Salmonellosis

Salmonellosis is a symptomatic infection caused by bacteria of the Salmonella type. It is the most common disease to be known as food poisoning (though the name refers to food-borne illness in general). These are defined as diseases, usually either infectious or toxic in nature, caused by agents that enter the body through the ingestion of food. In humans, the most common symptoms are diarrhea, fever, abdominal cramps, and vomiting. Symptoms typically occur between 12 hours and 36 hours after exposure, and last from two to seven days. Occasionally more significant disease can result in dehydration. The old, young, and others with a weakened immune system are more likely to develop severe disease. Specific types of Salmonella can result in typhoid fever or paratyphoid fever. Typhoid fever and paratyphoid fever are specific types of salmonellosis, known collectively as enteric fever, and are, respectively, caused by salmonella typhi and paratyphi bacteria, which are only found in humans. Most commonly, salmonellosis cases arise from salmonella bacteria from animals, and chicken is a major source for these infections.

There are two species of Salmonella: Salmonella bongori and Salmonella enterica with many subspecies. However, subgroups and serovars within a species may be substantially different in their ability to cause disease. This suggests that epidemiologic classification of organisms at the subspecies level may improve management of Salmonella and similar pathogens.

Both vegetarian and non-vegetarian populations are susceptible to Salmonella infections due to the consumption of contaminated meat and milk. Infection is usually spread by consuming contaminated meat, eggs, water or milk. Other foods may spread the disease if they have come into contact with manure. A number of pets including cats, dogs, and reptiles can also carry and spread the infection. Diagnosis is by a stool test or blood tests.

Efforts to prevent the disease include the proper washing, preparation, and cooking of food to appropriate temperature. Mild disease typically does not require specific treatment. More significant cases may require treatment of electrolyte problems and intravenous fluid replacement. In those at high risk or in whom the disease has spread outside the intestines, antibiotics are recommended.

Salmonellosis is one of the most common causes of diarrhea globally. In 2015, 90,300 deaths occurred from nontyphoidal salmonellosis, and 178,000 deaths from typhoidal salmonellosis. In the United States, about 1.35 million cases and 450 deaths occur from non-typhoidal salmonellosis a year. In Europe, it is the second most common foodborne disease after campylobacteriosis.

After a short incubation period of a few hours to one day, the bacteria multiply in the small intestine, causing an intestinal inflammation (enteritis). Most people with salmonellosis develop diarrhea, fever, vomiting, and abdominal cramps 12 to 72 hours after infection. Diarrhea is often watery and non-bloody but may be mucoid and bloody. In most cases, the illness lasts four to seven days, and does not require treatment. In some cases, though, the diarrhea may be so severe that the patient becomes dangerously dehydrated and must be hospitalized. At the hospital, the patient may receive fluids intravenously to treat the dehydration, and may be given medications to provide symptomatic relief, such as fever reduction. In severe cases, the Salmonella infection may spread from the intestines to the blood stream, and then to other body sites, and can cause death, unless the person is treated promptly with antibiotics.^{[citation needed]}

In otherwise healthy adults, the symptoms can be mild. Normally, no sepsis occurs, but it can occur exceptionally as a complication in the immunocompromised. However, in people at risk such as infants, small children, and the elderly, Salmonella infections can become very serious, leading to complications. In infants, dehydration can cause a state of severe toxicity. Extraintestinal localizations are possible, especially Salmonella meningitis in children, osteitis, etc. Children with sickle-cell anemia who are infected with Salmonella may develop osteomyelitis. Treatment of osteomyelitis, in this case, will be to use fluoroquinolones (ciprofloxacin, levofloxacin, etc., and nalidixic acid).^{[citation needed]}

Those whose only symptom is diarrhea usually completely recover, but their bowel habits may not return to normal for several months.