Laboratory Diagnosis of Malaria

Laboratory diagnosis of Malaria 4/3/2021 Laboratory Findings After getting History from patient , Then sample should be taken after Paroxysm(febrile)or fever If was negative repeated after6-48 hr Normochromic, Normocytic Anemia is usual WBC count is generally normal, although it may be raised in very severe infections Monocytosis, Lymphopenia, and Eosinopenia, with reactive Lymphocytosis and Eosinophilia in the weeks after the acute infection ESR,CRP High Severe infections may be accompanied by prolonged PT and partial thromboplastin times and by more severe Thrombocytopenia Fibrinogen,IgM,IgG, Potassium K, TNF ,Globulin are Higher than normal,especially IgM increase is important. Platelet ,Tcell less than normal proteinuria, hemoglobinuria Blood sugar, haemoglobin and creatinine and parasitemia tests must be checked every 6 hours 4/3/2021 The diagnosis of malaria may in fact into two ways : Direct diagnosis: direct demonstration of the parasite whole cell or of parasite’s nucleic acid or products in the blood Indirect Diagnosis: the demonstration of the patient’s immune response to the infection (immunodiagnosis). (A) Light microscopic observation - Sample preparation 1- thin film observation of malaria parasites is optimal when parasites are fixed and observed in their natural location within red blood cells after appropriate staining. This is best accomplished with the thin film preparation technique. Unfortunately, thin film has a low sensitivity and is thus inadequate for low parasitaemic infection. 2- thick film An adequate parasite concentration method is obtained by osmotic lysis of the red blood cells releasing the parasites, as is the case with the thick film preparation technique, the sensitivity is more than thin film. 4/3/2021 - Field staining procedure. Field staining is a good method to stain thick films but is not suitable for thin films. However, it has the remarkable advantage to be extremely quick (the smear may be stained in 1 minute). - Leishman staining procedure. Since Leishman staining solution uses methanol as a solvent, this method is only useful to stain thin films. 4/3/2021 (B ) Quantitative Buffy Coat (QBC ®) and the direct acridine orange staining Is a sensitive microscopic test based on the ability of acridine orange to stain nucleic acid containing cells A direct acridine orange (fluorochrome) staining This method recently proposed of thin and thick film to provide an economically convenient alternative to the QBC ® technique for use in the field by using specially designed interference filters that may be connected to conventional light (even sunlight) microscopes • (C) DNA probes and Polymerase Chain Reaction, Polymerase chain reaction (PCR) • -determine the species of plasmodium 4/3/2021 2- Indirect diagnosis (immunodiagnosis) Detection of Plasmodia specific antibodies by: 1-Immunofluorescene (IFAT),ELIZA,.. 2- Indirect haemoagglutination test (IHA) 3- Radioimmunoassay (RIA) 4/3/2021 Medical intervention: Examine blood under microscope (geimsa stain) chest x-ray: helpful if respiratory symptoms are present CT scan: to evaluate evidence of cerebral edema or hemorrhage 4/3/2021 Dipstick test - not as effective when parasite levels are below 100 parasites/mL of blood RAPID DIAGNOSTIC TESTS 4/3/2021 Clinical presentation • Varies in severity and course • Parasite factors – Species and strain of parasite – Geographic origin of parasite – Size of inoculum of parasite • Host factors – – – – Age Immune status General health condition and nutritional status Chemoprophylaxis or chemotherapy use • Mode of transmission – Mosquito – Bloodborne, no hepatic phase (transplacental, needlestick, transfusion, organ donation/transplant) 4/3/2021 Treatment drug resistance ( mortality) Chloroquine (Gold standard treatment for All kinds of malaria ) Very few areas now have chloroquinesensitive P. falciparum 4/3/2021 Radical Treatment Vivax or Ovale Primaquine to prevent relapse and . mild G6PD deficiency, Not be given in severe G6PD deficiency should not be given pregnancy 4/3/2021 Falciparum Artesunatec + ، Fancidar(Sulfadoxine+Pyrimethamine )as a single dose or Artesunatec + Amodiaquine 4/3/2021 Multidrug-resistant Falciparum Artemether-Lumefantrinec Artesunate + Mefloquine Artesunatec or Quinine Tetracycline Doxycycline Clindamycin or Atovaquone-Proguanil Quinine and quinidine 4/3/2021 Treatment Uncomplicated, P. Falciparum Chloroquine chloroquine sensitive P. Ovale and P. Vivax Uncomplicated P. Falciparum, chloroquine resistant Complicated/Severe P. Falciparum 4/3/2021 Chloroquine + PRIMAQUINE G6PD screen Quinine Sulfate + doxycycline or atovaquone + proguanil Quinidine gluconate IV, exchange transfusion if >15% 4/3/2021 Chemoprophylaxis Drug Chloroquine Phosphate Mefloquine Doxycycline Adult dose 500 mg q weekly retinopathy 1-2 weeks before travel, continue 4 weeks after leaving malarious area 250 q week 1-2 wks before travel 4 wks after leaving area 100 mg q day 250/100 mg q day 1-2 days before and Atovaquone plus proguanil continue 7 days after leaving area 4/3/2021 precaution Cardiac conduction Psychiatric dis Less 8 yrs pregnancy Pregnancy category C Chemoprophylaxis (used one or two weeks before traveling to malarial areas and about one month after trip is continues Under the supervision of an infectious specialist Chloroquine phosphate Atovaquone-Proguanil (Malarone) Doxycycline Mefloquine 4/3/2021 Endemicity(TSS, tropical splenomegaly syndrome or Malaria) is measured by two factors: 1.Parasitemia rates and 2.palpable-Spleen rates in children (2–9 years)and Getting blood from your fingertips Hypoendemic (<10%) Mesoendemic (11–50%) Hyperendemic (51–75%) Holoendemic (>75%) 4/3/2021