Epidemiology of malaria in India
Life cycle of plasmodium and pathophysiology of malaria
Clinical features and severe malaria
3. Know malaria and why
Malaria is an acute and chronic illness characterized by
paroxysms of fever, chills, sweats, fatigue, anemia, and
Malaria is of overwhelming importance in the developing world
today, with an estimated 300 to 500 million cases and more
than 1 million deaths each year.
Most malarial deaths occur among infants and young children.
4. 4 species of Plasmodium were known to cause malaria in humans:
P. ovale, and
In 2004 P. knowlesi (a primate malaria species) was also shown to
cause human malaria.
5. Epidemiology of malaria in india
Season: most common in July-November
Definitive host: Anopheles mosquito
Intermediate host: Man
Vector: Anopheles culicfacies(rural) and
Anopheles stephensi (urban)
Type Incubation period
P vivax 8-17 days (14days)
P falciparum 9-14 days (12 days)
P malariae 18-40 days (28 days)
P ovale 16-18 days (17 days)
6. Modes of malaria transmission
Bite of female anopheline mosquitoes: Infective form:
Infection of blood of a malaria patient containing asexual forms-
‘trophozoite’ induced malaria
1. Trasfusion malaria
2. Congenital malraia
3. Malaria in drug addicts
7. Hosts involved in transmission of
Man Female anopheles mosquito
Secondary host Primary host
Intermediate host Definitive host
Asexual cycle Sexual cycle
9. Human cycle of plasmodium
1. Pre erythrocytic schizogony
Development of sporozoites in liver parenchyma
Liberated merozoites are called as cryptozoites
No clinical manifestion; no pathological changes
Blood is sterile
2. Erythorcytic schizogony
Parasite resides inside RBCs; passes through stages of Trophozoite,
Parasitic multiplication brings clinical attack of malaria
10. 3. Gametogony
Some merozoites develop in RBCs of spleen and bone marrow
to form ‘Gametocytes’
4. Exo erythorocytic schizogony
Persistence of late tissue phase in liver
Seen in P vivax and P ovale
Cause relapses in Vivax and Ovale malaria
Liberated merozoites are known as ‘Phanerozoites’
11. Mosquito cycle of plasmodium
1. Completion of gametogomy
Exflagellation of microgamete and maturation of gametes
Fusion of gametes form Zygote; Zygote matures to Ookinite
Ookinite develops into oocyst
On 10th day of infection, oocyst ruptures, relasing sporozoites;
sporozoites reach salivary glands
Mosquito at this stage is capable of transmitting infection.
12. Once inside the erythrocyte, the parasite transforms into the
ring form, which then enlarges to become a trophozoite.
These latter 2 forms can be identified with Giemsa stain on
blood smear, the primary means of confirming the diagnosis of
14. Febrile paroxysms are characterized by high fever, sweats, and
headache, as well as myalgia, back pain, abdominal pain, nausea,
vomiting, diarrhea, pallor
15. Paroxysms coincide with the rupture of schizonts that occurs
every 48 hr with P. vivax and P. ovale, resulting in fever spikes
every other day- tertian malaria
every 72 hr with P. malariae, resulting in fever spikes every 3rd or
4th day- quartan marlaria
Periodicity is less apparent with
P. falciparum and mixed infections
travelers from nonendemic regions
16. Children with malaria often lack typical paroxysms and have nonspecific
symptoms, including fever (may be low-grade but is often greater than
104°F), headache, drowsiness, anorexia, nausea, vomiting, and diarrhea.
Signs- splenomegaly (common), hepatomegaly, and pallor due to anemia.
Typical laboratory findings include anemia, thrombocytopenia, and a normal
or low leukocyte count.
The erythrocyte sedimentation rate (ESR) is often elevated
18. WHO has identified 10 complications of P. falciparum malaria that define severe
1. Impaired consciousness
3. Multiple seizures
4. Respiratory distress
5. Pulmonary edema
8. Abnormal bleeding
9. Severe anemia
10. Circulatory collapse
19. The most common serious complication is severe anemia.
Serious complications that appear unique to P. falciparum
include cerebral malaria, acute renal failure, respiratory distress
from metabolic acidosis, algid malaria and bleeding diatheses.
