- Email: [email protected]
The aetiology of diarrhoea in a farming community in Zimbabwe
552
The aetiology
of diarrhoea
in a farming
community
in Zimbabwe
CLIFFORD SIMANGOAND JOHN DINDIWE Blair Research Laboratoy, Ministry of Health, P.O. Box 8105, Causeway, Harare, Zimbabwe Abstract A survey of enteric pathogens in 143 children with diarrhoea, 116 age-matched controls and 524 asymptomatic people of all ages in a commercial farming area was carried out over a period of one year. Giardia lamblia was detected in 34% of the cases, 29% of the controls and 23% of asymptomatic
people of all ages. Various bacterial pathogens (Campylobacter,Shigella, Salmonella and enteropathogenic Escherichia coli> were isolated from 23% of the cases and 15% of the controls. EnteroDathogenic E. coli was isolated as freauently from the cases as from the controls and asymptbmati:
people of all ages. coli were not available. G. lamblia cysts were sought using the formol-ether concentration method. Results
Introduction
Diarrhoeal disease is one of the main causes of morbidity
and mortality
among children
under 5
years old in developing countries (GORDON, 1971). Hospital-based aetiological studies on children with acute diarrhoea have been conducted in Zimbabwe at Wilkins and Harare hospitals where classical bacterial and viral pathogens were looked for (CRUICKSHANK et al., 1975; CRUICKSHANK & ZILBERG, 19763 ZILGERG, 1976). This study was carried out to idenufy some of the enteric pathogens in children with diarrhoea in a farming community who were not brought to treat-
The enteric pathogens which were detected are shown in Table 1. G. lamblia, observed in 34% of the casesand 29% of the controls, was the most common pathogen detected. The predominant bacterial pathogen, isolated from 11% of the casesand 10% of the controls, was enteropathogenic E. coli followed by Campylobacter sp. (8% of the cases and 2% of the controls). Shigella sp. was detected in 5% of the cases and 2% of the controls. Only one control excreted Salmonella sp. The distribution of enteric pathogens by agegroups is shown in Table 2. Campylobactersp. was isolated only from children less than 2 years old while enteropathogenic E. coli was observed in children less than 4 years old. G. lamblia and Shigella sp. were detected in children of all age groups, with G. lamb& being more common in older children. When people of all ages in the community were examined for asymptomatic carriers of some of the enteropathogens, 23% had G. lamblia cysts (Table 3). Enteropathogenic E. coli was isolated from 10% and Campylobacter sp. was detected in 3%.
ment centres. Materials and Methods This study was conducted on children, less than 6 years old, of farmworkers in the Marondera commercial farming area, 1OOkmfrom Harare. Stool specimens were collected from 143 children with diarrhoea and from 116 age-matched controls from November 1983 to October 1984 and were examined for Shigella species, Salmonella sp. entero. pathogenic Escherichia coli and Giardiu lamblia. Specimens were also examined for Campylobacter sp. between April and October 1984. A funher 524 specimens from asymptomatic people of all ages were collected during the hot wet season (November to March). 376 specimens were examined for G. ’ lamblia, 338 for Campylobacter sp. and 148 for enteropathogenic E. coli. Standard procedures were used to isolate bacterial pathogens. Isolates were identified using biochemical and serological methods (WHO, 1983). Non-typable E. coli were not recorded and facilities for identifying enterotoxigenic E. Table
l-Frequency
of isolation
of different
Discussion
G. lamblia is very common, being isolated from high percentagesof both diarrhoeal casesand asymptomatic carriers. Lower rates of giardial infection
enteric pathogens
Controls (n = 116)
Cases (n = 143) Giardia lamblia Enteropathogenic E. coli Shigella species Campylobacter species* Salmonella species
Number
Percentage
Number
Percentage
48
34
34
29
15
11
11
10
7
5
2
2
4
8
1
2
0
0
1
1
*51 cases and 43 controls were examined for Campylobacter species.
C.
Table
2-Frequency
of isolation
(percent.)
