Salmonellosis

infection spread by salmonella, various types of disease and treatment

1. Salmonellosis

A Dr. BHARAT KALIDINDI sus race zs
> MPH 2nd Sem 5,

S Padmashree School of Public Health Bangalore.
(Affitiated by Rajiv Gandhi University of Health Sciences, Bangalore)

2. [FACT]

+ Salmonella is a bacteria that makes people sick. It was discovered by
an American scientist named Dr. Salmon, and has been known to cause
illness for over 125 years.

Salmonella, the name of a group of bacteria, is one of the most
common causes of food poisoning in the United States

1.2 million illnesses and approximately 450 deaths occur due to non-
typhoidal Salmonella annually in the United States

An infection with Salmonella bacteria usually affects the
gastrointestinal system (the stomach and intestines) in humans. In
more severe cases, Salmonella can spread to the blood, the bones, or
even to the fluid around the brain, but these types of infection are less
common.

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4. + Gram Negative Bacteria + More than 2500 Serovars/Serotypes
+ Species: + Many are zoonotic

+ S. Bongori

+ S. Enterica

* Six sub species

5. » First isolated in 1884
» S. choleraesuis in pig intestine

+ Prevalence in the U.S.
» 1480: 30,000
+ 1486: 42,028
» 1998-2002: 128, 370

» Estimated 1.4 million cases/year
+ Only 40,000 culture-confirmed

6. Geographic Distribution

© Worldwide
+ Related to animal husbandry
+ Wild reservoirs

+ Serovar distribution varies
+ Some geographically limited
+» Ex: Subtyping of Salmonella Paratyphi A isolates from India,
Pakistan, Indonesia and Malaysia

+ Eradication programs in some countries
+ Sweden

7. U.S. Serotypes, 2009
Enteritidis
Typhimurium
Newport
Javiana
Heidelberg
Montevideo

Muenchen

8. Prevalence in Animals

&: 36%
86%

2-20%

50% 2% ie en

9. Human Transmission
Fecal-oral: direct or indirect

Commonly contaminated items
» Meat, eggs, water

Fecal material from:
+ Reptiles a a
° Chicks
¢ Ducklings
» Livestock, dogs, cats, adult
poultry

10. Number of reported isolates

Salmonella Isolates from Human sources
by Age Group and Sex, 2004

:

I

Y r r Y r r Y 7
1010 19 Years 201029 Yes 31039 Vous 400049 Vous S010 Yous OOP Years Tt Yeus 804 Years

Age Group
CG mu ESP |

11. Pathophysiology

Bacteria colonizes in the ilium - the end part of small intestine
They invade intestinal epithelium

They expand within the epithelium and lymphoid cavities

The invasion happens when organisms start to ruffle

This way they stimulate the pinocytosis

They multiply & spread through mesenteric lymph nodes

After reaching intestines they create an acute inflammation

12. Classification
Two broad classification:

+» Non-typhoidal salmonella
° Carried by both humans and animals
° Ex: salmonella javiana & salmonella enteritidis

+ Typhoidal salmonella
° Carried only by humans
° Ex: salmonella typhi

13. Salmonellosis (Nontyphoidal)

14. INFECTIOUS AGENT
+ Salmonella enterica, subspecies: enterica

EPIDEMIOLOGY
+» leading cause of bacterial diarrhoea worldwide
» 94 million cases of gastroenteritis and 115,000 deaths globally each
year
* 7.1 cases per 100,000 among travellers to Latin American and Caribbean
+ 5.8 cases per 100,000 among travellers to Asia
+ 25.8 cases per 100,000 among travellers to Africa.
+ Major Contributors of Reported cases in travellers:
+ Mexico (38% of travel-associated salmonellosis),
+ India (4%),
+» Jamaica (7%)
+ the Dominican Republic (4%)
* China (3%)
+ the Bahamas (2%)

15. CLINICAL PRESENTATION

Incubation period: 6-72 hours
but illness usually occurs within 12-36 hours after exposure

Symptoms:

acute diarrhea

abdominal pain

fever

Vomiting

Headache, fever, chills, myalgia
Severe dehydration: infants, elderly

+ The illness usually lasts 4-7 days, and most people recover without
treatment.

+ Rates of invasive infections and death are generally higher among infants,
older adults, and people with immunosuppressive conditions (including HIV),
hemoglobinopathies, and malignant neoplasms.

16. DIAGNOSIS
+ Diagnosis is based on isolation of Salmonella organisms
« About 90% of isolates are obtained from routine stool culture,
but isolates are also obtained from blood, urine, and material

from sites of infection

» Isolates of salmonellae are needed for serotyping and
antimicrobial susceptibility testing

+ PCR

17. Treatment

Uncomplicated salmonella infection with supportive therapy and no
antimicrobial agents

Antimicrobial therapy should be considered for patients who are severely ill
Fluoroquinolones: azithromycin and rifaximin are also commonly used

Resistance to antimicrobial agents varies by serotype and geographic
region.

Resistance to older antimicrobial agents: chloramphenicol, ampicillin, and
trimethoprim-sulfamethoxazole

Resistance to both fluoroquinolones and third-generation cephalosporins
has increased

18. Prevention

Food-borne diseases:
* Avoid raw or undercooked eggs, poultry, meat; unpasteurized milk/dairy
+ Wash foods before eating
* Avoid cross-contamination of food
+ Keep uncooked and cooked foods
+ Wash hands and kitchen tools
+ Do not feed infants or change diapers while handling food
+ Mother's milk is the safest food for young infants. Breastfeeding prevents
salmonellosis and many other health problems.
Animal contact:
+ Wash hands after contact
+ If immunocompromised, avoid contact with reptiles, young chicks, ducklings
Reptiles
+ Wash hands, cages, and surfaces
+ Change clothes after animal contact
* Do not allow reptiles to roam freely

19. Salmonella Control Programs in Denmark

Salmonella control programs of broiler chickens, layer hens, and pigs in
Denmark.

Major reductions in the incidence of foodborne human salmonellosis have
occurred by integrated control of farms and food processing plants.

Disease control has been achieved by monitoring the herds and flocks,
eliminating infected animals, and diversifying animals and animal food

products according to the determined risk.

In 2001, the Danish society saved U.S.$25.5 million by
controlling Salmonella.

The total annual Salmonella control costs in year 2001 were U.S.$14.1 million

20. Layers - Salmonella Testing under the National Control Programme - UK

» This programme was implemented in the UK on the Ist February
2008

» It required that from the Ist January 2004, eggs originating from
flocks infected with Salmonella Enteritidis or Salmonella
Typhimurium cannot be sent for human consumption unless
treated in a manner which will guarantee the elimination of
Salmonella.

21. cdc.gov
foodsafety.gov
salmonella.org
who.int
emedicine.medscape.
ncbi.nim.nih.gov
bmj.com