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MINISTRY OF

MINISTRY OF HEALTH

EDUCATION AND TRAINING
HA NOI MEDICAL UNIVERSITY

NGUYEN LE CAT

ASSESSMENT THE FORENSICALLY
HISTOPATHOLOGIC CHARACTERISTICS AND
IDENTIFICATION METHOD OF DROWNING VICTIMS

Specialized

: Pathology and Forensic Medicine

Code

: 62720105

ABSTRACT OF THE THESIS FOR MEDICAL DOCTOR

HA NOI - 2020


THE THESIS WAS COMPLETED
IN HA NOI MEDICAL UNIVERSITY

Scientific Supervisor:
1. PhD. Luu Sy Hung

2. Associate Professor Dinh Gia Duc

The first Reviewer:

Associate Professor Nguyen Phuc Cuong

The second Reviewer: PhD. Nguyen Duc Nhu

The third Reviewer:

PhD. Tran Ngoc Dung

The Thesis approved by Council of scientist in Ha Noi Medical
University.
At:

Date:

2020

References theThesis in:
1. Vietnam National Library
2. Library of Ha Noi Medical University


LIST OF PUBLICATIONS
This Thesis is based on the following papers:

1.

Nguyen Le Cat (2013), Signs and injuries of drowning in
forensic identification, Journal of Practical Medicine, 876 (7):
54-57.

2.

Nguyen Le Cat, Nguyen Van Hoa, Nguyen Tat Tho (2017),
Notes when receiving preserved corps for identification in
accidents and disasters, Journal of Military PharmacoMedicine, 323 (7-8): 9-11.

3.

Nguyen Le Cat, Nguyen Thi Ngoc Anh, Do Thi Xao Mai
(2018), DNA analysis results in the victim identification of
aircraft accidents at sea, Journal of Military PharmacoMedicine, 333 (11-12): 44-48.

4.

Nguyen Le Cat, Nguyen Thi Ngoc Anh, Do Thi Xao Mai,
Luu Sy Hung (2019), Assess the results of drowning victim
identification by DNA test in forensic examination, Journal of
Military Pharmaco-Medicine, 335 (3-4): 54-58.


1

INTRODUCTION
Drowning is being asphyxiated caused by submersion of noses or
mouth. The mechanism is complicated and varied depending on the
situation, not only the asphyxia in submersion. It is believed as the first

problem of public health, and early studied because of social valuation.
In evaluation of WHO, the proportion of drowning is 5.6/100.000
population, two third is accidental, 1/3 suicidal drowning, rarely
homicidal drowning. Most of victims are children or young people.
Vietnam is a tropical country, there are a large number of lakes and
rivers, long beach which are potential for drowning, especially in
hurricane season. As others countries, the most common cause is
occupational or daily activity. Others are homicidal or suicidal cause.
In Military Institute of Forensic Medicine, the proportion of
drowning is high. However, there is no research of epidemiology,
pathology and victims identification.
In forensic examination, there are some problems for solving:
- Who is the victim? The cause of death? The cause of death is
drowning or not? Which examination or test to confirm the drowning cause?
- Could the patient be identified ? Which test for identification?.
In order to do so, the forensic examiner has to fully collect the
primary evidences, analysis the scene, and forensic results, in
combination with proper identification method.
Therefore, the study “Assessment the forensically pathologic
characteristics and identification method of drowning victims” aims to:
1. Description of the pathologic signs and characteristics of
drowning victims.
2. Application of DNA analysis in identification of drowning victims.


2

1. The need of the thesis
The thesis is an answer for debating question regarding of
pathologic characteristics of drowning and proposes the DNA analysis

