RISK FACTORS ASSOCIATED TO THE PROLONGATION OF DIARRHEA IN CHILDREN BELOW 5 YEARS OF AGE IN MEKONG DELTA: A COHORT STUDY

 

 Nguyen Kim Tien.*, Nguyen Van Tam*, Huynh Thu Thuy*

                          Nguyen Thi Thu*, Le Hoang San**, Nguyen Van Trai**

* Pasteur Institute of HoChiMinh city

** Medicine Preventive Center of TienGiang Province CaiBe district

INTRODUCTION:

Diarrhoeal diseases are one of major causes of high morbidity and mortality in children, specially in Mekong delta region. The effectiveness of prevention has been limited because of environmental conditions. Some of acute diarrhea becomes persistent diarrhea that not only represents a difficult management for the health professional, but also has a severe adverse nutritional impact for children. The objective of this study is to identify the incidence, mortality of diarrhea and risk factors that lead to the development of prolonged diarrhoeal episodes in children under 5 years of age in CaiBe district, TienGiang province, South Vietnam.

METHOD OF STUDY:

1. Epidemiological method:

A community prospective cohort study method was applied for 2,100 children under 5 years of age selected randomly 24 communes of CaiBe district by 30 clusters method of WHO. The study children were visited and investigated at home every week by trained health workers of health commune and hamlet centers and supervised every two-week by epidemiologists from district, province health centers and Pasteur Institute. The diarrhoeal child was interviewed, recorded in a preceded form, distributed oral rehydration solution and collected stool sample. Diarrhea was defined as three or more liquid or semiliquid stools passed in 24-hour period.

The diarrhoeal density incidence was calculated as the number of episodes per child-year at risk. Child-years at risk of diarrhea included all days in the study period surveyed without diarrhea for a child. The child was only included in the study sample if he was observed for more than 3 months. Throughout study, children becoming 5 years old, absent for long time or die were eliminated then replaced by selected neighbor children.

Univariable analysis by software EPINIFO and multivariable logistic regressive analysis by EGRET were applied to evaluate the association between the exposed factors and the prolongation of diarrhoeal episode duration with the value of relative risk (RR) and 95% confidence interval (95% CI).

2. Microbiological methods:

Stool specimens were collected at home at the beginning of episode. Stools were preserved in Cary - Blair transport media and transported with cold packs to the laboratory. Rotavirus were detected by ELISA kit. Salmonella, Shigella, Vibrios and Campylobacter were identified using standard techniques. Identification of E.Coli (ETEC and EAEC) will be done by molecular biology method.

RESULTS:

1. Results of cross-sectional household survey.

At the beginning of the study, the survey was conducted in order to select 2,100 children and to understand the background of the study population.

-         Diarrhoeal prevalence of last two weeks: 5.6%

-         Number of diarrhoeal episodes/ child/ year: 1.5

-         Hygiene condition:

·         Latrine on river accounted for 58.8% of total of household, fish pond latrines: 37.4%, good hygiene latrines: 2.9%.

·         Source of water: 91% of households used river water, 4.6%: pond water, 4.6%: well water, 1.2%: pipe water.

·         Drinking water: 24.8% of households drank river water without boiling, 29.9%: boiling water.

2. Results of longitudinal study:

2.1. Incidence of diarrhea

Table 1: Incidence of diarrhea distributed by age and duration

 

 

 

 

 

 

Episode duration (days)

 

 

 

 

 

 

< 3 days

3-14 days

>14 days

Age group (month)

No children observed

No. following days

No Child-year
at risk

No. diarrheal episodes

Inc.D

No. diarrheal episodes

Inc.D

No. diarrheal episodes

Inc.D

No. diarrheal episodes

Inc.D

0-6

403

135,708

371.8

63

16.9

21

5.7

41

11.0

1

0.3

6-12

325

135,279

370.6

145

39.1

56

15.1

89

24.0

0

0.0

12-18

258

116,557

319.3

157

49.2

56

17.5

99

31.0

2

0.6

18-24

252

118,865

325.7

140

43.0

64

19.7

74

22.7

2

0.6

24-30

231

109,155

299.1

94

31.4

34

11.4

60

20.1

0

0.0

30-36

252

117,382

321.6

71

22.1

34

10.6

36

11.2

1

0.3

36-42

218

101,104

277.0

45

16.3

19

6.9

26

9.4

0

0.0

42-48

201

94,100

257.8

44

17.1

12

4.7

32

12.4

0

0.0

48-54

223

71,312

195.4

30

15.4

16

8.2

14

7.2

0

0.0

54-60

179

25,652

70.3

52

74.0

18

25.6

34

48.4

0

0.0

 

