# A Review on Food Safety: The Case of _Citrobacter_ sp., Fish and Fish Products
## 2 Foodborne Diseases  
Food safety refers to the guarantee that it will not cause harm or illness to the person who consumes it. This attribute is part of food's basic characteristics, along with nutritional, sensory, and commercial features, which make up the total quality of food. There exists correspondence between the safety and health of consumers, and its obtention is fundamental and indisputable in terms of public health issues around the world [11; 13]. Foodborne diseases (FDs) are syndromes derived from the consumption of food or beverages accidentally, incidentally, and/or intentionally contaminated at any stage of the food chain (from the farm to consumption) by pathogenic microorganisms or toxic substances, affecting consumer health, individually or collectively [14; 15]. FDs constitute an important health problem worldwide due to their incidence, sequelae, mortality, new forms of transmission, vulnerable population groups, increased resistance of causative agents to antimicrobial compounds, loss of productivity, costs associated with health services, implementation, and monitoring of food safety policies, in addition to their effects on trade and tourism [14; 16; 17; 18]. It is estimated that every year, around 600 million people worldwide become sick, from which 420,000 die [14; 18]. These diseases present a variety of gastrointestinal symptoms, including nausea, vomiting, diarrhea, abdominal pain, and fever, with occasional severe complications, such as sepsis, meningitis, abortions, Reiter's syndrome, Guillan-Barre syndrome, or death [15]. Its most affected population groups are children, pregnant women, immunocompromised people, the elderly, and the general population, especially those in a state of poverty [14; 15; 17]. It has been established that climate change; modification in society's eating habits, such as the consumption of packaged foods, consumption of food outside home, sale of prepared meals and fast foods; incorporation of new technologies in food production; travel; commerce international level; vulnerability; susceptibility of the human being; and the inability of clinical and/or environmental laboratories to perform timely diagnostic analyses are factors that have favored the increase in FDs [16; 19; 20]. Approximately 250 FD-causing agents have been reported, which may be chemicals released in nature (toxic inorganic compounds, antimicrobials, growth promoters, toxic food additives, lubricants, dyes, natural toxins, disinfectants, heavy metals, pesticides, and substances used in the cleaning industry), as well as those of physical origin (fragments of glass, metal, wood, or others) and biological origin (bacteria, parasites, viruses, fungi, and prions) [16; 17]. The most frequent FD, in cases and outbreaks, are those derived from biological contamination [15; 17]. Generally, foods of animal or vegetable origin are rarely sterile, containing microbial associations whose composition depends on the organisms that reach it and how they multiply, survive, and interact in the food over time [18]. The microorganisms responsible for diseases through food are numerous, with bacterial agents being the main culprits [15; 17], among which are adenovirus, rotavirus, norovirus, hepatitis A and E viruses, _Citrobacter freundii, Salmonella_ spp., _Vibrio_ sp., _E. coli_, _Clostridium_ sp., _Cronobacter_ sp., _L. monocytogenes_, _Campylobacter_ sp., _S. aureus_, _Aeronomus_ sp., _Y. enterocolitia_, _B. cereus_, _Shigella_ spp., _Crytoposporidium parvum_, _Entamoeba histolytica_, _Anisaklis_ sp., _Giardia lamblia_, _Trichinella_ sp., and _Toxoplasma_ sp., among others [5; 6; 14; 15; 20; 21; 22]. In FDs caused by microorganisms or toxins, symptoms can manifest hours to days after the consumption of the contaminated food.