for identification method. The description study concluded the valuable
pathologic signs and characteristics for diagnosis. In this study, the DNA
analysis was applied for victims identification.
2. The contribution of the thesis
Statistical description of general characteristics of drowning such as:
conjunctivitis (100%), lividity pattern (74.6%), rigor mortis (89.4%),
froth (66.4%), wrinkle skin (58.1%), exophthalmos (100%), flared mouth
(78.8%), peeling skin (72%), fluid and foam in the airway (54.8%),
pulmonary edema (88.5%), the foreign body in airway (35.5%), water in
stomach (30.8%), the laceration of aveoli (88.5%), rupture RBC in
vessels and organs (50%). Diatom test plays an important role in
diagnosis confirmation and location of drowning.
The application of DNA analysis is an appropriate method to victims
identification: there was 18.02% victims need to DNA analysis for
identification, successful identification was 100% (31/31); from 1-4
postmortem days, most of victims were identified by the normal method
(83.3%-84.2%); 85% victims was required the DNA analysis for
identification from 5-9 days postmortem. From 1-4 days postmortem, the
nucleus analysis was used for every victim. From 5-15 postmortem, the
mitochondrial analysis was more preferred, After 15 days postmortem,
most victims was identified by mitochondrial analysis.
3. The structure of the thesis
The thesis includes 108 pages. General description (02 pages),
Conclusion (02 pages), and proposal (01 page). Four chapters : Chapter
1 : General description (31 pages), Chapter 2 : Objects and Methodology
(13 pages), Chapter 3: Results (22 pages), Chapter 4: Discussion (37
pages). It also includes 26 tables, 04 images, 09 charts, 73 reference
materials, study form and victims list, the image illustrates.

3

Chapter 1
BACKGROUND
1.1. Definition and classification of drowning
1.1.1. Definition
In 2002, the International Congress of Drowning defined drowning
as : “The asphyxiated process caused by submersion in liquid”.
1.1.2. Classification
It is classified into two categories: intention and un-intention.
Intention: homicidal or suicidal, Un-intention: accident, or undefined
cause.
1.2. Statistical evidence of drowning
1.2.1. General statistics of drowning
According to WHO, there are 372000 death caused by drowning
each year; 42 death caused by drowning in average each hour. Drowning
is the top cause of death for 1-24 years old population.
1.2.2. The co-factor of drowning
1.2.2.1. Age
The most common is in 1-4 years old children, then 5-9 years old. It
is one of the most 5 cause of death for 1-14 years old population in 48/85
countries.
1.2.2.2. Gender
Most of study showed that the proportion was doubled in male
rather than female.
1.2.2.3. Location
In the low or average income countries, the scene of drowning is the
place of daily activities. In the other hand, in high income countries, the
scene is in the recreation park.
1.2.2.4. Time

It depends on the victims and seasons.
1.2.2.5. The causes
In the international congress, the causes was classified as:
Accidental (56.2%), suicidal (23.8%), homicidal (0.28%), unidentified
(16.5%).


4

1.2.2.6. Others risk factors
Alcohol, smoking, poorness, shortage of safety facility, climate, the
treatment approach, rehealibitation are the others risk factors.
1.3. The pathologic mechanism
1.3.1. The history of drowning knowledge
It was firstly introduced in Greek 2 AC by Galen. At that time, it
was supposed that the water filling in stomach and intestine causes the
death. The later studies showed that the water fills in the airway and lung
causing death.
1.3.2. The mechanism of drowning
There are four main mechanisms: water inhalation, the filtration of
water in blood stream, alveolus rupture and nervous reflex.
1.3.2.1. Water inhalation
a, Stage 1 (1.5 minutes): Submersion victim, strungling to breath, water
fills in the stomach, low blood pressure, low heart beat.
b, Stage 2 (1 minute): Because of reflexion, victims drink and inhale a
large amount flux of water, till the trachea and alveolus, tachycardia, the
water bubles from nose to the water surface.
c, Stage 3 (1-1.5 minutes): Epilepsy, coma, low BP, arrythmias,
ventricular fibrillation, cardiac arrest
1.3.2.2. The water filtration in blood stream

There are two situations:
a) Drowning in fresh water: The dilution of blood causing the
hypoosmolar natrium and chlorium causing the blood cells ruptures.
b) Drowning in salt water: Condensed blood. No rupture of blood cells,
the electrolyte equilibration is unchange.
1.3.2.3. The alveolus rupture
Water enter the alveolus causing dilation and rupture. Hemorrhage
in the lung parenchyma, other alveolus without water would be stressed
causing emphysema.
1.3.2.4. The nervous reflexion.
Beside the alveolus rupture, water in the airway causing inhibition
of respiratory and cardiovascular centers located in the medullar leading
to death.


