[Lymphatic Filariasis]

by

Acknowledgement

I would take this opportunity to thank my research supervisor, family and friends for their support and guidance without which this research would not have been possible.

DECLARATION

I, [type your full first names and surname here], declare that the contents of this dissertation/thesis represent my own unaided work, and that the dissertation/thesis has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the University.

Signed __________________ Date _________________

Abstract

Lymphatic filariasis is a mosquito-borne disease infecting more than 120 million people worldwide. The World Health Organization (WHO) ranks it as the second most common cause of long-term disability. In Thailand, lymphatic filariasis is caused by Wuchereria bancrofti and Brugia malayi. The domestic cats have been reported to be played the role as reservoir host in the B. malayi endemic area. B. pahangi is a common parasite of dogs and cats in endemic areas of B. malayi. Due to their similarity of B. malayi and B. pahangi make it difficult to distinguish the filarial species by conventional methods. The objective of this study was to detect and survey the distribution of Brugia spp. Infection in stray cats which live in the monasteries in Bangkok metropolitan by using nested-PCR technique to compare with conventional methods. The result of PCR demonstrated that the infection was found in 23 cases from 1,490 cat blood samples (1.5 % prevalence) while the microscopic examination and Modified Knott' s technique was shown only 9 positive sample in each method. These positives were identified as B. malayi by DNA sequencing. From the statistical analysis, there were not presented the correlation between Brugia spp. infection and environmental factor. However, as the result, Bangkok was possibly at risk of Malayan filariasis. The result data from this study will be beneficial for disease surveillance and control program in Bangkok metropolitan.

ABSTRACT4

LIST OF ABBREVIATIONS6

CHAPTER 1: INTRODUCTION8

Objectives10

CHAPTER 2: LITERATURE REVIEW11

Overview of filariae12

Lymphatic Filariasis: The Global situation13

Cause and Transmission15

Clinical Manifestations16

Diagnosis17

Control of Lymphatic Filariasis19

Vector Control19

Morbidity Control19

Mass Chemotherapy20

The Global Burden of Lymphatic Filariasis20

Brugia malayi23

Morphology23

Life cycle26

Epidemiology28

Brugia timori (The Timor filaria)29

Morphology30

Life cycle31

Epidemiology31

Clinical disease32

Diagnosis32

Detection of adult worms35

Detection of filarial antibodies35

CHAPTER 3: MATERIALS AND METHODS38

CHAPTER 3: MATERIALS AND METHODS39

Study area39

Animals39

Blood samples41

Health condition criteria41

Environmental condition41

Modified Knott' s technique42

The microscopic examination43

DNA extraction43

Primer Design43

PCR amplification44

Cloning of the PCR fragments45

Recombinant plasmid purification45

Recombinant plasmid DNA sequencing46

DNA sequence analysis47

Statistical Analysis47

CHAPTER 4: RESULTS AND DISCUSSION48

Results48

Animal data48

Modified Knott' s technique49

Microscopic examination50

PCR results51

Analysis of ITS2 nucleotide sequence56

Statistical Analysis57

Discussion59

Diagnosis method of Brugia spp. infection59

The spreading of Brugian flariasis61

CHAPTER 5: CONCLUSION AND RECOMMENDATION65

Conclusion65

Recommendation65

REFERENCES66

APPENDIX84

List of abbreviations

°C = Degree(s) Celsius

µg = Microgram(s)

µl = Microliter(s)

µm = Micrometer(s)

bp = Base pair(s)

DNA = Deoxyribonucleic acid

dNTP = Deoxynucleotide triphosphate

DW = Distilled water

EDTA = Ethylenediamine tetraacetic acid

ELISA = Enzyme linked-immunosorbent assay

et al = et alli

g = Gram(s)

kg(s) = Kilogram(s)

L (l) = Liter(s)

M = Mole

mg = Milligram(s)

min = Minute(s)

ml = Milliliter(s)

mm = Millimeter(s)

mM = Millimolar(s)

MW = Molecular weight

PCR = Polymerase chain reaction

pH = Negative logarithm of hydrogen ion activity

RNA = Ribonucleic acid

rpm = Round(s) per minute

TBE = Tris - boric acid - EDTA

U/µl = Unit(s) per microliter

U/g = Unit(s) per ...