Crisbert I. Cualteros, MD

Aka. enteric fever

a systemic infection by S. typhi or S. paratyphi.

Both are pathogenic exclusively in humans

a severe multisystemic illness characterized by:

classic prolonged fever

sustained bacteremia w/o endothelial or endocardial involvement.

bacterial invasion and multiplication w/in the mononuclear phagocytic cells of the liver, spleen, lymph nodes, and Peyer patches

potentially fatal if untreated

MOT: typically infected with S typhi and S paratyphi through food and beverages contaminated by a chronic stool carrier

Less commonly, carriers shed bacteria in urine.

Px maybe infected by drinking sewage-contaminated water or by eating contaminated shellfish or faultily canned meat

• Salmonellae gram-negative, flagellate, nonspore former, facultative anaerobic bacilli that ferment glucose, reduce nitrate to nitrite, and synthesize peritrichous flagella when motile.

• S typhi has O and H antigens,

an envelope (K) antigen, and a LPS macromolecular complex called endotoxin that forms the outer portion of the cell wall

Pathophysiology:• ingestion by the host

• 4-14 days incubation

• S typhi invades through the gut mucosa in terminal ileum

• S typhi crosses intestinal mucosa

• Enters mesenteric lymph nodes

• Into blood stream via lymphatics

• IP:

S. typhoid - averages 7-14 (range, 3-30) days.

S. paratyphoid - ranges from 1-10 days.

• During the incubation period, 10-20% of patients have transient diarrhea (enterocolitis) that usually resolves before the onset of the full-fledged disease.

High grade fever

Coated tongue

Anorexia

Vomiting

Hepatosplenomegaly

Diarrhea

Abdominal pain

Rash(rose spots)

• Mostly moderately anemic.

• CBC inc ESR and dec Platelet count

• lymphopenia.

• Most inc prothrombin time (PT) and activated partial thromboplastin time

• Dec. fibrinogen levels

• Elev (2x) Liver transaminase values and serum bilirubin levels Mild hyponatremia and hypokalemia .

• DIAGNOSIS:Blood,Urine,Stool

The most sensitive method of isolating S typhi is obtaining a BMA culture.

Widal test.

Monoclonal antibodies.

• Histologic Findings: The hallmark infiltration of tissues by macrophages (typhoid cells)

that contain bacteria, erythrocytes, and degenerated lymphocytes. Aggregates of these macrophages are called typhoid nodules, found in the intestine, mesenteric LN, spleen, liver, and bone marrow some in kidneys, testes, and parotid glands.

In the intestines, 4 classic pathologic stages occur : the course of infection:

(1) hyperplastic changes,

(2) necrosis of the intestinal mucosa,

(3) sloughing of the mucosa, and

(4) the development of ulcers. The ulcers may perforate into the peritoneal cavity.

Mesenteric LN, sinusoids are enlarged and distended by large collections of macrophages and RES. Spleen is enlarged, red, soft, and congested; its serosal surface may have a fibrinous exudate. Gallbladder is hyperemic and may show evidence of cholecystitis.

Liver: liver biopsy specimen from a person with typhoid often shows cloudy swelling, balloon degeneration with vacuolation of hepatocytes, moderate fatty change, and focal typhoid nodules. Intact typhoid bacilli can be observed at these sites.

SALMONELLA SHIGELLA EIEC

INCUBATION 7-14 days 2-3 days

INFXN SITE Ileus/colon Distal Ileus/colon S. intestine

P. MECHANISM Epithelial penetration

Epithelial penetration

ENTEROTOXIN

STOOL EXAM WBC/RBC WBC/RBC NONE

APPEARANCE LOOSE/SLIMY WATERY GREEN/YELLOW

VOLUME SMALL LOW PROFUSE

FREQUENCY FREQUENT GREAT FREQUENT

MUCUS PRESENT FREQUENT PRESENT

BLOOD SOMETIMES FREQUENT PRESENT

ODOR ROTTEN EGG ODORLESS FISHY

N/V PRESENT RARE NONE

FEVER COMMON FREQUENT PRESENT

PAIN TENESMUS TENESMUS TENESMUS

CRAMPS (-) COLIC (+)

MISC. HEADACHE BACTEREMIA CONVULSIONS

HEADACHE ABRUPT ONSET/ HYPOTENSION

Treatment:

Uncomplicated Typhoid fever:

A. Fully sensitive: Daily Dosemg/k/d Days

Chloramphenicol 50-75 14-21

Amoxicillin 75-100 14

B. Multidrug resistant:Fluroquinolone 15 5-7

Cefixime 15-20 7-14

C. Quinolone resistant:Azithromycin 8-10 7

Ceftriaxone 75 10-14

Severe typhoid:

A. Fully sensitive: Daily Dose mg/k/d Days

Ampicillin 100 14

Ceftriaxone 60-75 10-14

B. Multidrug resistant:Fluoroquinolone 15 10-14

C. Quinolone resistant:Ceftriaxone 60-75 10-14

• Prognosis: • Generally, the mortality rate untreated disease is

10-20%. In properly treated disease, < 1%.• 10% and 20% treated w antibiotics have a

relapse after initial recovery. • A relapse typically occurs approx 1 wk after

therapy is discontinued. • The blood culture results are again positive, and

high serum levels of H, O, and Vi antibodies and rose spots may reappear. A relapse generally is milder and shorter than the initial illness.

Prevention:

Oral live attenuated preparation Ty21A strain of S. Typhi

Vi Capsular polyssacharide

Thank you!!