Typhoid

Typhoid fever or abdominal typhus is a serious febrile intestinal disease caused by  Salmonella typhi. It is transmitted by contaminated water, milk or food (in the Czech Republic, the source is mostly bacillus carriers). The incubation period is usually  7-14 days (possibly 3-60 days). Typhoid fever is a human  disease only. In typhoid fever, there is also the possibility of bacillocarriers, where microorganisms most often survive in the inflammatory gallbladder or urinary tract.

In the Czech Republic,the incidence is low, approximately several dozen cases per year (almost exclusively of imported origin).

Originator
The causative agent is Salmonella typhi. Based on the determined antibodies, we distinguish:
 * acute infection – Ig against O-antigens 9,12
 * bacillocarriers – ong-term persistence of Ig against Vi surface antigen

Pathogenesis
The infection affects Payer's plaques  in the small intestine (mainly in the ileocecal region), which swell and necrotize by the action of bacterial endotoxin. Ulcers develop and a scar may form (risk of bowel perforation). Salmonella is reproducing in the lymphatic tissue and can subsequently disseminate by the lymphatic or bloodstream. Abdominal reactive lymphadenitis. may be present. After 2 weeks, the intestinal wall defects gradually scar.

This is followed by the so-called circulus vitiosus. Bacteria are present in the intestine (mainly in the distal ileum), they progress to the lymph and then to the blood. They are captured by RES and by this system they are introduced into the liver, from which the bacteria get back into the intestine.

Symptoms
Initially, there are typical symptoms, like headache , fever (continuous temperature unaffected by antipyretic therapy ), sickness, lethargy,  cough and constipation.

The next week there is pallor, brown tongue (cleansed of the V-shaped tip), pink rash on the abdomen ( typhoid roseola - not very common), hyperemia (salmonella embolism), hepatosplenomegaly (proliferation of Kupffer cells of the liver), bradycardia and hypotension.

In severe cases, alteration of consciousness and dehydration (from hyperpyrexia) may occur. The temperature then gradually decreases and the condition normalizes.

The abdomen is palpably sensitive in the right hypochondria (largest intestinal changes). Diarrhea is rare - rather constipation, the abdomen is meteoric, it can be sensitive.

Other symptoms include:
 * typhoid osteomyelitis (mainly ribs),
 * hair loss but alopecia is reversible,
 * enlarged mesenteric nodes (up to a plum),
 * severely damaged muscles - mainly rectus abdominis, femoral abductors, diaphragm, intercostal muscles - Zenker's wax necrosis.

Untreated disease lasts 2-3 weeks and leads to marked weight loss, sometimes hematemesis or melene. In adults, life-threatening complications of intestine perforation are common. Perforation is very rare in children.

Diagnosis

 * Blood count: normal leukocyte count (or slightly reduced), first shifting to the left, then relative lymphocytosis.
 * Positive blood culture for salmonella.
 * Isolation of the agent from faeces, blood or bile; there are numerous inflammatory cells in the stool.
 * Widal reaction - agglutination reaction (positive for antigens 9, 12, Vi and d ).

Complications
The course is milder in children and more complications in the elderly. There are frequent thrombophlebitis of the lower limbs, is less frequent bowel perforation, peritonitis. Cardiac decompensation or even septic shock ( endotoxin ) may occur in the elderly. In the 3rd week, bleeding from ulcers into the intestines may occur.

Therapy and prevention
Without treatment, the disease lasts 3-4 weeks, with antibiotic treatment the initial temperature is reduced to 3-5 days.

The drug of choice is ATB from the range of fluoroquinolones, possibly. ampicillin, cefotaxime, chloramphenicol. Hospitalization in the infectious diseases department.

Bacillus therapy - the patient is monitored one year after treatment, if the pathogen finds a positive positive in the stool (once a month) or bile (twice a year), cholecystectomy and treatment with ampicillin IV are performed.

Vaccination: Polysaccharide vaccine im (from 2 years of age) at least 10-14 days before entering the endemic area, revaccination every 2-3 years.

Links
https://www.wikiskripta.eu/w/Salmonella