1. CLASSICAL AND NEW EMERGING ENTERIC
PATHOGENS ASSOCIATED WITH
CHILDHOOD DIARRHEA IN
TRIPOLI-LIBYA
Prof. Khalifa Sifaw Ghenghesh
Faculty of Medicine, Tripoli University
Libya

2. Introduction
• In developing countries, infectious diarrhea is associated
with high rates of morbidity and mortality, mainly in
childhood.
• Classical enteric pathogens
– Salmonella sp., Shigella sp., enteropathogenic Escherichia coli
(EPEC), enteroinvasive E. coli (EIEC),Vibrio cholerae and
rotavirus.
• New emerging enteric pathogens
– bacteria (e.g., Campylobacter spp., enterohemorrhagic
Escherichia coli [EHEC], and enteroaggregative E. coli [EAEC]),
– viruses (e.g., norovirus, adenovirus, and astrovirus), and
– parasites (e.g., Cryptosporidium sp.).
• In Libya, rotavirus and Salmonella have been documented
as major causative agents of childhood diarrhea.

3. Agents of Infective Acute Diarrhea in Libyan Children
1980-2007
Agent
Rate of Occurrence
Bacterial
1. Enteropathogenic E. coli
3. Salmonella sp.
4. Shigella sp.
5. Yersinia enterocolitica
6. Campylobacter sp.
7. Aeromonas sp.
4 - 11 %
6 -25 %
4 - 10 %
<1 %
2-6%
0 - 15 %
Parasitic
1. Entamoeba histolyitca/disapr
2. Giardia lamblia
3. Cryptosporidium
12 %
1 - 18 %
13 %
Rotavirus
24 - 31 %
Multiple agents
12 - 14.5 %

4. • Major drawbacks of previous data from Libya:
– Available data based on few studies and some of
them dealt with single or few pathogens.
– No available data for some of the classical and new
emerging enteric pathogens that include:
•
•
•
•
•
•
•
Enterotoxigenic E. coli (ETEC)
Enteroinvasive E. coli (EIEC)
Enterohemorrhagic E. coli (EHEC)
Entroaggregative E. coli (EAEC)
Norovirus
Adenovirus
Astrovirus
– Available data on enteric protozoa obtained using wet
mount techniques.
• Not sensitive
• Do not differentiate between E. histolytica and E. dispar.

5. Patients and Methods
• Stool samples:
– 239 children (102 females) with diarrhea,
– a few days to 5 years,
– Outpatient Clinics of Aljala Children’s Hospital and Alkhadra
Hospital
– February-October 2008.
• Clinical history by MDs after informed consent from a parent
or guardian:
– Clinical symptoms include fever, vomiting, and dehydration were
recorded.
– Also recorded type of feeding (breast, artificial, or both).
– Other.
• Microbiology:
– Stools examined for bacterial, viral and parasitic agents enteric
pathogens using a combination of culture, enzyme-immunoassay,
and polymerase chain reaction (PCR) methods.

6. Results

7. Enteric pathogens isolated from 239 diarrheic
children in Tripoli, Libya.
Enteric pathogen (s)
No. (%)
positive
Single
89 (37.2)
Multiple
33 (13.8)
Total
122 (51.0)
Diarrheagenic Escherichia coli
27 (11.2)
Salmonella spp.
19 (7.9)
Shigella spp.
1 (0.8)
Campylobacter spp.
7 (2.9)
Aeromonas spp.
10 (4.2)
Rotavirus
32 (13.4)
Norovirus
37 (15.5)
Adenovirus
17 (7.1)
Astrovirus
4 (1.7)
Cryptosporidium spp.
5 (2.1)
Entamoeba histolytica
2 (0.8)
Giardia lamblia
3 (1.3)
No pathogen detected
117 (49)

8. Enteric Bacterial Pathogens
Diarrheagenic Escherichia coli1
27 (11.2)
-
pCVD432 (EAEC)
10 (4.1)
-
eaeA (EPEC/EHEC)
9 (3.8)
-
ipaH (EIEC)
4 (1.6)
-
pCDV432 + ipaH
2 (0.8)
-
eaeA + ipaH
1 (0.4)
-
pCVD432 + eaeA
1 (0.4)
Salmonella spp.
19 (7.9)
-
Salmonella group B
3 (1.3)
-
Salmonella group C1
1 (0.4)
-
Salmonella group C2
13 (5.4)
-
Salmonella group D1
2 (0.8)
Shigella spp.
1 (0.8)
Campylobacter spp.
- C. jejuni
- C. coli
7 (2.9)
6 (2.5)
1 (0.4)
Aeromonas spp.
10 (4.2)
1est
and
encoding
eltB
genes
for
enterotoxigenic E. coli (ETEC)
were not detected.

9. Clinical symptoms associated with enteric pathogens isolated from
diarrheic children in Tripoli, Libya
Agents
Cases
detected
No. (%) positive
Fever
Dehydration1
62(69.9)
30(33.7)
24(72.7)
13(39.4)
86(70.4)
43(35.2)
Single
Multiple
Total
89
33
122
Vomiting
73(82.8)
30(90.9)
103(84.4)
Diarrheagenic Escherichia coli
27
25(92.6)
20(74.1)
10(37.0)
Salmonella spp.
19
15(78.9)
15(78.9)
4(21.1)
Shigella spp.
Campylobacter spp.
1
7
1(100)
3(42.9)
1(100)
4(57.1)
0(0.0)
0(0.0)
Aeromonas spp.
10
10(100)
6(60)
5(50)
Rotavirus2
32
32(100)
24(75)
17(53.1)
Norovirus
37
34(91.9)
23(62.2)
9(24.3)
Adenovirus
17
14(82.4)
10(58.8)
7(41.2)
Astrovirus
4
3(75)
4(100)
2(50)
Cryptosporidium spp.
5
2(40)
4(80)
2(40)
Entamoeba histolytica
2
2(100)
2(100)
2(100)
Giardia lamblia
3
2(66.7)
3(100)
1(33.3)
117
95(81.2)
87(74.4)
2(1.7)
No pathogen detected
1Dehydration
associated
with
diarrheic children
positive for single,
multiple and total
enteric
pathogens
compared
with
children with no
pathogen detected.
2Rotavirus
associated with dehydration
compared
with norovirus.

