Podcast
Questions and Answers
What characteristic distinguishes the ring-form trophozoite of P.ovale from that of P.vivax?
What characteristic distinguishes the ring-form trophozoite of P.ovale from that of P.vivax?
Which of the following statements about P.knowlesi is accurate regarding its ring-form trophozoites?
Which of the following statements about P.knowlesi is accurate regarding its ring-form trophozoites?
What is a common feature of red blood cells infected by P.ovale?
What is a common feature of red blood cells infected by P.ovale?
Which of the following best describes the appearance of ring-form trophozoites in P.knowlesi?
Which of the following best describes the appearance of ring-form trophozoites in P.knowlesi?
Signup and view all the answers
How can one differentiate between different types of malarial trophozoites?
How can one differentiate between different types of malarial trophozoites?
Signup and view all the answers
What is the main advantage of Real-time PCR over traditional PCR methods?
What is the main advantage of Real-time PCR over traditional PCR methods?
Signup and view all the answers
Which statement correctly describes the method of Nested PCR?
Which statement correctly describes the method of Nested PCR?
Signup and view all the answers
What is the purpose of using antimalarial drugs in the treatment of malaria?
What is the purpose of using antimalarial drugs in the treatment of malaria?
Signup and view all the answers
What feature is unique to the LAMP method of DNA amplification?
What feature is unique to the LAMP method of DNA amplification?
Signup and view all the answers
What factor does not influence the choice of antimalarial drugs?
What factor does not influence the choice of antimalarial drugs?
Signup and view all the answers
What is the most severe complication of malaria?
What is the most severe complication of malaria?
Signup and view all the answers
Which mechanism contributes to the development of cerebral malaria?
Which mechanism contributes to the development of cerebral malaria?
Signup and view all the answers
What role does the protein secreted by late-stage schizonts of P.falciparum play in malaria complications?
What role does the protein secreted by late-stage schizonts of P.falciparum play in malaria complications?
Signup and view all the answers
What is a common outcome of the obstruction caused by sequestrated RBCs in the brain?
What is a common outcome of the obstruction caused by sequestrated RBCs in the brain?
Signup and view all the answers
What symptom is NOT typically associated with cerebral malaria?
What symptom is NOT typically associated with cerebral malaria?
Signup and view all the answers
How does hemolytic anemia occur in the context of malaria?
How does hemolytic anemia occur in the context of malaria?
Signup and view all the answers
What type of inflammation is notably involved in the complications seen with P.falciparum?
What type of inflammation is notably involved in the complications seen with P.falciparum?
Signup and view all the answers
What is a potential result of endothelial dysfunction due to malaria infection?
What is a potential result of endothelial dysfunction due to malaria infection?
Signup and view all the answers
What is the primary aim of supportive treatment for patients?
What is the primary aim of supportive treatment for patients?
Signup and view all the answers
Which type of drug acts on tissue schizonts to prevent symptomatic malaria?
Which type of drug acts on tissue schizonts to prevent symptomatic malaria?
Signup and view all the answers
What is the significance of artemisinin-based combination therapy (ACT) in malaria treatment?
What is the significance of artemisinin-based combination therapy (ACT) in malaria treatment?
Signup and view all the answers
Which drug is commonly used as the first-line treatment for P.vivax infections?
Which drug is commonly used as the first-line treatment for P.vivax infections?
Signup and view all the answers
What is the role of primaquine in the treatment of malaria?
What is the role of primaquine in the treatment of malaria?
Signup and view all the answers
What characteristic does Chloroquine have that poses problems in treatment?
What characteristic does Chloroquine have that poses problems in treatment?
Signup and view all the answers
Which of the following drugs is derived from the Cinchona plant?
Which of the following drugs is derived from the Cinchona plant?
Signup and view all the answers
Which drug is effective against multi-resistant strains of P.falciparum?
Which drug is effective against multi-resistant strains of P.falciparum?
Signup and view all the answers
What is NOT one of the four principles of malaria prevention and control according to the WHO's ABCD guidelines?
What is NOT one of the four principles of malaria prevention and control according to the WHO's ABCD guidelines?
Signup and view all the answers
Which of the following medications is commonly used for prophylaxis in endemic areas?
Which of the following medications is commonly used for prophylaxis in endemic areas?
Signup and view all the answers
How can standing water help in the transmission of malaria?
How can standing water help in the transmission of malaria?
Signup and view all the answers
Which method of personal protection is NOT recommended for preventing malaria?
