Acute infectious diarrheal disease - Salmonellosis - DONE

Question 1

Salmonella:

Answer 1

• gram negative
• non-spore forming
• facultatively anaerobic bacillus

Question 2

Nontyphoidal serotypes of Salmonella…..

Answer 2

Nontyphoidal serotypes of Salmonella are highly adapted for growth in human and animals

Question 3

What is restricted to human host?

Answer 3

Only serotypes S.typhi and S.paratyphi are restricted to human host

Question 4

How many serotypes of Salmonella are pathogenic to humans?

Answer 4

More then 200 serotypes of Salmonella are pathogenic to humans

Question 5

How does Salmonella infections begin?

Answer 5

All Salmonella infections begin with ingestion of organisms, most commonly in contaminated food or water

Question 6

What causes the transmission of Salmonella?

Answer 6

Food-borne or water-borne transmission results from fecal contamination by ill or asymptomatic person

Question 7

What is important determinant of incubation period and disease severity?

Answer 7

Ingested dose of pathogen is important determinant of incubation period and disease severity

Question 8

Salmonellosis - Risk factors:

Answer 8

• Decreased stomach acidity

- Decreased intestinal integrity

Question 9

Decreased stomach acidity:

Answer 9

• age less then 1 year
• antacid digestion
• achlorhydric disease

Question 10

Decreased intestinal integrity:

Answer 10

• inflammatory bowel diseases
• prior gastrointestinal surgery
• alteration of intestinal flora by antibiotic administration

Question 11

Typhoid (enteric) fever:

Answer 11

Typhoid fever is a systemic disease caused by dissemination of S.typhi or S.paratyphi
- S.paratyphi may cause milder disease

Question 12

Where does typhoid (enteric) fever occur?

Answer 12

Typhoid fever occurs worldwide, primarily in developing nations whose sanitary conditions are poor

Question 13

Typhoid (enteric) fever is endemic in:

Answer 13

• Asia
• Africa
• Latin America
• the Caribbean
• Oceania
• but 80% of cases come from Bangladesh, China, India, Indonesia, Laos, Nepal, Pakistan, or Vietnam

Question 14

Typhoid (enteric) fever - incubation fever:

Answer 14

10-14 days (ranges from 5-21 days)

Question 15

Typhoid (enteric) fever - symptoms:

Answer 15

• prolonged up to 4 weeks fever (the most prominent symptom) plus fatigue
• headache, malaise, and anorexia are nearly universal
• abdominal pain, diarrhea, or constipation are common
• bronchitic cough is common in the early stage of the illness

Question 16

What is the most prominent symptom Typhoid (enteric) fever?

Answer 16

prolonged up to 4 weeks fever (the most prominent symptom) plus fatigue

Question 17

What is common in the early stage of Typhoid (enteric) fever?

Answer 17

bronchitic cough is common in the early stage of the illness

Question 18

Typhoid (enteric) fever - Clinical findings:

Answer 18

• transient, macular rash of rose-colored spots on the trunk on the end of the first weak of disease, resolves after 2-5 days
• hepatosplenomegaly
• relative bradycardia at the peak of high fever
• gastrointestinal bleeding and intestinal perforation
• meningitis
• neuropsychiatric syndrome (muttering delirium)

Question 19

Typhoid (enteric) fever - Chronic carriage:

Answer 19

• up to 10% of untreated persons excrete S.typhi in feces for up to 3 months
• 1-4% of patients for more than 1 year

Question 20

Typhoid (enteric) fever - Chronic carriage are common amongst:

Answer 20

• women
• infants
• persons with biliary anatomic biliary abnormalities and concurrent infections

Question 21

Typhoid (enteric) fever - Diagnosis:

Answer 21

• Blood culture is the mainstay of the diagnosis.
  Definitive diagnosis requires isolating of S.typhi or S.paratyphi from blood, bone marrow, other sterile sites, rose spots, stool, intestinal secretions
• The presence of clinical symptoms characteristic of typhoid fever or the detection of a specific antibody response is suggestive of typhoid fever but not definitive.
• Antimicrobial susceptibility testing is crucial for the guidance of clinical management.

Question 22

Typhoid (enteric) fever - Diagnosis - Laboratory tests: non-specific:

Answer 22

• leukopenia
• neutropenia
• anaemia
• elevated values of liver function and muscle enzyme levels

Question 23

Typhoid (enteric) fever - Diagnosis - Serologic tests:

Answer 23

Salmonellae can be characterized by their somatic (O) and flagellar (H) antigen

Question 24

Widal test:

Answer 24

• For Typhoid (enteric) fever diagnosis
• Widal test measures agglutinating antibody levels against O and H antigens.
• Test has only moderate sensitivity and specificity. It can be negative in up to 30% of culture-proven cases of typhoid fever.

Question 25

Typhoid (enteric) fever - Treatment:

Answer 25

- Appropriate antimicrobials should be administer promptly to prevent severe complications - Supportive treatment: * oral or intravenous hydration * the use of antipyretics * appropriate nutrition * blood transfusions if indicated

Question 26

Drug-susceptible S. typhi and S. paratyphi - treatment:

Answer 26

- fluoroquinolones are the optimal treatment. | - ciproflaxacin or oxofloxacin for 5-7 days

Question 27

MDR S.typhi or S. paratyphi - Treatment:

Answer 27

- ceftriaxon iv for 10-14 days | - or azithromycin p.o. for 5 days

Question 28

Chronic carriers – treatment:

Answer 28

4-6 weeks of appropriate oral antibiotic | - e.g. amoxicillin, TMP-SMX, ciprofloxacin, norfloxacin

Question 29

Typhoid (enteric) fever - prevention:

Answer 29

Prevention is based on ensuring access to safe water, promoting safe food handling practices and by vaccination. - wash hands - drink boiled water - clean fruits and vegetables - get vaccinated!

Question 30

Typhoid (enteric) fever - prevention - vaccination:

Answer 30

polysaccharide capsule Vi is present in about 90% of all freshly isolated S.typhi has a protective effect against the bactericidal action of the serum of infected patients

Question 31

How many vaccines do we have against Enteric (typhoid) fever?

Answer 31

two currently available improved typhoid vaccines

Question 32

Two currently available improved typhoid vaccines:

Answer 32

- parenteral Vi polysaccharide is given in a single dose with a booster every 2 years subcutaneous or i.m. - oral live attenuated Ty21a given on days 1, 3, 5, 7 with a booster every 5 years