With an estimated 80.3 million cases each year, food-borne Salmonella infections are a worldwide concern . In developing areas in Africa, Asia and South-America, Salmonella Typhi and Paratyphi are an important cause of severe illness, leading to more than 20 million cases and 200.000 deaths in children and young people every year . A typical Salmonella infection can lead to fever, diarrhea, nausea, vomiting, abdominal cramps, and headache. Symptoms usually appear between 24 to 48 hours after eating contaminated food, and last three to seven days. The incidence rate of Salmonella is highest among infants and young children. As there are many different types of food-borne Salmonella, each with their own food sources, control is difficult. Proper hygiene in the kitchen (e.g., washing hands, thoroughly heating and baking meat) can prevent a Salmonella infection. However, studies among the general public in Italy , Turkey  and New Zealand  showed that compliance with preventive hygiene advice is low to very low. A possible explanation is that most people believe that a food-borne infection is “something that happens to others” [6, 7].
Educating the public about food safety is crucial in preventing food-borne infections. According to Medeiros and colleagues , food-borne Salmonella infections should be prevented by educating the general public about adequate cooking of food, and by instructing them about the risks of cross-contamination. Traditional communication means, such as flyers, are well suited to achieve these educational goals . However, when a food-borne infection breaks out on a large scale, the dynamics of the situation shift tremendously. Due to an uncertain course of events, decisions have large consequences, the general public is stressed, and the media is eager for news . In these circumstances, health organizations should inform the public about the situation and persuade them to take preventive actions. To be effective in this endeavor, they should use the communication channels the general public expects them to use, and provide the public with the information they want and need. A study among Malaysians during the A(H1N1) influenza outbreak in 2009, uncovered that their main sources of information were newspapers, television and family members; their information needs were instructions on how to prevent or treat infections . In the Netherlands, the 2003 Severe Acute Respiratory Syndrome (SARS) outbreak and the 2011 Enterohaemorrhagic E. Coli (EHEC) outbreak showed us that the Dutch general public mostly turns to traditional media (i.e., television and radio), and news websites [12, 13].
In recent years, the rise of social media (e.g., Facebook, Twitter) has provided new avenues for reaching the general public during infectious disease outbreaks. Although social media have proven very valuable during disaster relief as a crowdsourcing tool , an exploratory study of their worth as a communication tool during an infectious disease outbreak suggested their value to be limited . Research on the information behavior of the general public during infectious disease outbreaks is scarce. But this knowledge is crucial in serving the general public in their information needs, and in maximizing citizen compliance with preventive advice.
In this study, we uncovered the general public’s perceptions, knowledge, preventive behavior, and sources of information during a large, national Salmonella outbreak by a large-scale online survey. As a result, we were able to answer our main research question: Which information should health organizations convey during a large-scale Salmonella outbreak, and by which channels, to maximize citizen compliance with preventive advice?