Dr Ajit Thesis Title pages 2074-1-19 CS4 FINAL.indd

407 Pages·2017·11.96 MB·English

TOWARDS IMPROVING THE
MANAGEMENT OF ACUTE ENCEPHALITIS
SYNDROME IN NEPAL
by
Ajit Rayamajhi MBBS, MD
A thesis submitted in partial fulfi lment of the
requirements of the University of Liverpool for
the degree of Doctor in Philosophy
Institute of Infection and Global Health,
University of Liverpool
April, 2016
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ABSTRACT
Acute Encephalitis Syndrome (AES) is a group of clinical symptoms and signs, used by
the World Health Organisation (WHO) and clinicians, to screen for acute encephalitis.
Viruses are the most important cause of AES worldwide. Japanese encephalitis virus
(JEV), which causes Japanese encephalitis (JE), accounts for approximately one-quarter
of AES cases in Nepal. In the absence of defi nite treatments for JE and many other viral
enecpahlitides, improvements in supportive management are vital.
In my thesis, the predictors of bad outcome (neurological sequelae or death) among
patients with AES and JE were investigated. The relationships between weight-
for-age (WFA), hydration status, intravenous fl uids and outcome were studied. In
addition, a preliminary randomised double blind placebo controlled trial of intravenous
immunoglobulin (IVIG), as a novel adjunctive treatment for JE, was conducted.
Prolonged fever duration was identifi ed to be a signifi cant predictor of bad outcome
in both AES and JE patients. Prolonged fever, low Glasgow coma score (GCS) and
focal neurological defi cit at hospital admission were signifi cantly associated with bad
outcome in AES patients. AES patients with focal neurological defi cit were signifi cantly
more likely to have a fi nal diagnosis of JE. JE patients presented with a signifi cantly
lower body weight and higher respiratory rate. They also presented with a trend for
higher urea and potassium levels compared to other AES patients. These fi ndings led
me to investigate further whether children with JE were more likely to suffer from
dehydration during acute illness.
When children are grouped into different weight categories by WFA (Z score), low
WFA can indicate dehydration or malnutrition. I found a signifi cant association between
frequency of bad outcome and low WFA among both AES and JE patients at hospital
admission. To help distinguish dehydration and malnutrition in low WFA children, I
then studied additional indicators of malnutrition and dehydration status, including mid-
upper arm circumference, blood lactate levels and fl uid status at admission and during
hospital stay. I found AES patients suffering a bad outcome had signifi cantly higher
admission serum lactate levels, drunk a lower volume of oral fl uids, and were more
likely to be prescribed a restricted regimen of intravenous fl uids. These results suggest
AES patients with bad outcome were more likely to be dehydrated. The implications of
my fi ndings are that earlier hospital admission during the course of the illness and better
in hospital administration of adequate and appropriate fl uids may improve outcome
among AES and JE patients. Since the majority of families self-refer to hospitals,
provision of this simple message into the community, could help improve the lives of
people living in high risk areas for JE, like Nepal.
Improvement in the treatment of JE is necessary to improve the outcome of the disease
in Nepal. Intravenous immunoglobulin, which contains anti-JE virus neutralising
antibodies and has anti-infl ammatory properties, may be a useful adjunctive treatment.
In a preliminary Phase II study, I showed IVIG could be safely administered to JE
patients, without any signifi cant increase in drug related adverse events. JE patients
treated with IVIG exhibited higher levels of neutralising antibodies and higher IL-4 and
IL-6 cytokine levels compared with placebo (saline) treated patients. Although, there
was no difference in clinical outcome, the data from this small pilot study suggests
IVIG may be an appealing adjunctive treatment option for a phase III trial in the future.
