:: Workshop – Bayesianism II: Foundations and Applications ::

Invited Talk 8 (friday – 10h00)
Costs Considerations Of Malaria Prophylaxis For Travelers To Endemic Areas.
Eduardo Massad (IOF – FMUSP).

Abstract:
Many regions of the world where malaria transmission intensity is seasonal or declining the risk for travellers is either unknown or assumed equivalent to that of the endemic population and preventative recommendations are based these criteria. Chemoprophylaxis prescribing has a known toxicity; more precise data on malaria would allow a more balanced risk benefit analysis.
Method
We estimated the risk of catching malaria, trough a mathematical model, for the Amazon region, which used an observed attack rate of 10% per year. Malaria transmission was modelled in human as was mosquito populations using a deterministic compartmental structure and basic reproduction number, along with variables including vectorial factors, season, biting rate and human variables including chemoprophylaxis use and efficacy, days exposed and time of travel to model risk of disease and correlate this to endemic transmission.
Results
We calculated the risk for a traveller who arrive at the Amazonian region in four different moments of time, namely, in the dry season (winter) in the spring, in the wet season (summer) and in the fall. The model assumes that the Amazonian region has around 300,000 cases of falciparum malaria per year and the region is in a holoendemic situation.
Discussion
Mathematical modelling are well suited to take into account seasonality and annual variations. To the best of our knowledge, this is the first time that risk estimates for acquiring malaria when traveling to malaria endemic countries have been calculated using mathematical modeling.
Our data highlight that the risk for non-immune travellers to acquire malaria in the Amazonian region is substantial but varies greatly with seasons and epidemic cycles. For example, the risk is almost 10 fold higher for a traveller who arrive in the fall and remains in the area for 120 days versus a traveller who arrive in the spring and remains in the area for the same amount of time. As expected, the risk increases with duration of stay.

Promotion and Support:
			CAPES-Proex Pós–graduação em Estatística-USP