Download Cholera Definition

Malaria
Dept. of Infectious Disease
Shengjing Hospital
CMU
Definition
 Malaria is a parasitosis caused by plasmodia.
 It is transmitted to human by the mosquito.
 Clinical feature: cyclic chill, high fever &
profuse sweating. In chronic illness, there are
anemia & splenomegaly.
Etiology
 Causative organism: Plasmodia
 P. Vivax: tertian malaria
 P. Malariae: quartan malaria
 P. Falciparum: malignant malaria
 P. Ovale: tertian malaria
 Pathogenicity: merozoite, malarial pigment &
products of metabolism
Etiology
Tachysporozoite
Bradysporozoite
Merozoite
Sporozoite
Parasitemia
Etiology
Two periods:
 human - whole asexual reproduction
 mosquito - sexual parasitic stage
Two hosts:
 human - intermediate host
 mosquito - final host
notes:
 clinical symptoms: erythrocytic stage
 relapse: exerythrocytic stage
 infectivity: sporozoite
Life cycle of the malaria parasite
zygote
oocyst
sporozoite
microgametocyte
Blood stream
gametocyte
tachysporozoite
Bradysporozoite
mature
mosquito
rupture
merozoite
merozoite
mature
release
reenter
human
shizont
merozoite
trophzoite
Blood stream
phagocyte
Exoerythrocytic stage
Erythrocytic phase
Epidemiology
 Source of infection
Patient, parasite carrier
 Route of transmission
 female mosquito biting person
 blood transfusion
 Susceptibility:
 universal susceptibility
 no-cross-immunity
 re-infection
 Epidemic features:
 sporadic or endemic, tropic or subtropic
Pathogenesis
 Mechanism of attack
merozoite
RBC rupture
malaria pigment
products of metabolism
blood stream
allergy
 P. Faciparam: produce microvascular disease
 magnitude of the parasitemia & age of patient
 no specific Ab or cell -mediated response
Pathology
 Anemia:
 P. Vivax - retiform RBC
 P. Malariae - mature RBC
 P. Falciparum - every RBC
 Prolifeation of mononuclear phagocyte
 hepatomegaly
 splenomegaly
 Cerebral edema & congestion
Clinical manifestation
Incubation period:
quartan malaria: 24-30 day
tertian malaria: 13~15 day
malignant malaria: 7~12 day
Clinical manifestation
Typical attack
 Chill: abrupt onset, shivering, pale face,cyanosis.
Last 10 min or 1~2hr.
 High fever: T rise to 40oC with malaise, myalgia,
thirsty. Last 2~6 hr.
 Sweating: profuse sweating with restlessness
 regular 48 hr. or 72 hr. Cycle
Clinical manifestation
Sings
 anemia
 splenomegaly
 hepatomegaly, ALT elevate
Clinical manifestation
Pernicious attack: caused by P. Falciparum
 cerebral malaria
high fever, headache, vomiting,
delirium, respiratory failure
 hyperpyrexia type
T> 420C, convulsion, delirium
 Relapse: early relapse - <3m,
later relapse - >6m
convulsion
Clinical manifestation
Malaria caused by transfusion
 incubation period: 7~10 day
 no exoerythrogenic phase, no relapse
Complications
 Black- water- fever:

cause:1/inadequate G-6-PD

2/The toxin release by malarial parasite
3/Allergic reaction to anti-malarial drugs
feature:1/chill & fever
2/dark red or black urine
3/severe hemolytic anemia
 Acute glomerulonephritis
Laboratory Findings
 Blood picture: decrease in RBC & Hb
 blood film for parasite
 serological examination

ELISA for P. antigen
 DNA hybridization
Diagnosis
Epidemiological data


endemic zone
blood transfusion
Clinical manifestation
Laboratory findings
Diagnostic treatment:

chloroqunine for 3 days
Differential Diagnosis
Typhoid fever
Septicemia
Leptospirosis
Encephalitis B
Treatment
Anti-malarial drugs
Chloroquine-susceptable infection


chloroquine : 1g /d, for 3 day, p.o.
primaquine: for 8day, p.o.
Chloroquine-resistant infection


mefloguine:
artemisinine
Treatment
Pernicious attack
 Chloroquine: 10mg/kg iv drop in 4 hr. Then 5mg/kg,
iv drop in 2 hr.
 Quinine: 500mg iv drop in 4 hr.
 Radical therapy
Chloroquine (3 day) + primaquine ( 8 day )
Prevention
Drug prophylaxis
 chloroquine: 0.3g once a week
 doxycycline
 Kill mosquito
 Vaccination