5

1.4. The forensic pathology of drowning
1.4.1. The external signs
1.4.1.1.
The foam
It is typical sign of drowning. It is different with foam caused by
pulmonary edema, this foam is more diluted and fragile.
1.4.1.2.
The rapid death in drowning
Cold cadaver, the temperature is equal with enviroment in primary
8-24 hours, pale and wrinkle skin, eyes swelling.
1.4.1.3.
Signs of body soaked in water
Skin spikes, cold corpses, body temperature decreased by the

ambient temperature of the autopsy detected in 8-24h, skin of palms and
feet pale, wrinkled, eye mucus bulging due to water absorption.
1.4.1.4.
The traumas and evidences before and post mortem.
a, Traumas and evidences before mortem: water jumping, epilepsy,
trauma injuries.
b, Trauma and evidences post mortem: Caused by floating cadavers.
1.4.1.5.
The decomposition signs
In the water, it is pale cadavers. In the early of air exposure, the skin
color change from green to black. The cadavers will be decomposed
rapidly, especially in summer.
1.4.2. The internal signs
1.4.2.1.
New cadavers
a) Special signs:
- The respiratory system: The trachea is fulfilled with the pink foam.
Swelling lungs, motley lung surface. Foregin body in airway.
- The circulation system: Congestion organs, diluted blood, and red
blood cells ruptures.
- The gastrointestinal system: Water in stomach and intestine.
Hepatomegaly, pale kidney, pale intestin, submucosal hemorrhage.
- Brain: Congesion and edema.
b) Others signs:
Water infiltrates in the sinus of head and face. Hemorrhage in the
middle ear and mastoid bone. Emphysema. Soil, grass ... in the palm.
Parasites.


6

1.4.2.2.

Decomposed cadavers
The importants signs are disappeared: deflated lungs, foam and
water in trachea. Water is in the shallow of chest. The foreign body could
appear in the airway.
1.4.3. The signs of untypical drowning
Inhibition reflexion (cardiac arrest, larynx spasm, dry drowning,
death because of drowning complication)
1.4.4. The evolution of signs
In general: Self water absorption, decomposition and self movement
Floating time: depends on the water temperature and characteristics
of cadavers.
1.4.5. The characteristics of forensic organs pathology

1.4.5.1.

Lungs
Water and foreign bodies in the alveolus, hemorrhaging, alveolus
dilation. Micropathology could be suggession, thin alveolus wall, rupture
of alveolus. The gold diagnosis is the appearance of water foreign body
in small bronchi and alveolus.
1.4.5.2.
Liver
The dilation hepatic and portal veins are filled with blood and
water. The portal areas are dilated, swelling vessel wall, the parenchyma
is filled with water and blood. Congestion of organs.
1.4.6. The change of biochemistry
Imbalance serum electrolyte caused by water filtration.

1.4.7. The biologic agents.
Diatoms test: In 1941, Incze proposed the diatoms test to define
location of drowning.
1.5.
Some new studies of drowning
In 2015, Hosahally J.S et al conclued that: in fresh water drowning
victims, the intima of aorta root was darker. In 2005, J.Blanco Pamoin et
al showed that 21.58% victims had the rupture of gastric mucosa. Milone
A et al also showed that CT scanner could help to define the death before
or after asphyxia.


7

1.6. The forensic assessment of drowning
1.6.1. The methods
It is much more exact if there is a combination of methods to
examine the cadaver.
1.6.2. DNA forensic examination
The DNA identification of drowning is exact and efficient.
Especially in case of decomposed cadavers.
1.6.3. DNA structure
DNA is double chains created by two single nucleotids chain. In
DNA, there are a lots of genes in particular order. The location of gene in
chromosome is called locus. In nuclear DNA, each locus has two allens,
one from dad, the other from mom. Mitochondrial DNA is completely
maternally generated.
1.6.4. The DNA analysis
1.6.4.1. The nuclear DNA
Nuclear DNA analysis is based on the structure and genetic

characteristics. With this method, the individual could be well identified
only by small sample.
1.6.4.2. The mitochondrial DNA
Beside nuclear, the DNA also exists inside the mitochondrial in the
circle form, and maternal heredity. Therefore the mitochondrial DNA
analysis gave lots of success
1.6.4.3. The comparison in DNA analysis
- Direct comparison: Between the victims DNA and the stored
victims DNA
- Indirect comparison: Between the victims DNA and the DNA of
victims familial members.
1.6.4.4. The comparison of nuclear and mitochondrial DNA
- Nuclear DNA analysis: It is unstable in the nature enviroment. It is
easy, cheap and rapid analysis.
- Mitochondrial DNA analysis: Circle form, stable in nature
enviroment. It is more difficle, poorly exact, long time for analysis.


