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DYNAMICS OF COVID-19 PANDEMIC IN CAMEROON:
IMPACTS OF SOCIAL
DISTANCIATION AND FACE
MASK WEARING
Thesis presented in partial fullfilment of the requirements for
the award of
the degree of Master of Science in Physics
Specialty:
Biophysics, Atomic and Molecular Physics
Option:Biophysics
by
YAMENI STEINLEN DONAT
DONY
Registration Number: 16N2590
Bachelor of Science in
Physics
Under the supervision of
MVOGO ALAIN
Doctor, University of Yaounde I
2021
Dedication
I dedicate this thesis to,
My parents Mr DJOUADJI VICTOR and Mrs
TCHIBONSOU BLANDINE.
iii
Acknowledgments
I would like to express my deepest gratitude to God Almighty for
having once again given me the chance to do this work and to all the people
who, through their good deeds, have supported me in the realisation of this
work. I would particularly like to thank the following people:
- My thesis director Doctor MVOGO Alain who
inspired us to initiate this subject of scientific research. I am grateful to
him for the immense attention he paid to this work and for the rigor he imposed
on our scientific acuity.
- The members of the jury for their availability and the
attention given to this work.
I also thank the entire teaching team of the University of
Yaoundé 1 and the professional speakers responsible for my training for
providing the theoretical part of it. Special thanks, to:
- Professor OWONO OWONO Luc Calvin in his
capacity as coordinator of the physical sector at CRFD.
- Professor NDJAKA Jean Marie, Head of
Department of Physics.
- Professor EBOBENA FOUDA Henri Paul for his
judicious advice which contributed to my reflection.
- Professor BEN-BOLIE Germain Hubert for
teaching throughout my University career.
- The other teachers of the Department of Physics, in particular
Pr NANA ENGO Serges, Pr SAÏ-DOU for
their teachings and the many advices they gave us.
- Dr BELOBO BELOBO Didier, Dr TEUMA
Michel, the aminators of biophysics seminars. - Classmates of batch
KOMBOU ARIELLE, ENAMA IDRISS, MAFEU ORNELLA, YURIKA JUSTICE, TCHEUDJUI
RACHEL TSEMO PENIEL, YOUBI ROSE, KOUOTOU KADIJA for their invaluable
help throughout this work. You have been a great help to me throughout our
university career.
- My father Mr DJOUADJI VICTOR, for his sense of
righteousness, his tolerance, his support on all
Master's thesis II * Molecular Atomic Physics and
Biophysics Laboratory-UYI * YAMENI STEINLEN DONAT D
(c)2021
iv
fronts and his calm which allowed my instinct to quickly grasp
the responsability that awaits me. May you be completely satisfied with this
work.
- My mother Mrs TCHIBONSOU BLANDINE, after so
much tireless effort, here is one of the fruits that you have sown since
birth.
- To my big brother BOUYOM DJOUADJI CAMILLE for
his moral support and his precious advice. - To my brothers NGAMENI
YAMENI FRANCK, NOUBIWO FUBEL RUCEL, NOUBISSI DJOUADJI PATRICK for
moral support and encouragement.
-To my uncle Mr KEUMENI AUGUSTIN for his moral
support and his precious advice.
- To my cousins MENINEM MIAMO, NOUTCHIBIWO JAQUELLINE,
DIEJOU ARNOL, NGAMENI MARIE JISELLE, NKEUKO SANDRA for moral support
and encouragement. - My friends MVEMBE FANNY, FONGOU .D, MVUH .F,
OUAFEU DUCET, KENNE BASILE, DONGMO LOIW, DJOUSSE GAVINI, MAFEUSI KEVINE,
NGOUNOU STELLA for the encouragement and wise advice they have kindly
given me.
- To all those who have contributed to the achievement of this
work. May the find here the expression of my deep gratitude.
