Association between recent internal travel and malaria in Ugandan highland and highland fringe areas.

OBJECTIVE: To examine the association between travel (recency of travel, transmission intensity at destination compared to origin and duration of travel) and confirmed malaria in Uganda. METHODS: Health facility-based case-control study in highland (~2200 m), and highland fringe (~1500 m) areas with adjustment for other covariates. RESULTS: In the highland site, patients who had travelled to areas of higher transmission intensity than their home (origin) areas recently were nearly seven times more likely to have confirmed malaria than those who had not (OR 6.9; P = 0.01, 95% CI: 1.4-33.1). In the highland fringe site, there was also a statistically significant association between travel and malaria (OR 2.1; P = 0.04, 95% CI: 1.1-3.9). CONCLUSIONS: For highland areas, or areas of low malaria transmission, health authorities need to consider internal migrants when designing malaria control programs. Control interventions should include information campaigns reminding residents in these areas of the risk of malaria infection through travel and to provide additional mosquito nets for migrants to use during travel. Health authorities may wish to improve diagnosis in health facilities in highland areas by adding travel history to malaria case definitions. Where routine monitoring data are used to evaluate the impact of interventions on the malaria burden in highland areas, health authorities and donors need ensure that only cases from the local area and not 'imported cases' are counted

Economics of water recovery in the Murray-Darling Basin, Australia

We review recent water reforms and the consequences of water recovery intended to increase stream flows in the Murray-Darling Basin (MDB), Australia. The MDB provides a natural experiment of water recovery for the environment that includes (a) the voluntary buy-back of water rights from willing sellers and (b) the subsidization of irrigation infrastructure. We find that (a) the actual increase in the volumes of water in terms of stream flows is much less than claimed by the Australian government; (b) subsidies to increase irrigation efficiency have reduced stream and groundwater return flows; (c) buy-backs are much more cost effective than subsidies; (d) many of the gains from water recovery have accrued as private benefits to irrigators; and (e) more than a decade after water recovery began, there is no observable basin-wide relationship between volumes of water recovered and flows at the mouth of the River Murray.R. Quentin Grafton and Sarah Ann Wheele