8

Chapter 2
OBJECTS AND METHODOLOGY
2.1. Objects
172 drowning victims was examined from Feb 2005 to Feb 2017 in
Military Institute of Forensic Medicine (31), the Departement of Forensic
- Hanoi Medical University (22), Forensic center of Vinh Phuc (58),
Forensic center of Phu Tho (61).
2.1.1. Inclusion criteria
- Fulfilled forensic profile.
- According to examination protocol

- Identification by DNA analysis.
2.1.2. Exclusion criteria
- Unfulfilled profile
- Unrespect the protocol
- During investigation period.
2.2.
Study design
- Retrospective, perspective, cross sectional study
- Time: From Jun 2014 to Jun 2018
- Location: The Military Institute of Forensic Medicine, Forensic
Departement of Hanoi Medical University, Forensic center of Vinh Phuc,
Forensic center of Phu Tho.
2.3.
The objects of study
2.3.1. General characteristics of objects.
Age, gender, time of death, time of examination, location, situation
2.3.2. External signs
Statistical, assessing and evaluating common signs
2.3.3. Internal signs
Statistical, assessing and evaluating common signs
2.3.4. The test
2.3.4.1. Pathology
Evaluation of histopathologic results
2.3.4.2. Diatoms test
To identify the location of drowning


9

2.3.4.3. Other complimentary tests

For Alcohol, drug, toxic in organs
2.3.5. Statistic of untypical drowning
2.3.6. Victims identification by DNA analysis
2.3.6.1. Nuclear DNA analysis
2.3.6.2. Mitochondrial DNA analysis
2.4. Ethic consideration
2.5. Biostatistic method
- Excel 2016 and SPSS 16.0
- Biostatistic analysis with significance in p<0,05.
2.6. Bias and confounder

Chapter 3
RESULTS
3.1. General characteristics
3.1.1. Age and gender
Table 3.1.
Age
group
1-5
6 -14
15- 29
30 – 44
45-59
Up to 60
Undefine
Total

The distribution of age and gender

Male

Female

Total

Proportion %

3
15
50
36
16
5
11
136

2
2
11
9
3
3
6
36

5
17
61
45
19

8
17
172

2.9
9.9
35.5
26.2
11.0
4.7
9.9
100

3.1.2. Time of year
Table 3.2.

The months of the year

p

0.37


10
Month
Group

1

2

3

4

5

6

7

8

9

10 11 12

n

1-5

0

1

1

0

2

0

0

0

0

0

0

1

5

6-14

0

0

0

5

6

0

0

3

2

1

0

0

17

15-29

0

4

2

9

8

3

10

6

9

2

5

3

61

30-44

0

0

0

9

4

5

5

7

7

4

3

1

45

45 - 59

2

1

1

1

0

3

5

2

1

1

1

1

19

More 60

0

0

1

1

1

1

2

1

1

0

0

0

8

Undefine

0

2

0

2

2

2

3

4

2

0

0

0

17

Total

2

8

5

27 23 14 25 23 22

8

9

6

172

p

0.1

3.1.3. Time of forensic examination
Table 3.3. Post mortem forensic examination
1st

Day
Day
Day
>15
Time
Undefine Total
day
2-4
5-9
10-15 days
n
108
36
20
4
3
1
172
%

62.1

20.9

11.6

2.3

1.7

0.6

100

3.1.4. Place of death
Table 3.4. Place of death
Location River Lake

Well-

n

69

53

water
9

%

40.1

30.8

5.2

Sewer Pool

Sea

24

8

water
1

14.0

4.7

0.6

Tank Flood Total
5

3

172

2.9

1.7

100


11

Manner of death

3.1.5.

