A Review on Gastro-Enteritis in The Living System

Typhoid fever is endemic in the developing world, where unsanitary conditions are more likely to prevail, and which can affect as many as 21.5 million people each year. Recorded cases of typhoid fever in the developed world are mostly related to recent travel in areas where Salmonella Typhi is endemic.

After a short incubation period of a few hours to one day, the bacteria multiply in the intestinal lumen, causing an intestinal inflammation. Most people with salmonellosis develop diarrhea, fever, vomiting, and abdominal cramps 12 to 72 hours after infection. Diarrhea is often mucopurulent (containing mucus or pus) and bloody. 

Diagram of S. Enterica

Salmonellosis is an infection caused by Salmonella bacteria.

Typhoid fever occurs when Salmonella bacteria enter the lymphatic system and cause a systemic form of salmonellosis. Endotoxins first act on the vascular and nervous apparatus, resulting in increased permeability and decreased tone of the vessels, upset thermal regulation, vomiting and diarrhea. In severe forms of the disease, enough liquid and electrolytes are lost to upset the water-salt metabolism, decrease the circulating blood volume and arterial pressure, and cause hypovolemic shock. 

TYPES OF ENTERITIS

(1) Enteric Fever (Typhoid fever): Enteric fever is a clinical syndrome characterized by constitutional and gastrointestinal symptoms and by headache. It can be caused by any salmonella species. The term “typhoid fever” applies when serotype typhi is the cause of enteric fever accompanied by bacteremia. Infection is transmitted by consumption of contaminated food or drink. The incubation period is 5-14 days. 

SALMONELLA GASTROENTERITIS: This common form of salmonellosis is acute enterocolitis. Numerous salmonella serotypes may cause enterocolitis. The incubation period is 8-48 hours after ingestion of contaminated food or liquid.

SALMONELLA BACTEREMIA: Salmonella infection may be manifested by prolonged or recurrent fevers  accompanied by bacteremia and  local infection in bone, joints, pleura, pericardium, lungs, or other sites. Mycotic abdominal aortic aneurysms may also be a complication. 

Serotypes other than typhi usually are isolated. This complicationn tends to occur in immunocompromised persons and is seen in HIV- infected individuals , who typically have bacteremia without an obvious source. Treatment is the same as for typhoid fever . 

LABORATORY INVESTIGATION

Laboratory investigation can be done in two ways

Widal Test

Identify the presence of salmonella  spp in stool mlcls

(1)Widal Test-the procedure should be carried out for a minimum  of times. All that is needed is to check for an increase in titre in minimum of two times test and an interval of one week. It involves the use of widal rat which is made up of antigen of salmonella.

Typhi and salmonella para  typhi A,B,C and is able to aggglutinate with the antibody if present in the blood. The strength of agglutination is directly proportional to the trait of salmonella typhi and salmonella para typhi.

(2) The identification of salmonella spp in stool culture,  this is more diagnostic than the widal test. It involves  culturing stool over night and checking the plate for salmonella growth. 

An infographic illustrating how Salmonella spreads from the farm .

Contaminated food, often having no unusual look or smell;

Poor kitchen hygiene, especially problematic in institutional kitchens and restaurants because this can lead to a significant outbreak;

Excretions from either sick or infected but apparently clinically healthy people and animals (especially dangerous are caregivers and animals);

Polluted surface water and standing water (such as in shower hoses or unused water dispensers);

Unhygienically thawed fowl (the meltwater contains many bacteria);

An association with reptiles (pet tortoises, snakes, iguanas, and aquatic turtles) is well described. 

Amphibians such as frogs may also carry the disease.

CAUSES OF SALMONELLOSIS. 

The most severe human Salmonella infection is caused by S. enterica subsp. enterica ser. Typhi which leads to typhoid fever; an infection that often proves fatal if not treated with the appropriate antibiotics. This serovar is restricted to humans and is usually contracted through direct contact with the fecal matter of an infected person. 

In most cases, the illness lasts four to seven days, and most people recover without treatment. In some cases, though, the diarrhea may be so severe that the patient becomes dangerously dehydrated and must be taken to a hospital. At the hospital, the patient may receive intravenous fluids 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.

In otherwise healthy adults, the symptoms can be mild. Normally, no sepsis occurs, but it can occur exceptionally as a complication in the immuno-compromised. 

However, in people at risk such as infants, small children, 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 .

Though Salmonella infection is frequently the cause of osteomyelitis in sickle-cell anemia patients, it is not the most common cause; the most common cause remains Staphylococcus infection.

Septic shock may also develop. Shock of mixed character (with signs of both hypovolemic and septic shock) are more common in severe salmonellosis. Oliguria and azotemia develop in severe cases as a result of renal involvement due to hypoxia and toxemia.

Salmonella bacteria can survive for some time without a host; thus, they are frequently found in polluted water, with contamination from the excrement of carrier animals being particularly important.

PREVENTION

The FDA has published guidelines to help reduce the chance of food-borne salmonellosis. Food must be cooked to 68–72 °C (145–160 °F), and liquids such as soups or gravies must be boiled. Freezing kills some Salmonella, but it is not sufficient to reliably reduce them below infectious levels. While Salmonella is usually heat-sensitive, it does acquire heat resistance in high-fat environments such as peanut butter. 

Maintaining a personal hygiene is of paramont important as a precautionary measure in the prevention of salmonellosis.

Poultry, pork, beef and fish (seafood), if the meat is prepared incorrectly or is infected with the bacteria after preparation

Infected eggs, egg products, and milk when not prepared, handled, or refrigerated properly can cause salmonella infection.

TREATMENTS

Electrolytes may be replenished with oral

 rehydration supplements (typically containing

 salts sodium chloride and potassium chloride).

 Appropriate antibiotics, such as ceftriaxone,

 are given to kill the bacteria. 

Azithromycin has been suggested to be better at

 treating typhoid in resistant populations than both

 fluoroquinolone drugs and ceftriaxone. Antibiotic

 resistance rates are increasing throughout the

 world, so health care providers should check current

 recommendations before choosing an antibiotic.

Treatment of osteomyelitis, in this case, will be to use fluoroquinolones (ciprofloxacin, levofloxacin, etc. and nalidixic acid).

Those whose only symptom is diarrhea usually completely recover, but it can be several months until their bowel habits are normal. A small number of people afflicted with salmonellosis experience reactive arthritis, which can last months or years and can lead to chronic arthritis. In sickle-cell anemia, osteomyelitis due to Salmonella infection is much more common than in the general population. 

  Intravenous fluids may be used to treat dehydration. Medications may be used to provide symptomatic relief. In some cases, the diarrhea may be so severe that the patient becomes dangerously dehydrated and must be hospitalized.

CONCLUSION

To be Totally free from salmonellosis ,you must try to maintain personal hygiene in the food you eat and wash your hand thoroughly, wash vegetables with clean water and Salt, Cook every meat to done properly and drink purified water . Please keep fit and be healthy.