MBBS Year
2nd Year
Subject
What Is Usually Asked
Life cycle, morphology on smear, laboratory diagnosis
ReferenceAll Years (1st-Final)All Universities Malaria
Malaria: Notes, PPT and PYQs for MBBS
Malaria is a protozoal disease caused by Plasmodium species and transmitted by the bite of an infected female Anopheles mosquito. It is a core topic in Microbiology, Pathology and Pharmacology in 2nd Year, Community Medicine in 3rd Year, and General Medicine and Paediatrics in Final Year.
SME-reviewed. Updated 2026.
Open in GeckoMed for PPT slides and offline notesQuick Summary: What You Need to Know for University Exams
- Five species infect humans: P. falciparum, P. vivax, P. ovale, P. malariae and P. knowlesi. In India, P. falciparum and P. vivax are the main species.
- The vector is the female Anopheles mosquito; the mosquito is the definitive host and humans are the intermediate host.
- P. vivax and P. ovale form hypnozoites in the liver, which cause relapses.
- P. falciparum causes severe malaria because of cytoadherence and sequestration of infected red cells.
- Peripheral blood smear (thick and thin) is the gold standard; rapid diagnostic tests (RDTs) are widely used in the field.
- Under India's national guidelines, vivax is treated with chloroquine plus a 14-day course of primaquine, and falciparum with an artemisinin-based combination therapy (ACT).
- Artesunate is the drug of choice for severe malaria.
Malaria Across MBBS Subjects
| MBBS Year | Subject | What Is Usually Asked |
|---|---|---|
| 2nd Year | Microbiology | Life cycle, morphology on smear, laboratory diagnosis |
| 2nd Year | Pathology | Pathogenesis, cerebral malaria, spleen, haemolysis |
| 2nd Year | Pharmacology | Classification of antimalarials, chloroquine, primaquine, artemisinins |
| 3rd Year | Community Medicine | Epidemiology, vector control, national programme, malariometric indices |
| Final Year | General Medicine | Clinical features, severe malaria, management |
| Final Year | Paediatrics | Malaria in children |
MBBS Year
2nd Year
Subject
What Is Usually Asked
Pathogenesis, cerebral malaria, spleen, haemolysis
MBBS Year
2nd Year
Subject
What Is Usually Asked
Classification of antimalarials, chloroquine, primaquine, artemisinins
MBBS Year
3rd Year
Subject
What Is Usually Asked
Epidemiology, vector control, national programme, malariometric indices
MBBS Year
Final Year
Subject
What Is Usually Asked
Clinical features, severe malaria, management
MBBS Year
Final Year
Subject
What Is Usually Asked
Malaria in children
Definition and Classification
Definition: Malaria is an acute or chronic infection caused by protozoa of the genus Plasmodium, transmitted by infected female Anopheles mosquitoes, and characterised by periodic febrile paroxysms, anaemia and splenomegaly.
Species and Their Features
| Species | Fever Periodicity | Relapse (Hypnozoites) | Key Feature |
|---|---|---|---|
| P. falciparum | Tertian pattern, often irregular (malignant tertian) | No | Causes most severe and fatal malaria |
| P. vivax | Tertian (every 48 hours) | Yes | Common in India; relapses |
| P. ovale | Tertian (every 48 hours) | Yes | Uncommon in India |
| P. malariae | Quartan (every 72 hours) | No | Associated with nephrotic syndrome |
| P. knowlesi | Daily (24 hours) | No | Zoonotic, mainly in Southeast Asia |
Species
P. falciparum
Fever Periodicity
Tertian pattern, often irregular (malignant tertian)
Relapse (Hypnozoites)
No
Key Feature
Causes most severe and fatal malaria
Species
P. vivax
Fever Periodicity
Tertian (every 48 hours)
Relapse (Hypnozoites)
Yes
Key Feature
Common in India; relapses
Species
P. ovale
Fever Periodicity
Tertian (every 48 hours)
Relapse (Hypnozoites)
Yes
Key Feature
Uncommon in India
Species
P. malariae
Fever Periodicity
Quartan (every 72 hours)
Relapse (Hypnozoites)
No
Key Feature
Associated with nephrotic syndrome
Species
P. knowlesi
Fever Periodicity
Daily (24 hours)
Relapse (Hypnozoites)
No
Key Feature
Zoonotic, mainly in Southeast Asia
Clinical Classification
- Uncomplicated malaria: Symptomatic malaria without features of severe disease
- Severe (complicated) malaria: Malaria with evidence of vital organ dysfunction (see below)
Aetiology and Transmission
Modes of transmission:
- Bite of an infected female Anopheles mosquito (main route)
- Blood transfusion
- Sharing of needles
- Congenital (mother to fetus)
Risk factors: Living in or travelling to endemic areas, stagnant water near homes, poor housing, lack of bed nets, pregnancy, young age and lack of immunity.
