Post on 16-Jul-2015
MalariaDr S C Majhi
Introduction
Epidemiology of malaria in India
Life cycle of plasmodium and pathophysiology of malaria
Clinical features and severe malaria
Differential diagnosis
Complications
Diagnosis
Treatment
Prevention
Malaria
Malaria is an acute and chronic illness characterized byparoxysms of fever, chills, sweats, fatigue, anemia, andsplenomegaly.
Malaria is of overwhelming importance in the developing worldtoday, with an estimated 300 to 500 million cases and morethan 1 million deaths each year.
Most malarial deaths occur among infants and young children.
Know malaria and why
4 species of Plasmodium were known to cause malaria in humans:
P. falciparum,
P. malariae,
P. ovale, and
P. vivax.
In 2004 P. knowlesi (a primate malaria species) was also shown to cause human malaria.
Season: most common in July-November
Definitive host: Anopheles mosquito
Intermediate host: Man
Vector: Anopheles culicfacies(rural) and
Anopheles stephensi (urban)
Epidemiology of malaria in india
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)
Bite of female anopheline mosquitoes: Infective form: sporozoites
Infection of blood of a malaria patient containing asexual forms-‘trophozoite’ induced malaria
1. Trasfusion malaria
2. Congenital malraia
3. Malaria in drug addicts
Modes of malaria transmission
Man Female anopheles mosquito
Secondary host Primary host
Intermediate host Definitive host
Asexual cycle Sexual cycle
Schizogony Sporogony
Hosts involved in transmission of malaria
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, Shcizont, Merozoite
Parasitic multiplication brings clinical attack of malaria
Human cycle of plasmodium
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’
1. Completion of gametogomy
Exflagellation of microgamete and maturation of gametes
Fusion of gametes form Zygote; Zygote matures to Ookinite
2. Sporogony
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.
Mosquito cycle of plasmodium
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 malaria
Febrile paroxysms are characterized by high fever, sweats, and headache, as well as myalgia, back pain, abdominal pain, nausea, vomiting, diarrhea, pallor
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
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
Symptoms Signs lab
Fever Splenomegaly Anemia
Headache hepatomegaly Thrombocytopenia
Drowsiness Pallor Normal/ low TLC
Anorexia Elevated ESR
Nausea
Vomiting
Diarrhea
WHO has identified 10 complications of P. falciparum malaria that define severe malaria
1. Impaired consciousness 2. Prostration3. Multiple seizures4. Respiratory distress5. Pulmonary edema6. Jaundice7. Hemoglobinuria8. Abnormal bleeding9. Severe anemia10. Circulatory collapse
123 CNS45 RS6789 hematological10 CVS
Severe malaria
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 complications
P. falciparum -immature and mature erythrocytes
P. ovale and P. vivax - immature erythrocytes
P. malariae- only mature erythrocytes.
Parasite and RBCs
The diagnosis of malaria Giemsa-stained smears of peripheral blood or rapid immunochromatographic assay.
Stains used for diagnosisGiemsa 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 erythrocytes.
The thin smear allows for positive identification of the malaria speciesand determination of the percentage of infected erythrocytes and is useful in following the response to therapy
Diagnosis
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.
Diagnosis
viral infections such as influenza and hepatitis,
sepsis,
pneumonia,
meningitis, encephalitis,
endocarditis,
gastroenteritis,
pyelonephritis,
babesiosis, Brucellosis, leptospirosis,
tuberculosis,
relapsing fever,
typhoid fever,
yellow fever,
amebic liver abscess,
Hodgkin disease, and
collagen vascular disease
Differential diagnosis
Severe malarial anemia (hemoglobin < 5 g/dL) is the most common severe complication of malaria in children.
Anemia-
hemolysis
removal of infected erythrocytes by the spleen and
impairment of erythropoiesis
The primary treatment -blood transfusion.
Complications
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 –antimalarial medications Supportivetreatment of seizures and hypoglycemia.
Cerebral malaria
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. Nephroticsyndrome associated with P. malariae infection is poorly responsive to steroids.
Facts to remember
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.
ovale, or persistence within the erythrocyte -P. malariae, P. falciparum(rare).
Congenital malaria 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.
Terminology
Uncomplicated malaria
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
New malaria treatment guidelines in India
Initial treatment
Parenteral Artemisin derivatives (Artesunate, Artemether, Arteether) or
Parenteral Quinine
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
Complicated malaria
Malaria prevention consists of
Reducing exposure to infected mosquitoes and
Chemoprophylaxis
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 patients.
Prevention
Short term chemoprophylaxis (<6 weeks): Doxycycline(2 days before to 4 weeks after leaving area)
Long term chemoprophylaxis (> 6 weeks): Mefloquine (2 weeks before to 4 weeks after leaving area)
Chemoprophylaxis
Thank you