THE INVADING MECHANISM OF PLAMODIUM VIVAX

ASSOCIATED WITH DUFFY-NEGATIVES FROM THE

ETHIOPIAN POPULATIONSKristie Hanh Bich NguyenDr. Guiyun Yan Post-doc Eugenia Lo

CONTENTS

• WHY should we care about malaria?• WHO are in danger?• WHAT is malaria?• HOW should we approach it?

WHY SHOULD WE CARE ABOUT MALARIA?

• Number of Malaria cases is 214 million (2015)

• Number of people at risk of malaria infection is 3.3 million

• 3.45 million people are not at risk

• ~80% of cases occurred in Africa, 12% in South Asia, and 5% in Eastern Mediterranean region

WHO ARE IN DANGER?• It locates in the North of

Africa• All age groups are at risk,

and mortality rate is high among children under age of 5

• Plasmodium Falciparum and Plasmodium Vivax are the two most dominant malaria parasites in Ethiopia

WHAT IS MALARIA?(VECTOR-BORNE DISEASE)

• Transmitted by female Anopheles mosquito

• Plasmodium parasitesP. falciparum P. vivaxP. malariae P. ovale P. knowlesi

INVADING MECHANISM

Malaria

Evolution

Infection

Growth

CLINICAL CHALLENGE

• Humans lacking Duffy antigen resistant to P. vivax1

• The human DARC gene determines the presence of Duffy2

• P. vivax recently evolved the capability to infect Duffy (-)3

• Parasites becoming more prevalent and widespread3

Duffy (-)

Duffy (+)

INVADING MECHANISM

• DBP II is a 330 amino acid region characterized by 12 conserved cysteine residues

• The central 170-aa that includes cysteine 4-7 are critical binding residues

• Any key mutations in PvDBP II of Duffy-negative red cells?

PVDBP REGION II POLYMORPHISM

HOW SHOULD WE APPROACH IT?

What is the proportion of Duffy-negative in local populations?

What is the frequency of P.Vivax infection among the Duffy-negatives?

What is P.Vivax’s invading mechanism to Duffy-negative population?

METHODOLOGIES

Sample collection

DNA purification

Parasite detection

NESTED POLYMERASE CHAIN REACTION (NESTED PCR)

QUANTITATIVE REAL-TIME PCR (QPCR)

Well CqE1 27.05E2 N/AE3 26.54E4 N/AE5 25.70E6 N/AE11 N/AE12 N/AF1 43.30F2 N/AF3 N/AF4 30.20

Based on nested PCR and qPCR assays Based on DARC

Site Sample size Falciparum only Vivax only Co-infectionDuffy genotype

of vivax infection Alaba 49 18 1 0 1 +Mankush 298 179 41 33 73 +; 1-Metehara 275 151 97 11 107+; 1 -Jimma 104 8 92 0 91 +; 1- Asendabo 390 49 23 1 21+; 2-

SUMMARY OF MALARIA INFECTION IN ETHIOPIA

TWO CONTENT LAYOUT WITH SMARTART• First bullet point here• Second bullet point here• Third bullet point here

Group A

• Task 1

• Task 2

Group B

• Task 1

• Task 2

Group C

IDEAS?• Migration to different areas in Africa• Prevention• Vaccine production