Table 3.5. Manner of death
Situation

Accident

Suicide

Homicide

Undefine

Total

n

119

12

1

40

172

%

69.2

7.0

0.6

23.2

100

3.1.6. Others characteristics
 Occupation
Table 3.6.

Occupation

Occupation

Related

Unrelated

Undefine

Total

n

5

150

17

172

%

2.9

87.2

9.9

100



Educational level of the victim
Table 3.7. Educational level of the victim

Educationa
Non
Primary Secondary High
l level
educated school
school school

Graduation

Unof high
Total
define
school

n

7

30

87

20

11

17

172

%

4.1

17.4

50.6

11.6

6.4

9.9

100



Ethnic
Table 3.8.

Ethnic distribution

Ethnic

Ethnic
minority

Ethnic
major

Undefine

Total

N

73

82

17

172

%

42.4

47.7

9.9

100


12

3.2.

The external signs

Table 3.9. Statistical of external signs
Yes

Signs

No

Undefine Total

Froth

n
42

%
24.42

130

172

Lividity pattern

128

74.42

44

172

Conjunctivitis

123

71.51

41

Rigor mortis

137

79.65

35

172

Submersion skin

110

63.95

62

172

Flaring mouth

44

25.58

128

172

Occular change

47

27.32

125

172

Necrosis

52

30.23

120

172

Foreign bodies in palm

15

8.72

157

172

Decomposition

3

1.74

168

172

Trauma by the water flux

35

20.35

137

172

Trauma by the animal

7

4.07

165

172

8

172

3.2.1. Froth
Table 3.10. Froth
First
day

Day
2-4

Day
5-9

Yes

39

3

0

0

0

No

69

33

20

4

Total

108

36

20

4

Froth

Day >15
Un10-15 days define

Total
p
n

%

0

42

24.42

3

1

130

75.58 0.001

3

1

172

100


13

3.2.2.

Lividity pattern
Table 3.11. Lividity

pattern

Day 1

Day
2-4

Day
5-9

Yes

107

19

1

0

0

1

128 74.42

No

1

17

19

4

3

0

44

25.58

Total

108

36

20

4

3

1

172

100

3.2.3.

Day >15
Undefine
10-15 Days

Total

Lividity
pattern

n

%

p
0.001

Conjunvitis
Table 3.12.

Conjucnvitis

Day Day Day
1
2-4 5-9

Conjuncvitis

Day
>15
10Undefine
Days
15

Total
n

%

Yes
No

89
19

20
14

10
5

2
1

1
2

1
8

123
49

Total

108

34

15

3

3

1

172

3.2.4.

p

71.51
0.02
28.49
100

Rigor mortis
Table 3.13.

Rigor
Day
Day 1
mortis
2-4

Day
5-9

Rigor mortis

Day >15
Undefine
10-15 Days

Total
n
%

p

Yes
No

106
2

28
8

2
18

0
4

0
3

1
0

137
35

79.7
0.001
20.3

Total

108

36

20

4

3

1

172

100

3.2.5.

Submersion skin
Table 3.14.

Submersion
skin

Day
1

Submersion skin characteristics

Day
2-4

Day Day >15 Un5-9 10-15 Days define

Total

n

p

%

Slight change
Pale

58
49

4
8

0
0

0
0

0
0

0
1

62
58

36.05 0.001
33.72

Scale off
Total

1
108

24
36

20
20

4
4

3
3

0
1

52
172

30.23
100

3.2.6.

Flaring mouth


14

The flaring mouth post mortem

Table 3.15.
Flaring
mouth

Day
1

Day
2-4

Day
5-9

21

19

3

1

Yes

Total

Day
>15 Un10-15 days define

n

%

0

44

25.58

No

108

15

1

1

2

1

128

74.42

Total

108

36

20

4

3

1

172

100

3.2.7.

p
0.001

Occular change
Table 3.16.

Occular change post mortem

Day
1

Day Day >15 Un5-9 10-15 Days define

Occular
change

Day
2-4

Less change 105
Exophthalmos 3
Deflated eye
Total

3.2.8.

0
108

Total
n

%

p

16
20

3
16

0
3

0
1

1
0

125 72.67
43
25 0.001

0
36

1
20

1
4

2

3

0
0

4 2.33
172 100

Decomposition post mortem
Table 3.17.