10. Distribution of enteric pathogens isolated from diarrheic children in Tripoli
according to seasons of the year covered in the study.
Spring
(n=47)
Summer
(n=112)
Autumn
(n=66)
Total
(n=239)
Single1
22(46.8)
36(32.1)
31(48.5)
89(37.2)
Multiple
Total2
7(14.9)
29(61.7)
16(14.3)
52(46.4)
10(15.2)
41(62.1)
33(13.8)
122(51)
Diarrheagenic E. coli
Salmonella spp.
Shigella spp.
Campylobacter spp.
7(14.9)
2(4.3)
0(0.0)
0(0.0)
9(8)
11(9.8)
1(0.9)
6(5.4)
11(16.7)
6(9.1)
0(0.0)
1(1.5)
27(11.3)
19(7.9)
1(0.4)
7(2.9)
Aeromonas spp.3
Rotavirus4
5(10.6)
16(34)
5(4.5)
3(2.7)
0(0.0)
13(19.9)
10(4.2)
32(13.4)
Norovirus5
Adenovirus
3(6.4)
3(6.4)
19(17)
9(8)
15(22.7)
5(7.6)
37(15.5)
17(7.1)
Astrovirus
Cryptosporidium spp.
Entamoeba histolytica
Giardia lamblia
No pathogen detected
0(0.0)
1(2.1)
1(2.1)
0(0.0)
16(34)
3(2.7)
4(3.6)
0(0.0)
2(1.9)
59(52.7)
1(1.5)
0(0.0)
0(0.0)
1(1.5)
38(54.5)
4(1.7)
5(2.1)
2(0.8)
3(1.3)
117(49)
Enteric pathogen (s)
1,2,4Single
and total
pathogens and
rotavirus detected
more in spring and
autumn compared with
summer. 3Aeromonas
detected more in spring
compared with
autumn. 5Norovirus
detected more in
autumn compared with
spring.

11. Resistance of Salmonella, Shigella and Aeromonas species isolated from Libyan
children with diarrhea to antimicrobial agents
Antimicrobial agent
Ampicillin (10µg)
Amoxicillin/clavulanic
acid (30µg)
Imipenem (10µg)
Chloramphenicol (30µg)
Cephalothin (30µg)
Ceftriaxone (30µg)
Ceftazidime (10ug)
Cefepime (30µg)
Aztreonam (30µg)
Ciprofloxacin (5µg)
Nalidixic acid (30µg)
Streptomycin (10µg)
Tetracycline (30µg)
Trimethoprim/
sulfamethoxazole (25µg)
Salmonella Shigella Aeromonas
(n=19)
(n=1)
(n=10)
Total
(n=30)
9 (47.3 )
1 (100)
10 (100)
20 (66.7)
1 ( 5.2)
0 (0.0)
1 ( 5.2)
11 (57.8)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
12 (63.1)
16 (84.2)
15(78.9)
12 (63.1)
0 (0.0)
0 (0.0)
1 (100)
1 (100)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
1 (100)
0 (0.0)
5 (50)
1 (10)
0 (0.0)
7 (70)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
2 (20)
3 (30)
0 (0.0)
6 (20)
1 (3.3)
2 (6.6)
19 (63.3)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
12 (40)
18 (60)
19 (63.3)
12 (40)
4 (21)
0 (0.0)
1(10)
5 (16.6)

12. Conclusion
• To our knowledge this is the first study to identify
norovirus, adenovirus, and astrovirus as enteric
pathogens causing children diarrhea in Libya.
• The findings of the present investigation indicate,
in addition to Salmonella and rotavirus, the enteric
pathogens norovirus, adenovirus and EAEC are
important causative agents of children diarrhea in
Tripoli.
• On
the
other
hand,
Cryptosporidium,
Campylobacter and Aeromonas spp. appear to play
a minor role in pediatric diarrheal disease in Tripoli.

13. • The
emergence
of
ciprofloxacin-resistant
Salmonella is a very serious health problem that
should be addressed by public health authorities.
• More studies are necessary in other major cities of
Libya as well as a dedicated national pathogenspecific surveillance system to identify various
etiologies of pediatric diarrhea to determine the
exact role of these enteric pathogens.
• Furthermore, introduction of a rotavirus vaccine
into the vaccination program in Libya to protect
the pediatric population is urgently needed.

14. • Rahouma A., Klena JD., Krema Z., Abobker AA.,
Treesh K., Franka E., Abusnena O., Shaheen HI.,
El Mohammady H., Abudher A., and Ghenghesh
KS. 2011. Enteric Pathogens Associated with
Childhood Diarrhea in Tripoli-Libya. American
Journal of Tropical Medicine and Hygiene; 84:
886-891.
• ghenghesh_micro@yahoo.com
• ghenghesh@yahoo.com