Under National Vector Borne Diseases Control Programme, operational efficiency of antimalarial measures is assessed by-
**Core Concept**
The National Vector Borne Diseases Control Programme (NVBDCP) is a government initiative aimed at controlling and preventing vector-borne diseases, including malaria. The operational efficiency of antimalarial measures is a critical aspect of this program, which involves assessing the effectiveness of interventions in reducing malaria transmission.
**Why the Correct Answer is Right**
The correct answer is **Entomological Inoculation Rate (EIR)**. EIR is a key indicator used to assess the operational efficiency of antimalarial measures. It measures the number of infectious mosquito bites per person per unit time, reflecting the intensity of malaria transmission. EIR is calculated by multiplying the number of infective mosquitoes per unit area by the human biting rate. This indicator helps in evaluating the effectiveness of interventions, such as vector control measures, and in identifying areas where additional efforts are needed.
**Why Each Wrong Option is Incorrect**
**Option A:** Case fatality rate (CFR) is a measure of the proportion of deaths among confirmed cases, which is not directly related to the operational efficiency of antimalarial measures.
**Option B:** Annual Parasite Incidence (API) is a measure of the number of confirmed malaria cases per 1000 population per year, which does not account for the intensity of transmission.
**Option C:** Malaria prevalence is a measure of the proportion of the population infected with malaria, which does not provide information on the operational efficiency of antimalarial measures.
**Clinical Pearl / High-Yield Fact**
EIR is a critical indicator for assessing the operational efficiency of antimalarial measures, and a reduction in EIR is a key indicator of successful vector control interventions.
**Correct Answer: D. Entomological Inoculation Rate (EIR)**