Decomposition post mortem

Day
2-4

Yes

1

24

20

4

3

0

n
52

No
Total

107
108

12
36

0
20

0
4

0
3

1
1

120 69.77
172 100

3.2.9.

Day Day >15 Un5-9 10-15 days define

Total

Day
1

Decomposition

%
30.23

p
0.001

Foreign bodies in palms
Table 3.18.

Foreign
bodies

Foreign bodies in palms

Day Day 2- Day
1
4
5-9

Day >15
Un10-15 Days define

Total

Yes

13

2

0

0

0

0

n
15

No
Total

95
108

34
36

20
20

4
4

3
3

1
1

157
172

%
8.72
91.28
100

p
0.49

3.2.10. Injuries caused by floating and animal

Table 3.19. Injuries caused by floating and animal


15
Injuries

Front of

body

Back of
body

Total

Chafing of shallow skin

6

20

26

Torning skin

3

6

9

Making underwater animal

-

-

7

p
0.54

3.3.

Internal signs
In the our research, there were 172 cases in which 48 cases only
external examination, 20 cases with external examination and the
tracheostomy, 104 cases examinated inside and outside of body.
3.3.1.

Signs and lesions in the trachea and bronchi

Table 3.20. List of signs and lesions in the trachea and
bronchi
Characteristics

Fluid,
air
bubbles

Foreign
object in
airway,
bronchi

Decomposition

Unknown

Total

n

68

44

1

11

124

%

54.8

35.5

0.8

8.9

100

3.3.2.

Signs in the organ

Table 3.21. Statistics of signs in the organ
Signs

Yes

No

Unknown Total

n

%

n

%

n

%

Pulmonary edema

92

88.5

8

7.7

4

8.8

104

Congestive of other organ

95

91.3

9

8.7

0

0

104

Water in stomach

85

81.7

16

15.4

3

2.9

104

Water in sphenoid sinus

9

8.6

1

0.9

94

90.5

104

p

0.001

16

3.3.2.1. Pulmonary lesions

Table 3.22. Characteristics of pulmonary lesions
Pulmonary lesions
Paltauf sign
Petechiae (Tardieu sign)
Lung stretch and slice with more blood
Lung bland and slices with little blood
Unknown

Yes
32
43
92
8
4

n
104
104
104
104
104

%
30.8
41.3

88.5
7.7
8.8

3.3.2.2. Congestive of organs
Table 3.23. Characteristics of congestive
Congestive of organs
Heart
Liver
Kidney
Spleen
Brain

Yes
82
91
93
67
56

in organs
n
104
104
104
104
104

%
78.8

87.5
89.4
64.4
53.8

3.3.2.3. Objects in stomach

Table 3.24. Characteristics of objects in stomach
Objects in stomach
Water
Water and food
Food
None of food and water
No information
Total

3.3.3.

n
32
45
8
16
3
104

%
30.8
43.2
7.7

15.4
2.9
100

Mixed lesions

Table 3.25. Characteristics of mixed lesions
Lesions
Injures of soft tissue
Fracture
Brain trauma

Yes
n

%

No

n
%
10
4 3.85
96.15
0
98.0
2 1.92 102
8
2 1.92 102 98.0
8

Unknown

Total

n

%

0

0

104

0

0

104

0

0

104

p
0.001

17
Hanging trauma

1

Cutting wist

1

0.9
99.0
103
0
0
6
4
0.9
99.0
103
0
0
6
4
0
0
0
104 100
0 104 100
0

0

Hematoma around shoulder joint 0
Breaking stomach
0

3.4.

104
104
104
104

Atypical drowning
Table 3.26.

List of atypical drownings

Type
Near-downing
Dry-downing
Drowning with heart and vessel disease

n
0
8
2

Total
104

104
104

%
0
7,7
1.9

3.5. Other test
3.5.1. Histopathology
Table 3.27. Signs and lessions of histopathology
Signs and lessions
Foreign objects in the airway
Alveolus rupture and oedema
Breaking red blood cells
Congestive in liver
Congestive and bleeding in heart
Congestive and oedema in brain
Congestive and oedema in kidney

3.5.2.

