In a block with a population of 40,000, 6,000 blood smears were examined during a year and 120 were positive for malaria parasites. The Annual Parasite Incidence (API) of this block is:
- A 0.3
- B 2.0
- C 3.0 ✓
- D 20.0
Correct answer: C. 3.0
Explanation
API equals the number of positive slides divided by the total population under surveillance, multiplied by 1000, giving 120 divided by 40,000 times 1000, which is 3.0. The figure 20.0 comes from wrongly using the number of smears examined as the denominator, and 2.0 results from dividing positives by smears examined directly. Under the National Framework for Malaria Elimination, an API of 1 to 2 places a district in Category 2.
Reference: Park's Textbook of Preventive and Social Medicine, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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