Name two metrics used to assess impact of vector control programs on malaria transmission.

• A. Entomological inoculation rate (EIR) and vector density reduction.
• B. Human landing rate and rainfall.
• C. Blood meal analysis and parity rate.
• D. Mosquito reproduction rate and wing length.

Answer: (A)

The key idea is identifying measures that link mosquito populations to the risk of people getting infected. The two most informative metrics are the Entomological Inoculation Rate (EIR) and a reduction in vector density.

EIR combines how often people are bitten by mosquitoes with how many of those mosquitoes carry the malaria parasite. It directly reflects the amount of transmission occurring in a community because it estimates the rate at which infectious bites reach people. If a vector control program lowers either the rate of bites or the fraction of infectious mosquitoes, the EIR drops, signaling reduced transmission risk.

Reducing vector density is the other essential metric because fewer mosquitoes mean fewer opportunities for transmission. By measuring how many mosquitoes are present after interventions (adult traps, larval indices, etc.), you can gauge how much the population was suppressed and how that suppression is likely to affect transmission potential.

Other metrics describe biting exposure, feeding behavior, age structure, or basic biology, but they don’t tie directly to how much transmission is occurring. For example, human landing rate tells you exposure risk but not whether mosquitoes are infectious; rainfall, blood meal analysis, parity, wing length, and reproduction rate provide valuable biology context but don’t directly quantify transmission impact.