Abstract of the thesis for medical doctor: Assessment the forensically histopathologic characteristics and identification method of drowning victims

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.

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):

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

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

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

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

1.2.2.6 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

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

1.4 The forensic pathology of drowning

1.4.1 The external signs

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

1.4.2.2 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 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

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

Chapter 2 OBJECTS AND METHODOLOGY

- 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

2.3.4.3 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 The distribution of age and gender

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

3.1.3 Time of forensic examination

Table 3.3 Post mortem forensic examination

st

day

Day 2-4

Day 5-9

Day 10-15

>15 days Undefine Total

3.1.4 Place of death

Table 3.4 Place of death

Location River Lake

Well-water Sewer Pool

Sea water Tank Flood Total

n 69 53 9 24 8 1 5 3 172

% 40.1 30.8 5.2 14.0 4.7 0.6 2.9 1.7 100

3.1.5 Manner of death

Table 3.5 Manner of death

Situation Accident Suicide Homicide Undefine Total

• Educational level of the victim

Table 3.7 Educational level of the victim

Educational

level

Non educated

Primary school

Secondary school

High school

Graduation

of high school

define Total

3.2 The external signs

Table 3.9 Statistical of external signs

Trauma by the water flux 35 20.35 137 172

Day 5-9

Day 10-15

>15 days

define

Day 5-9

Day 10-15

>15 Days Undefine

Day 5-9

Day 10-

15

>15 Days Undefine

Day 5-9

Day 10-15

>15 Days Undefine

Day 5-9

Day 10-15

>15 Days

Un- define

Total p

n % Slight change 58 4 0 0 0 0 62 36.05 0.001

Pale 49 8 0 0 0 1 58 33.72

Scale off 1 24 20 4 3 0 52 30.23

Total 108 36 20 4 3 1 172 100

Day 5-9

Day 10-15

>15 days

define

Day 5-9

Day 10-15

>15 Days

define

Un-Total

p

n % Less change 105 16 3 0 0 1 125 72.67

0.001

Exophthalmos 3 20 16 3 1 0 43 25

Deflated eye 0 0 1 1 2 0 4 2.33

Total 108 36 20 4 3 0 172 100

3.2.8 Decomposition post mortem

Table 3.17 Decomposition post mortem

Decomposition Day

1

Day 2-4

Day 5-9

Day 10-15

>15 days

define

3.2.9 Foreign bodies in palms

Table 3.18 Foreign bodies in palms

Day 10-15

>15 Days

define

3.2.10 Injuries caused by floating and animal

Table 3.19 Injuries caused by floating and animal

Injuries Front of

body

Back of body Total p

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

3.3.2 Signs in the organ

Table 3.21 Statistics of signs in the organ