Yes
n %
20 19.2
92 88.5
52 50
76.
79
0

81 77.9
56 53.8
68.
71
3

n
76
2
52

No
Unknown
Total
%
n
%
73.1 8 7.7 104
1.9 10 9.6 104
50
0
0
104

4

3.8

6

5.8

5
3

4.8
2.9

18 17.3 104
45 43.3 104

3

2.9

30 28.8 104

p

104

0.001

Diatom test

Table 3.28. Results of diatom test
Categories of diatom
Bacillary diatom
Stellar diatom
Polygonal diatom

3.5.3.

Yes
5
4
1

No
2
3
6

Total
7
7
7

p
0.154

Other test

Table 3.29. Results of other test
Yes
Test

Positive
n
%

No
Negative
n
%

n

%

Total

p


18
Alchohol in blood
Narcotics in
blood
Toxic in organs

5

2.9

48

27.9

119

69.2

172

1

0.6

28

16.3

143

83.1

172 0.08

0

0

40

23.3

132

76.7

172


19

3.6. Identification of asphyxiated victims by DNA analysis technique
3.6.1. Distribution of victim identification based on indentified time
Table 3.30. Distribution of victim identification based on indentified time
Number
of
victim
108
36
20
4
3
1
172

Time
The1st day
Day 2-4
Day 5-9
Day 10-15
Over 15 dáy
Unknown
Total

3.6.2.

Normal
DNA
No
identification identification identification
p
n
%
n
%
n
%
91
84.2
2
1.9
15
13.9
30
83.3
4
11.1
2
5.6
3
15.0
17
85.0
0
0

0.001
0
0
4
100
0
0
0
0
3
100
0
0
0
0
1
100
0
0
124
72.1
31
18.0
17
9.9

Result of victim sampling

Table 3.31. Result of victim sampling
Time

The first day
Day 2-4
Day 5-9
Day 10-15
Over 15
days
Unknown
Total

3.6.3.

Victim sampling
Hair Tissue Tooth Bone
2
0
0
0
2
4
0
0
6
12
12
5
1
3
3
1

Number of
victim
2
4
17
4

Blood
2
4
8
0

3

0

0

2

2

1

5

1
31

0
14

0
11

0
21

1
18

0
7

1
71

Total
4
10
43
8

Sampling results of relatives

Table 3.32. Sampling results of relatives
Time
The first day
Day 2-4

Day 5-9
Day 10-15
Over 15 days
Unknown
Total

Number
of
victim
2
4
17
4
3
1
31

Sampling of relatives

Number of
relatives

Blood

Hair

Mucosa

Total

3
6
26
5
4
1
45

3
6
26
3
3
1
42

3
6
9
5
1
1
25

3
2
9
3
0
0

17

9
14
44
11
4
2
84


20

3.6.4.

DNA extraction results of victim sampling

Table 3.33. Mean of DNA level of extraction in victim
Time
The first day
Day 2-4
Day 5-10
Day 10-15
> 15 days
Unknown

Number Number
of
of
Small

victim corpses (ng/µl)
2
4
17
4
3
1

4
10
43
8
5
1

0.1721
0.1322
0.0944
0.0833
0.021
0

sampling

Mean of DNA level
Large
Y
CT
(ng/µl) (ng/µl)
0.1842

0.1288
0.0619
0.0612
0.01
0

0.1798
0.1211
0.0797
0.198
0.01
0

28.5
28.5
28.5
29.5
33
0

DI
0.93
1
1.36
1.52
2.1
0

3.6.5. Result of identification by technique of DNA analysis

Table 3.34. Result of identification by technique of
DNA analysis
Time
The first day
Day 2-4
Day 5-9
Day 10-15
Over 15 days
Unknown
Total

Number
of
victim
2
4
17
4
3
1
31

Identification by
the nucleus DNA
n
2
4
16
1
0

0
23

%
100
100
94.1
25
0
0
74.2

Identification by
mitochondrial
DNA
n
%
0
0
0
0
1
5.9
3
75
3
100
1
100
8

25.8

p

0.001

Chapter 4
DISCUSSIONS
4.1.
General characteristics
4.1.1. Age and gender
Age: It is an important risk factor
In this study, Table 3.1 showed that the dominant drowning was
from 15 to 29 years old (35.5%). It is different with others studies. This
difference could be caused by the social and epidemiology
characteristics, and unrecorded of victims.


