DR.M.F MOUSSAB.Sc,M.B.B.SDiplomé en Santé PubliqueVictoria Hospital,Candos.

Epidemiological study of isolates of salmonella,shigella and campylobacter from stool samples cultured at candos laboratory in 1998-99 and 2004-05.

Prepared by: Dr.M.Fazil MOUSSA

Tutor:Dr.M.I.Issack

Introduction Salmonella, shigella and campylobacter are

among the most common bacterial enteric pathogens worldwide.

These bacterial pathogens cause illnesses ranging from loose stools to dysentery.

Common symptoms are:1. Diarrhea2. Fever3. abdominal cramping4. rarely death can occur primarily in infants,

the elderly and patients with underlying illnesses.

5. rare complication such as osteomyelitis with Salmonella typhimurium,Guillain-Barré syndrome with Campylobacter and Reiter ‘s syndrome with Shigella.

MAJOR PUBLIC HEALTH ISSUE

Infections due to salmonella ,shigella and campylobacter are recognised as major health problem in several industrialized countries.

In U.S.A; Salmonellosis is estimated at 1,4

millions cases annually. 168 000 visits to physicians , 15 000 hospitalizations and 580 deaths.

(OMS,aide –mémoire,139)

The FDA (Food and Drug Administration,U.S) estimates 300 000 annual cases of shigellosis in U.S.A.

In France: Campylobacter infections are

estimated between 16 000 to 21 600 cases annually

3 200 to 3 400 hospitalization (Centre national de référence des

campylobacter et helicobacter,Oct.2005)

• Figure 1. Cases of Campylobacter and other foodborne infections by month of specimen collection; Centers for Disease Control and Prevention/U.S Department of Agriculture /Food and Drug Administration Collaborating Sites Foodborne Disease Active Surveillance Network, 1996.

Cost of Salmonellosis

• In the U.S, a case of salmonellosis is estimated to cost from 40US$ to 4.6 million US$ depending on whether it results in hospitalization or even death.The total cost can estimates around 3 billion US$.

• In Denmark,the annual cost of illness due to salmonella was estimated to be 15.5 million US$ in 2001. (OMS,Aide-mémoire,no.139)

Resistance rate in bacterial stool pathogens

Barcelona 1985-87 & 1995-98

Organism AntibioticResistance (percentage)

1985-87 1995-98

Salmonella

Ampicillin 8 44

Chloramphenicol 1.7 26

Co-trimoxazole 0.5 11

Nalidixic acid 0.1 11

CamopylobacterQuinolone (NA,Cip) 1 82

Tetracycline 23 72

Shigella

Ampicillin 55 43

Co-trimoxazole 55 76

Nalidixic acid <1 4.1

Antimicrob Agents Chemother 2000; 44: 1140-45

Aim of the study.

To describe the relative incidence of salmonella, shigella and campylobacter isolated from stool samples of diarrheal patients.

To study the seasonal variation during these periods.

To compare the occurrence in both sexes and in different age groups in the population during these two periods.

To study the antimicrobial susceptibility pattern.

To study the epidemiological trend during the two periods.

Methods.A descriptive study on diarrheal patients who attended hospitals and health centres in several areas of Mauritius from 1998-99 and 2004-05 whereby stool samples were sent for bacterial culture.

The data was collected from the laboratory records and analysed using Epi-info version 6.04cfr.The data collected included:

the patient identification age sex stool specimen source the date of collection of stool specimen the antibiotic susceptibility results.

Number of bacterial pathogen isolates

No. of stool samples.

8,068 (1998-99)5,033 (2004-05)

Salmonella190(50%) 1998-99282(63%) 2004-05

Campylobacter175(46%) 1998-99112(25%) 2004-05

Shigella10(3%) 1998-9936(8%) 2004-05

no. of isolates 382 (1998-99)450 (2004-05)

Number of different bacterial pathogens isolated in 1998-99 and 2004-05

0

50

100

150

200

250

300

1998-99 2004-05

year

no. o

f isola

tes

salmonella campylobacter shigella

• Salmonella is most common among the three pathogens studied.There was a higher frequency for the year 2004-05.

• Shigella was the least common.

• This finding differs from studies

published in other developing countries.

Salmonella

Distribution of Salmonella isolates by age groups.

0

50

100

150

200

250

0-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 41-45 46-50 51-55 56-60 61-65 >65

age groups(year)

no.o

f iso

late

s

1998-99 2004-05 total no.