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ACKNOWLEDGEMENT
This work would not have been possible without the love, trust, respect
and affection shown to me by patients and parents with Acute encephalitis
Syndrome particularly Japanese encephalitis during my fruitful interaction with
them. First and foremost, I would like to thank Professor Tom Solomon, my
academic supervisor, for his constant encouragement, guidance and support
throughout this work. Similarly, I also would like to thank my co-supervisor Dr
Mike Griffi ths with utmost respect and gratitude for his constant supervision,
support and encouragement throughout this work. I also feel fortunate to
have Professor Nigel Cunliffe as my co-supervisor, who has been a constant
source of inspiration and motivation in this work. I would also like to take this
opportunity to thank my local supervisor Professor Rajendra Kumar B.C. for
his support and encouragement.
This work would not have been possible without partial funding from the
Institute of Infection and Global Health. Therefore, I feel extremely grateful
to the Director Professor Tom Solomon and the staff of Institute of Infection
and Global Health for providing me with this opportunity. I am also indebted
to Dr. Geeta Shakya, Ms Supriya Sharma, Mr. Khagendra KC and Professor
Basudha Khanal who have helped me by conducting JE ELISA of my patients
through the National AES Surveillance Programme. I would again like to thank
Dr. Mike Griffi ths for allowing me to use his laboratory to perform DNA PCR
for this work. I am also thankful to him to have tested cytokine levels of my
patients. I am also thankful to Dr. Sam Nightingale and Dr. Elizabeth Ledger
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from the University of Liverpool for assisting me recruit, collect samples,
monitor and follow up patients for the clinical trial. I would specially like to
thank Dr Barbara W Johnson and Dr Jaimie Sue Robinson for conducting
JE virus and Dengue virus ELISA, plaque reduction anti-JEV antibody
neutralizing titres and real-time reverse transcription-polymerase chain reaction
tests in their laboratory at the Centres for Disease Control and Prevention, Fort
Collins, Colorado, USA.
I would also like to thank Dr Daniel Impoinvil, Dr Malgorzata Wnek, Dr
Rachel Herbert, Dr Jennifer Lemon, Dr Esther Platt, Dr Barney Fontaine,
Dr Emma Fall, Dr Stephen Ray and Dr Sarah Cousin from the University of
Liverpool for their help. I am grateful to Ms Angela Cucchi and Ms Shauna
Mahoney for their assistance and administrative support. I am also obliged and
thankful to Professor Brian Faragher form the Liverpool School of Tropical
Medicine for helping me with the statistical analysis. I would also like to
extend my appreciation to Dr Ninu Maskey Shrestha and Dr Pramina Shrestha,
my research assistants, for helping me.
I am grateful to Professor Rupa Singh from BPKIHS, Dr Imran Ansari from
Patan Hospital, Dr Krishna Bista from Kanti Children's Hospital and Dr
Rachel Kneen from Alder Hey Children's NHS Foundation Trust Hospital for
rendering necessary help and support both in Nepal and UK.
Special thanks to all the staff of Kanti Children's Hospital, Patan Hospital and
Department of Paediatrics of BPKIHS, particularly past hospital directors
Dr Rameswor Man Shrestha and Dr Tirtha Raj Burlakoti of Kanti Children's
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Hospital and Professor Rajesh Nath Gangol of Patan Hospital and Heads of
Department of Paediatrics of BPKIHS, previously Professor Nisha Keshary
Bhatta and current Professor Gauri Shanker Sah for their help, support and
permission to conduct this study.
I would also like to thank Dr. Jeff Partridge, Dr. William Schluter, Dr. Rajendra
Bohara, Dr. Santosh Gurung, Dr. Sukhdev Neupane from the WHO-IPD, Nepal
for providing all the necessary support.
I would again like to thank the Solomon family, Griffi ths family and Dr.
Sam Nightingale for inviting me to stay in their homes and extending local
hospitality whenever I visited Liverpool for academic activities. I would also
like to thank the Liverpool Brain Infection Group for funding and extending
local support for my academic activities; without which this research work
would not have been possible.
A big thank you to my wife Dr. Anjana Karki Rayamajhi for her support
throughout this work. I would also like to thank my children Amod and
Ameesha for bearing with me patiently and allowing me to complete this work,
occasionally even at the cost of parental duties. I feel sad to mention that I
had to lose my father Late Janak Singh Rayamajhi in the middle of this work.
