Importance of real time pcr in diagnosis of infectious diseases
UROP presentation
1. THE INVADING MECHANISM OF
PLAMODIUM VIVAX ASSOCIATED
WITH DUFFY-NEGATIVES FROM
THE ETHIOPIAN POPULATIONS
Kristie Hanh Bich Nguyen
Dr. Guiyun Yan
Post-doc Eugenia Lo
2. CONTENTS
• WHY should we care about malaria?
• WHO are in danger?
• WHAT is malaria?
• HOW should we approach it?
3. 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
4. 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
5. WHAT IS MALARIA?
(VECTOR-BORNE DISEASE)
• Transmitted by female
Anopheles mosquito
• Plasmodium parasites
P. falciparum
P. vivax
P. malariae
P. ovale
P. knowlesi
8. 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 (+)
10. • 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
11. 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?
15. Based on nested PCR and qPCR assays Based on DARC
Site Sample size Falciparum only Vivax only Co-infection
Duffy 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
16. 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
7 billion world population
In 2015, 95 countries and territories had ongoing malaria transmission
Between 2000 and 2015, malaria incidence among populations at risk (the rate of new cases) fell by 37% globally. In that same period, malaria death rates among populations at risk fell by 60% globally among all age groups, and by 65% among children under 5.
Sub-Saharan Africa carries a disproportionately high share of the global malaria burden. In 2015, the region was home to 88% of malaria cases and 90% of malaria deaths.
Answer: all of us but this project specially dedicates to Ethiopia
The climate environment suits the growing condition for malarial species
Due to the unstable and seasonal transmission of malaria in the country, protective immunity of the population is generally low and all age groups are at risk.
Children is group at risk the most due to low immunity and lack of education, health facilities
About 75% of the land and 60% of the population is exposed to malaria in Ethiopia
Why Mankush, Jimma Metehara? – tackle different regions to detect the prevalence
Why vivax?
P. vivax is difficult to control and eliminate due to its unique genetic biology to cause relapses of high fever preceded by unbearable headache over months and years after the original infection.
focus on the interactions between P. vivax binding protein and the human erythrocyte surface receptor with the goal to understand the invasion mechanism of the parasite and develop vaccines that can inhibit invasion.
It is important to monitor closely the genetic basis and evolution of the invasion mechanism in order to introduce a better vaccine.
However, the main obstacles are the natural selection and genetic polymorphism of P. vivax Duffy binding protein (PvDBP-II), which allow the parasite to bind to the erythrocyte receptor in the absence of the Duffy antigen and challenge the development of effective vaccine. Therefore, better understanding the nature of invading mechanism of P. vivax is one of the keys in providing accurate epidemiological data for vaccine development and to broadly evaluate the prevalence of the derived P. vivax invasion.
Definition of Duffy (+) and (-)
DBP 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
P.vivax, P.fal and co-infection
Footnote:
Number in red denotes vivax infections observed in Duffy negative individuals
