10/3/2012 1:30:00 PM

LLIN wash resistance recognized as a key factor in effective lifespan.

The insecticidal efficacy of long-lasting insecticide treated nets (LLINs) is an essential part of malaria control, ensuring mosquitoes cannot transmit the disease through the net. For LLINs to remain effective, the insecticide they contain must be able to withstand repeated washing – at least 20 washes, according to minimum WHOPES standards.
Because individual users take care of their nets in different ways, the frequency of washing can vary significantly (the 20 washes indicated by WHO is expected to translate, on average, to about 3 years of use). In situations where users wash their nets once a month*, nets which only just meet WHOPES standards are unlikely to retain their biological effectiveness beyond two years.

The new Bayer LifeNet, however, retains biological efficacy that meets the WHOPES standards after 30 washes, a performance which was recognized in the WHOPES 14th Working Group Report (2011). LifeNet has been the only LLIN to achieve such recognition. Added to that, further testing carried out by Bayer and independent laboratories has shown that LifeNet remains effective beyond 35 washes. This unparalleled wash resistance is a result of LifeNet’s innovative composition, which incorporates deltamethrin into polypropylene and uses a unique release process.
LifeNet therefore offers a clear advantage and, based on the average assumed in WHOPES Standards, is expected to provide an effective lifespan exceeding five years.

*One retrospective study cited during a Roll Back Malaria Working Group meeting in 2012 indicates that in some areas users will wash their nets as many as 14 times a year: Surveillance, M & E. Innovative approaches to SME: Monitoring the durability of LLINs under operational conditions. Technical session 4: Program Management Aug. 11th 2011, by Majhalia Torno, RITM, Wilfredo E. Aure, RITM, Mario Baquilod, DOH, Ray Angluben, PSFI, Jeffrey Hii, WR CO WHO, p. 10