Although he barely recognized me because of his prolonged neurological
illness, his smiles and mumbles were a huge source of inspiration to me to
carry on this work. I would like to dedicate this work to him.
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DECLARATION
Except for the assistance as outlined in the acknowledgements above, the work
described is my own work and has not been submitted for a degree or other
qualifi cation to this or any other university.
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TABLE OF CONTENTS
ABSTRACT ....................................................................................................................2
ACKNOWLEDGEMENTS ............................................................................................3
DECLARATION .............................................................................................................6
LIST OF CONTENTS ....................................................................................................7
LIST OF TABLES ........................................................................................................13
LIST OF FIGURES ......................................................................................................15
PUBLICATION AND PRESENTATIONS ARISING FROM THIS WORK ..............17
ABBREVIATIONS .......................................................................................................19
CHAPTER 1: INTRODUCTION ..............................................................................21
1.1 Acute Encephalitis Syndrome ............................................................................21
1.2 Aetiology of AES ................................................................................................22
1.3 Incidence of AES ................................................................................................24
1.4 Clinical features of patients of AES ...................................................................25
1.5 Diagnosis of AES ................................................................................................25
1.6 Treatment of AES ...............................................................................................26
1.7 Clinical outcome of AES ...................................................................................27
1.8 Sequelae of AES .................................................................................................27
1.9 Prognostic indicators of AES .............................................................................28
1.10 Recovery of sequelae in AES .............................................................................28
1.11 Japanese encephalitis and other Flaviviruses .....................................................29
1.12 Morphology of JEV ............................................................................................31
1.13 Enzootic cycle of JE ...........................................................................................31
1.14 Pathogenesis of JE ..............................................................................................32
1.15 Cytokines in JE ...................................................................................................33
1.16 Immunology of JE ..............................................................................................35
1.17 Clinical features of JE .........................................................................................36
1.18 Diagnosis of JE ...................................................................................................37
1.19 Principle of MAC-ELISA developed by AFRIMS .............................................41
1.20 Outcome of JE ....................................................................................................41
1.21 Sequelae of JE ....................................................................................................42
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1.22 Recovery profi le of patients of JE ......................................................................42
1.23 Prognostic indicators of JE .................................................................................43
1.24 Immunization against JE ....................................................................................43
1.25 JE as a cause of AES in Nepal ............................................................................44
1.26 JE control strategies ............................................................................................49
1.27 National Guideline for the diagnosis of JE in Nepal ..........................................54
1.28 Clinical and laboratory features as a predictor of JE from other AES ...............55
1.29 Hydration and nutrition status in AES ................................................................56
1.30 Treatment trials for JE ........................................................................................59
1.31 Scope of this thesis .............................................................................................61
CHAPTER 2: GENERAL METHODS ....................................................................63
2.1 Study Location ....................................................................................................63
2.2 Study Sites ..........................................................................................................67
2.3 Study design .......................................................................................................69
2.4 Timeline of the study .........................................................................................69
2.5 Patient recruitment and diagnostic criteria .........................................................70
2.6 General Case Defi nitions ....................................................................................87
2.7 Sample size .........................................................................................................92
2.8 Data analysis .......................................................................................................94
2.9 Ethical Consideration ........................................................................................94
CHAPTER 3: CLINICAL AND PROGNOSTIC FEATURES AMONG
CHILDREN WITH ACUTE ENCEPHALITIS SYNDROME IN NEPAL; A
RETROSPECTIVE STUDY ......................................................................................96
Abstract ........................................................................................................................96
3.1 Introduction ........................................................................................................98
3.2.1 Aim ...................................................................................................................100
3.2.2 Objectives .........................................................................................................100
3.3 Methods ............................................................................................................100
3.3.1 AES and JE case defi nitions ............................................................................101
3.3.2 JE diagnostic test .............................................................................................102
3.3.3 Statistical methods ............................................................................................102
3.4 Results ..............................................................................................................103
3.4.1 Baseline characteristics ....................................................................................103
3.4.2 Patient outcome ................................................................................................105
3.4.3 Prognostic features associated with bad outcome at discharge .......................106
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3.4.4 Clinical features that distinguish between confi rmed JE and AES of
