The Camino Verde trial of community mobilisation for control of dengue reported a significant impact on entomological indices of the Aedes aegypti vector , and on serological dengue virus infection and self-reported dengue cases .
One reason for doing r and omised controlled trials ( RCTs ) is that experiments can be convincing .
Early epidemiological experimenters , such as Jenner and the smallpox vaccine and Snow and his famous Broad Street pump h and le , already knew the answer they were demonstrating ; they used the experiments as knowledge translation devices to convince others .
More sophisticated modern experiments include cluster r and omised controlled trials ( C RCTs ) for experiments in the public health setting .
Those who are convinced by a trial and want to act , need to know how the trial relates to their own context , what contributed to success , and what might make it even more effective .
Beyond efficacy in water containers: Temephos and household entomological indices in six studies between 2005 and 2013 in Managua, Nicaragua
Background A cluster-r and omized controlled trial of  community mobilisation for dengue prevention in Mexico and Nicaragua reported , as a secondary finding , a higher risk of dengue virus infection in households where inspectors found temephos in water containers . Data from control sites in the preceding pilot study and the Nicaragua trial arm provided six time points ( 2005 , 2006 , 2007 and 2011 , 2012 , 2013 ) to examine potentially protective effects of temephos on entomological indices under every day conditions of the national vector control programme . Methods Three household entomological indicators for Aedes aegypti breeding were Household Index , Households with pupae , and Pupae per Person . The primary exposure indicator at the six time points was temephos identified physically during the entomological inspection . A stricter criterion for exposure at four time points included households reporting temephos application during the last 30 days and temephos found on inspection . Using generalized linear mixed modelling with cluster as a r and om effect and temephos as a potential fixed effect , at each time point we examined possible determinants of lower entomological indicators . Results Between 2005 and 2013 , temephos exposure was not significantly associated with a reduction in any of the three entomological indices , whether or not the exposure indicator included timing of temephos application . In six of 18 multivariate models at the six time points , temephos exposure was associated with higher entomological indices ; in these models , we could exclude any protective effect of temephos with 95 % confidence . Conclusion Our failure to demonstrate a significant protective association between temephos and entomological indices might be explained by several factors . These include ecological adaptability of the vector , resistance of Aedes to the pesticide , operational deficiencies of vector control programme , or a decrease in preventive actions by households result ing from a false sense of protection fostered by the central ized government programme using chemical agents . Whatever the explanation , the implication is that temephos affords less protection under routine field conditions than expected from its efficacy under experimental conditions . Trial registration IS RCT N 27581154
The Camino Verde trial of community mobilisation for control of dengue reported a significant impact on entomological indices of the Aedes aegypti vector , and on serological dengue virus infection and self-reported dengue cases .
One reason for doing r and omised controlled trials ( RCTs ) is that experiments can be convincing .
Early epidemiological experimenters , such as Jenner and the smallpox vaccine and Snow and his famous Broad Street pump h and le , already knew the answer they were demonstrating ; they used the experiments as knowledge translation devices to convince others .
More sophisticated modern experiments include cluster r and omised controlled trials ( C RCTs ) for experiments in the public health setting .
Those who are convinced by a trial and want to act , need to know how the trial relates to their own context , what contributed to success , and what might make it even more effective .