21

Gender: Male dominated 79.1%, female proportion was 20.9%. This
result is different with WHO index, however it fits in others studies in
Vietnam, Katrina showed the ratio 3/1, L.Quan and P.Cummings in 2003
showed the ration 3.5/1.
4.1.2. The frequence of drowning regarding the months of the year
In this study, the victims concentrated in the second and third
trimester (77.9%). In April, the frequence was highest (15.7%). The low
frequence was from Oct to March. It is the same result with L.Quan and
P.Cummings studies: 50% victims was from May to August, Luis K. Lee
with 65% victims from July to September, Nguyen Thanh Uyen, Bui

Quoc Thang with 43% from April to July.
4.1.3. The time of forensic examination
From Table 3.3, the most of patients was examined in the first day
(62.1%), the low proportion patients was examined after 10 days (4%). In
the othes studies, it has not been mentioned.
4.1.4. Place of death
In this study, the highest proportion was in the lake and stream
(40.1%); then lake (30.8%), swimming pool (4.7%). This result respects the
statistical one of UNICEF in Vietnam (river 59%, lake 29.2%); similar to
Nguyen Hoang Thanh Uyen and Bui Quoc Thang studies (71% in lake).
However it is different with Weinstein (beach 75%, swimming pool
22%), Richard in Australia (beach 8.3%, swimming pool 17.3%).
4.1.5. Manner of death
Table 3.5 showed that 119.172 (69.2%) victims was the accident
drowning, 12/172 7%) was suicidal drowning, only 1/172 (0.6%) was
homicidal drowning; 40/172 (23.2%) undefined the situation
This result fits in the report of Drowning international conference:
accident 893/1590 (56.2%), suicidal drowning (23.8%), undefined
drowning (16.5%), homicidal drowning (0.82%). This result also fits in
other study in Thuong Hai China from 2000 to 2009.
4.1.6. Others characteristics
- Occupation: only 5/172 (2.9%) victims was related with watery
occupation
- The victims in secondary school was dominant (50.6%); then
primary school (17.4%), high school (11.6%). It is similar with the result
in China, Uganda, Bangla-Desh
- Ethnic: There was no difference between ethnic minority and others.
4.2.
External signs
4.2.1. Foam

22

In this study, 24.42 % victims had foam cone in the primary 1-4
days post mortem. There was no victim with froth after 5 days. It is
similar with others studies in China, Uganda, Bangla-Desh.
4.2.2.

Lividity pattern
In this study, 74.2% victims had lividity pattern. The first day
was apprearant. From 2-4 primary days, this proportion decreased to
19/36 victims (52.78%), and from the fifth day, only 1/27 victim had this
sign. This result is similar with Weinstein and Richard in Australia.
4.2.3. Conjuctivitis
In this study, 123/164 (75.51%) victims with conjuntivitis,
predominantly from 2-4 primary days. From fifth day, it disappeared.
This is similar with Sydney, Smith, Bajanowski et al.
4.2.4. The submersion skin sign
In this study, 58/108 victims had slight change of skin; 49/108
victims had wrinkle palm and sole skin, only one had peel off. It is
similar with Simonin result. However it is earlier than the study result of
M. Durigon.
4.2.5. Decomposition sign
In this study, flaring mouth, exophthalamos, necrosis appreared
from second day: 44/172 flaring mouth victims (25.58%)(Table 3.15);
43/172 exophthalmos victims (25%); 52/172 necrosis victims (30.23%).
It is more rapid than European study.
4.2.6. The foreign objects in palm
In this study, 15/172 (8.72%) victims had the foreign objects in

palm, these were in the first day of drowning.
The analysis of the foreign bodies and compare it to others
scenes could help to identify the scene of drowning. However, it is not
available in Vietnam because of facility shortage.
4.2.7. Floating trauma
In this study, 26 victims had the floating trauma. Among them,
20/26 victims had injuries in the posterior. 9 victims had the laceration
injuries. 7 victims had injuries caused by the animal.
4.2.8. Time of drowning
In this study, the most common signs in the first two days was
congestion, conjuncvitis (100%); rigor mortis (89.4%); wrinkle skin