2,542

1,025,114

2,808.5

841

29.9

330

11.8

505

18.0

6

0.2

Inc.D: Diarrhea incidence / 100x child-year at risk

2.2. Exposed factors associated to duration of diarrhea

Table 2: Exposed factors associated to the duration of diarrhea (evaluated by test c2)

 

Episode duration (days)

Exposed factors

< 3 days

3-14 days

>14days

Total

p

 

n = 330

n = 494

n = 17

841

 

Stool frequency > 5 episodes in 24 h*

30

74

9

113

4.10-7

Mucus in stool *

50

129

6

185

4.10-4

Blood in stool *

12

29

6

47

2.10-8

Eating meat, fish, shrimp..**

302

244

9

555

7.10-4

Oil, fat diet ***

60

150

7

217

1.10-4

* Clinical symptoms detected on the first day of episode

** Food consumed one day prior to episode

*** Nutrition regime during the episode

All these factors were associated significantly to duration of diarrhea

2.3. Risk factors associated to diarrhea

Table 3: Risk factors associated to prolongation of diarrhea according to univariable analysis


Exposed factors

Episode duration
> 7 days

Episode duration
< 7 days


Total


RR


CI 95%


p

 

n = 511

n = 330

841

 

 

 

Stool frequency > 5 episodes in 24 h *

83

30

113

1.3

1.1-1.4

0.003

Blood in stool *

35

12

47

1.2

1.04-1.5

0.05

Mucus in stool *

135

50

185

1.3

1.2-1.4

0.0001

Using antibiotic*

116

87

203

1.04

0.9-1.2

0.6

Acute respiratory infection* *

79

18

97

1.4

1.3-1.7

0.00001

Oil, fat diet

157

60

217

1.3

1.1-1.4

0.00006

Free domestic animals in house

106

40

146

1.2

1.1-1.4

0.001

Poor and very poor

149

50

199

1.3

1.2-1.4

0.00008

Bottle feeding***

26

9

35

1.2

1.0-1.5

0.1

Stopping breast - feeding < 12 months of age****

50

26

76

1.2

1-1.6

0.08

*     Characters detected on the first day of episode

**    Diseases getting, one month prior to the episode

*** Nutrition regime one day prior to the episode (only for cases below 2 years of age)

**** Only for cases below 2 years of age

Comments: Three risk factors: bottle feeding, stopping breast-feeding and using antibiotic were not associated statistical significantly to the duration of diarrhea. The rest were associated significantly to the prolongation of episode

2.4. Protective factors:

Table 4: Protective factors associated to the duration of episode


Factors

Episode duration
> 7 days

Episode duration
< 7 days


Total


RR


CI 95%


p

 

n = 511

n = 330

841

 

 

 

Eating meat, fish, shrimp

311

244

555

0.8

0.7-0.9

0.0002

Eggs

67

70

137

0.8

0.7-0.9

0.0002

Rice

379

268

647

0.9

0.8-0.9

0.03

Vegetables, fruits

103

123

226

0.7

0.6-0.8

1.10-7

 

Foods consumed one day prior to episode were associated significantly to duration of episode as the protective factors

3. Microbiological results:

Table 5: Enteropathogen isolated in stool of diarrheal cases and health children in Caibe district, Tiengiang province (15, April 1996 - 30, June 1997)

 

Diarrhoeal cases in community

inincommunity

Diarrhoeal hospitalised cases

Healthy children in community

Entropathogen

Total

Total

 

Total

Total

 

Total

Total

 

 

Sample

positive

%

Sample

positive

%

Sample

positive

%

1. Salmonella:

167

5

3%

39

4

10.30%

568

23

4%

OMA

 

4

2.40%

 

4

10.30%

 

23

4%

Sal.para B

 

3

1.80%

 

1

2.60%

 

6

1%

Sal.para C

 

 

 

 

1

2.60%

 

17

3%

Sal.group E

 

1

0.60%

 

1

2.60%

 

 

 

Indetermined

 

 

 

 

1

2.60%

 

 

 

OMB

 

1

0.60%

 

 

 

 

 

 

2. Shigella

167

2

1.20%

39

1

2.60%

568

0

0%

Shi.sonnei

 

2

1.20%

 

1

2.60%

 

 

 

Shi.flexneri

 

 

 

 

 

 

 

 

 

3. E coli: EPEC

167

5

3%

39

3

7.70%

568

20

3.50%

4. Rotavirus

167

17

10.20%

39

12

30.80%

568

4

0.70%

5. Candida albicans

167

11

6.60%

39

1

2.60%

568

7

1.20%

6. Cryptosporidium

167

1

0.60%

39

0

0%

568

0

0%

7. Ascaris

167

1

0.60%

39

0

0%

568

2

0.30%