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A total of 255 bednets were collected 38 months after distribution in Lawra District of northwest Ghana to examine their physical condition and residual insecticide levels. Physical condition varied from nearly pristine to highly damaged. In 50 selected nets, 2023 holes ≥ 0.5 cm and 31 holes ≥ 10 cm were counted. The incidence of holes increases toward the bottom edge of the net. Seam failures were found in 50% of the nets. Repairs, mostly sewn, were evident in 64% of the nets. Using a combination of bromine x-ray fluorescence (XRF) spectrometry, high-pressure liquid chromatography, and cone bioassays, it was determined that 14.9% of the nets had retained full insecticidal strength. These results highlight the value of real-world data on bednet longevity to guide decisions regarding mosquito control strategies, bednet purchasing, frequency of bednet replacement, and product development.

DONNEES DE BASE La distribution de masse, gratuite (rattrapage) de moustiquaires traitees aux insecticides (MTI) durant les campagnes de vaccination contre la rougeole, permet la couverture immediate, etendue et equitable a la fois pour les MTI et pour le vaccin contre la rougeole. Le maintien d'une couverture etendue au cours du temps necessite l'acces continue et a long terme a de nouvelles moustiquaires (maintien). Nous avons investigue les effets de trois annees de campagne de rattrapage suivie d'un marketing social base sur la clinique, pour le maintien continue de la couverture et de l'usage des MTI. METHODES En decembre 2002, les MTI ont ete distribues a tous les enfants participant a une campagne de vaccination contre la rougeole dans un district rural du Ghana. Au cours des trois annees suivant la campagne, le district a commence a offrir des MTI a un prix subventionne aux femmes enceintes visitant les cliniques prenatales. Ce schema de maintient n'est seulement devenu totalement operationnel que deux ans apres la campagne. Une enquete sur la couverture a ete menee pendant 38 mois apres la campagne en utilisant une methode standard d'echantillonnage a deux niveaux. RESULTATS La couverture en moustiquaires etait haut elevee grâce aux contributions combinees du rattrapage et du maintien. 475 menages dans l'etude avait au moins un enfant de moins de cinq ans. Parmi ces menages, la couverture etait de 95,6% pour n'importe quel type de filet, 83,8% pour un filet obtenu via la campagne de promotion et 73,9% pour un MTI. De tous les enfants, 95,7% dormaient dans un menage ayant un filet, 86,1% dormaient dans un menage ayant un filet obtenu via la campagne. Tous les filets disponibles n'etaient pas utilises car seuls 59,6% des enfants dormaient sous une MTI. La source des filets etait dans 77,7% des cas, la campagne et dans 20% des cas, les cliniques habituelles. Compare aux menages qui ont participe a la campagne, les menages avec des enfants nes apres la campagne avaient des taux plus eleves de possession de filets (75,1% contre 67,7%; P = 0,04). L'equite etait elevee car le rapport entre la couverture dans la quintile la moins riche et celle dans la quintile la plus riche etait de 0,95 pour la possession de MTI et de 1,08 pour l'usage des MTI. Ces taux de couverture et d'usage etaient similaires a ceux precedemment rapporte dans une etude avec 5 mois de suivie post campagne et qui suggerait aucune diminution sur trois ans. CONCLUSION Un niveau de couverte elevee et d'usage de MTI a ete atteint et maintenu par une campagne sequentielle de masse basee sur la communaute par un rattrapage et un maintien de la distribution au niveau de la clinique. Les filets de la campagne de promotion ont couvert pratiquement tous les menages existants alors que la distribution au niveau de la clinique fournissait des filets pour les nouveaux espaces de sommeil survenus apres la campagne. Comme les filets peuvent etre partages et la plupart des enfants sont nes dans des familles ayant deja un filet, le nombre de nouveaux filets requis pour maintenir la couverture etendue est substantiellement inferieur au nombre d'enfants nouveau-nes. La strategie de rattrapage/ maintien combinant des campagnes de masse pour les enfants et la distribution aux femmes enceintes au niveau des cliniques est une strategie efficace pour atteindre et maintenir une couverture etendue en terme de filets. Assurer l'usage approprie des filets demeure un autre defi.

Mass, free distribution (Catch-up) of insecticide-treated bednets (ITNs) during measles vaccination campaigns achieves immediate, high and equitable coverage for both ITNs and measles vaccine. Maintaining high coverage over time requires long-term, routine access to new nets (Keep-up). In many settings, only one approach--either campaign or routine delivery--has been available and have been seen as competing methods. Relying only on campaigns achieves high coverage at the cost of lack of later access. Relying solely on routine coverage builds a delivery infrastructure but may lead to slower rates of coverage and inequities. A combined Catch-up/Keep-up approach has been a common feature of vaccination programs for many years. We assessed the 3-year effects of a one-time Catch-up campaign followed by clinic-based social marketing for routine Keep-up on ITN coverage and use.In December 2002, ITNs were distributed to all children attending a measles vaccination campaign in a rural district of Ghana. In the 3 years following that campaign, the district began offering ITNs at a subsidized price to pregnant women attending ante-natal clinics. This Keep-up scheme did not become fully operational until 2 years after the campaign. A coverage survey was conducted 38-month post-campaign using a standard two-stage cluster sampling method.Coverage of nets was high due to the combined contributions of both Catch-up and Keep-up. There were 475 households in the survey with at least one child less than 5 years of age. Among these households, coverage was 95.6% with any net, 83.8% with a campaign net, and 73.9% with an ITN. Of all children, 95.7% slept in a household that had a net, 86.1% slept in a household that had a campaign net. Not all available nets were used as only 59.6% of children slept under an ITN. The source of the nets was 77.7% from the campaign and 20% from routine clinics. Compared to households that participated in the campaign, households with children born after the campaign had higher rates of net ownership (75.1% vs. 67.7%, P=0.04). Equity was high as the ratio of coverage in the lowest wealth quintile to that in the highest was 0.95 for ITN ownership and 1.08 for ITN use. These coverage and use rates were similar to those previously reported 5-month post-campaign, suggesting no decrease over 3 years.A high level of ITN coverage and use was achieved and sustained by sequential community-based mass campaign Catch-up and clinic-based Keep-up distribution. The campaign nets covered virtually all extant households while clinic-based distribution provided nets for the new sleeping spaces created post-campaign. Because nets can be shared, and most children are born into families that already have a net, the number of new nets needed to sustain high coverage is substantially lower than the number of newborn children. A Catch-up/Keep-up strategy combining mass campaigns for children and clinic-based distribution to pregnant women is an efficient strategy for achieving and sustaining high net coverage. Assuring proper use of nets is a remaining challenge.