protozoa of humans

Class sporozoaGenus Plasmodium

P.vivax---- Benign tertian malaria P.malariae--- Quartan malaria P.falciparum---Malignant tertian Subtertian malaria P.ovale----- ovale tertian Benign tertian malaria

P vivax Mature schizont

P vivax Trphozoites

P vivax trophozoite

P malariae

P malariae

P falciparum (rings & gametocyte)

P falciparum

P Ovale

Life cycle

Vertebrate host---asexual cycle---schizogony Invertebrate host---sexual cycle---sporogony


Prepatent period Incubation period Latent malaria Relapse Recrudescence

Pathology

Anemia & tissue anoxia Anemia: Destruction of RBC by the parasite Haemolysis of non infected RBC(Autoimmune process) Hypersplenism Bone marrow depression Increase RBC fragility

Tissue anoxia

Congestion Reduced blood flow Stasis of blood Thrombi Obstruction of small blood vessels Petechial hemorhages Anoxia of the affected organ

Complications

Cerebral malaria Hyperpyrexia Gastrointestinal Algid malaria Black water fever Renal complications Tropical spleenomegaly

Cerebral malariaHyperpyrexiaGastrointestinal complicationsAlgid malaria

Parasitemia is high > 5% Multiple infection in the RBC is common Trophozoits &schizonts appear in the peripheral blood

Epidemiology

Prevalence: Reservoir Transmission Endemicity study

Transmission

Bite of female anophiline mosquito Blood transfusion,Contaminated syringes Across the placenta(placental defect)

Endemicity study

Statistical data for morbidity &mortality Splenic index Parasite index Mosquito density & infection rate Environmental factors affect the transmission

Splenic index

Holo endemic Hyper endemic Mesoendemic Hypoendemic

Environmental factors

Climate Socio-economic state of the population

Immunity

Innate resistance(natural immunity: Black people immune to P vivax Sickle Hb Trait immune to P falciparum G6 PD deficiency of RBC limits parasitemia especially to P falciparum

Acquired immunity

Stimulated by erythrocytic parasites Immunity is specific for spices & strain

Premunition

Diagnosis
History Clinical signs Blood films: Thick film Thin film Sero-dignosis

Treatment

General measures Chemotherapy

Drugs acting on asexual erythrocytic parasites(Schizontocides)

Quinine 4 aminoquinolene: Chloroquine Nivaquine Amodiaquine Mefloquine Mepacrin Proguanil Pyrimethamine Sulphonamide & sulphones(in combination with other drugs

Drugs acting on tissue forms

Proguanil & pyrimethamin 8 aminoquinolene( primaquine),has gametocidal activity

Treatment of all uncomplicated attacks except resistant P falciparum

Chloroquine phosphate orally: day one : 1 Gm 0.5 Gm after 6 hours day two ; 0.5 Gm day three; 0. 5 Gm In P falciparum If no response = Drug Resistance In P vivax & Ovale: destroy hypnozoites in the liver Primaquine phosphate(15 mg /orally /day for 14 day

Treatment of severe illnessexcept resistant P falciparum

Chloroquine hydrochloride I.M until oral therapy is possible

Treatment of P falciparum resistant to Chloroquine

Combined therapy: Quinine sulphate Pyrimethamine Sulfadiazine