List of Abreviations
· WHO : World Health Organization
· RNA: Ribonucleic Acid
· EE : Endemic Equilibrium
· MERS-CoV : Middle East Respiratory
Syndrome Coronavirus
· SARS-CoV : Severe Acute Respiratory
Syndrome Coronavirus
· SARS-CoV-2 : Severe Acute Respiratory
Syndrome Coronavirus 2
· INS : National Institute of
Statistics
· EDO : Ordinary Differential
Equation
· DFE : Disease Free Equilibrium
vi
Table of contents
Dedication ii
Acknowledgments iii
List of abbreviations v
Table of contents x
List of figures x
List of tables xi
Abstract xii
Résumé xiii
GENERAL INTRODUCTION xiii
1 GENERAL INFORMATION ON COVID-19 3
1.1 Introduction 3
1.2 History of the coronavirus 3
1.2.1 The Severe Acute Respiratory Syndrome Coronavirus Outbreak
(SARS-
CoV) 4
1.2.2 The Middle East Respiratory Syndrome
Coronavirus Outbreak ( MERS-
CoV) 5
1.2.3 The Coronavirus disease pandemic (COV ID - 19)
5
TABLE OF CONTENTS vii
Master's thesis II * Molecular Atomic Physics and
Biophysics Laboratory-UYI * YAMENI STEINLEN DONAT D
(c)2021
1.3 Origin of SARS-CoV-2 6
1.4 symptoms of COVID-19 7
1.5 Transmission mode 8
1.6 Diagnosis of COVID-19 9
1.7 Course of virus infection 10
1.8 Prevention and Treatment 11
1.9 Causes of COVID-19 12
1.10 Consequences on COVID-19 13
1.11 Some types of viruses 13
1.12 Lethality 14
1.13 Conclusion 15
2 MATHEMATICAL MODEL AND METHODS OF INVESTIGATIONS
16
2.1 INTRODUCTION 16
2.2 Formulation of the model 16
2.3 Basic properties of the model 19
2.4 Local asymptotic stability of disease-free equilibrium (DFE)
of the model (2-2) . . 20
2.4.1 Basic reproduction number 20
2.4.2 Local stability of balance without disease (DFE) 23
2.5 Global asymptotic stability of the disease-free equilibrium
of model (2.2) 25
2.6 Conclusion 26
3 RESULTS AND DISCUSSION 27
3.1 Introduction 27
3.2 Numerical method 27
3.3 Model fitting 27
3.4 Model sensitivity analysis 29
3.5 Short-term predictions 31
3.5.1 Effect of quarantine of undetected individuals on the
dynamics of disease
transmission 31
3.5.2 Effect of the proportion p on the dynamics of disease
transmission 33
TABLE OF CONTENTS viii
Master's thesis II * Molecular Atomic Physics and
Biophysics Laboratory-UYI * YAMENI STEINLEN DONAT D
(c)2021
3.5.3 Effect of the quarantine of detected individuals on the
dynamics of disease
transmission 36
3.5.4 Effect of social distancing and the use of the face mask
38
3.6 Discussion 44
GENERAL CONCLUSION AND OUTLOOK 45
ix
List of figures
1.1
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Structure of the covid 19 virus [8]
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4
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1.2
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Zoonotic cycle emergence of Coronaviruses
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7
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1.3
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respiratory droplets given off when a person sneezes [9].
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8
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1.4
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Evolution of the virus in the respiratory tract [9].
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9
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1.5
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nasal swab [10]
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9
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1.6
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saliva sample [10].
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10
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1.7
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Course of virus infection.
10
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1.8
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Prevention.
11
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1.9
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Treatment[11].
12
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2.1
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Compartmental structure of the model.
16
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3.1
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Model adapted to the new cumulative cases of COVID-19 reported
for
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the period 01 January 2020 to 10 April 2021
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28
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3.2
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Histogram of the sensitivity analysis between Rc and
each parameter . . .
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30
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3.3
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Evolution of quarantine rate of undetected contagious over a
period of
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180 days for different values ( á = 0.02, á =
0.04, á = 0.1 ).
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32
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3.4
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Evolution of quarantine rate of undetected contagious over a
period of
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180 days for different values ( á = 0.02, á =
0.04, á = 0.1 ).
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33
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3.5
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Evolution of Fraction of exposures that become infectious
undetected
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over a period of 180 days for different values ( p = 0.95, p =
0.65, p = 0.25 ).
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34
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3.6
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Evolution of Fraction of exposures that become infectious
undetected
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over a period of 180 days for different values ( p = 0.95, p =
0.65, p = 0.25 ).
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35
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LIST OF FIGURES X
Master's thesis II * Molecular Atomic Physics and
Biophysics Laboratory-UYI * YAMENI STEINLEN DONAT D
(c)2021
3.7 Evolution of the quarantine rate of contagious diseases
detected over a
period of 180 days for different values ( E = 0.09, E = 0.02,
E = 0.1 ). 36
3.8 Evolution of the quarantine rate of contagious diseases
detected over a
period of 180 days for different values ( E = 0.09, E = 0.02,
E = 0.1 ). 37
3.9 Evolution of social distancing and face mask use over a
180-day period
for different values ( = 0, = 0; = 0, = 0.2; = 0, = 0.3 ).
38
3.10 Evolution of social distancing and face mask use over a 180-day
period
for different values ( = 0, = 0; = 0, = 0.2; = 0, = 0.3 ).
39
3.11 Evolution of social distancing and face mask use over a period of
180 days
for different values ( = 0, = 0.2; = 0.1, = 0.3; = 0.2, = 0.5
) 40
3.12 Evolution of social distancing and face mask use over a 180-day
period
for different values ( = 0, = 0.2; = 0.1, = 0.3; = 0.2, = 0.5
) 41
3.13 Evolution of social distancing and face mask use over a 180-day
period
for different values ( = 0.2, = 0; = 0.3, = 0.2; = 0.5, = 0.3
) 42
3.14 Evolution of social distancing and face mask use over a 180-day
period
for different values ( = 0.2, = 0; = 0.3, = 0.2; = 0.5, = 0.3
) 43
xi
List of Tables
1.1 Lethality 15
2.1 Representation of model parameters. 17
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