Life Cycle of Plasmodium
| Phase | Host | Key Events |
|---|---|---|
| Pre-erythrocytic (exo-erythrocytic) schizogony | Human liver | Sporozoites injected by the mosquito enter hepatocytes and multiply to form merozoites; in P. vivax and P. ovale some remain dormant as hypnozoites |
| Erythrocytic schizogony | Human red cells | Merozoites invade red cells and develop into ring forms, trophozoites and schizonts; rupture releases new merozoites and causes fever |
| Gametogony | Human red cells | Some merozoites form male and female gametocytes |
| Sporogony (sexual cycle) | Female Anopheles mosquito | Gametocytes fuse in the mosquito gut to form a zygote, ookinete and oocyst, which releases sporozoites that travel to the salivary glands |
Phase
Pre-erythrocytic (exo-erythrocytic) schizogony
Host
Human liver
Key Events
Sporozoites injected by the mosquito enter hepatocytes and multiply to form merozoites; in P. vivax and P. ovale some remain dormant as hypnozoites
Phase
Erythrocytic schizogony
Host
Human red cells
Key Events
Merozoites invade red cells and develop into ring forms, trophozoites and schizonts; rupture releases new merozoites and causes fever
Phase
Gametogony
Host
Human red cells
Key Events
Some merozoites form male and female gametocytes
Phase
Sporogony (sexual cycle)
Host
Female Anopheles mosquito
Key Events
Gametocytes fuse in the mosquito gut to form a zygote, ookinete and oocyst, which releases sporozoites that travel to the salivary glands
Infective form to humans: Sporozoite. Infective form to mosquitoes: Gametocyte.
(Examiner may ask you to draw the life cycle of Plasmodium.)
Pathophysiology
Flowchart
- Synchronous rupture of infected red cells releases merozoites, pigment and parasite products
- Release of cytokines such as tumour necrosis factor causes the febrile paroxysm
- Destruction of infected and uninfected red cells causes anaemia
- The spleen enlarges as it clears damaged red cells
- In P. falciparum, infected red cells develop knobs and stick to the lining of small blood vessels (cytoadherence) and to uninfected red cells (rosetting)
- Sequestration in small vessels of the brain, kidneys and other organs causes microvascular obstruction and organ dysfunction
Classical Paroxysm
| Stage | Features |
|---|---|
| Cold stage | Intense chills and shivering |
| Hot stage | High fever, headache, flushing |
| Sweating stage | Profuse sweating as the temperature falls |
Stage
Cold stage
Features
Intense chills and shivering
Stage
Hot stage
Features
High fever, headache, flushing
Stage
Sweating stage
Features
Profuse sweating as the temperature falls
Clinical Features
Uncomplicated malaria:
- Fever, which may be periodic or irregular
- Chills, rigors and sweating
- Headache, body ache and fatigue
- Nausea and vomiting
- Anaemia, splenomegaly and mild jaundice
Features of Severe Malaria (WHO)
| Clinical Features | Laboratory Features |
|---|---|
| Impaired consciousness (cerebral malaria) | Severe anaemia |
| Prostration | Hypoglycaemia |
| Multiple convulsions | Metabolic acidosis |
| Shock | Renal impairment |
| Pulmonary oedema or respiratory distress | Jaundice |
| Significant bleeding | Hyperparasitaemia |
Clinical Features
Impaired consciousness (cerebral malaria)
Laboratory Features
Severe anaemia
Clinical Features
Prostration
Laboratory Features
Hypoglycaemia
Clinical Features
Multiple convulsions
Laboratory Features
Metabolic acidosis
Clinical Features
Shock
Laboratory Features
Renal impairment
Clinical Features
Pulmonary oedema or respiratory distress
Laboratory Features
Jaundice
Clinical Features
Significant bleeding
Laboratory Features
Hyperparasitaemia
Other forms:
- Blackwater fever: Massive intravascular haemolysis with haemoglobinuria, associated with P. falciparum
- Algid malaria: Shock with circulatory collapse
- Malaria in pregnancy: Higher risk of severe disease, anaemia, miscarriage and low birth weight
Diagnosis
| Test | Key Points |
|---|---|
