Salmonellosis

Salmonellosis is an acute zoonotic infectious disease with a fecal-oral mechanism of transmission of the pathogen, characterized by a primary lesion of the gastrointestinal tract, the development of intoxication and dehydration.

Non-phytophagous salmonella, predominantly Salmonella Enteritidis, primarily cause gastroenteritis, bacteremia and focal infection. Symptoms of salmonellosis include diarrhea, a high laxative fever and signs of focal infection. Diagnosis of salmonellosis is based on a culture of blood, feces from lesions. Treatment of salmonellosis, if indicated, is performed with trimethoprim-sulfamethoxazole or ciprofloxacin, with surgical treatment of abscesses, vascular lesions, bones and joints.

ICD-10 codes

• A02. Other salmonella infections.
• A02.0. Salmonella enteritis.
• A02.1. Salmonella septicemia.
• A02.2. Localized salmonella infection.
• A02.8. Other specified salmonella infection.
• A02.9. Salmonella infection, unspecified.

Epidemiology of Salmonella

The reservoir and source of the causative agent of infection are sick animals: large and small cattle, pigs, horses, domestic birds. At them the disease proceeds sharply or in the form of bacteriocarrier. A person (sick or bacterial carrier) can also be a source of S. Typhimurium. The mechanism of transmission is fecal-oral. The main way of transmission is food, through products of animal origin. Infection of meat occurs endogenously during the life of the animal, as well as exogenously in the process of transportation, processing, storage. In recent years there has been a significant increase in the incidence rate (S. Enteritidis) associated with the spread of the pathogen through poultry and eggs. The waterway transmission mainly plays a role in the infection of animals. Contact-household way (through the hands and tools), as a rule, the transmission of pathogens in hospitals. The greatest risk of infection with salmonellosis is in children of the first year of life and those with immunodeficiency. The air-dust path plays an important role in the spread of infection among wild birds. High incidence of salmonellosis in large cities. Cases of the disease are recorded throughout the year, but more often in the summer months due to poor storage conditions. Sporadic and group morbidity is observed. The susceptibility of people to the pathogen is high. Postinfectious immunity persists for less than a year.

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What causes salmonellosis?

Salmonella enteritidis is most often caused by salmonella. These infections often occur and pose a serious problem in the United States. Many serotypes of Salmonella enteritydis have names and are called not strictly, as if they are separate species, which is really not the case. The most common salmonella species in the United States are Salmonella thyphimurium, Salmonella heidelberg, Salmonella newport, Salmonella infantis, Salmonella agona, Salmonella montevidel, Salmonella saint-paul.

Human salmonellosis occurs with direct and indirect contact with infected animals, with products derived from them, their secret. Infected meat, poultry, raw milk, eggs and products from them are the most frequent sources of salmonella. Other possible sources of infection are infected domestic turtles and reptiles, red carmine stain and marijuana.

Salmonellosis is predisposed to such diseases as subtotal gastrectomy, akhporhydria (or antacids), sickle cell anemia, splenectomy, epidemic recurrent licefish, malaria, bartonella, cirrhosis, leukemia, lymphoma, HIV infection.

All serotypes of Salmonella can cause the clinical syndromes described below, either individually or together, although each serotype is often associated with a particular syndrome. Intestinal fever is caused by Salmonella parathifi of types A, B and C.

Asymptomatic carriage may also occur. However, carriers do not play an important role in the occurrence of outbreaks of gastroenteritis. Constant isolation of pathogens with stool for a year or more is observed only in 0.2-0.6% of non-typhoid-affected salmonellosis.

What are the symptoms of salmonellosis?

Salmonella infection can be clinically manifested as gastroenteritis, typhoid-like form, bacteremia syndrome and focal form.
Gastroenteritis begins 12-48 hours after ingestion of salmonella. First, nausea and spastic pain in the abdomen, then diarrhea, fever, sometimes vomiting.
 
The stool is usually watery, but it is mushy semi-liquid, occasionally with impurities of mucus and blood. Salmonella is lean and lasts 1-4 days. Sometimes there is a more severe and prolonged course.

Typhoid-like form is characterized by fever, prostration and septicemia. Salmonellosis proceeds in the same way as typhoid fever, but more easily.

Bacteremia is not common in patients with gastroenteritis. However, Salmonella choleraesuis, Salmonella thyphimurium heidelberg among others can cause lethal bacteremia syndrome lasting 1 week or more with prolonged fever, headache, weight loss, chills, but rarely with diarrhea. Patients may have transient episodes of bacteremia or signs of focal infection (eg, septic arthritis). And in patients with disseminated salmonella infection without risk factors, a test for HIV infection should be conducted.

Focal salmonellosis can occur with and without bacteremia. Patients with bacteremia can be affected by the gastrointestinal tract (liver, gall bladder, appendix, etc.), endothelium (atherosclerotic plaques, aneurysms of the iliac or femoral artery or aorta, heart valves), pericardium, meninges, lungs, joints, bones, genitourinary tract, soft tissues.

Sometimes there are solid tumors with the formation of an abscess, which become a source of salmonella bacteremia. Salmonella choleraesuis, Salmonella thyphimurium is the most common cause of focal infection.

How is salmonella diagnosed?

Diagnosis of salmonellosis is based on the isolation of the causative agent from feces and from other materials. With bacteremia and local forms, the culture of the blood is positive, but the stool culture is negative. The stool samples are stained with methylene blue, leukocytes are often found, indicating the inflammatory process in the colon - colitis.

How is salmonella treated?

Gastroenteritis is treated symptomatically, with abundant drinking and a sparing diet. In uncomplicated cases, the use of antibiotics is undesirable, since they prolong the period of excretory excretion from the stool. Nevertheless, treatment with antibiotics is indicated in the elderly, children and HIV-infected with an increased risk of mortality. Resistance to antibiotics in non-typhoid-typhoid salmonella is even more common than in S. Typhi.

Salmonellosis with a moderate and severe localized form is treated with the administration of entericum two capsules three times a day for 5-6 days; chlorohinaldol 0.2 g 3 times a day for 3-5 days.

Trimethoprim-sulfamethoxazole 5 mg / kg (according to trimethoprim) every 12 hours for children and ciprofloxacin inside every 12 hours for adults. In a normal immune system, salmonellosis treatment lasts 3-5 days, whereas AIDS patients may require longer treatment. Systemic or focal forms of the disease are treated with antibiotics in the same doses as in typhoid fever. With persistent bacteremia, you usually need to continue therapy for 4-6 weeks. Abscesses should be opened. Then within 4 weeks of antibiotic therapy. Infection of aneurysms, heart valves and bones or joints usually requires surgical treatment and prolonged use of antibiotics.

With asymptomatic carriage, the infection usually passes by itself and the need for antibiotics rarely occurs. In special cases (for example, workers in food businesses or health care), you can try to eliminate the carriage with ciprofloxacin 500 mg every 12 hours for 1 month. To confirm the elimination of salmonella, control stools are required for several weeks after the treatment is completed.

How to prevent salmonellosis?

Salmonellosis can be prevented if the infection of food from animals and humans is prevented. All cases of the disease should be recorded.

Specific prevention of salmonellosis

Specific prevention of salmonellosis is absent.

Nonspecific prevention of salmonellosis

Veterinary and sanitary supervision of slaughter of cattle and poultry, technology of carcass processing, cooking and storage of meat dishes. Compliance with sanitary and hygienic and anti-epidemic norms at the enterprises of trade and public catering.