P. falciparum is the most severe form of malaria and is
associated with higher density parasitemia and a number of
20. Parasite and RBCs
P. falciparum -immature and mature erythrocytes
P. ovale and P. vivax - immature erythrocytes
P. malariae- only mature erythrocytes.
The diagnosis of malaria
Giemsa-stained smears of peripheral blood or
rapid immunochromatographic assay.
Stains used for diagnosis
Giemsa stain >Wright stain or Leishman stain.
Thick and Thin blood smears
The concentration of erythrocytes on a thick smear is 20-40 times
that on a thin smear and is used to quickly scan large numbers of
The thin smear allows for positive identification of the malaria species
and determination of the percentage of infected erythrocytes and is
useful in following the response to therapy
A single negative blood smear does not exclude malaria.
Most symptomatic patients with malaria will have detectable
parasites on thick blood smears within 48 hr.
Severe malarial anemia (hemoglobin < 5 g/dL) is the most common
severe complication of malaria in children.
removal of infected erythrocytes by the spleen and
impairment of erythropoiesis
The primary treatment -blood transfusion.
25. Cerebral malaria
Cerebral malaria is defined as the presence of coma in a child with P. falciparum
parasitemia and an absence of other reasons for coma.
Cerebral malaria is associated with long-term cognitive impairment in children.
Physical findings- high fever, seizures, muscular twitching, rhythmic movement of the head
or extremities, contracted or unequal pupils, retinal hemorrhages, hemiplegia, absent or
exaggerated deep tendon reflexes, and a positive Babinski sign.
LP- increased pressure and cerebrospinal fluid protein with no pleocytosis and normal
glucose and protein concentrations.
treatment of seizures and hypoglycemia.
26. Facts to remember
Severe disease and death from P. vivax are usually due to severe
anemia and sometimes to splenic rupture.
P. ovale malaria is the least common type of malaria.
P. malariae is the mildest and most chronic of all malaria infections.
Nephrotic syndrome is a rare complication of P. malariae infection
that is not observed with any other human malaria species. Nephrotic
syndrome associated with P. malariae infection is poorly responsive
Recrudescence after a primary attack may occur from the survival of
erythrocyte forms in the bloodstream.
merozoites from an exoerythrocytic source in the liver- P. vivax and P.
persistence within the erythrocyte -P. malariae, P. falciparum(rare).
is acquired from the mother prenatally or perinatally.
Causes-abortions, miscarriages, stillbirths, premature births, intrauterine
growth retardation, and neonatal deaths.
Presentation- between 10 and 30 days of age (range 14 hr to several
months of age).
Signs and symptoms - fever, restlessness, drowsiness, pallor, jaundice,
poor feeding, vomiting, diarrhea, cyanosis, and hepatosplenomegaly.
29. New malaria treatment guidelines in
Uncomplicated P. vivax-
Chloroquine for 3 days (Day 1: 10 mg/kg + Day 2: 10 mg/kg + Day 3: 5mg/kg)
+ Primaquine 0.25 mg/kg daily for 14 days
Uncomplicated P. falciparum-
Artesunate (4 mg/kg body weight) daily for 3 days and
sulfadoxine pyrimethamine (25 mg/kg + 1.25 mg/kg body weight) on Day 0;
+ Primaquine 0.75 mg/kg body weight single dose on day 2
Mixed Infections (P. vivax + P. falciparum)-
Full course of artemisinin-based combination therapy (ACT) + Primaquine 0.25 mg/kg
daily for 14 days
30. Complicated malaria
Parenteral Artemisin derivatives (Artesunate, Artemether,
Once patient can take Oral therapy
Those on parenteral Artemisin derivatives: oral ACT(full course)
ACT- Artesunate Sulfalene Pyrimethamine Combination Therapy
Those on parenteral Quinine: oral quinine+Doxycycline 7 days
Complicated malaria in pregnancy
I trimester: parenteral quinine
II and III trimester: Parenteral Artemisin derivatives
Malaria prevention consists of
Reducing exposure to infected mosquitoes and
Chemoprophylaxis is necessary for
all visitors to and
residents of the tropics who have not lived there since infancy,
including children of all ages.
Health care providers should consult the latest information on
resistance patterns before prescribing prophylaxis for their
Short term chemoprophylaxis (<6 weeks):
Doxycycline(2 days before to 4 weeks after leaving
Long term chemoprophylaxis (> 6 weeks):
Mefloquine (2 weeks before to 4 weeks after leaving