| Peripheral blood smear (thick and thin) | Gold standard. Thick smear detects parasites (more sensitive); thin smear identifies the species. Stained with Giemsa, Leishman or JSB (Jaswant Singh-Bhattacharji) stain |
| Rapid diagnostic tests (RDTs) | Detect parasite antigens: HRP2 (specific to P. falciparum) and pLDH; useful in the field |
| Quantitative buffy coat (QBC) | Fluorescent staining method for rapid detection |
| PCR | Species identification and low parasitaemia; mainly in research and reference labs |
| Supportive tests | Complete blood count (anaemia, low platelets), blood glucose, renal and liver function, blood gases |
Test
Peripheral blood smear (thick and thin)
Key Points
Gold standard. Thick smear detects parasites (more sensitive); thin smear identifies the species. Stained with Giemsa, Leishman or JSB (Jaswant Singh-Bhattacharji) stain
Test
Rapid diagnostic tests (RDTs)
Key Points
Detect parasite antigens: HRP2 (specific to P. falciparum) and pLDH; useful in the field
Test
Quantitative buffy coat (QBC)
Key Points
Fluorescent staining method for rapid detection
Test
PCR
Key Points
Species identification and low parasitaemia; mainly in research and reference labs
Test
Supportive tests
Key Points
Complete blood count (anaemia, low platelets), blood glucose, renal and liver function, blood gases
Smear Differences: P. falciparum Versus P. vivax
| Feature | P. falciparum | P. vivax |
|---|---|---|
| Infected red cell size | Normal | Enlarged |
| Ring forms | Small, often multiple per cell, accolé forms | Larger, usually one per cell |
| Stages seen in blood | Mainly rings and gametocytes | All stages |
| Gametocytes | Crescent or banana-shaped | Round |
| Red cell stippling | Maurer's dots | Schüffner's dots |
Feature
Infected red cell size
P. falciparum
Normal
P. vivax
Enlarged
Feature
Ring forms
P. falciparum
Small, often multiple per cell, accolé forms
P. vivax
Larger, usually one per cell
Feature
Stages seen in blood
P. falciparum
Mainly rings and gametocytes
P. vivax
All stages
Feature
Gametocytes
P. falciparum
Crescent or banana-shaped
P. vivax
Round
Feature
Red cell stippling
P. falciparum
Maurer's dots
P. vivax
Schüffner's dots
Management
National Treatment Principles in India (MBBS Level)
| Situation | Treatment Approach |
|---|---|
| P. vivax | Chloroquine for 3 days plus primaquine for 14 days (radical cure against hypnozoites) |
| P. falciparum (uncomplicated) | Artemisinin-based combination therapy (ACT) for 3 days plus a single dose of primaquine as a gametocidal drug. Artesunate with sulfadoxine-pyrimethamine is used in most of India; artemether-lumefantrine is used in the North-Eastern states |
| Mixed infection | Treated as falciparum malaria, with a 14-day course of primaquine |
| Severe malaria | Parenteral artesunate is preferred (quinine is an alternative), followed by a full course of oral ACT |
| Pregnancy | Primaquine is avoided; drug choice for falciparum depends on trimester, as per national guidelines |
Situation
P. vivax
Treatment Approach
Chloroquine for 3 days plus primaquine for 14 days (radical cure against hypnozoites)
Situation
P. falciparum (uncomplicated)
Treatment Approach
Artemisinin-based combination therapy (ACT) for 3 days plus a single dose of primaquine as a gametocidal drug. Artesunate with sulfadoxine-pyrimethamine is used in most of India; artemether-lumefantrine is used in the North-Eastern states
Situation
Mixed infection
Treatment Approach
Treated as falciparum malaria, with a 14-day course of primaquine
Situation
Severe malaria
Treatment Approach
Parenteral artesunate is preferred (quinine is an alternative), followed by a full course of oral ACT
Situation
Pregnancy
Treatment Approach
Primaquine is avoided; drug choice for falciparum depends on trimester, as per national guidelines
Important precautions:
- Primaquine can cause haemolysis in G6PD deficiency.
- Primaquine is not given in pregnancy or in infants, as per national guidelines.
- Doses are weight- or age-based and must follow current national drug policy.
