Malaria Quiz on Diagnosis and Complications

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Questions and Answers

Which of the following is NOT a chronic complication of malaria?

Cachexia

Hyperglycemia (correct)

Hepatomegaly

Tropical splenomegaly syndrome

What is the primary purpose of a thin blood film in malaria diagnosis?

To assess renal function

To demonstrate the presence of liver involvement

To identify the species and severity of infection (correct)

To evaluate the patient's immune response

In which type of malaria is fever expected to occur every 72 hours?

P. ovale

P. vivax

P. malariae (correct)

P. falciparum

Which of the following criteria defines severe malaria?

Cerebral malaria with severe anemia Signup and view all the answers

What is a limitation of the HRP-2 antigen test in diagnosing malaria?

It may remain positive after effective treatment Signup and view all the answers

What is the mortality rate of malaria for the individuals affected each year?

1% Signup and view all the answers

Which species of malaria is reported as the most common in African countries?

P.falciparum Signup and view all the answers

Which of the following factors contributes to 45% of female Anopheles mosquitoes being efficient for malaria transmission?

Efficiency of biting Signup and view all the answers

What is the duration of the complete malaria cycle from the liver to the red blood cells for P.vivax?

8 days Signup and view all the answers

Which mechanism describes the hypoglycemic effect during malaria infection?

Inhibition of gluconeogenesis due to liberated substances Signup and view all the answers

Which immunological factor is not associated with natural immunity to malaria?

Acquired T-cell activity Signup and view all the answers

What characterizes the asexual cycle of malaria in red blood cells?

Multiple asexual cycles followed by gametocyte formation Signup and view all the answers

What pathology primarily results from the sequestration of parasitized red blood cells in malaria?

Ischemia Signup and view all the answers

What is an indication of the severity of P. falciparum malaria?

More than 10% of parasitized RBCs contain more than one ring Signup and view all the answers

What is a major complication associated with cerebral malaria?

Disturbed consciousness and coma Signup and view all the answers

What characterizes the cold stage of classical malaria?

Marked vasoconstriction lasting 30 minutes to one hour Signup and view all the answers

What is the potential outcome of post malarial neurological syndrome in children?

Permanent hemiplegia and sensory loss Signup and view all the answers

Which of the following conditions is primarily associated with black water fever?

I/V hemolysis and rapid onset of multiple symptoms Signup and view all the answers

What symptom is least likely to occur during the hot stage of malaria?

Marked vasoconstriction Signup and view all the answers

What distinguishes the metabolic changes seen in malaria?

Acidosis due to parasitic lactate production Signup and view all the answers

Which stage of P. vivax and ovalae malaria typically has an incubation period ranging from 10 to 15 days?

Initial incubation period Signup and view all the answers

Study Notes

Malaria Epidemiology

40% of the global population lives in malaria-endemic areas.
Malaria affects approximately 270 million people annually, with a mortality rate of 1%.
This results in 1.27 to 2.7 million deaths yearly, predominantly within the 2-30 year age bracket in Africa.
P. falciparum is prevalent in most African countries, the Pacific Ocean, and Central South America.
P. vivax is found mainly in northern Africa.

Malaria Geographic Distribution

A map depicts malaria transmission areas globally.
Areas with limited malaria transmission or risk are also shown.
The majority of transmission clusters are shown in Africa.

Malaria Parasite Prevalence

P. ovale is endemic to West Africa.
P. malariae is uncommon outside of Africa.
In Sudan, P. falciparum is common, along with P. vivax and P. malariae, but not P. ovale.

Malaria Etiology

Malaria is caused by four species of Plasmodium.
P. falciparum causes malignant tertian malaria.
P. vivax and P. ovale cause benign tertian malaria.
P. malariae is associated with quartan malaria.

Malaria Transmission

Transmission occurs primarily through infected female Anopheles mosquitoes.
Approximately 45% of these mosquitoes are efficient vectors.
Key efficiency factors include longevity and biting efficiency.
Other transmission routes exist.

Malaria Life Cycle

The sexual cycle of Plasmodium occurs within mosquitoes (8-35 days).
The asexual cycle begins with the mosquito bite, which introduces sporozoites into the bloodstream.
Sporozoites infect the liver, releasing merozoites into the circulation.
Merozoites infect red blood cells (RBCs) initiating the erythrocytic cycle, producing more parasites.
Some merozoites develop into gametocytes in the RBCs to complete the cycle.
The cycle from liver to RBCs takes 5 days for P. falciparum, 8 for P. vivax, 9 for P. ovale, and 15 for P. malariae.

