Home NATNETS Catch Up versus Keep Up

Catch Up versus Keep Up

Two terms are regularly used when talking about LLIN distribution: “Catch Up” and “Keep Up”.


The former refers to the rapid attainment of universal coverage (“Catch Up”), usually by the implementation of mass campaigns which rapidly scale up net ownership and usage. The latter refers to the maintenance of universal coverage thereafter (“Keep Up”).

Ideally, universal coverage is best maintained by a complementary continuous distribution channels. Both experience and modeling show that coverage begins to decline almost immediately after the conclusion of a campaign as new sleeping spaces are created and nets start to wear out and require replacement. Hence, mechanisms of "keep-up" must also be established with 9 -12 months after the completion of campaigns, before coverage drops.

Catch Up versus Keep Up

Keep Up Campaigns can be demand-driven, for example through a voucher scheme providing subsidized LLINs to people if and when they need it. Keep Up can also be supply driven, for example the School Net Programme which pushes nets to communities based on estimated number of nets needed each year.

According to the mathematical modelling approximately 7 million nets are needed annually to maintain universal coverage in Tanzania. This amount increases to 7.8 million by 2020. A combination approach of TNVS and a school-based net distribution programme has been assessed to be the most cost-effective and efficient keep-up strategy for Tanzania in the current situation. The TNVS is a tried and tested programme. By expanding the distribution point from clinics to schools, the TNVS and the School Net Distribution Model combined will reach 85% of the population. This model has the lowest cost per net delivered and the least number of excess nets. It also ensures continuity across geographical areas and over time. The strength of the model lays in the combination of the two distribution approaches, with the TNVS providing 30% of the LLIN to pregnant women and children under 5 years, a key target group that cannot be reached through school-distribution.