Supportive Care in Severe Malaria
- Monitor consciousness, blood glucose, urine output and vital signs
- Correct hypoglycaemia promptly
- Manage convulsions
- Careful fluid management to avoid pulmonary oedema
- Blood transfusion for severe anaemia
- Dialysis for acute kidney injury when needed
Classification of Antimalarial Drugs (by Stage of Action)
| Action | Examples |
|---|---|
| Blood schizonticides | Chloroquine, artemisinins (artesunate, artemether), quinine, mefloquine, lumefantrine |
| Tissue schizonticides (radical cure) | Primaquine, tafenoquine |
| Gametocides | Primaquine (for P. falciparum) |
| Sporontocides | Proguanil, pyrimethamine |
Action
Blood schizonticides
Examples
Chloroquine, artemisinins (artesunate, artemether), quinine, mefloquine, lumefantrine
Action
Tissue schizonticides (radical cure)
Examples
Primaquine, tafenoquine
Action
Gametocides
Examples
Primaquine (for P. falciparum)
Action
Sporontocides
Examples
Proguanil, pyrimethamine
Complications
- Cerebral malaria
- Severe anaemia
- Acute kidney injury
- Acute respiratory distress syndrome and pulmonary oedema
- Hypoglycaemia
- Metabolic acidosis
- Disseminated intravascular coagulation and bleeding
- Splenic rupture
- Blackwater fever
- Relapse in P. vivax and P. ovale
Prevention and Control (Community Medicine Angle)
| Measure | Examples |
|---|---|
| Vector control | Indoor residual spraying, long-lasting insecticidal nets, larval source management, larvivorous fish such as Gambusia |
| Personal protection | Bed nets, repellents, protective clothing |
| Early diagnosis and complete treatment | Reduces transmission and deaths |
| Chemoprophylaxis for travellers | For example doxycycline or mefloquine, according to guidelines |
| Vaccines | WHO has recommended the RTS,S and R21 vaccines for children in endemic regions, mainly in Africa; malaria vaccine is not part of India's routine immunisation schedule |
Measure
Vector control
Examples
Indoor residual spraying, long-lasting insecticidal nets, larval source management, larvivorous fish such as Gambusia
Measure
Personal protection
Examples
Bed nets, repellents, protective clothing
Measure
Early diagnosis and complete treatment
Examples
Reduces transmission and deaths
Measure
Chemoprophylaxis for travellers
Examples
For example doxycycline or mefloquine, according to guidelines
Measure
Vaccines
Examples
WHO has recommended the RTS,S and R21 vaccines for children in endemic regions, mainly in Africa; malaria vaccine is not part of India's routine immunisation schedule
National programme: Malaria control in India falls under the National Centre for Vector Borne Diseases Control (NCVBDC). India's National Framework for Malaria Elimination (2016 to 2030) aims to eliminate malaria by 2030.
Malariometric Indices
| Index | Definition |
|---|---|
| Annual Parasite Incidence (API) | Confirmed malaria cases in a year per 1,000 population |
| Annual Blood Examination Rate (ABER) | Blood smears examined in a year as a percentage of the population |
| Slide Positivity Rate (SPR) | Percentage of examined slides found positive |
| Slide Falciparum Rate (SFR) | Percentage of examined slides positive for P. falciparum |
Index
Annual Parasite Incidence (API)
Definition
Confirmed malaria cases in a year per 1,000 population
Index
Annual Blood Examination Rate (ABER)
Definition
Blood smears examined in a year as a percentage of the population
Index
Slide Positivity Rate (SPR)
Definition
Percentage of examined slides found positive
Index
Slide Falciparum Rate (SFR)
Definition
Percentage of examined slides positive for P. falciparum
Prognosis
Uncomplicated malaria has an excellent outcome with prompt, complete treatment. Severe falciparum malaria carries a significant risk of death, which is reduced by early diagnosis and parenteral artesunate.
Quick Viva Questions
Q: What is the infective form of Plasmodium for humans? A: The sporozoite.
Q: Which species is associated with nephrotic syndrome? A: Plasmodium malariae.
Q: Why is primaquine given in vivax malaria? A: To kill liver hypnozoites and prevent relapse (radical cure).
Q: Which species has banana-shaped gametocytes? A: Plasmodium falciparum.
Q: Which enzyme deficiency must be considered before primaquine? A: G6PD deficiency, because primaquine can cause haemolysis.
How Malaria Appears in MBBS University Exams
Typical question styles (not attributed to specific papers or years):
- "Describe the life cycle of Plasmodium falciparum. Add a note on the laboratory diagnosis of malaria." (Long essay, Microbiology)
- "Discuss the clinical features, complications and management of falciparum malaria." (Long essay, General Medicine)
- "Classify antimalarial drugs. Write a note on primaquine." (Long essay or short note, Pharmacology)
- "Write a short note on cerebral malaria." (Short note, Medicine or Pathology)
- "Describe the epidemiology and control of malaria in India." (Long essay, Community Medicine)
Frequently Asked Questions
Which Plasmodium species cause relapse?
P. vivax and P. ovale, because they form dormant liver stages called hypnozoites. Primaquine is given to eliminate them (radical cure).
What is the gold standard test for malaria?
Microscopy of stained thick and thin peripheral blood smears. Rapid diagnostic tests are useful where microscopy is not available.
Can I download the malaria PPT for my presentation?
Yes. Use the Download PPT button at the top of this page. The GeckoMed app also gives offline access to the slides and notes.
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