SIMANGO
of enteric
0 - 1 year 11 months 2 years - 3 years 11 months 4 years - 6 years Table 3-Asymptomatic
Giwdia hmblia EnteropathogenicE. coli Campylobactm species
pathogens
Controls 25.8 20.7 52.4
CaSt!S
13.2 8.6 0
carriers of some entcric pathogens NUlllXr
NUdXr
376
88 (23%)
148
15 (10%)
examined
338
J. DINDIWE
positive
9 (3%)
by MASON & NATHOO (1985) at Parirenyatwa Hospital in Harare, where the parasite was detected in 15% of children with diarrhoea and 9% of asymptomatic carriers, but comparable high percentageswere observed by hiASON et al. (1986) in primary school children. Further studies on the epidemiology of G. Zumblia infection may explain its high prevalence. Enteropathogenic E. co& was the most common bacterial pathogen in both casesand controls, as also noted by AKINTERINWA & PAUL (1982) in Nigeria. ZILBERG(1976) found Shigella to be the commonest pathogen in Harare, whereas we found ShigeZZu in only 5% of the cases; Shigella f&waeri was the predominant type. ZILBERG (1976) also observed a similar predominance of S. jexneri. The isolation rate of Campylobacter sp. in this study was less than those observed in Rwanda by DE MOL 81 BOSMANS(1978), in South Africa by MAUFF & CHAPMAN (1981) and in The Gambia by BILLINGHAM were reported
(1981). The specimens which we examined for Cumpylobacrer were collected during the dry season
(April fo November), which may explain the relatively low rate. Since G. lumblia and enteropathogenic E. coli were isolated as frequently from children with diarrhoea as from controls and asymptomatic people of all ages, they were not necessarily the causative organisms of diarrhoea.
553
by age group
Enteripathigenic
Giardia lamblia Cases 31.9 31.4 47.1
AND
Controls 12.1 10.3 0
Campylobacter
species
Shigella species
Controls 1.5 3.5 0
ChSfS
5.5 2.9 5.9
Cases 12.1 0 0
Controls 4.6 0 0
Ackaowledgements
We are grateful for technical assistancefrom Martin
Ndhlovu and Alex Baya. We thank the Secretary for Health for permission to publish. References
Akinterinwa, M. 0. & Paul, M. 0. (1982). Bacteriological investigations of infantile gastro-enteritisin Ife, Nigeria. Journal of Tropical Medicine and Hygiene, 85, 139-141. Billingham, J. D. (1981). Campylobacter enteritis in The Gambia. Transactions of the Royal Society of Tropical Medicine and Hygiene, 75, 641-646.
Cruickshank,J. G. & Z&erg, B. (1976).Winter diarrhoea and rotavirus in Rhodesia. South African Medical Journal, 50, 1895-1896.
Cruickshank,J. G., Zilberg, B. & Axton, J. H. M. (1975). Virus particles and gastro-enteritis in l$ack and white ;$-d;;;
in Rhodesia. South African Medzcal Journal, 49,
De Mol, P. ‘S, Bosmans,E. (1978).Campylobacter enteritis in Central Africa. Lancer, i, 604. Gordon, J. E. (1971). Diarrhoeal diseaseof early childhood - worldwide scope of the problem. Annals of the New York Academy of Science, 176, 9-15. Mason, P. R. & Nathoo, K. J. (1985). Giardiasis, diarrhoea and malnutrition. Central African 3ownal of Medicine, 31, 125-126. Mason, P. R., Patterson, B. A. & Loewenson, R. (1986). Piped water supply and intestinal parasitism in Zimbabwean schoolchildren. Transactions of the Royal Society of Tropical Medicine and Hygiene, 80, 88-93.
Mauff, A. C. & Chapman, S. R. (1981). Campylobacter enteritis in Johannesburg. South African MedicalJournal, 59, 217-218. WHO (1983). Manual for Laboratory Investigation of Acute Enteric Infections,
tion, Geneva.
