Salmonella is a genus of rod-shaped Gram-negative enterobacteria that causes typhoid fever, paratyphoid and foodborne illness.
Disease causing salmonellae are in a class of species called salmonella enterica.
Salmonella enterica has numerous strains or serovars. Salmonella typhi is one of the well-known serovar. It causes typhoid fever.
Other salmonellae are frequent causes of foodborne illness, and can mainly be caught from poultry and raw eggs. They can also be caught from food that has been cooked or frozen, and not eaten straight away.
Salmonellosis or salmonella infection is the illness that can occur if live salmonella bacteria enter the human body. Salmonellosis is one of the most common bacterial food borne illnesses.
Children are the most likely to get salmonellosis. Young children, the elderly, and those with impaired immune systems are particularly susceptible to severe infections.
Salmonellosis is more common in the summer than winter and is contagious (can be spread from person to person).
Transmission of Salmonella
Salmonella live in the intestines of animals, birds and humans. Salmonella are transmitted to humans by eating foods contaminated with animal excrement.
Strains of the bacteria that cause no symptoms in animals can make people sick, and vice versa.
Contaminated foods are normally of animal origin and include beef, poultry, milk, and eggs. However, all foods including vegetables may become contaminated.
Food may also become contaminated by an infected food handler who did not wash his or her hands with soap after using the bathroom.
Contaminated food does not taste, smell, or appear different from uncontaminated food. Thorough cooking food kills the salmonella bacteria.
In addition to contaminated food, people are likely to get an infection through a reptile. Reptiles such as turtles, iguanas, lizards, and snakes often harbour salmonella.
You should always wash your hands immediately after handling a reptile even if the reptile is healthy. It is also important to ensure that children wash their hands after handling a reptile.
Symptoms are usually gastrointestinal. The symptoms can be severe especially in the old and very young.
They appear 6-72 hours after ingestion of the bacterium and can last up to 7 days. These symptoms can include,
Many types of illnesses can cause nausea, diarrhoea, fever, and other symptoms of salmonella. The determination that salmonella is the cause of the illness is dependent on laboratory tests.
Salmonella can be identified if the laboratory is specifically instructed to look for the bacteria.
Further testing can determine its type and the antibiotics that can treat it.
Most persons recover from salmonella without treatment.
However, some patients may have severe diarrhoea and need hospitalisation due to dehydration.
In such patients, the salmonella infection may spread from the intestines to the blood stream. It can then spread to other body sites and cause death unless the patient is treated promptly with antibiotics.
Patients with severe diarrhoea require rehydration. Intravenous fluids are used for rehydration.
Antibiotics may not be necessary unless the infection spreads from the intestines. It can then be treated with drugs such as ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or ciprofloxacin.
Some Salmonella bacteria have become resistant to antibiotics.
Long-term Effects of Salmonella Infection
A few individuals who get salmonella infection may experience Reiter's syndrome. Reiter's syndrome is characterised with pains in the joints, irritation of the eyes, and painful urination.
It can last for months or years. This can cause long-lasting disabling effects such as arthritis.
Chronic arthritis is difficult to treat. Antibiotic treatment of salmonella does not make a difference in whether or not the person later develops arthritis.
There is no vaccine to prevent salmonellosis.