DR.M.F MOUSSA
B.Sc,M.B.B.S
Diplomé en Santé Publique
Victoria 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
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1.
2.
3.
4.
5.
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:
Diarrhea
Fever
abdominal cramping
rarely death can occur primarily in infants,
the elderly and patients with underlying
illnesses.
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,Aidemémoire,no.139)
Resistance rate in bacterial stool pathogens
Barcelona 1985-87 & 1995-98
Organism
Antibiotic
Ampicillin
Salmonella
Camopylobacter
Shigella
Resistance (percentage)
1985-87
1995-98
8
44
Chloramphenicol
1.7
26
Co-trimoxazole
0.5
11
Nalidixic acid
0.1
11
Quinolone (NA,Cip)
1
82
Tetracycline
23
72
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.
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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)
no. of isolates
382 (1998-99)
450 (2004-05)
Salmonella
190(50%) 1998-99
282(63%) 2004-05
Campylobacter
175(46%) 1998-99
112(25%) 2004-05
Shigella
10(3%) 1998-99
36(8%) 2004-05
Number of different bacterial pathogens
isolated in 1998-99 and 2004-05
no. of isolates
300
250
•
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.
200
150
100
50
0
1998-99
2004-05
year
salmonella campylobacter shigella
Salmonella
Distribution of Salmonella isolates by age groups.
250
no.of isolates
200
150
100
50
0
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
age groups(year)
1998-99
2004-05
total no.
>65
Antimicrobial susceptibility results (% resistance)
for salmonella for 1998-99 and 2004-05.
ciprofloxacin
antibiotics
cefotaxime
gentamicin
mecillinam
nalidixic acid
sulfamethoxazole
cephalexin
ampicillin
0
5
10
15
20
% resistance
1998-99
•
2004-05
A decrease frequency of antibiotic resistant salmonella was noted.
25
The seasonal variation in Salmonella isolation for the
period 1998-99 & 2004-05
60
no. of isolates
50
40
30
20
10
0
Jan
Feb
M ar
Apr
M ay
Jun
Jul
Aug
m onth
1998-99
2004-05
Sep
Oct
Nov
Dec
Campylobacter.
Distribution of campylobacter isolates by age groups.
200
180
160
no. of isolates
140
120
100
80
60
40
20
0
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)
1998-99
2004-05
total no.
% sensitive/resistant
Antibiotics susceptibility results for campylobacter
in 1998-99(chart 1) and 2004-05(chart 2)
100
100
90
90
80
80
70
70
60
60
50
50
40
40
30
30
20
20
10
10
0
0
erythro
cipro
antibiotics
sensitive resistant
nalidixic
erythro
cipro
sensitive
resistant
nalidixic
shigella
Antibiotics susceptibility results( % resistance) for
shigella during 1998-99 and 2004-05.
ciproxin
•
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 trimethoprimsulfamethoxazole was
observed.
antibiotics
mecillinam
nalidixic acid
sulfamethoxazole
ampicillin
0
20
40
60
% resistance
1998-99 2004-05
80
100
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.
n o . o f sto o l sa m p l e s
1000
900
800
700
600
500
400
300
200
100
0
0-5 6-10
11-
16-
21-
26-
31-
36-
41-
46-
51-
56-
61-
15
20
25
30
35
40
45
50
55
60
65
age group(year)
no.of stool sampes for 2004
>65
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