1. WATERBORNE PATHOGENS
OF CONCERN IN
DEVELOPING COUNTRIES:
with Special Reference to Libya
Prof. Khalifa Sifaw Ghenghesh
Dept. of Medical Microbiology,
Faculty of Medicine
Tripoli - Libya

2. INTRODUCTION
 Drinking
water is a major source of
microbial pathogens in developing
countries.
 Waterborne disease cause more than 2
million deaths and 4 billion cases of
diarrhea annually.
 9 out of 10 deaths are in children and
virtually all of the deaths are in developing countries

3. WATERBORNE PATHOGENS IN
DEVELOPING COUNTRIES

4. BACTERIA
Microorganism
Major disease
--------------------------------------------------------------------------Salmonella typhi
Typhoid fever
S. paratyphi
Paratyphoid fever
Other Salmonella
Salmonellosis
Shigella spp.
Bacillary dysentery
(Shigellosis)
Vibrio cholerae
Cholera
Diarrheagenic E. coli
Gastroenteritis
Yersinia enterocolitica
Gastroenteritis
Campylobacter jejuni
Gastroenteritis
Aeromonas spp.
Gastroenteritis
Various mycobacteria
Pulmonary illness

5. ENTERIC VIRUSES
Enteroviruses
Polio viruses
Coxsackie A & B
Other enteroviruses
Poliomyelitis
Aseptic meningitis
Encephalitis
Rotavirus
Gastroenteritis
Adenoviruses
Hepatitis A & E viruses
Upper respiratory and
gastrointestinal illness
Infectious hepatitis
Norovirus
Gastroenteritis

6. PROTOZOA & HELMINTHS
Balantidium coli
Balantidosis (dysentery)
Cryptosporidium parvum
Cryptosporidiosis
(gastroenteritis)
Entamoeba histolytica
Amoebic dysentery
Giardia lamblia
Giardiasis (gastroenteritis)
Ascaris lumbricoides
Ascariosis

7. Causative Agents of Childhood Diarrhea in Libya
% positive
Agent
Tripoli
Benghazi
Zliten
-------------------------------------------------------------------------------------------------Single
41
35
44
Multiple
19
6
12
Rotavirus
32
24
27
Salmonella
11
7
14
Shigella
6
5
4
Enteropathogenic E. coli
11
8
ND
E. coli O157
7
ND
ND
Campylobacter
6
2
ND
Yersinia enterocolitica
0.6
0
ND
Aeromonas
15
0
6
Cryptosporidium
ND
ND
13
Giardia lamblia
ND
ND
1
Entamoeba histolytica
ND
ND
12

8. Bacteriological Quality of Drinking Water
in Libya
Type of
No
% positive for
Water
tested
E. coli
Aeromonas
---------------------------------------------------------------------Well
1000
37
49
Fasghia
56
27
73
Majin
62
ND
60
From Mosques 50
14
18
Mineral
216
0
0

9. Outbreaks of waterborne disease in England and Wales from
1991 to 2000
Cause
Number of
Number
Outbreaks
of cases
--------------------------------------------------------------------------------------------------------Public water supplies:
Cryptosporidium
23
2837
Campylobacter
1
281
Gastroenteritis
1
229
Total
25
3347
Private water supplies:
Campylobacter
Mixed Campylobacter
and Cryptosporidium
Cryptosporidium
Gastroenteritis
Giardia
E. coli O157
Total
8
1
178
43
3
2
1
1
16
74
81
31
14
421

10. Recreational contact with surface water
Viral gastroenteritis
1
7
Swimming pool contact
Cryptosporidium
23
337
--------------------------------------------------------------------------------------------------------Overall total
65
4112

11. Outbreaks of waterborne disease in Tripoli
1992-2004
Number of
outbreaks
Number
of cases
-------------------------------------------------------------------------------Public water supplies:
Shigella sonnei
1
>1500
Private water supplies:
Shigella flexneri
1
6

12. Some Concerns Regarding Waterborne
Pathogens
 Efficacy
of treatment (filtration and
chlorination) and the use of E. coli as a
fecal indicator:

Chlorine-resistant parasitic protozoa
• Oocysts of Cryptosporidium parvum

Various enteric viruses
 Important
to match the appropriate
indicator for the group of pathogen(s)
of interest.

13. Emerging Waterborne Issues

Rapid urbanization of humans in developing
regions:


Places further stress on inadequate water supply
and sanitation.
Climate change:

A change in the distribution of rainfall
• Heavy rain fall
• Flooding

Greater extremes in global weather patterns
• Major waterborne outbreaks typically follow large storm
events in developing countries

Evolution of new pathogens

15. What We Should Do?
A
combination of both monitoring of
water quality and epidemiological
surveillance.
 A comprehensive public health
surveillance strategy seems the most
efficient approach to better understand
and control the impact of water quality
on gastrointestinal disease.

16. CONCLUSION

Despite our efforts, waterborne pathogens will
always be a major issue for human health, and
particularly so in developing countries