Which method of personal protection is NOT recommended for preventing malaria?
Signup and view all the answers
What is the main goal of vector control in malaria management?
What is the main goal of vector control in malaria management?
Signup and view all the answers
What is the shape of the infected red blood cells for Plasmodium vivax?
What is the shape of the infected red blood cells for Plasmodium vivax?
Signup and view all the answers
Which type of stippling is observed in Plasmodium ovale infected red blood cells?
Which type of stippling is observed in Plasmodium ovale infected red blood cells?
Signup and view all the answers
What is a distinguishing feature of the mature schizont of Plasmodium falciparum?
What is a distinguishing feature of the mature schizont of Plasmodium falciparum?
Signup and view all the answers
What type of gametocyte shape is associated with Plasmodium falciparum?
What type of gametocyte shape is associated with Plasmodium falciparum?
Signup and view all the answers
Which species has indecipherable chromatin features due to its averaging?
Which species has indecipherable chromatin features due to its averaging?
Signup and view all the answers
How many merozoites are typically found in the mature schizont of Plasmodium malariae?
How many merozoites are typically found in the mature schizont of Plasmodium malariae?
Signup and view all the answers
Which stippling feature can be seen in Plasmodium knowlesi infected red blood cells?
Which stippling feature can be seen in Plasmodium knowlesi infected red blood cells?
Signup and view all the answers
What characteristic feature helps distinguish Plasmodium falciparum trophozoites?
What characteristic feature helps distinguish Plasmodium falciparum trophozoites?
Signup and view all the answers
Study Notes
Malaria Overview
- Malaria is a disease caused by protozoan parasites of the Plasmodium genus
- The disease is transmitted to humans through the bite of infected female Anopheles mosquitoes.
- The presentation of the disease includes a range of symptoms and complications.
- The severity and outcome of malaria vary depending on the parasite species, the patient's immune status, and timely treatment.
- The most common species of Plasmodium are falciparum, vivax, ovale, malariae, and knowlesi.
Lecture Outline
- The lecture covers laboratory diagnosis (microscopy and molecular techniques),
- Complications of malaria, including cerebral malaria and hemolytic anemia,
- Prevention and control of malaria,
- Treatment for malaria.
Malaria Complications
-
Cerebral malaria: Most severe, causing fatal complications, headache, neck stiffness, disorientation, coma, death.
- A multi-factorial process involving sequestration, inflammation, and endothelial dysfunction.
- Late stage schizonts produce adhesive proteins, causing infected red blood cells (RBCs) to clump in the brain's microvasculature. This obstructs blood flow, leading to anoxia, ischemia, and hemorrhage, causing cerebral malaria.
-
Hemolytic anemia: Destruction of a large number of RBCs by complement-mediated or autoimmune hemolysis, and suppression of erythropoiesis in bone marrow.
- Increased clearance of parasitized and non-parasitized RBCs by the spleen.
- Failure of the host to recycle iron bound in hemozoin pigment.
- Antimalarial therapy in G6PD deficient patients
-
Blackwater fever: Seen in falciparum malaria in patients with repeated infections or inadequate treatment with quinine. Symptoms include:
- Bilious vomiting and prostration
- Passage of dark red or blackish urine (blackwater)
- Pathogenesis involves massive intravascular hemolysis caused by anti-erythrocyte antibodies.
- Complications include renal failure, acute liver failure, and circulatory collapse.
-
Gastrointestinal syndrome Symptoms include jaundice, hepatomegaly epigastric pain, nausea, vomiting, diarrhea.
-
Algid malaria: Adrenal insufficiency-like syndrome. Low blood pressure, rapid pulse, difficulty in breathing, hemoconcentration.
-
Hypoglycemia: Especially during pregnancy, leading to neurological problems like restlessness, dyspnea, convulsions, and loss of consciousness.
- A result of liver glycogen depletion due to reduced oral intake, glucose consumption by the parasite, and hypoglycemic effect of TNF.
-
Pulmonary edema (PO): Increased level of TNF can lead to PO, sometimes due to over-infusion
-
Acute renal failure (ARF): Severe case. Due to tubular necrosis
-
Septicemic malaria: High continuous fever, parasite dissemination to various organs, leading to multi-organ failure; often resulting in high fatality rates (80% of cases).
Other Plasmodium species complications
-
P. vivax and P. ovale: May develop serious disease, but complications are rare.
- Main complication is nephrotic syndrome due to immune complex causing glomerular damage.
