Halfway through this year, it is looking like most any other year when it comes to Salmonella.

In eight multistate outbreaks involving a range of three to 41 states since the first of the year, Salmonella has sickened 527 people. One out of every four of those people have been so sick they had to be admitted to a hospital. Luckily, Salmonella outbreaks this year have yet to take a life.

A variety of sources are responsible for this year’s Salmonella outbreaks: turkey, tuna, pre-cut melon, pet hedgehogs, pig ear dog treats, Cavi brand papayas, backyard poultry, and Karawan brand tahini. The outbreak strain of Salmonella I 4,[5],12:i:- spread by those dog ear treats is  resistant to multiple antibiotics.

Were it not for the Journal for Food Protection (JFP) published by the International Association for Food Protection (IAFP), years like this one for Salmonella might be forgotten relatively quickly.

But JFP’s current issue won’t let that happen. Writing under the title: “Salmonellosis Outbreaks by Food Vehicle, Serotype, Season, and Geographical Location, United States, 1998-2015.” three Pennsylvanian experts remind us of Salmonella’s impact in the past.

The article’s authors are Teah R. Snyder, Sameh W. Boktor and Nkuchia M. M’Ikanatha. Snyder is with Pennsylvania State University College of Medicine. And, Boktor and M’Ikanatha are with the Pennsylvania Department of Health.

Findings by the Keystone State researchers include these:

• Outbreaks due to Salmonella enterica stereotypes Braenderup and I 4,[5],12:i:- have increased;
• Deaths were most often due to seeded vegetable, nuts and seeds, and fruits;
• Multistate salmonellosis outbreaks were often due to nuts and seeds, sprouts, and fruits;
• Alaska, Minnesota, and Hawaii had the highest number of outbreaks per 100,000 people; and
• Delaware and Wyoming had the lowest number of outbreaks per 100,000 people.

The research paper says Salmonella is a significant cause of foodborne illness in the United States. “Although salmonellosis outbreaks are relatively common, food vehicles and other characteristics are not well understood,” the authors wrote.

The researchers obtained data for the 17 years from the federal Centers for Disease Control and Prevention in Atlanta. According to the CDC’s Foodborne Disease Outbreak Surveillance System, there were 2,447 outbreaks from 1998 to 2015 for an average of 136 per year.

The data identified all 2,447 outbreaks as being “confirmed or suspected etiology of nontyphoidal Salmonella.” The patient count for all those outbreaks totaled 65,916.  Food was the source of almost half of the outbreaks. Eggs, chicken, and pork were the most common food sources of Salmonella.

Salmonella killed a total of 87 people in just 55 of the outbreaks during those 17 years.  The three most common stereotypes experienced over that time were Enteritidis at 29.1 percent, Typhimurium at 12.5 percent, and Newport at 7.6 percent. Serotypes Braenderup and I 4,[5],12:i:- are marking the most significant increases among those reported, according to the research.

“Some serotypes were commonly associated with outbreaks due to certain food vehicles,” the authors said. For example, 81 percent of the outbreaks involving eggs involved the serotype Enteritidis. The 9-page article also confirms summer as the most likely season for an outbreak to occur.

“Trends in food vehicles over time, season, and geographical location can be used to identify changes in salmonellosis in recent years as well as to justify further research,” the research paper continued.   “Outbreaks associated with nuts and seeds and pork have increased over time, wheras outbreaks associated with eggs have decreased.   Decreases over time could be due to novel prevention methods that are implemented for food vehicles that are commonly associated with salmonellosis, such as eggs.”

Salmonella is a significant cause of foodborne illness throughout the world, according to the World Health Organization (WHO).

There are more than 2,000 strains of Salmonella, which are categorized based on the specific antigen set of each. Antigens are substances that stimulate the body to fight pathogens. These antigen-based subsets are called serotypes.

The symptoms of Salmonella infection usually appear 12 to 72 hours after exposure to the bacteria. Symptoms include fever, abdominal pain, diarrhea, nausea, and sometimes vomiting.

The illness usually lasts four to seven days. Most people recover without treatment. However, antibiotic treatment can be necessary for young children and elderly people and in cases when the bacteria has entered the bloodstream.