Health worker must visit all houses in his area to check for malaria case:-
**Core Concept**
Malaria control requires a comprehensive approach, including active surveillance and case detection. The strategy of visiting all houses in an area is known as **house-to-house survey** or **door-to-door survey**, which is an essential component of malaria elimination programs.
**Why the Correct Answer is Right**
A house-to-house survey involves visiting every household in a defined area to search for suspected malaria cases. This approach helps in early detection, prompt treatment, and prevention of malaria transmission. The strategy relies on the active participation of health workers, who conduct thorough searches, collect information, and provide education on malaria prevention and control measures.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the strategy or approach for malaria case detection.
**Option B:** This option is incorrect because it does not describe a specific method for identifying malaria cases in a community.
**Option C:** This option is incorrect because it does not provide a comprehensive approach to malaria case detection, which involves more than just visiting a few selected houses.
**Clinical Pearl / High-Yield Fact**
Active surveillance and case detection through house-to-house surveys are critical components of malaria elimination programs. This approach helps in reducing malaria transmission, preventing outbreaks, and ultimately achieving malaria-free status.
**Correct Answer: A. House-to-house survey.**