20.08.2018 | Technische Universität Dresden

nachricht Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>