Paper II — 2019 July (Supplementary) (2010 Scheme) — Q1
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Paper II
2019 July (Supplementary) (2010 Scheme) · 40 marks · 120 min
Question
A 52 years old man presents with the complaints of intermittent high fever, rigors and
headache for the past 6 days. He gives a history of fever on alternate days and on
examination has hepatosplenomegaly. Answer the following.
What is the diagnosis of this condition
List the species of the causative agent
Name the definitive and intermediate hosts
Discuss the laboratory diagnosis of this condition
Enumerate the important preventive measures to prevent this disease
(1+2+1+4+2)
Q110 marksEssays
Answer
Diagnosis: Malaria — intermittent high fever with rigors on alternate days, headache, and hepatosplenomegaly over 6 days is classical (the alternate-day pattern suggesting tertian malaria — P. vivax or P. falciparum).
Species of causative agent: Plasmodium vivax, Plasmodium falciparum, Plasmodium malariae, and Plasmodium ovale (with P. knowlesi an additional zoonotic species in some regions).
Peripheral blood smear microscopy — gold standard; thick smear for screening, thin smear for species identification and parasitaemia quantification (Giemsa stain), ideally taken during/soon after a febrile episode.
Rapid diagnostic tests (RDTs) — immunochromatographic detection of parasite antigens (HRP-2 for P. falciparum; pLDH/aldolase for pan-species detection).
QBC (Quantitative Buffy Coat) method — fluorescence-based concentration technique, more sensitive but does not allow precise species identification.
PCR — highly sensitive/specific, useful for detecting low-level/mixed infections.
Serology — detects past exposure, not useful for diagnosing acute infection.
Preventive measures
Vector control (insecticide-treated bed nets, indoor residual spraying, source reduction of mosquito breeding sites); personal protective measures (mosquito repellents, protective clothing); chemoprophylaxis for travellers to endemic areas; prompt diagnosis and treatment of cases to reduce the infectious reservoir; and health education/community awareness programmes.