Antimicrobial susceptibility results (% resistance) for salmonella for 1998-99 and 2004-05.

0 5 10 15 20 25

ampicillin

cephalexin

sulfamethoxazole

nalidixic acid

mecillinam

gentamicin

cefotaxime

ciprofloxacinan

tib

ioti

cs

% resistance

1998-99 2004-05

• A decrease frequency of antibiotic resistant salmonella was noted.

The seasonal variation in Salmonella isolation for the period 1998-99 & 2004-05

0

10

20

30

40

50

60

Jan Feb M ar Apr M ay Jun Jul Aug Sep Oct Nov Dec

month

no

. of

iso

late

s

1998-99 2004-05

Campylobacter.

Distribution of campylobacter isolates by age groups.

0

20

40

60

80

100

120

140

160

180

200

0-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 41-45 46-50 51-55 56-60 61-65 >65

age group(year)

no. o

f iso

late

s

1998-99 2004-05 total no.

Antibiotics susceptibility results for campylobacter in 1998-99(chart 1) and 2004-05(chart 2)

0

10

20

30

40

50

60

70

80

90

100

erythro cipro nalidixic

sensitive resistant

0

10

20

30

40

50

60

70

80

90

100

erythro cipro nalidixic

antibiotics

% sen

sitive/

resista

nt

sensitive resistant

shigella

Antibiotics susceptibility results( % resistance) for shigella during 1998-99 and 2004-05.

0 20 40 60 80 100

ampicillin

sulfamethoxazole

nalidixic acid

mecillinam

ciproxin

antib

iotics

% resistance

1998-99 2004-05

• The frequency of shigella spp. Isolates was negligible during this study,thus the distribution by age group was insignificant.

• An increase frequency of

antibiotic resistance among strain of shigella to ampicillin and trimethoprim-sulfamethoxazole was observed.

Discussion 1. This study shows that Salmonella species is more

frequent in Mauritius as compared to Campylobacter and Shigella.Salmonella accounted for 60% of the total bacterial pathogens isolated.

Shigella which accounted for 5% of the total pathogens isolated is least frequent.

The above trend differs from the reports published in other developing countries such as India and Bangladesh where Shigella is more frequent. – There is better standard of living with easy accessibility to

clean drinkable water and adequate sewage disposal in Mauritius.

– The population in Mauritius consumes more poultry and meat;more risk of exposure to Salmonella and Campylobacter.

We also observed that Shigella sonnei is the predominant species among Shigella during this study.This finding is similar to the trend seen in the U.S.A and France whereas in African and Asian countries ,Shigella dysenteriae predominates

Discussion

2.There is also a seasonal variation in the isolation of Salmonella with a peak during summer.No such pattern was observed for Campylobacter.

– This trend is consistent with other reports worldwide as warm temperature in summer encourage the multiplication and emergence of salmonella.

Discussion

3.The study revealed that the incidence of enteric bacterial pathogen infection is higher in children but it is also true that more stool sampes were received among children.

0

100

200

300

400

500

600

700

800

900

1000

0-5 6-10 11-

15

16-

20

21-

25

26-

30

31-

35

36-

40

41-

45

46-

50

51-

55

56-

60

61-

65

>65

age group(year)

no

.of

sto

ol

sam

ple

s

no.of stool sampes for 2004

Discussion

4.There is a higher rate of antibiotic resistance among Shigella species,namely to commonly used over –the-counter drugs as ampicillin and trimethoprim-sulfamethoxazole.• Shigella being strictly human pathogens, the increase

frequency of antibiotic resistance is due to excessive use of antibiotics in human.

The frequency of antibiotic resistance among salmonella and campylobacter is less significant.• These two bacterial pathogens are zoonoses and any

recrudescence of resistant strain is usually due to overuse of antibiotics in animals as seen in many developing countries such as Pakistan,India and Philippines.But no official data is available in Mauritius about the amount of antibiotics used in animals.

Conclusions.

• There is need to institute long term surveillance programs which are essential in identifying change in the spectrum of antimicrobial pattern of bacterial pathogens.

• It is a good measure that all stool samples are automatically cultured for Salmonella,Shigella and Campylobacter,but there is necessity to encourage physicians to send more stool for culture in order to gather more epidemiological data and monitor the incidence of enteric bacterial pathogen infection in the population.

• There is need to carry out studies on the different serotypes of bacterial intestinal pathogens.

• There is necessity to regulate the excessive use of antibiotics to reduce the emergence of antibiotic resistant strains.

• Thank you