-
P. malariae: Mild infection, but can become chronic.
- Main complication is nephrotic syndrome due to immune complex causing glomerular damage.
P. knowlesi complications
- Single or multi-system failure. Presenting symptoms:
- Acute respiratory distress syndrome
- Acute renal failure
- Hepatic dysfunction
- Metabolic acidosis
- Hypoglycemia
- Hypotension
- Thrombocytopenia/lymphopenia
Recrudescence and Relapse
-
Recrudescence: Seen in P. falciparum and P. malariae, due to parasite persistence at subclinical levels. Occurs within weeks/months of a previous attack. Treatment with drugs or new antimalarials can prevent it.
-
Relapse: Seen in P. vivax and P. ovale. Due to reactivation of hypnozoites in liver cells. Occurs 24 weeks to 5 years after the primary attack. Primaquine can prevent it.
Laboratory Diagnosis
- History and symptoms from the patient
- Laboratory investigations (blood films) confirm diagnosis.
- Blood smears are stained to distinguish the cytoplasm from the nuclear chromatin.
- Two types of blood films are used: thin and thick films.
Investigating Suspected Malaria
- Blood Film for Malaria Parasite (BFMP): Done immediately, repeat if negative; crucial for initial diagnosis.
- Full Blood Count (FBC): In falciparum malaria, WBC count is typically normal but often shows relative lymphopenia. Neutrophilia may suggest a secondary bacterial infection. Thrombocytopenia is common (in over 90% of Plasmodium non-immune patients).
- Blood Urea & Serum Electrolytes (BUSE): May indicate low levels of sodium, calcium, and albumin.
- CRP level: Typically elevated in malaria.
- Liver profile: Bilirubin sometimes elevated as a result of hemolysis. Liver enzymes may be elevated, but should be assessed in the context of normal liver function when evaluating possible viral hepatitis as a contributing factor.
- Blood glucose: May be low in severe cases with high parasitaemia or during quinine treatment in adults.
Parasite Identification
- Size of infected RBC: Only in P. vivax infections, RBCs become enlarged.
- Shape of infected RBC: Oval shape in P. ovale infections.
- Shape of gametocyte: Banana or crescent shape in P. falciparum infections; round in other infections.
- Shape of trophozoite: Band form in P. malariae and P. knowlesi; ring form in other infections.
Other Diagnostic Methods
-
Serodiagnosis: Useful for epidemiological studies and identifying infected donors for blood transfusion, but not useful in acute cases (since antibodies may not be present yet). Uses indirect hemagglutination (IHA), indirect fluorescent antibody (IFA), and enzyme-linked immunosorbent assay (ELISA)
-
Rapid diagnostic tests (RDTs): Based on antigen detection. Can aid diagnosis but are not a substitute for microscopy and must be interpreted with the microscopy results. Can be important in areas with limited expertise and during non-peak hours.
-
Molecular diagnosis (PCR): Primarily for confirmation and species determination when standard microscopy isn't conclusive, e.g., in cases with clinical symptoms, but no parasite seen, in mortality cases, or cases with P. malariae characteristics. Uses whole blood samples where available.
Treatments for Malaria
-
Specific treatment: Use of antimalarial drugs to eliminate parasitaemia, prevent relapse, recurrence, and transmission, and for prophylaxis.
- Drug choice depends on patient location, types of infection, and drug resistance. Drug resistance is a significant problem.
-
Supportive treatment: Focused on relieving patient symptoms, e.g., high temperature, managing dehydration, blood replacement in severe anemia cases, controlling convulsions, treatment of DIC with fresh frozen plasma or plasma-rich platelets.
-
Anti-malarial drugs:
- Drugs targeting tissue schizont are tissue schizonticides.
- Drugs targeting blood schizont are blood schizonticides.
- Drugs acting on gametocytes are gametocidal agents.
-
Treatment regimens:
- Specific combinations are recommended depending on the Plasmodium species, and risk factors, such as pregnancy or drug resistance, as laid out in treatment tables.
Prevention of Malaria
- Awareness, Bite prevention: Understanding risk factors, avoiding mosquito bites (especially during dusk and dawn), using mosquito repellant, and wearing protective clothing.
- Chemoprophylaxis: Taking antimalarial drugs when appropriate.
- Diagnosis: Seeking immediate testing and treatment in cases of suspected malaria.
- Vector control: Eliminating mosquito breeding areas, using insecticide sprays, and installing protective screens.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
