In the United States, we generally assume that the food that we eat won’t get us sick. To be sure, the next meal you eat probably won’t be laced with disease-causing bacteria. However, food borne illnesses are hardly uncommon. In fact, roughly one in six Americans is sickened by tainted food each year, resulting in 128,000 hospitalizations and 3,000 deaths annually. In order to make food safer for consumers, medical researchers have adopted a new tactic – mapping the DNA of common food contaminants.
Improving Testing Methods
For years, scientists have had the ability to map the DNA sequences of various organisms. This technology has been used to get a better understanding of new threats to public health, such as strains of bird flu. The Centers for Disease Control and Prevention (CDC) now hopes to utilize genome mapping to limit the impact of food-borne illnesses.
Ideally, such a breakthrough would allow for food contaminants to be quickly identified. The tests currently available to health officials are not especially effective, using sections of DNA that can yield misleading and inaccurate results. A prime example of this occurred in 2012, when testing initially traced salmonella outbreaks in the United States and the Netherlands to the same source. Later tests proved this finding to be inaccurate. The bacteria found in these two countries had different genetic profiles.
Protecting the Public
The first target of CDC’s efforts is listeria, a type of bacteria that infects roughly 1600 people annually in the United States. Though it is not especially common, listeria infection (also known as listeriosis) is not to be taken lightly. This illness has an estimated mortality rate that ranges from 20 to 30 percent.
To achieve the project’s goals, the CDC plans to map the DNA of all 2014 listeria infections. Researchers will not only review samples from listeriosis patients, but also listeria uncovered in food and in factories. Sequencing may be able to do more than simply identify food contaminants. Compared with current tests, DNA mapping might provide officials with a clearer picture of food-borne germs in a shorter amount of time. Specifically, this technology could quickly reveal how dangerous outbreaks are to public health, and if certain bacteria and viruses are drug-resistant.
The CDC has been given $30 million by the US Congress in order to meet its objectives. In addition, the project will utilize a massive federal database of genetic maps, which can store and compare thousands of samples. Genome sequencing has recently proved its usefulness in containing outbreaks. Using this approach, officials were able to link listeria cases in Maryland to a California death caused by listeriosis. Furthermore, the source of the listeria was traced back to a Delaware-based company.
Controlling Listeria Outbreaks
Listeriosis generally strikes only certain segments of the general population. Pregnant women, newborn infants, senior citizens and adults with compromised immune systems face the greatest risk of infection. While otherwise healthy adults can be sickened by listeria bacteria, such cases are rare and usually cause relatively minor problems. The more common listeriosis symptoms are listed as follows:
- Muscle aches
As troublesome as these problems might be, listeria can quickly become a much bigger health threat if it infects the nervous systems. Should this occur, the patient could experience a stiff neck, headaches, confusion, balance difficulties and even convulsions.
There are several ways in which listeria can contaminate an area’s food supply. For example, listeria bacteria can seep in to soil or manure used to cultivate vegetables. Shoppers can also contract listeriosis by eating meat made from infected farm animals. Foods like cold cuts or soft cheeses can be contaminated after undergoing food processing. Finally, listeria can sneak into milk that has not undergone pasteurization.