CDD183.3.World Health Organiza-
Zilberg, B. (1976). A clinical and epidemiological study of gastro-enteritis. South African Medical Journal, 50, 2038-2040. Accepted
for publication 21
May
1986
The aetiology
of diarrhoea
in a farming
community
in Zimbabwe
CLIFFORD SIMANGOAND JOHN DINDIWE Blair Research Laboratoy, Ministry of Health, P.O. Box 8105, Causeway, Harare, Zimbabwe Abstract A survey of enteric pathogens in 143 children with diarrhoea, 116 age-matched controls and 524 asymptomatic people of all ages in a commercial farming area was carried out over a period of one year. Giardia lamblia was detected in 34% of the cases, 29% of the controls and 23% of asymptomatic
people of all ages. Various bacterial pathogens (Campylobacter,Shigella, Salmonella and enteropathogenic Escherichia coli> were isolated from 23% of the cases and 15% of the controls. EnteroDathogenic E. coli was isolated as freauently from the cases as from the controls and asymptbmati:
people of all ages. coli were not available. G. lamblia cysts were sought using the formol-ether concentration method. Results
Introduction
Diarrhoeal disease is one of the main causes of morbidity
and mortality
among children
under 5
years old in developing countries (GORDON, 1971). Hospital-based aetiological studies on children with acute diarrhoea have been conducted in Zimbabwe at Wilkins and Harare hospitals where classical bacterial and viral pathogens were looked for (CRUICKSHANK et al., 1975; CRUICKSHANK & ZILBERG, 19763 ZILGERG, 1976). This study was carried out to idenufy some of the enteric pathogens in children with diarrhoea in a farming community who were not brought to treat-
The enteric pathogens which were detected are shown in Table 1. G. lamblia, observed in 34% of the casesand 29% of the controls, was the most common pathogen detected. The predominant bacterial pathogen, isolated from 11% of the casesand 10% of the controls, was enteropathogenic E. coli followed by Campylobacter sp. (8% of the cases and 2% of the controls). Shigella sp. was detected in 5% of the cases and 2% of the controls. Only one control excreted Salmonella sp. The distribution of enteric pathogens by agegroups is shown in Table 2. Campylobactersp. was isolated only from children less than 2 years old while enteropathogenic E. coli was observed in children less than 4 years old. G. lamblia and Shigella sp. were detected in children of all age groups, with G. lamb& being more common in older children. When people of all ages in the community were examined for asymptomatic carriers of some of the enteropathogens, 23% had G. lamblia cysts (Table 3). Enteropathogenic E. coli was isolated from 10% and Campylobacter sp. was detected in 3%.
ment centres. Materials and Methods This study was conducted on children, less than 6 years old, of farmworkers in the Marondera commercial farming area, 1OOkmfrom Harare. Stool specimens were collected from 143 children with diarrhoea and from 116 age-matched controls from November 1983 to October 1984 and were examined for Shigella species, Salmonella sp. entero. pathogenic Escherichia coli and Giardiu lamblia. Specimens were also examined for Campylobacter sp. between April and October 1984. A funher 524 specimens from asymptomatic people of all ages were collected during the hot wet season (November to March). 376 specimens were examined for G. ’ lamblia, 338 for Campylobacter sp. and 148 for enteropathogenic E. coli. Standard procedures were used to isolate bacterial pathogens. Isolates were identified using biochemical and serological methods (WHO, 1983). Non-typable E. coli were not recorded and facilities for identifying enterotoxigenic E. Table
l-Frequency
of isolation
of different
Discussion
G. lamblia is very common, being isolated from high percentagesof both diarrhoeal casesand asymptomatic carriers. Lower rates of giardial infection
enteric pathogens
Controls (n = 116)
Cases (n = 143) Giardia lamblia Enteropathogenic E. coli Shigella species Campylobacter species* Salmonella species
Number
Percentage
Number
Percentage
48
34
34
29
15
11
11
10
7
5
2
2
4
8
1
2
0
0
1
1
*51 cases and 43 controls were examined for Campylobacter species.
C.
Table
2-Frequency
of isolation
(percent.)
