1. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a genetic disorder that results in low levels of the G6PD enzyme in red blood cells. 2. The G6PD enzyme protects red blood cells from oxidative damage. Without sufficient G6PD, red blood cells are vulnerable to destruction when exposed to certain drugs or foods. 3. Primaquine, a drug used to prevent relapses of P. vivax malaria, can cause hemolysis or acute hemolytic anemia in people with low or intermediate G6PD levels due to its oxidative effects on red blood cells. It is important to test patients for G6PD status before administering primaquine to avoid

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General information on G6PD deficiency
Plasmodium vivax malaria & Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency
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2. P.vivax Life cycle in Humans
No test for liver
stage of vivax
NB: Some infections may not lead to
hypnozoites; some hypnozoites may not
relapses
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3. P. vivax malaria can relapse without a bite from an infected
mosquitoes a bite from an infected mosquito ted mosquito
Many relapses
weeks / months
after first infection
Illness, anemia,
possible
complications
including death
First
infection
Acute malaria
Obstacle to
malaria
elimination
Onward transmission
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4. P. vivax has a dormant liver stage which causes relapses
No test for liver
stage of vivax
NB: Some infections may not lead to
hypnozoites; some hypnozoites may not
relapses
Primaquine
(14-days)
[Chloroquine]
(3-days)
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5. Any questions?
• P. vivax malaria causes relapse of the malaria disease
• Relapse can lead to anemia, other illnesses and even death
• P. vivax malaria causes most malaria cases in countries / areas close to malaria
elimination
• P. vivax malaria is treated with chloroquine or an ACT to treat the acute malaria
infection and primaquine to prevent relapses
Key points to remember:
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6. What is G6PD deficiency?
By the end of this session you should be able to:
- Explain G6PD deficiency and how it affects P. vivax malaria care
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Why is G6PD deficiency important for vivax patients?
 WHO guidelines state that “the G6PD status of patients should be used to guide administration of
primaquine for preventing relapse” of vivax malaria.
 To prevent drug-induced hemolytic anemia it is important to identify a patient’s G6PD status
before prescribing primaquine or tafenoquine for vivax malaria.
 In Myanmar, the treatment for patients infected by P. vivax malaria is Chloroquine (CQ) (3 days)
and Primaquine (PQ) (14 days)
 The dosage for PQ is usually a total dose of 0.25 mg/kg day over 14 days in G6PD normal patients or
eight weeks treatment with a weekly dose in G6PD deficient patients.
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What is G6PD Enzyme and its deficiency
 Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency: An X-linked recessive disorder which
results in the decreased activity of the G6PD enzyme.
 G6PD enzyme protects red blood cells from oxidative stress:
 Leads to decreased synthesis of NADPH (reduced form of nicotinamide adenine dinucleotide
phosphate)& glutathione (antioxidants)
 NADPH helps restore glutathione stores so that glutathione can then reduce reactive oxygen
species (H2O2) to less harmful compounds (H2O).
 The G6PD enzyme plays a critical role in protecting red blood cells (RBCs) from damage
and premature destruction from by-products of normal cell processes as well as external
challenges.
 Many mutations have been identified that cause G6PD deficiency. Some of these mutations disrupt
the normal structure and stability of the enzyme – leading to low levels of G6PD activity inside the
red blood cells – or G6PD deficiency.
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• G6PD Status can be categorized as deficient, intermediate, or normal.
• People can have a mix of red blood cells – some with low G6PD activity and some with high G6PD activity.
If someone has mostly red blood cells with low G6PD activity, they are considered G6PD deficient.
If someone who has mostly blood cells with high G6PD activity, they are considered G6PD normal.
If someone has mixed blood cells, with high and low activity, they are considered G6PD intermediate. Only
females can be considered G6PD intermediate.
G6PD status

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G6PD
Gender Male Female
Low (deficient) <= 3.9 U/g Hb <= 3.9 U/g Hb
Gender Male Female
Medium (Intermediate) - 4-6 U/g Hb
G6PD status category by gender
Gender Male Female
Normal >= 4 U/g Hb >6 U/g Hb

11. Any questions?
• The G6PD enzyme helps protect red blood cells from damage
• If people have low or medium G6PD enzyme activity, they are at risk of hemolysis with anti-relapse
treatment
• About 0.5-8.6% of the Myanmar population is estimated having G6PD deficiency – it is important
to identify them before treating with primaquine
Key points to remember:
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G6PD and RBC lifespan
Partnership for Vivax Elimination

13. What does it mean to have medium or low levels of G6PD?
 G6PD activity level is inherited and affects 400 million people globally
 More than 180 G6PD deficiency genetic variants ranging from mild to severe
 G6PD deficiency is more common in males
 People with low levels of G6PD activity can lead a totally normal life; they only need to
avoid certain medicines and food
G6PD enzyme activity
Normal
Deficient /
low
Normal
Deficient / low
Intermediate /
medium
G6PD enzyme activity
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PQ effect on RBC
 Due to PQ’s oxidant nature, Primaquine metabolites oxidize hemoglobin and generate
reactive oxygen compounds
 leading to depletion of protective Glutathione (Bloom et al., 1983, Summerfield and
Tudhope, 1978) --- lead to a dose related hemolytic anemia.
The severity of hemolysis is determined by
 dose of primaquine
 extent of G6PD-deficiency
 patient's physiological condition (Clyde, 1981, Youngster et al., 2010).
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How G6PD enzyme protect RBC
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PQ treatment effect on RBC among G6PD vivax/mix malaria
cases
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17. Risks to patients with medium or low levels of G6PD
 Most people with G6PD deficiency never experience any symptoms unless
exposed to certain foods or medicines
 One serious potential side effect of some drugs taken by patients with low
or medium levels of G6PD activity is Acute Haemolytic Anaemia.
 Haemolysis or Acute Haemolytic Anemia is when red blood cells to rupture
/ burst (haemolysis)
 Red blood cells can be destroyed faster than the body can replace them
(acute hemolytic anemia - AHA)
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G6PD enzyme activity within RBC and risk factors
Partnership for Vivax Elimination

19. DARK URINE
Hemolysis
Dark urine caused by acute hemolytic anemia
NORMAL URINE
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THANK YOU
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