Malaria Erythrocytic Cycle

Infected RBCs release merozoites, initiating asexual cycles, and some mature into gametocytes.
P. falciparum infects all RBC types, particularly younger cells.
P. vivax & P. ovale mostly infect new RBCs.

Malaria Immunity

Natural immunity factors include sickle-cell trait, thalassemia, G6PD deficiency, Duffy antigen negativity, HLA antigen types and spleen versus splenectomy.
Acquired immunity results from macrophage stimulation by activated T lymphocytes.
Merozoite generation produces antigens different from previous ones resulting in antigenic variability.

Malaria Pathogenesis

Parasitized RBCs block vital organs (sequestration) leading to ischemia, hypoperfusion and anaerobic glycolysis.
Inflammatory cytokines (e.g., TNF, IL-1) release when merozoites rupture causing inhibition of gluconeogenesis and hypoglycemia.
Brain involvement can cause loss of consciousness due to elevated CSF lactate or neurotransmission interference.
Additional effects include kidney glomerulus blockage, lung edema, hemolytic anemia, dyserythropoiesis, and metabolic changes, including lactic acidosis.
Hypoglycemia can be caused by hepatic gluconeogenesis failure.
Malaria parasites increase glucose demand in patients with fever.

Malaria Clinical Picture

Incubation periods vary between 10-14 days (P. vivax, P. ovale) and 18 days to 6 weeks (P. falciparum) and up to 30-40 days ( P. malariae).
Prodromal symptoms include flu-like symptoms.
Classical malaria stages: cold (vasoconstiction), hot (vasodilation), and sweating stages.
Additional symptoms like herpes labials (oral herpes), enlarged spleen after day 10, tender liver, relative lymphocytosis, leucopenia.

P. falciparum Malaria Severity

P. falciparum is more serious due to broader cell infection.
It produces more parasites and greater tissue and RBC multiplication.
Severe cases present with ≥5% parasitized RBCs, >10% with multiple rings, and schizonts (parasite forms) in blood.

Malaria Complications

Cerebral malaria: includes disturbed consciousness, seizures, coma, papilledema, and cranial nerve palsies.
- 15% in children and 20% in adults
Convulsions: as a complication.
Post-malarial neurological syndrome: early symptoms may include hemiplegia and sensory loss; late symptoms may involve psychosis, encephalitis, and cerebellar ataxia.
GIT (Gastrointestinal) syndrome: heavy infiltration causing bilious remittent fever, dysenteric malaria.
Black water fever: rapid onset of fever, hemoglobinuria, jaundice, vomiting, and acute renal failure in non-immune individuals treated with quinine or primaquine.
Acute renal failure: an early symptom in patients with serious complications; renal failure can occur after malaria recovery.
Metabolic acidosis: a frequent finding.
Hypoglycemia: due partially to reduced hepatic gluconeogenesis capacity and increased glucose demands by fever and/or the parasites.
Pulmonary edema (often 80% in severe cases).

Malaria Diagnosis

Blood films (thin and thick smears) are critical for species identification and parasite density assessment.
Bone marrow examination can be more sensitive than blood smears.
Rapid diagnostic tests (RDTs) based on antibodies (antigen-antibody reactions) are also used.
- HRP-2 is detectable even after treatment.

Malaria Treatment and Prevention

Malaria management involves vector control, chemoprophylaxis, and treatment.
Classification of antimalarials is made based on how they affect the parasite's life stages.

Malaria Definition of Severity

Cerebral malaria, severe anemia, renal failure (including acute tubular necrosis), acute respiratory distress syndrome (ARDS).
Hypoglycemia, disseminated intravascular coagulation (DIC), and seizures ( ≥2).
Parasitemia level of 5-10% and potential acidemia
Jaundice as a symptom of possible severe complications.

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Description

Test your knowledge on malaria with this quiz focused on its diagnosis and chronic complications. Questions cover aspects such as blood films, species prevalence, and immunological factors related to malaria. Challenge yourself and learn more about one of the world's most significant infectious diseases.