SALMONELLOSIS

ENTERIC BACTERIA: SALMONELLOSIS

Introduction

Salmonella is a gram negative rods genus belonging to the Enterobacteriaceae family. Within 2 species, Salmonella bongori and Samonella enterica, over 2500 different serotypes or serovars have been identified to date.

•Salmonella is a ubiquitous and hardy bacteria that can survive several weeks in a dry environment and several months in water.

Salmonella Species

Zoonotic infection

Gram negative intracellular organism

Family: Enterobactericeae

Genus: Salmonella

•2 Species: S. enterica (choleraesuis) 6 subspecies and S. bongori

– S. enterica subsp. enterica (I) Warm-blooded animals

– S. enterica subsp. salmae (II) Cold-blooded animal

– S. enterica subsp. arizonae (IIIa) Cold-blooded animal

– S. enterica subsp. diasonae (IIIb) Cold-blooded animal

– S. enterica subsp. houtenae (IV) Cold-blooded animal

– S. enterica subsp. Indica (VI) Cold-blooded animal

– S. bongori (V) Cold-blooded animal

Salmonellosis

•Enteric fever (systemic illness with fever and abdominal symptoms)

– Typhoid fever: Salmonella Typhi

– Paratyphoid fever: Salmonella Paratyphi A, B, or C

•Non-typhoidal salmonellosis: other Salmonella serotypes

– GASTROENTERITIS

– BACTEREMIA & VASCULAR INFECTION

– SALMONELLOSIS & HIV INFECTION

– LOCALIZED INFECTION

– CARRIER STATE

Epidemiology

The burden of foodborne diseases is substantial: every year almost 1 in 10 people fall ill and 33 million of healthy life years are lost.

• Foodborne diseases can be severe, especially for young children.

•Diarrhoeal diseases are the most common illnesses resulting from unsafe food, 550 million people falling ill each year, including 220 million children under the age of 5 years.

• Salmonella is 1 of the 4 key global causes of diarrhoeal diseases.

S. Typhi and S. Paratyphi: reservoir only in human

• Typhoid fever is decreasing in incidence

• Non-typhoidal infection is increasing

• Rare typhoid fever in the Northeast of Thailand

• Risk factors: eat contaminated food, i.e.- water,

raw vegetable, ice cream.

TRANSMISSION

•FOOD, WARTER BORNE

•FECAL-ORAL ROUTE

Common Source of infection

•Contaminated food

•Poor hygiene kitchen

•Excretions from either sick or carrier of human and animal

•Polluted surface water and standing water

•Unwashed fruit

•Un-hygienically thawed fowl

FACTORS DETERMINE DISEASE DEVELOPING

•Number of organism 10,000,000-10,000,000,000
•Virulencity
•Host factors
HOST FACTORS
•High gastric pH: antacid, achlohydria
•Immunocompromise (CMIR)
–HIV
–Steroid (SLE)
–Malignancy
–Malnutrition
–Immunosuppressive therapy
–Extreme age

Pathophysiology

SIGNS & SYMPTOMS ENTERIC FEVER

•FEVER
•ABDOMINAL SYMPTOMS
•HEPATOMEGALY 50%
•SPLENOMEGALY 50%
•ROSE SPOT 30%
•CERVICAL LYMPHADENOPATHY
•NEUROLOGICAL SYMPOTOMS
•RALES

CLINICAL OF ENTERIC FEVER

•Insidious onset
•Non specific constitutional symptoms 
(malaise, myalgia, chills, headache, dizziness, cough)
•GI symptoms (Anorexia/Nausea/ Vomitting/ diarrhea /abdominal cramps)
•Fever remittent
•Respiratory symptom
•SECOND AND THIRD WEEK
–PERSISTENT FEVER
–SYMPTOMS CONTINUE
•FORTH WEEK
–SPONTANEOUS REMISSION

LABORATORY: Enteric fever

•CBC : Anemia, thrombocytopenia
•Transient leukocytosis then normal to leukopenia, PMN predominant
•LFT: mild elevation of liver enzymes
•jaundice mild
•BUN Cr: normal
•UA: normal
•CXR: normal to non-specific

LABORATORY: Enteric fever

•Blood culture
•Bone marrow culture 90%
•Stool, urine culture
•Duodenal content culture
•Serology : Widal test not reliable, insufficiently sensitive, specific, or rapid enough for clinical use

TREATMENT

•EFFECTTIVE ATB

–FLUROLOQUINOLONE

–AMPICLLIN

–CHLORAMPHENICOL

–CO-TRIMOXAZOLE

–3rd GENERATION CEPHALOSPORIN

•Uncomplicated Typhoid Fever

–Ciprofloxacin 500mg BID 5-7Days
–Ofloxacin 400mg BID 5-7Days–Ceftriaxone 2g I.V daily 10-14 days
–Cefixime 200mg BID 7-14days
–Azithromycin 1g PO daily for 7 days
–Trimethoprim-sulfamethoxazole 160/800mg BID 7days

•Sever complicated Typhoid Fever:
–Ampicillin 2g every 6 hrs for 14day
–Chloramphenicol 1.5 IV every 6hours 14-21days 

Prevention:

Sanitation improvement
•Personal hygienic
•Limit use of antibiotics in animals
•Vaccines for travelers, children in endemic area but not for adults
–Oral vaccine: live attenuated vaccine
–Injection vaccine: heat-phenol-inactivated s. Typhi vaccine, Vi capsular polysaccharide vaccine