How many mosquito nets are needed to maintain universal coverage: an update.

Area of Science:

• Global health
• Vector control
• Epidemiology

Background:

• Insecticide-treated nets (ITNs) are crucial for malaria vector control in sub-Saharan Africa.
• Current ITN distribution relies on mass campaigns every three years, but net retention is often less than two years.
• This discrepancy challenges effective malaria control strategies and quantification methods.

Purpose of the Study:

• To model various ITN quantification approaches and distribution strategies.
• To estimate population access to ITNs under different scenarios.
• To recommend optimal quantification and distribution methods to meet global malaria control targets.

Main Methods:

• A stock and flow model with annual timesteps was employed for ITN distribution modeling (2020-2035).
• Five distribution scenarios were analyzed across 40 countries, including mass campaigns and continuous distribution.
• All scenarios incorporated ITN distribution to pregnant women and infants.

Main Results:

• Triennial mass campaigns with current quantifiers fail to achieve 80% ITN access due to short net retention times.
• Annual continuous distribution proved more efficient than tailored mass campaigns in most settings.
• Continuous distribution required 20-23% fewer ITNs than mass campaigns in countries with ≥2.5-year median ITN retention.

Conclusions:

• Tailored quantification and distribution strategies are necessary due to varying ITN retention times.
• Continuous distribution offers a more efficient method for maintaining ITN coverage with fewer resources when retention is ≥2.5 years.
• Efforts should focus on increasing ITN availability to vulnerable populations and extending net lifespan.