This illustration depicts a three-dimensional (3D) computer-generated image of Salmonella serotype Typhi bacteria. (Source: CDC)
For the first time, the U.S. Centers for Disease Control and Prevention (CDC) is providing online surveillance data gathered over more than 40 years on 32 Salmonella isolates from people, animals and other sources. Organized by demographic, geographic and other categories, the “Atlas of Salmonella in the United States, 1968-2011” is available as of Wednesday as one online 248-page document or as 32 individual serotype reports. “Salmonella causes a huge amount of illness and suffering each year in the United States,” said Robert Tauxe, M.D., deputy director of CDC’s Division of Foodborne, Waterborne and Environmental Diseases. “We hope these data allow researchers and others to assess what has happened and think more about how we can reduce Salmonella infections in the future. The more we understand Salmonella, the more we can make progress in fighting this threat all along the farm-to-table chain.” As the number-one cause of foodborne illness and death in the U.S., Salmonellosis sickens an estimated 1.2 million people annually and causes more than 23,000 hospitalizations and 450 deaths, according to CDC. Salmonella infections most often cause gastroenteritis, which can range from mild to severe. However, invasive infections can also occur and can be severe and life-threatening. Salmonella infection is usually caused by eating raw or undercooked meat, poultry, eggs or egg products. The incubation period ranges from several hours to two days. Possible signs and symptoms include nausea, vomiting, abdominal pain, diarrhea, fever, chills, headache, muscle pains and blood in the stool. The Salmonella group of bacteria has more than 2,500 different serotypes, but fewer than 100 cause the vast majority of infections in people, CDC said. Older adults, people with weakened immune systems, and children under five years old have a higher risk for Salmonella infection. Infections in these groups can be more severe, resulting in long-term health consequences or death. CDC’s new online atlas breaks down Salmonella surveillance data by age, sex, geography and season of the year, allowing users to see national trends in reported cases of human Salmonella infection over time, problems in specific geographic areas, sources of Salmonella, and the connection between animal and human health. In addition to reports of human infections, the atlas includes reports of Salmonella in animals, the environment and animal feeds, which can be sources of antibiotic-resistant strains. Serotyping has been the core of public health monitoring of Salmonella infections for more than 50 years. Now scientists use DNA testing to further divide each serotype into more subtypes and to detect more outbreaks, CDC said. With the next generation of sequencing technology, advancements continue as the laboratory can find information about the bacteria in just one test. CDC officials noted that the data presented in the atlas are just the tip of the iceberg since many cases of human Salmonellosis are not diagnosed and reported to health departments. This underreporting may occur because the ill person does not seek medical care, the health-care provider does not obtain a stool culture for testing, or the culture results are not reported to public health officials. More information on Salmonella is available on the CDC website.