MCQ – 100290

Which of the following is the most sensitive indicator for surveillance of recent malaria transmission in a community?

Correct Answer » C Explanation

Surveillance in malaria involves tracking the extent and intensity of transmission in a population. Several indices are used for this purpose, but sensitivity refers to how early and reliably the indicator can detect the presence of transmission.

Infant Parasite Rate (IPR):

• Defined as the percentage of infants (under 1 year of age) who test positive for malaria parasites.

• It reflects recent transmission, since infants would only acquire the infection recently (no long-term exposure).

• Hence, it is considered the most sensitive index for ongoing or new malaria transmission in an area.

Reasons to Rule Out Other Options:

A. Spleen rate

• Measures proportion of children (2–10 years) with enlarged spleens.

• Useful for endemicity classification, but less sensitive for current or recent transmission.

B. Parasite density index

• Measures parasite load in positive individuals.

• Indicates severity, not necessarily transmission dynamics.

D. Proportional case rate

• Refers to the proportion of malaria cases out of all reported illnesses.

• Less specific and not as sensitive for detecting fresh transmission.