suspected non-JE viral aetiology .....................................................................108
3.5 Discussion ........................................................................................................110
3.6 Limitation of study ...........................................................................................115
3.7 Summary ...........................................................................................................116
CHAPTER 4:WEIGHING A CHILD MAY HELP PREDICT OUTCOME IN
ACUTE ENCEPHALITIC SYNDROME ..............................................................127
Abstract .......................................................................................................................127
4.1 Introduction ......................................................................................................128
4.2.1 Aim ...................................................................................................................131
4.2.2 Objectives .........................................................................................................132
4.3 Methods ............................................................................................................132
4.3.1 Setting ...............................................................................................................132
4.3.2 Case defi nition ..................................................................................................133
4.3.3 Sample size .......................................................................................................134
4.3.4 Recruitment ......................................................................................................134
4.3.5 JE serology .......................................................................................................135
4.3.6 Management .....................................................................................................135
4.3.7 Outcome assessment .........................................................................................135
4.3.8 Ethics ...............................................................................................................136
4.3.9 Statistical analysis .............................................................................................136
4.4 Results ..............................................................................................................136
4.5 Discussion .........................................................................................................140
4.6 Limitation of study ...........................................................................................148
4.7 Summary ...........................................................................................................149
CHAPTER 5: ROLE OF FLUID MANAGEMENT IN THE OUTCOME OF
CHILDREN WITH ACUTE ENCEPHALITIS SYNDROME ............................161
Abstract .......................................................................................................................161
5.1 Introduction ......................................................................................................162
5.2.1 Aim ...................................................................................................................166
5.2.2 Objectives .........................................................................................................166
5.3 Methods ............................................................................................................166
5.3.1 Case Defi nition .................................................................................................169
5.3.2 Ethics ................................................................................................................169
5.3.3 Data analysis .....................................................................................................170
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5.4 Results ..............................................................................................................170
5.5 Discussion .........................................................................................................173
5.6 Limitation of study ...........................................................................................182
5.7 Summary ...........................................................................................................184
CHAPTER 6: A PRELIMINARY RANDOMISED DOUBLE BLIND
PLACEBO-CONTROLLED TRIAL OF INTRAVENOUS IMMUNOGLOBULIN
FOR JAPANESE ENCEPHALITIS IN NEPAL ....................................................193
Abstract .......................................................................................................................193
6.1 Introduction ......................................................................................................194
6.2.1 Aim ...................................................................................................................197
6.2.2 Objectives .........................................................................................................197
6.3 Methods ............................................................................................................198
6.3.1 Ethics Statement ...............................................................................................198
6.3.2 IVIG selection ...................................................................................................198
6.3.3 Patients ..............................................................................................................199
6.3.4 Procedures ........................................................................................................200
6.3.5 Diagnostic and Pathogenetic studies ................................................................201
6.3.6 Sample size .......................................................................................................203
6.3.7 Statistical analysis .............................................................................................203
6.4 Results ..............................................................................................................204
6.4.1 Patients ..............................................................................................................204
6.4.2 Intravenous immunoglobulin ...........................................................................206
6.4.3 Outcomes .........................................................................................................206
6.4.4 Neutralising antibodies .....................................................................................207
6.4.5 Cytokines ..........................................................................................................208
6.5 Discussion .........................................................................................................209
6.6 Limitation of study ...........................................................................................217
6.7 Summary ...........................................................................................................218
CHAPTER 7: FINAL DISCUSSION AND CONCLUSION ................................237
7.1 Clinical features that distinguished confi rmed JE from non- JE AES ..............238
7.2 Patient outcome at discharge ............................................................................240
7.3 Prognostic features suggesting bad outcome at discharge ................................242
7.4 Validation of prognostic features of bad outcome at discharge in AES and JE ...244
7.5 Admission weight for age as a marker of hydration status in AES and
JE patients .........................................................................................................246
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