SIMANGO
of enteric
0 - 1 year 11 months 2 years - 3 years 11 months 4 years - 6 years Table 3-Asymptomatic
Giwdia hmblia EnteropathogenicE. coli Campylobactm species
pathogens
Controls 25.8 20.7 52.4
CaSt!S
13.2 8.6 0
carriers of some entcric pathogens NUlllXr
NUdXr
376
88 (23%)
148
15 (10%)
examined
338
J. DINDIWE
positive
9 (3%)
by MASON & NATHOO (1985) at Parirenyatwa Hospital in Harare, where the parasite was detected in 15% of children with diarrhoea and 9% of asymptomatic carriers, but comparable high percentageswere observed by hiASON et al. (1986) in primary school children. Further studies on the epidemiology of G. Zumblia infection may explain its high prevalence. Enteropathogenic E. co& was the most common bacterial pathogen in both casesand controls, as also noted by AKINTERINWA & PAUL (1982) in Nigeria. ZILBERG(1976) found Shigella to be the commonest pathogen in Harare, whereas we found ShigeZZu in only 5% of the cases; Shigella f&waeri was the predominant type. ZILBERG (1976) also observed a similar predominance of S. jexneri. The isolation rate of Campylobacter sp. in this study was less than those observed in Rwanda by DE MOL 81 BOSMANS(1978), in South Africa by MAUFF & CHAPMAN (1981) and in The Gambia by BILLINGHAM were reported
(1981). The specimens which we examined for Cumpylobacrer were collected during the dry season
(April fo November), which may explain the relatively low rate. Since G. lumblia and enteropathogenic E. coli were isolated as frequently from children with diarrhoea as from controls and asymptomatic people of all ages, they were not necessarily the causative organisms of diarrhoea.
553
by age group
Enteripathigenic
Giardia lamblia Cases 31.9 31.4 47.1
AND
Controls 12.1 10.3 0
Campylobacter
species
Shigella species
Controls 1.5 3.5 0
ChSfS
5.5 2.9 5.9
Cases 12.1 0 0
Controls 4.6 0 0
Ackaowledgements
We are grateful for technical assistancefrom Martin
Ndhlovu and Alex Baya. We thank the Secretary for Health for permission to publish. References
Akinterinwa, M. 0. & Paul, M. 0. (1982). Bacteriological investigations of infantile gastro-enteritisin Ife, Nigeria. Journal of Tropical Medicine and Hygiene, 85, 139-141. Billingham, J. D. (1981). Campylobacter enteritis in The Gambia. Transactions of the Royal Society of Tropical Medicine and Hygiene, 75, 641-646.
Cruickshank,J. G. & Z&erg, B. (1976).Winter diarrhoea and rotavirus in Rhodesia. South African Medical Journal, 50, 1895-1896.
Cruickshank,J. G., Zilberg, B. & Axton, J. H. M. (1975). Virus particles and gastro-enteritis in l$ack and white ;$-d;;;
in Rhodesia. South African Medzcal Journal, 49,
De Mol, P. ‘S, Bosmans,E. (1978).Campylobacter enteritis in Central Africa. Lancer, i, 604. Gordon, J. E. (1971). Diarrhoeal diseaseof early childhood - worldwide scope of the problem. Annals of the New York Academy of Science, 176, 9-15. Mason, P. R. & Nathoo, K. J. (1985). Giardiasis, diarrhoea and malnutrition. Central African 3ownal of Medicine, 31, 125-126. Mason, P. R., Patterson, B. A. & Loewenson, R. (1986). Piped water supply and intestinal parasitism in Zimbabwean schoolchildren. Transactions of the Royal Society of Tropical Medicine and Hygiene, 80, 88-93.
Mauff, A. C. & Chapman, S. R. (1981). Campylobacter enteritis in Johannesburg. South African MedicalJournal, 59, 217-218. WHO (1983). Manual for Laboratory Investigation of Acute Enteric Infections,
tion, Geneva.
CDD183.3.World Health Organiza-
Zilberg, B. (1976). A clinical and epidemiological study of gastro-enteritis. South African Medical Journal, 50, 2038-2040. Accepted
for publication 21
May
1986